Pet Dermatology Problems

Our furry friends suffer from several common dog skin problems including:

• Itchy Skin - Clinically referred to as pruritis, itchy skin affects several dogs and is the most common reason dog dermatologists see their patients. If left untreated, itchy skin can lead to lesions, infections, and hair loss. To treat itchy skin, our dog dermatologist first needs to diagnose the cause of the itching, whether related to parasites, allergies, or another condition.

• Allergies - Common in dogs, allergens typically fall into one of three categories: food, fleas, and environment. Sensitivities to allergens range from moderate to severe, with some dogs experiencing systemic reactions from only minor exposure. Our veterinarian will help you pinpoint the cause of your dog's allergies and remove the allergen from his or her environment or diet.

• Hot Spots and Sores - Hot spots and sores such as mange result from the numerous tiny bites of mite and flea infestation. The presence of hot spots and sores prompts our veterinarian to look for parasites, and treatment usually includes a medicated bath designed to both soothe your dog and rid his coat of those pesky parasites.

• Hair Loss - Parasites and conditions which cause a hormonal imbalance can cause hair loss in dogs. The reason for canine hair loss can be difficult to determine, but our veterinarian uses a skin scraping test to diagnose the cause of hair loss in dogs.

• Dull and Dry Coats - If your dog's coat lacks luster, chances are his diet does, too. Our veterinarian will work with you to balance your dog's diet and improve the appearance and state of his coat.

Recognizing Dog Skin Problems

Although the cause of dog skin problems might be difficult to determine without the help of a veterinary expert, the signs are easy to recognize. Look for excessive scratching or biting at skin, sores, dandruff, hair loss, and shaking of the head. If you notice signs of a skin problem in your dog, we encourage you to schedule an appointment for diagnosis, relief, and treatment right away.

Animal Dermatology Specialists of Vancouver – Your Pet Dermatology Experts

At Animal Dermatology Specialists of Vancouver our team of veterinarians and certified pet dermatology specialist have the experience and training to recognize, diagnose, and effectively treat your pet's skin problem.

Allergens Affecting Cats

Cats have allergies to all sorts of potential allergens, the symptoms of which can make them quite uncomfortable, and even negatively impact their health. Some of these allergens include environmental allergens such as the pollen from trees, grass, and weeds; mold; mildews; and dust. In addition, certain foods, parasites, medications, perfumes, cigarette smoke, cleaning products, fabrics, rubber, and some plastic products can also irritate a cat's immune system. This can lead to a myriad of uncomfortable and even painful symptoms.

Signs and Symptoms of Cat Skin Allergies, Food, and Respiratory Allergies

Cat skin allergies and respiratory allergies result in very distinct signs and symptoms in your pet. Although some of the respiratory symptoms could also point to a viral or bacterial infection, noticing any significant change in your pet's behavior is good reason to see a veterinarian. The following are signs and symptoms of feline skin, food, and respiratory allergies:

• sneezing
• coughing
• wheezing
• snoring
• runny eyes
• excessive scratching and itching
• hair loss
• hair matting
• scabby or flaky skin
• skin color change
• itching ears and/or excessively shaking head
• ear infection
• vomiting
• diarrhea
• swollen paws
• excessively biting at paws

If your cat displays any of these symptoms, we encourage you to schedule an appointment right away.

Dosing

The recommended dose in pet dermatology is 0.5-0.6/mg/kg every 1 hour up to two weeks. It does need to be administered daily to be effective and the dose range is very strict due to immune suppression. According to manufacturer Zoetis, 60 percent of atopic dermatitis cases are controlled with daily dosing.

Apoquel usually delivers results in one week. If it doesn’t work within one week, likely it won’t work with longer usage. When given with Benadryl and Temaril P, there may be increased sleepiness with pet patients. Other side effects listed include lethargy, dermal masses, diarrhea, and vomiting, increased cholesterol and decreased leukocytes.

If the dog is on steroids, there’s really no need to transition to Apoquel slowly. However, if the patient’s been on high dosages of steroids, a transition period may be needed to prevent an Addisonian crisis. In some studies, a few dogs developed polydipsia, ear infections and increased appetite, which is akin to some of the side effects of taking steroids.

Your Local Pet Dermatology Clinic in Richmond and Vancouver, BC

At the Animal Dermatology Clinic of BC, we implement extraordinary care with all of the animals we treat. Specializing in allergies, immune disorders, cancer, breed disorders and much more, we offer state-of-the art diagnostics to identify and understand the underlying cause of your pet’s condition. We also take the time to educate pet owners about their pets’ condition. We are the leading specialist in pet dermatology Vancouver and pet dermatology Richmond.

Dog food hypersensitivity is characterized by nonseasonal itching that may or may not respond to steroid treatment. This itching, scratching or licking may be regional or generalized and usually involves the paws, ears, inguinal or axillary areas, face, neck and perineum (anal area). Affected skin is often red and inflammed, and papular rash may be present. Secondary bacterial or yeast infection, and Otitis externa (ear infection) are common. Other symptoms that may be seen are acral lick dermatitis, oily, smelly skin or ears dermatitis. Some dogs are minimally itchy, with only symptom being recurrent infection with Pyoderma (bacterial skin infections), yeast infections or Otitis (ear infection). In these cases, the pruritus (itching) is present only when secondary infections are left untreated. Concurrent gastrointestinal signs (frequent bowel movements, vomiting, diarrhea, gas are reported in 20-30% of cases.

• Diagnosis- Intradermal or serologic (blood) allergy testing is not recommended because test results are unreliable. Response to hypoallergenic diet trial, symptoms improve within 10-12 weeks of initiation of a strict home-cooked or commercially prepared restricted diet (one protein and one carbohydrate). The hypoallergenic diet should not contain food ingredients previously administered in dog food, treats, or table scraps. Nor should flavored heartworm preventative, flavored mediations, nutritional supplements, or chewable treats (pigs ears, cows hooves, rawhides, dog biscuits, table food such as cheese or peanut butter to hide pills in) be used during trial.
• Treatment- Any secondary skin infections (bacterial, yeast),Ear infection should be treated Controlling secondary infection is an essential component of treating food allergic dogs. A flea-control program should be instituted to prevent flea bites from aggravating the itch. Food trial identifying offending substances to avoid. Prognosis is good. In dogs that are poorly controlled, owner noncompliance should be ruled out, along with development of hypersensitivity (allergy) to an ingredient in hypoallergenic diet, secondary infection, scabies, demodicosis, atopy, flea allergy, dermatitis, and contact hypersensitivity.

The next step after confirming the diagnosis of atopy with the allergy skin test is to check for a co-existing food allergy, by doing an elimination food trial over the next 6-8 weeks. During this time you can commence treatment for atopy. The best treatment for atopy causes multi-modal therapy utilizing both specific, non-specific treatment and controlling infection in dog and cat.

The 4 Keys To Success

1. Diagnose and treat any bacterial and or yeast infections caused by the allergic disease. These infections will produce odour, contribute to the itch and will upregulate allergic disease in cat and dog (make the allergies worse)
2. Diagnose and control any concurrent food allergies (approximately 30% of atopic patient will also have food allergies attributing to the itching)
3. Non-Specific treatment for atopy
   • A) Drugs Treatment
     • Cyclosporine (atopica) ~60% effective, expensive, few side effects
     • Antihistamines, ~20-30% effective, few side effects
     • Essential Fatty Acids- helps ~20-50% of cases =fish, borage, flaxseed oil
     • Cortisone (Corticosteroids) ~70-80% effective, cheap, lots of side effects
     • Pentoxyfylline- helps reduce cortisone dosage, never used by itself
4. Specific therapy treatment for atopy
   • A) Avoidance
     Reduce exposure to offending allergens, not practical in all cases, works well with house dust mites in the house
   • B) "Allergy Shots" (A.S.I.T. =Allergy Specific Immuno Therapy)
     The atopic cat or dog receives weekly or biweekly/monthly injections of allergens that were positive on the allergy skin test. A good to excellent response is seen in 60-75% of atopic patients. The response is rarely seen in the first month of therapy. The majority will show improvement in the first 3-4 months. Some will show improvement after 6-12 months

Localized Demodex

Skin lesions occur when there is a localized overpopulation of demodex on the skin, normal amounts of demodex are natural. Demodectic overgrowth is often associated with a predisposing factor such as endoparasitism (worms), poor nutrition, immunosuppressive drug therapy (e.g, prednisone or other steroid drugs), or transient stress (e.g, estrus (dog in heat), pregnancy, surgery, boarding etc) Localized Demodex may appear as one to five patchy areas of alopecia (hair loss) with variable erythema (redness of the skin), hyperpigmentation (black skin), and dry skin. Lesions are not usually pruritic (itchy) unless they are secondarily infected.

• Diagnosis- Is made by performing deep skin scrapes to look under a microscope or sometimes by skin biopsies.

• Treatment- Prognosis is good, most cases resolve within 4-8 weeks. Treatments may include a topical medication or dips. Sometimes no treatment is required and will resolve on it’s own, however a few may progress to generalized demodicosis if not treated. Any predisposing factors and secondary infections should be identified and treated as well.

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Generalized Demodex

Adult-Onset Demodex

Occurs in dogs older than 18 months of age, with highest incidence in middle-aged to older dogs that are immunocompromised because of underlying conditions such as hyperadrenocorticism (Cushings), hypothyroidism, steroid use, diabetes, or cancer. To date, highest incidence noted in terrier breeds and their crosses, especially West Highland White Terriers. Symptoms can appear as five or more focal lesions, or two or more body regions. Usually patchy, regional, multifocal, or diffuse hair loss is observed with variable redness, scaling, pimple like spots, or itching. Affected skin may become infected. Lesions can be anywhere on the body, including the paws.

• Diagnosis- Is made by performing deep skin scrapes to look under a microscope or sometimes by skin biopsies.

• Treatment/Prognosis- Underlying conditions should be identified and corrected. Intact dogs, especially females should be fixed. Estrus or pregnancy may trigger relapse. Skin infections should be treated appropriately with long term (minimum 3-4 weeks ) with antibiotics and continue at least 1 week beyond clinical resolution. Topical medications, oral medications or injectables may be prescribed. Prognosis is good to fair. Relapses may occur, requiring periodic or lifelong treatment in some dogs. Steroid use should be avoided in dogs diagnosed with demodex.

Juvenile Demodex

Occurs in young dogs, usually between 3-18 months of age with highest incidence in medium-sized and large purebred dogs.

• Treatments- For all types of Demodex should be continued for at least 1 month beyond the time when follow-up skin scrapings become negative for mites.

• Because of it’s hereditary predisposition, neither female nor male dogs with juvenile-onset generalized demodicosis should be bred.

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Scabies

Scabies is a superficial burrowing skin mite, Mites secrete allergenic substances that cause an intensely itchy allergy reaction in sensitized dogs. Affected dogs often have a previous history of being in an animal shelter, having contact with stray dogs, or visiting a grooming or boarding facility. In multiple dog households, more than one dog is usually affected. Scabies is a nonseasonal intense pruritus that responds poorly to corticosteroids. Lesions include papules, alopecia (hairloss), erythema (redness), crusts, and excoriations (chafed skin). Initially, less-hairy skin is involved, such as the hocks, elbows, ear flaps and chest/abdomen. With chronicity, lesions may spread over the body.

• Diagnosis- Is achieved by a positive response to treatment, Pinnal-pedal reflex (rubbing the ear margin to elicit a scratch reflex) or by superficial skin scrapings, however false negative results are common because mites are extremely difficult to find.

Affected and all in-contact dogs should be treated with a scabicide. Topical treatments are repeated for 7 days for at least 5 weeks, it is noted that systemic treatments are generally more effective than topical products. Treatment often includes oral medication weekly or weekly injections depending on the case. Treatment for any concurrent infection must be treated as well to determine the response to scabies treatment. In kennel situations, bedding should be disposed of and the environment thoroughly cleaned and treated with parasiticidal sprays.

• Prognosis- Is good, keep in mind scabies is a highly contagious parasite of dogs that can also transiently infect humans and rarely cats.

Idiopathic Nasodigital Hyperkeratosis

Idiopathic Nasodigital Hyperkeratosis is an idiopathic (unknown cause) condition that is characterized by the excessive formulation of nasal or footpad keratin. This type of nose disorder is common in older dogs. Thickened, hard, dry keratin accumulates on the top of the nose, footpads, or both. The accumulated keratin is usually most prominent on the top of the nose and at the edges of the footpads. Nasolacrimal (tear) duct blockage may present a contributing factor. Affected dogs are otherwise healthy and have no other skin signs.

• Diagnosis- Is made by ruling out other medical problems such as Zinc deficiency, distemper, pemphigus foliaceus and discoid lupus and others.

• Treatment- The intensity of treatment depends on the severity of the lesions. Tear ducts should be flushed. For mild, asymptomatic cases, no treatment may be appropriate. For moderate to severe cases, affected areas should be hydrated and a softening agent will be prescribed.

• Prognosis- Is good. Although it is incurable, this is a cosmetic disease that can usually be managed symptomatically.

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Discoid Lupus

This disease is considered by many to be many to be a benign variant of systemic lupus erythematosus. It is common in dogs and rare in cats.

Nasal depigmentation, erythema (redness), scaling, erosions, ulcerations, and crusting are characteristic. Similar lesions may involve the lips, bridge of the nose, periocular skin, ear flaps, and, less commonly, distal legs or genitalia. Hyperkeratotic footpads and oral ulcers are rarely present.

• Diagnosis- Is made by biopsy.

• Treatment- Is usually symptomatic shampooing therapy to remove crusts. Avoiding sunlight exposure and using topical sunscreens. Sometimes supplemental vitamins are prescribed, as is medicated ointments.

• Prognosis- Is good, but lifelong treatment is usually necessary. Permanent scarring or depigmentation and rarely, squamous cell carcinoma are possible.

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Vitiligo

Is a condition that is characterized by one or more areas of depigmented skin or hair. Lesions are usually first noted in your adulthood and often affect the nose, lips, face, buccal mucosa, and footpads. It is uncommon in dogs, with the highest incidence in Belgian Tervurens, German shepherds, Rottweilers, and Dobermans. It is rare in cats, with the highest incidence in Siamese.

• Diagnoses- Is confirmed by biopsy.

• Treatment- Is unknown.

• Prognosis- Is good. This is a cosmetic disease that does not affect the animals quality of life. The depigmentation is usually permanent, but in some animals, spontaneous repigmentation may eventually occur.

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Canine Eosinophilic Furunculosis of the Face

Is an acute, usually self-limiting disease of the face. Although its exact cause is not known, a hypersensitivity reaction to insect stings or spider bites is suspected. It is uncommon to rare in dogs, with the highest incidence in inquisitive, young adult dogs with ready access to the outdoors. Blister, Erythematous (red) papules, and nodules, ulcerations, crusts, and hemorrhage may develop acutely and usually peak in severity within 24 hours. Lesions are not itchy or not very itchy but may be painful and typically involve the muzzle, bridge of the nose, and around the eyes. Occasionally, the abdomen, chest or ear flaps may be involved.

•Diagnosis- Is made by ruling out other causes, performing a cytology to look for numerous eosinophils, and sometimes biopsy.

• Treatment- Is often short term steroids with hydrotherapy to speed clinical improvement. Also secondary infections (if present) should be treated for 3-4 weeks with antibiotics.

• Prognosis- Is good.

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Nasal Pyoderma

Is a facial bacterial skin infection that may occur secondary to trauma or insect bites. It is uncommon in dogs and rare in cats. Nasal pyoderm appears as papules, pustules, redness, hair loss, crusting, swelling, erosions, or ulcerative fistulae that develop over the bridge of the nose. Lesions may be painful.

• Diagnosis- Is determined by ruling out other medical condition. Performing cytology of pus with bacterial cocci or rods viewed under microscope, biopsy and or cultures.

• Treatment- Gentle warm water soaks and antibiotics for 3-4 weeks (continue 2 weeks beyond complete clinical resolution).

• Prognosis- Is good, but scarring may be a permanent.

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Mycosis Fungoides (Epitheliotropic Lymphoma)

Is a malignant cancer that arises from T lymphocytes. It is uncommon in dogs and cats, with highest incidence in older animals. Among dogs, Scottish terriers and Golden Retriever are predisposed. Symptoms of the skin may include sing to multiple plaques or nodules that range from a few millimeters to several centimeters in diameter. Mucocutaneous depigmentation (skin color changes on mucous membranes like nose and anus) and ulceration or generalized erythema, alopecia (hair loss), scaling, dry skin, dandruff and pruritus (itching) may occur.

• Diagnosis- Biopsy, affected animals should also be screened for internal metastasis (xray chest/internal organs).

• Treatment- Certain chemo drugs may be used for this disease. Oral supplementation with safflower oil (which contains high levels of linoleic acid) may improve clinical signs in some animals.

• Prognosis- Regardless of treatment, the prognosis is poor, with most animals surviving less than 1 year after diagnosis.

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Otitis Externa (External Ear Infection)

Is an acute or chronic inflammatory disease of the external ear canal. Causes of this type ear infection are numerous. Food Allergy, Atopy, ear mites, Hypothyroidism, Excessive ear cleaning, trauma from cleaning, over treatment, under treatment, cancer plus many more are examples of potential causes or exasperating conditions. Itchy ears or pain is a common symptom of Otitis externa. Head rubbing, ear scratching, head shaking, aural hematomas, and a head tilt, with the affected ear tilted down, may be noted. A discharge that may be smelly is often present ear wax accumulates.

• Diagnosis- Based on history and clinical findings, Otoscopic examination (or videoscopy) to assess degree of inflammation, ulceration, stenosis, and other changes. Ear swabs for cytology are routinely preformed and occasionally cultures may be required.

• Treatment- Ear wax and debris must be cleared away from the ear canal by a veterinarian and the primary causes of the Otitis should be identified and corrected, if possible. Topical antibiotics or antifungals (depending on the type of infection present) for usually a week or two are often required with systemic (oral) medications for 3-4 weeks. Without proper diagnosis of the cause, treatments will not be completely successful.

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Otitis Media

Severe or Chronic Otitis (infection) leading into the medial (middle) ear.

• Diagnosis/Treatment- In-hospital deep ear cleaning/flushing (using our videocopy machine) should be preformed to remove accumulated ear wax, pus and debris from the vertical and horizontal ear canals (under anesthesia). Oral steroids are often used if the ear is painful and the canal swollen and closing/closed off. These ears need long treatments of antibiotics/antifungals and again determining the cause is of most importance to help prevent re-peat infections.

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Pseudomonas

Is a bacterial infection that is often associated with a really bad odour and very painful ears. This type of infections needs to be treated aggressively for at least 4 weeks and beyond until complete clinical symptoms are gone. All underlying/primary diseases should/need to be identified and addressed.

• Diagnosis/Treatment- A cytology and culture are commonly preformed to diagnosis this problem. Cultures help the veterinarian determine what antibiotics will kill the offending bacteria, some infections develop resistance to certain drugs and cultures are our only hope of picking the proper medication. Often with this type of infection multiple ear medications are used topically and orally to combat the problem.

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Aural Hematoma

(swelling of the ear flap, “ballooning”) is caused by the traumatic rupture of vessels and capillaries within the ear flap. As the animal shakes its head severely, the centrifugal action and flopping of the ear flaps cause the vessels to rupture. The blood then pools in the space between the skin and cartilage, thereby creating a hematoma.

• Diagnosis- Visually and sometimes fine needle aspirate of the hematoma revealing blood.

• Treatment- Rule out underlying causes of excessive shaking (most often Otitis Externa) Treat infections to decrease the head shaking. Depending on the severity and stage of hematoma steroids may be prescribed for the swelling but most often veterinarians choose surgery to drain it then the ear, then it is sutured in many places to keep the tissue layers adhered as it heals.

• Prognosis- Is good, but recurrence is common, especially if the primary cause of the head shaking (usually ear infections) is not controlled.

Alopecia X

The cause of this alopecic (hair loss) condition in dogs is unclear, but several theories have been proposed. One theory is that the disorder is caused by abnormal adrenal steroidogenesis and is a mild variant of pituitary dependent hyperadrenocorticism. Others have suggested that it may be due to growth hormone deficiency, an adrenal sex hormone imbalance, or excessive production of androgenic steroids by the adrenal glands. Current theories suggest that a local follicular receptor dysregulation may be the underlying disorder. The condition is uncommon in dogs, with the incidence in adult dogs 2-5 years old, especially Chow Chows, Pomeranians, Keeshonds, Samoyeds, Alaskan malamutes, Siberian huskies, and miniature poodles. Gradual loss of primary hairs progresses to complete alopecia of the neck, tail, caudodorsum, perineum, and caudal thighs. The alopecia eventually becomes generalized over the trunk, but the head and front limbs are spared. Hair loss is bilaterally symmetrical, remaining hairs epilate easily, and the alopecic skin may become hyperpigmented, thin, and hypotonic. Mild secondary seborrhea and superficial Pyoderma may occur. No systemic signs of illness are noted.

• Diagnosis- Blood test to rule out other endocrine alopecia (Hormonal hairloss), like Cushings and Hypothyroidism. ACTH stimulation test but false-positive and false-negative results are common, and breed-specific normal values have not been established.

• Treatment- Observation without treatment is reasonable because this disease is purely cosmetic and affected dogs are otherwise healthy. Neutering of intact dogs may induce permanent or temporary hair regrowth. A variety of medical therapies have been used but with inconsistent results. Regardless of the therapy used, hair regrowth may be incomplete or transient. Initial hair regrowth should be seen within 4-8 weeks. If no response is seen after 3 months of treatment, a dosage adjustment or different therapy agent should be considered. The prognosis for hair regrowth is unpredictable. This is a cosmetic disease only that does not affect the dogs quality of life.

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Color Dilution Alopecia

Alopecia is a follicular dysplasia of color-dilute hairs that is associated with defective hair pigmentation and formation. An autosomal recessive mode of inheritance is suspected (It is believed to be inherited). It is common in color-dilute dogs such as those bred to be blue, or fawn. The disorder is especially common in Dobermans, but also occurs in other breeds, including Yorkshire terriers, miniature pinschers, Great Danes, Whippets, Italian greyhounds, Salukis, Chow Chows, Dachshunds, Silky terriers, Boston terriers, Newfoundlands, Bernese Mountain dogs, Shetland sheep dogs, Schiperkes, Chihuahuas, Poodles, and Irish setters. Affected dogs appear normal at birth but usually begin losing hair over the dorsum of the trunk between 6 months and 2 years of age. Although the hair coat thinning often progresses to partial or complete hair loss, only the color-diluted hairs are lost. The dog’s normal colored markings are not affected. Secondary skin infection is common.

• Diagnosis- Rule out other hair loss diseases, test with microscopic examination of plucked hairs and sometimes biopsy.

• Treatment- No specific treatment is know that reverses or prevents further hairloss. Treat symptomatically with mild antiseborrheic or antibacterial shampoos and conditioners as needed. Some dogs need antibiotics if infection present. Prognosis is good, Although hair loss is irreversible. This is a cosmetic problem that does not affect the dogs quality of life, however symptomatic skincare may be needed.

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Black Hair Follicular Dysplasia

Is a color-linked follicular dysplasia of black hairs that is associated with defective hair pigmentation and formation. It is believed to be inherited, affected puppies appear normal at birth but begin losing hair at around 1 month of age. Only black hairs are affected, with the alopecia progressing until all the black hairs have been lost.

• Diagnosis- Rule out other alopecic diseases, microscopic examination of plucked hairs, and biopsy.

• Treatment- No treatment is know, prognosis is good. Although the alopecia is irreversible, this is a cosmetic problem only that does not affect the dog’s quality of life.

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Misc Follicular Dysplasia

Like the other follicular diseases this is believed to be inherited. This type of follicular dysplasias are poorly understood, it is not development or structural , color linked nor seasonal. It is rare in young adult to middle aged dogs, although it is sporadically reported in many breeds; it’s highest incidence is documented in Irish water spaniels, Portuguese water dogs, Pont-Audemer spaniels, black or red Doberman pinchers, and Weimaraners.

• Diagnosis- Again rule out other alopecic causes, perform microscopic examination of plucked hairs and or biopsy.

• Treatment- The animal is treated symptomatically with mild anti-seborrheic or antibacterial shampoos and conditioners as needed. Antibiotics are used if Pyoderma is present. No specific treatment is known, but fatty acid supplementation has been reported in some Irish water spaniels. The prognosis is good, although hair loss is usually irreversible. Again this is a cosmetic problem and does not affect quality of life. Affected dogs should not be bred.

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Rabies Vaccine Reaction Hair Loss

With this condition, a focal area of hair loss occurs at the site where a subcutaneous injection of rabies vaccine (or praziquantel, glucocorticoids, or progestational compounds has been administered) A focal, circumscribed to ovoid area of alopecia develops at the injection site 2-4 months post injection. With canine rabies vaccine, the injection site lesion is characterized by a 2-5cm slowly enlarging, flat to slightly indurated patch of alopecia (hairloss) with variable erythema (red skin) that may become mildly scaly, shiny, and centrally hyperpigmented (black skin).

• Diagnosis- Is based on history, clinical findings, ruling out other differentials and occasionally biopsy.

• Treatment- For dogs, no treatment is usually needed. Spontaneous hair regrowth is typical but can take as long as a year to occur. Sometimes topical creams/ointments or oral drugs are prescribed. For dogs whose lesions remain permanently bald surgical excision is curative. Prognosis is usually good, but hair regrowth may not be complete or may have altered pigmentation (black skin).

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Flank Alopecia (Hair Loss)

Is a seasonally recurring follicular dysplasia. The exact cause is unknown, but photoperiod control of melatonin and prolactin secretion may be involved. The onset of alopecia in the Northern hemisphere usually occurs between November and March. Most dogs regrow their hair spontaneously 3 to 8 months later. Episodes of hair loss may occur sporadically only once or twice, or regularly each year. With repeated episodes, a progressive increase in the amount and duration of hair loss may be seen. It is uncommon in dogs, with highest incidence in young adult Boxers, bulldogs, Airdales, and Schnauzers.

• Diagnosis- History and clinical findings, rule out other differentials and or Biopsy.

• Treatment- Observation without treatment is reasonable because this disease is purely cosmetic and affected dogs are otherwise healthy. Treatments with melatonin may be effective. The prognosis for hair regrowth is variable. Spontaneous hair regrowth often occurs within 3-8 months, even without treatment. However, regrowth maybe incomplete, and new hairs may be duller in color and drier in texture.

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Sex Hormone

Dermatosis Is an endocrinopathy (hormonal disease) associated with the excessive production of sex hormones or precursor sex hormones by the testes (usually caused by testicular tumors). It is common in intact male dogs , with the highest incidence in middle-aged to older dogs. Sex hormone dermatosis manifests as bilaterally symmetrical alopecia of the neck, rump, perineum, flanks, or trunk that may become generalized but spares the head and limbs. Remaining hairs epilate easily. Alopecic skin may become hyperpigmented. Secondary seborrhea, superficial Pyoderma, and yeast dermatitis may be present. The testicles may be normal, asymmetrical, or cryptorchid on palpatioin. The owner may report that the dog is exhibiting abnormal(eg. Attractiveness to other males, standing in a female posture to urinate) or overly aggressive sexual behavior toward other dogs or humans.

• Diagnosis- Rule out other causes of endocrine (hormonal) alopecia, sex hormone assays: serum levels of one or more sex hormones may be elevated, but false-negative and false-positive results are common. Testicular biopsy (castration) may be normal, atrophic, or neoplastic (sertoli cell tumor, interstitial cell tumor, or seminoma) Response to castration: hair regrowth may occur.

• Treatment- The treatment of choice is castration. Treatment of secondary infections should be treated. The prognosis is excellent for dogs with no tumor metastasis or estrogen-induced myelotoxicity. Hair regrowth should occur within 3 months after castration. Remission followed by relapse may indicate excessive sex hormone production by the adrenal glands (alopecia x) or metastatic testicular neoplasia.

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Hypothyroid

Endocrinopahthy is most often associated with primary thyroid dysfunction caused by Lymphocytic thyroditis or idiopathic thyroid atophy. It is common in dogs, with highest incidence in middle-aged to older dogs. Young adult large and giant-breed dogs are also occasionally affected.

A variety of skin symptoms can be seen. Alopecia (hairloss) on the bridge of the nose occurs in some dogs as an early symptom. The hair coat may be dull, dry and brittle. Bilaterally symmetrical alopecia that spares the extremities may occur, with easily epilated hairs. Alopecic skin may be hyperpigmented, thickened, or cool to the touch. Thicken and dropy facial skin from dermal mucinosis, chronic seborrhea sicca (dry skin) or oleosa (Oily skin with must smell), or ceruminous (ear wax accumulated) Otitis externa may be present. Seborrheic skin and ears may be secondarily infected with yeast or bacteria. In some dogs, the only symptom is recurrent Pyoderma (skin infection) or adult –onset generalized demodicosis. Pruritus is not a primary feature of hypothyroidism and, if present, reflects secondary Pyoderma, malassezia (yeast) infection, or demodicosis. Non cutaneous (skin) symptoms of hypothyroidism are variable and may include aggression, lethargy or mental dullness, exercise intolerance, weight gain or obesity, thermophilia (cold intolerance), bradycardia, vague neuromyopathic or gastrointestinal signs, central nervous system involvement (eg head tilt, nystagmus, hemiparesis, cranial nerve dysfunction, hypermetria) and reproductive problems (eg. Decreased libido, prolonged anestrus, infertility) Puppies with congenital hypothyroidism are disproportionate dwarfs with short limbs and neck relative to their body length.

• Diagnosis- Rule out other causes of hair loss, blood chemistry analysis of total T4 (care must be taken if dog is currently on medications as certain drugs can give false results on the blood test).

• Treatment- Thyroid replacing drugs administered daily for life of pet. Prognosis is good with lifelong replacement of thyroxine therapy. Blood tests should be preformed 4-6 hours post pill to monitor serum level after the first 2-4 months of therapy, and occasionally throughout treatment.

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Cushings

Spontaneously occurring Cushings is excessive production of endogenous steroid (cortisone) hormones, caused by a hyperfunctioning adrenal tumor or pituitary tumor. Iatrogenically induced cushings is secondary to excessive administration of steroids. This type can occur at any age. Spontaneously occurring Cushings tends to occur in middle-aged to older dogs, with an increased incidence noted in Boxers, Boston terriers, Dashshunds, Poodles and Scottish terriers. The hair coat often becomes dry and lusterless, and slowly progressing, bilaterally symmetrical alopecias (hair loss) is common. Cutaneous stria and comedones may be seen on the ventral abdomen. The skin may be mildly seborrhea (fine, dry scales) bruise easily, and exhibit poor wound healing. Chronic secondary or superficial or deep Pyoderma (skin infections) , dermatophytosis (ring worm- fungus infections), or demodicosis is common and may be the clients primary complaint. Calcinosis cutis may develop, especially on the dorsal midline of the neck or ventral abdomen, or the inguinal area. Increase water drinking, and appetite are common, increased urination, muscle wasting or weakness, a pot-bellied appearance, increased susceptibility to infection and excessive panting are often present.

• Diagnosis- ACTH stimulation test is a blood test preformed in a two part test done 90 minutes apart. An exaggerated poststimulation cortisol level is considered a positive Cushings result.

• Treatment-Any concurrent infections should be treated with appropriate therapies. Treatment of choice for iatrogenically induced cases is to progressively taper, then discontinue steroid therapy. For spontaneous Cushings cases oral medications are prescribed daily then ACTH is re-tested after 7-10 days when desired levels are reached medication is continued on a bi-weekly basis for life. With occasional ACTH test to monitor levels as required, based on clinical signs. The prognosis ranges from good to poor, depending on the cause and severity of the disease, with the average survival time for dogs being approximately 2.5 years after diagnosis.

Lupoid Onchodystrophy

This condition, which is suspected to be immune mediated, causes nail loss. It is uncommon to rare in dogs, with the highest incidence report in young adult to middle-aged dogs. German shepherds and rottweilers may be predisposed. Usually, an acute onset of nail loss occurs. Initially, 1 to 2 nails are lost, but over the course of a few weeks to several months, all nails slough. Replacement claws are misshapen, soft or brittle, discolored, and friable and usually slough again. Affected paws are often painful and pruritic.

• Diagnosis- Rule out other differentials such as fungal and bacterial nailbed infection, food allergy autoimmune skin disorders, drug eruption and vasculitis.

• Treatment- Systemic antibiotics for at lest 6 weeks if secondary infection present. New nails should be trimmed frequently (approx every 2 weeks), daily oral fatty acid supplementation. Sometimes other drugs are required. Prognosis for nail regrowth is good, although some nails may remain deformed or friable. In some dogs, therapy can be successfully discontinued after 6 months. In others, long-term maintenance therapy is necessary to maintain remission.

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Bacterial & Fungal (yeast) Infections

Bacterial Claw Infections

Are almost always secondary to an underlying cause. When one claw is affected, previous trauma should be suspected. When many claws are infected, underlying conditions to be ruled out include hypothyroidism, cushings, allergies, autoimmune disorders, symmetrical lupoid onchyodystrophy, and neoplasm. Affected claws are often fractured and oozing with associated paronychia, toe swelling, and pain.

• Diagnosis- Ususally based on history, clinical findings, and ruling out other differentials. Cytology, culture and occasionally x-rays.

• Treatment- Underlying cause should be identified and corrected. Any loose nails or fractured portions of traumatized nails should be removed. Long term antibiotics should be continued at least 2 weeks beyond complete clinical resolution. Antibiotic selection should be based on culture results. Topical foot scrubs or soaks may be recommended. Prognosis for nail regrowth is good.

Fungal Nail Infections

Are usually caused by dermatophytes, although isolated cases of nail infection from other fungi have been reported. Typically only one or two nails are affected. These infections are rare in dogs and cats. Secondary yeast paronychia is common in allergic dogs.

• Diagnosis- Rule out other differentials, fungal cultures, biopsy.

• Treatment- Any loose or sloughing nails should be removed. For true nail infections long term antifungal therapy should be administered at least 1-3 months beyond complete nail regrowth. Frequent nail trims should be performed to remove infected portions. Trimmings should be submitted for follow up fungal cultures and treatment continued until culture results are negative. Foot soaks and topical treatments may be recommended. Prognosis is guarded to fair. Many dogs have incomplete resolution in spite of aggressive antifungal therapy. In these cases, amputation or long-term, low dose therapy with antifungals may be needed.

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Acral Lick Dermatitis (Acral Lick Granulomas)

Is first noted as excessive, compulsive licking at a focal area on a limb, resulting in a firm, proliferative, ulcerative, alopecic lesion. The causes of the licking are multifactoria, and, although environmental stress (eg, boredom, confinement, loneliness, separation anxiety) may be a contributor, other factors are usually more important. Such as, hypersensitivity (food and environment), fleas, trauma (cut, bruise), foreign body reaction, infection, demodicosis, hypothyroidism, neuropathy, osteopathy & arthritis. The lesion usually begins as a small area of dermatitis that slowly enlarges because of persistent licking. The affected area becomes alopecic, firm, raised, thickened, and plaque like to nodular, and it may be eroded or ulcerated. With chronicity, extensive fibrosis, hyperpigmentation, and secondary infection are common. Lesions are usually single but may be multiple and are most often found on the lower leg.

• Diagnosis- Usually based on history, clinical findings and ruling out other differentials. Biopsy and cultures are often helpful tools.

• Treatment- Underlying causes should be identified and corrected. Treat secondary infections with long term antibiotics for minimum 6-8 weeks and as long as 4-6 months in some dogs. Mechanical barriers such as wire muzzles, and Elizabethan collars may be helpful. When no underlying cause can be found, treatment with behavior-modifying drugs may be beneficial to some dogs. Surgery is not recommended because postoperative complications, especially wound dehiscence (re-opening) are common. Prognosis is variable, chronic lesions that re unresponsive or extensively fibrotic and those for which no underlying cause can be found have a poor prognosis for resolution. Although this disease is rarely life threatening, its course may be intractable(hard to treat, relieve, or cure).

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Food Allergy

Canine food hypersensitivity is an adverse reaction to a food or food additive. It can occur at any age, from recently weaned puppies to elderly dogs that have been eating the same food for years. Approximately 30% of dogs diagnosed with food allergy are younger than 1 year of age. It is common in dogs. Canine food hypersensitivity is characterized by nonseasonal pruritus that may or may not respond to steroid therapy. This pruritus (itching) may be regional or generalized and usually involves the feet, ears, inguinal or axillary areas, face, neck and perineum. Affected skin is often Erythematous, and popular rash may be present. Secondary superficial Pyoderma (skin infections), yeast dermatitis, and Otitis externa are common. Other symptoms that may be seen are acral lick dermatitis, chronic seborrhea, and recurring pyotraumatic dermatitis. Some dogs are minimally pruritic, with only symptom being recurrent infection with Pyoderma, yeast infections or Otitis. In these cases, the pruritus is present only when secondary infections are left untreated. Concurrent gastrointestinal signs (frequent bowel movements, vomiting, diarrhea, gas are reported in 20-30% of cases).

• Diagnosis- Intradermal or serologic (blood) allergy testing is not recommended because test results are unreliable. Response to hypoallergenic diet trial, symptoms improve within 10-12 weeks of initiation of a strict home-cooked or commercially prepared restricted diet (one protein and one carbohydrate). The hypoallergenic diet should not contain food ingredients previously administered in dog food, treats, or table scraps. Nor should flavored heartworm preventative, flavored mediations, nutritional supplements, or chewable treats (pigs ears, cows hooves, rawhides, dog biscuits, table food such as cheese or peanut butter to hide pills in) be used during trial.

• Treatment- Any secondary infections (bacterial, yeast), Otitis externa should be treated Controlling secondary infection is an essential component of managing food allergic dogs. A flea-control program should be instituted to prevent flea bites from aggravating the pruritus. Food trial identifying offending substances to avoid. Prognosis is good. In dogs that are poorly controlled, owner noncompliance should be ruled out, along with development of hypersensitivity to an ingredient in hypoallergenic diet, secondary infection, scabies, demodicosis, atopy, flea allergy, dermatisis, and contact hypersensitivity.

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Thickening of Paws

Zinc Responsive Dermatosis

Is a zinc deficiency induced disorder of keratinization. An inherent diminished ability to absorb zinc from the intestinal tract, a diet low in absolute zinc concentration, or mineral antagonisms that prevent zinc absorption from the food can cause zinc deficiency. Crusting, scaling, erythema, and alopecia typically develop around the eyes and mouth; the muzzle, nasal planum, ear flaps, and genitalia may also be involved. Hyperkeratotic or thick, crusty plaques may be present on the elbows, stifles, and other pressure points, and at sites of trauma. The footpads may be hyperkeratotic and fissured. Lesions may be asymmetrical and mildly to moderately pruritic in some dogs. Secondary bacterial and yeast skin infections are common. Concurrent depression, anorexia, lymphadenomegaly, and pitting edema of the distal extremities may be seen. Severely affected puppies may have stunted growth.

• Diagnosis- Rule out other causes, biopsy and of course response to zinc therapy.

• Treatment- Any secondary infections should be treated with appropriate therapy. Dog with diet induced zinc deficiency, the dietary imbalance should be identified and corrected. Zinc supplementation may be needed in some dogs, either initially for the first few weeks of the dietary change, or lifelong if there is a diminished ability to absorb zinc. Concurrent symptomatic therapy with warm water soaks, antiseborrheic shampoos and topical applications of ointments on the lesions may be helpful. Intact females who are not well controlled with zinc supplementation should be spayed because estrus may exacerbate the disease. Prognosis is good for most dogs, although life long zinc supplementation is sometimes needed.

Hepatocutaneous

Is a unique skin disease in animals that have chronic liver disease or glucagons-secreting pancreatic tumors. The exact pathogenesis is unknown, it is uncommon in dogs and rare in cats, with the highest incidence in older animals. Among dogs, shetland sheep dogs, West Highland White Terriers, cocker spaniels, and Scottish terriers may be predisposed. Skin lesions are characterized by minimally to intensely pruritic, bilaterally symmetrical erythema, scaling, crusting, erosions, and ulcers on the distal limbs and around the mouth and eyes. Lesions may also involve the ear pinnae, elbows, hocks, external genitalia, ventrum, and oral cavity. The footpads are usually mildly to markedly hyperkeratotic, fissured, and ulcerated. Lameness secondary to footpad lesions may be evident. Increase in drinking and urination may be present if there is concurrent diabetes mellitus. Otherwise, system signs of underlying metabolic disease are rarely evident at initial presentation but usually become apparent a few to several months later.

• Diagnosis- Blood testing looking for anemia may be present, liver failure, hyperglycemia Ultrasound of abdomen looking for evidence of liver disease, biopsy of liver, skin biopsy.

• Treatment- Secondary infections should be treated, if the underlying cause is a respectable glucagonoma, surgical excision of the tumor is curative. If the underlying problem is liver disease, its cause should be identified and corrected, to symptomatically improve liver function, with antioxidants may be helpful. Amino Acid supplements may be helpful. Symptomatic topical therapies may help improve skin lesions. Prognosis for animals with chronic hepatic disease or metastatic pancreatic neoplasia is poor, and survivial time after the onset of skin lesions may be only a few months.

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Pemphigus Foliaceous

Is an autoimmune skin disease that is characterized by the production of autoantibodies that attack the skins ability to stay attached. Pemphigus Foliaceus is probably the most common autoimmune skin disease in dogs and cats. Any age, sex, or breed can be affected. Pemphigus Foliaceus is usually idiopathic, but some cases may be drug induced, or it may occur as a sequela to a chronic inflammatory skin disease. The primary lesions are superficial pustules. However, intact pustules are often difficult to find because they are obscured by trhe hair coat, are fragile and rupture easily. Secondary lesions include superficial erosions, crusts, scales, epidermal collarettes, and alopecia. Lesions on the nasal planum, ear pinnae, and footpads are unique and characteristic of autoimmune skin disease. The disease often begins on the bridge of the nose, around the eyes, and on the ear pinnae, before it becomes generalized. Nasal depigmentation frequently accompanies facial lesions. Skin lesions are variably pruritic and may wax and wane. Footpad hyperkeratosis is common and may be the only symptom in some dogs and cats. With generalized skin disease, concurrent lymphadenomegaly, limb edema, fever, anorexia, and depression may be present.

• Diagnosis- Rule out other differentials. Biopsy is the only way to diagnose the disease.

• Treatment- Symptomatic shampoo therapy to remove crusts may be helpful. Treat any secondary infections. Immunosuppressive drugs are given over a couple of months with a decreasing dosage to get to the lowest possible effective dose. Prognosis is fair to good. Although some animals remain in remission after immunosuppressive therapy is tapered and discontinued, most animals require lifelong therapy to maintain remission. Regular monitoring of clinical signs and blood testing with treatment adjustments as needed is essential. Potential complications of immunosuppressive therapy include unacceptable drug adverse effects and immunosuppression-induced bacterial infection, demodex, or dermatophytosis.

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Viral Flat Papilloma (Flat Warts)

Canine papillomavirus is characterized by benign tumors induced by infection of epithelial cells by species-specific DNA papillomaviruses. Viral oncogenes induce host epithelial cell growth and division and cause chromosomal instability and mutations. Papillomaviruses are transmitted by direct and indirect contact, with an incubation period of 1-2 months in the mouth and 6-12 months on the skin before regression occurs. Cellular immunity is key to papilloma regression; immunosuppressive conditions (including feline immunodeficiency virus in cats and immunosuppressive medications may exacerbate and prolong infection). At lest five types of canine papillomavirus and up to eight types of feline papillomavirus have been identified; each has a distinct clinical presentation or site of infection.

Canine Footpad Papilloma (Wart)

This is an infrequently reported disease of adult dogs that has not been consistently demonstrated to have a viral cause. Lesions are firm, hyperkeratotic masses on multiple footpads. Interdigital lesions have been described in Greyhounds. Lameness and secondary bacterial infection may occur.

• Diagnosis- By Biopsy.

• Treatment- Most papillomavirus infections regress spontaneously after development of host cell-mediated immune response. Surgery may be curative for persistent solitary lesions, but care should be taken with tissue handling to avoid seeding the surgical site with viral particles. Cryotherapy and laser ablation are often effective, but they may need to be repeated. Oral medications, subcutaneous injections or topical creams may be prescribed in certain cases. Prognosis is usually good, as most cases will spontaneously regress.

Famillal Footpad Hyperkeratosis

Hyperkeratosis is a familial disorder that results in severe digital hyperkeratosis by 5-6 months of age. It is rare in dogs, with the highest incidence in Irish terriers, Dogues de Bordeaux, and Kerry blue terriers. An autosomal recessive mode of inheritance is suspected in Irish terriers. At birth, the footpads appear to be normal, but by 4-6 months of age, affected dogs begin to develop marked hyperkeratotic, thickened, hard, and cracked footpads. The entire surface of all footpads are involved, and the subsequent information of horny growths, expanding fissures, and secondary bacterial infection usually results in severe, intermittent lameness. No other skin involvement occurs, but concurrent abnormal nail development, characterized by slightly faster growth and round profiles instead of the normal U-shaped ones, may be seen in Irish terriers.

• Diagnosis- Rule out other differentials, and performing biopsy.

• Treatment- No specific treatment is known, but treatments as for idiopathic nasodigital hyperkeratosis may be effective. Symptomatically treat with daily foot soaks prescribed by doctor and frequent filing of the footpads to remove surplus keratin. Significant improvement should be seen within 5 days, but life long maintenance therapy is required for control. For fissured lesions, a cream may be recommended and systemic antibiotics for 3-4 weeks if footpads are secondarily infected. Fast-growing nails should be trimmed frequently. Prognosis for cure is poor, but most dogs enjoy a good quality of life with routine symptomatic therapy. Affected dogs should not be bred.

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Idiopathic Nasodigital Hyperkeratosis

Is an idiopathic (unknown cause) condition that is characterized by the excessive formulation of nasal or footpad keratin. It is common in older dogs. Thickened, hard, dry keratin accumulates on the top of the nose, footpads, or both. The accumulated keratin is usually most prominent on the top of the nose and at the edges of the footpads. Nasolacrimal (tear) duct blockage may present a contributing factor. Affected dogs are otherwise healthy and have no other skin signs.

• Diagnosis- Is made by ruling out other medical problems such as Zinc deficiency, distemper, pemphigus foliaceus and discoid lupus and others.

• Treatment- The intensity of therapy depends on the severity of the lesions. Tear ducts should be flushed. For mild, asymptomatic cases, no treatment may be appropriate. For moderate to severe cases, affected areas should be hydrated and a softening agent will be prescribed.

• Prognosis- Is good. Although it is incurable, this is a cosmetic disease that can usually be managed symptomatically.

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Swollen Paws

Interdigial Cysts

The etiopathogenesis is unclear, but one hypothesis is that sterile pedal furunculosis is a persistent, immune –mediated, inflammatory response to keratin and triglycerides liberated from ruptured hair follicles, sebaceous glands, and the panniculus. The condition is thought to develop after the initiating cause of the furunculosis (e.g., mechanical, infectious, parasitic, allergic) has been resolved. It is uncommon in dogs, with short-coated breeds possibly predisposed. Canine pedal furunculosis manifests as single to multiple, erythematous papules; firm to fluctuant nodules; or bullae of 1 foot or more that appear in the interdigital areas. The lesions may be painful or pruritic, may ulcerate, may develop draining tracts with serosanguineous or purulent exudates, and , with chronicity, may become fibrotic. Lesions spontaneously resolve, was and wane, or persist indefinitely. Regional lymphadenopathy is common, but no systempic signs of illness are noted. Secondary bacterial and yeast infections are common.

• Diagnosis- Based on history, clinical finding and ruling out other differentials. Cytology (aspirate of nodule or nonruptured bulla), biopsy, cultures.

• Treatment- The clinician should make sure that the initiating cause of the furunculosis (eg, food allergy, wet environment, dirt kennels, friction in short-coated breeds) has been identified and corrected. Secondary infections should be treated with antibiotics or antifungas. For solitary lesions, surgical excision or laser ablation may be curative. Topical ointments may be prescribed. The prognosis is good to fair. Lifelong medical therapy may be needed to maintain remission, and interdigital fibrosis may be a permanent sequela in chronic cases.

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Interdigital Deep Pyoderma (Bacterial Pododermatitis-paw infection)

Bacterial Pododermatitis is a deep bacterial infection of the feet that almost always occurs secondary to some underlying factor (Foreign body, parasite, fungus, food allergy, atopy, hypothyroidism, Cushings, trauma from stones, stubble, gravel, sands, autoimmune and immune-mediated skin disorders). It is common in dogs and rare in cats. One or more feet may be affected by interdigital erythema, pustules, papules, nodules, hemmorhagic bullae, fistulae, ulcers, alopecia, or swelling. Pruritus (licking, chewing), pain, or lameness may be present. Regional lymphadenomegaly is common. Occasionally, pitting edema of the associated metatarsus or metacarpus is seen.

• Diagnosis- Rule out other differentials, cytology, biopsy and culture.

• Treatment- Any underlying cause should be identified and corrected. Systemic antibiotics long term, adjunctive topical therapy can be helpful. Foot trauma should be minimized by having the dog confined indoors, leash-walked, and kept away from rough surfaces. Fusion podoplasty, whereby all diseased tissue is removed and digits are fused together, is a radical surgical alternative that is available for severe cases. The prognosis is good to guarded, depending on whether the underlying cause can be identified and corrected. In severe and chornic cases, permanent fibrosis and scarring may contribute to future relapses by predisposing feet to traumatic injury.

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Lymphocytic Plasmocytic Pododermatitis

This disease is characterized by swollen paws, usually all four paws are involved. The paws are red, have hair loss, painful with no other areas of the body involved. Skin biopsies reveal a tissue infiltrated with lymphocytes and plasma cells. The cause is unknown, there is no response to antibiotics. There is marked clinical improvement with long term immunosuppressive drug therapy.

Abnormal Skin Formation (Keratinization)

Seborrhea, describes skin which is dry, dull, lusterless hair coat, excessive scaling (dandruff), scaly and crusty, greasy, smelly patches.

Most cases of seborrhea are secondary to other disease like allergies and infections. However if it starts in the first year of life it can be primary seborrhea.

Primary seborrhea is a hereditary disorder of skin formation (keratinization). The highest incidence is in American Cocker Spaniels, English Springer Spaniels, West highland White Terriers and Bassett hounds .

Vitamin A – Responsive Dermatosis of American cocker Spaniel

Focal areas of crusting and scale forming plugs or discrete patches. Occurs almost exclusively in 2-3 year old American cocker spaniels.

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Ichthyosis

Ichthyosis is another congenital defect in skin formation (keratinization) which covers the body with large accumulations of scale (dead skin) in large sheets. In the first year of life it may effect Westhighland White Terriers, Golden Retreivers, Cavalier King charles Spaniels, Doberman Pincers, Jack Russell Terriers, Norfolk Terriers and Yorkshire Terriers .

Sebaceous Adenitits

Mild to severe scaling, localized, multifocal or generalized. In short or long hair coated breeds. Highest occurrence is in young to middle aged Standard Poodles, Hungarian vizslas, Akitas and Samoyeds .

Zinc Responsive Dermatosis

Zinc responsive dermatosis is a zinc deficiency induced disorder of skin formation (keratinization). An inherent diminished ability to absorb zinc from the intestinal tract. It occurs mostly in adult northern breeds, Siberian Huskies, Samoyeds and Alaskan Malamutes . Crusting, scaling and hair loss around the eyes, mouth, muzzle, nose, ears, genitals, elbows, stifles and other pressure points.

Schnauzer Comedone Syndrome

Schnauzer Comedone Syndrome is an acne-like disorder of formation of hair follicle keratin comedones or blackheads and crusted papules are found on the back.

Hereditary Nasal Parakeratosis of Labrador Retrievers

Crusts and scabs form on the nose of Labrador Retrievers between 6-12 months of age.

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Hair Loss Associated with Breeds

• Alopecia X- Generalized hairloss which may be due to adrenal sex hormone imbalance or local follicle receptor dysregulation. Most common at 2-5 years of age especially in Chow Chow’s, Pomeranians, Keeshounds, Samoyeds, Alaskan Malamutes, Siberian Huskies and Mini Poodles .

• Color Dilution Alopecia (color mutant alopecia)- This is a hair follicle dysplasia of hairs associated with defective pigmentation and formation. It is common in color-dilute dogs such as those bred to blue (dilutions of black) or fawn (dilutions of brown). The disorder is especially common in Doberman Pincers but also occur in other breeds including, Yorkshire Terriers, Minature Pincers, Great Danes, Whippets, Italian Greyhounds, Salukis, Chow Chows, Dachshunds, Silky Terriers, Boston Terriers, Newfoundlands, Bernese Mountain Dogs, Shetland Sheepdogs, Schipperkes, Chihuahuas, Poodles and Irish Setters . Dogs appear normal at birth, but start losing hair over the back and trunk between 6 months and 2 years.

• Black Hair Follicular Dysplasia- This disorder is a color linked follicular dysplasia of black hairs that is associated with defective hair pigmentation and formation. Puppies are normal at birth but begin losing hair at 1 month of age. Only black hairs are lost.

• Canine Pattern Baldness- Unknown cause hairloss disorder mostly of Dachshunds but also occurs in other short haired breeds Chihuahuas, Whippets, Manchester terriers, Boston Terriers, Boxers, Greyhounds . Hair loss usually starts in late puberty to early adult hood. The symmetrical hair loss usually affects the ears, around the ears, thighs, neck, chest and abdomen.

• Canine Recurrent Flank Alopecia- This disorder is a seasonal recurrent follicular dysplasia. Hair is usually lost between November and then regrows in the summer. Hair loss occurs on both flanks of mostly adult Boxers, Bulldogs, Airedales, and Schnauzers .

• Canine Follicular Dysplasia- This is a disorder of hair follicle development that affects young to middle aged dogs. The breeds mostly affected are Irish Water Spaniels, Portuguese Water Dogs, Black or Red Dobermans, Weimaraners, and Pont-Audemer Spaniels .

In a study of dogs in northern California conducted at the University of California at Davis, 31 breeds were found to be at elevated risk for skin diseases, including Doberman pinscher, Irish setter, Dalmatian, Dachshund, Golden Retriever, various terrier breeds, Shar pei, Chow Chow, and Akita. In the same study, decreased risk of skin disease was found for dogs of mixed breeding and for 12 purebred breeds, including St. Bernard, Standard Poodle, Beagle, Basset Hound, German Shorthaired Pointer, Afghan Hound, and Australian Shepherd.

Breed predilection determines the incidence of some skin disorders, see below for some examples. Breeds in (brackets) are popular mixes of the primary breed that may or may not be affected by the same predilection.

Cats:

Abyssinian	Follicular dysplasia
	Idiopathic ceruminous Otitis externa
	Psycogenic dermatitis or alopecia
Himalayan	Cheyletiellosis
	Dermatophytosis (microsporum canis)
	Idiopathic facial dermatitis
	Primary Seborrhea
Persian	Cheyletiellosis
	Dermatophytosis
	Facial fold intertrigo
	Hair mats
	Idiopathic facial dermatitis
	Seborrhea, primary
Rex	Hypotrichosis
Siamese cat	Food hypersensitivity
	Hypotrichosis
	Periocular leukotrichia
	Psycogenic dermatitis or alopecia
	Vitiligo

Dogs:

Afghan hound	Hypothyroidism
Airedale	Adult-onset demodicosis
	Atopy
	Demodicosis
	Follicular dysplasia, flank
Akita	Pemphigus Foliaceus
	Sebaceous adenitis
	Uveodermatologic syndrome
Basenji	Immunoproliferative enteropathy
Bassett hound	Atopy
	Masassezia dermatitis
	Seborrhea, primary
	Skin fold intertrigo
Beagle (Puggle)	Atopy
	Demodicosis
	Imunoglobulin A (IgA) deficiency
Belgian sheepdog	Sebaceous adenitits
	Vitiligo
Berger de Beauce	Epidermolysis bullosa
Borzoi	Hypothyroidism
Boston terrier	Atopy
	Demodicosis
	Facial fold intertrigo
	Hyperadrenocorticism
	Patterned alopecia
	Tail fold intertrigo
Boxer	Atopy
	Demodicosis
	Food Allergy
	Follicular dysplasia (flank)
	Hyperadrenocorticism
	Hypothyroidism
	Muzzle furunculosis, bacterial
	Pedal furunculosis, bacterial
	Sertoli cell syndrome
	Solar dermatitis (white dogs)
	Sterile pyogranuloma syndrome
	Sternal callus
Brittany spaniel	Complement deficiency
	Discoid lupus erythematosus
	Hypothyroidism
Bullmastiff and Mastiff	Folliculitis and furunculosis, bacterial
	Atopy
	Furunculosis, scarring and bacterial
	Lethal acrodermatitis
	Solar dermatitis
	Zinc-responsive dermatosis
Cavalier King Charles Spaniel	Syringohydromelia
Chesapeake Bay Retriever	Atopy
	Folliculitis and furunculosis, bacterial
Chihuahua	Demodicosis
	Pinnal thrombovascular necrosis
Chow Chow	Adrenal sex hormone abnormalities
	Pemphigus Foliaceus
	Color dilution alopecia
	Demodicosis
	Hyposomatotropism
	Hypothyroidism
	Uveodermatologic syndrome
Collie	Bullous pemphigoid
	Dermatomyositis
	Discoid lupus erythematosus
	Nasal furunculosis, bacterial
	Pemphigus erythematosus
	Pyotraumatic dermatitis
	Sertoli cell syndrome
	Systemic lupus erythematosus
	Vesticular cutaneous lupus erythematosus
Curly-coated retriever	Follicular dysplasia
Dachshund	Acanthosis nigricans
	Alopecia areata
	Color dilution alopecia
	Demodicosis
	Folliculitis and pedal furunculosis, bacterial
	Hyperadrenocorticism
	Hypothyroidism
	Idiopathic onychodystrophy
	Juvenile cellulitis
	Linear IgA pustular dermatosis
	Malassezia dermatitis
	Nodular panniculitis (sterile)
	Pattern alopecia (ears & ventral)
	Pemphigus Foliaceus
	Sterile pyogranuloma syndrome
	Sternal callus
	Vasculitis (idiopathic)
Dalmatian	Atopy
	Demodicosis
	Drug reactions
	Folliculitis and furunculosis, bacterial
	Solar Dermatitis
Doberman pinscher	Acral furunculosis, bacterial
	Acral lick dermatitis
	Color dilution alopecia
	Demodicosis
	Drug reaction (sulfas)
	Flank sucking
	Follicular dysplasia
	Folliculitis and pedal furunculosis, bacterial
	Hypothyroidism
	Muzzle furunculosis, bacterial
	Vitiligo
Dogue de Bordeaux	Hereditary footpad hyperkeratosis
	Sterile pyogranuloma syndrome
English Bulldog	Atopy
	Demodicosis
	Facial fold intertrigo
	Folliculitis and pedal furunculosis, bacterial
	Follicular dysplasia (flank)
	Hypothyroidism
	Malassezia dermatitis
	Muzzle furunculosis, bacterial
	Sterile pyogranuloma syndrome
	Tail fold intertrigo
German Shepherd	Atopy
	Cellulitis (folliculitis and furunculosis), bacterial
	Collage disorder of footpads
	Contact hypersensitivity
	Discoid lupus erythematosus
	Erythema multiforme
	Familial vasculopathy
	Flea bite hypersensitivity
	Fly dermatitis of ear tips
	Food allergy
	Lupoid onychodystrophy
	Insect or arachnid-related eosinophilic furunculosis (face)
	Medullary trichomalacia
	Metatarsal fistulae
	Mucocutaneous bacterial Pyoderma
	Nasal furunculosis, bacterial
	Otitis Externa
	Pemphigus erythematosus
	Pituitary dwarfism
	Pythiosis
	Seborrhea, primary
	Systemic lupus erythematosus
	Vitilgo
Golden Retriever (goldendoodle)	Acral furunculosis, bacterial
	Acral lick dermatitis
	Atopy
	Folliculitis and furunculosis, bacterial
	Hypothyroidism
	Juvenile cellulitis
	Nasal hypopigmentation
	Pyotraumatic dermatitis
	Pyotraumatic folliculitis and furunculosis, bacterial
	Sterile pyogranuloma syndrome
	Trichoptilosis
Gordon Setter	Atopy
	Hypothyroidism
	Juvenile cellulitis
Great Dane	Acral furunculosis, bacterial
	Acral lick dermatitis
	Callus formation, hygroma
	Demodicosis
	Hypothyroidism
	Muzzle furunculosis, bacterial
	Pedal furunculosis, bacterial
	Solar dermatosis in Harlequin
	Sterile pyogranuloma syndrome
Great Pyrenees	Demodicosis
	Pyotraumatic dermatitis
Greyhound	Drug reactions
	Vasculopathy
Irish Setter	Acral furunculosis, bacterial
	Atopy
	Acral lick dermatitis
	Color dilution alopecia
	Folliculitis and furunculosis, bacterial
	Granulocytopathy
	Hypothyroidism
	Seborrhea, primary
Irish water spaniel	Follicular dysplasia
	Idiopathic onychodystrophy
Irish wolfhound	Elbow hygroma
	Hypothyroidism
Keeshond	Adrenal hyperplasia syndrome
	Hypogonadism of intact male
	Hyposomatotropism
	Hypothyroidism
Labrador retriever (Labradoodle)	Acral furunculosis, bacterial
	Acral lick dermatitis
	Atopy
	Familial nasal hyperkeratosis
	Folliculitis and furunculosis, bacterial
	Food allergy
	Pyotraumatic dermatitis
	Seborrhea, primary
	Waterline disease (Malassezia dermatitis?)
Lhasa apso (Lhasapoo)	Atopy
	Injection reaction
	Malassezia dermatitis
Malamute	Demodicosis
	Hypothyroidism
	Zinc-responsive dermatosis
Newfoundland	Folliculitis and furunculosis, bacterial
	Hypothyroidism
	Pemphigus Foliaceus
	Pyotraumatic dermatitis
Old English sheepdog	Atopy
	Demodicosis
	Drug reactions
	Pedal furunculosis, bacterial
Pekingese (pekapoo)	Facial fold intertrigo
	Injection reactions
	Sertoli cell syndrome
Pointers	Acral mutilation
	Demodicosis
	Epidermolysis bullosa
	Exfoliative cutaneous lupus erythematosus
	Follicular dysplasia (flank)
	Nasal and muzzle folliculitis
Pomeranians	Adrenal sex hormone abnormalities
	Hyposomatotropism
	Injection reactions
Poodle (Multipoo, Goldendoodle, Schnoodle, Labradoodle, cockapoo, lhasapoo, yorkipoo, pekapoo)	Ectodermal defect Epiphora Hyperadrenocorticism Hyperadrenocorticism Hyposomatotropism Hypothyroidism Injection reactions Otitis Externa Sebaceous adenitis (standard)
Portuguese water dog	Follicular dysplasia
Pug (Puggle)	Facial fold and tail fold intertrigo
Rhodesian Ridgeback	Dermoid sinus in midline of back
Rottweiler	Folliculitis and furunculosis, bacterial
	Follicular lipidosis
	Follicular parakeratosis
	Idiopathic vasculitis
	Vitiligo
Samoyed	Adrenal hyperplasia syndrome
	Hyposomatotropism
	Sebaceous adenitis
	Uveodermatologic syndrome
Schipperke	Pemphigus Foliaceus
Shar pei	Atopy
	Demodicosis
	Fold intertrigo
	Folliculitis, bacterial
	Food hypersensitivity
	Hypothyroidism
	Idiopathic mucinosis
	IgA deficiency
Schnauzer, minature (Schnoodle)	Atopy Aurotrichia Drug reaction Follicular dysplasia (flank) Hypothyroidism Pseudohermaphroditism Schnauzer comedo syndrome Subcorneal pustular dermatosis Superficial suppurative necrolytic dermatitis
Shetland sheepdog	Dermatomyositis
	Discoid lupus erythematosus
	Drug reaction
	Folliculitis, bacterial
	Sertoli cell syndrome
	Systemic lupus erythematosus
	Vesticular cutaneous lupus erythematosus
Shih tzu	Atopy
	Malassezia dermatitis
Siberian husky	Discoid lupus erythematosus
	Eosinophilic granuloma
	Follicular dysplasia
	Hypogonadism in intact male
	Idiopathic onychodystrophy
	Uveodermatologic syndrome
	Zinc responsive dermatosis
Spaniels= Cocker & Springer (cockapoo)	Acral mutilation –English Springer
	Atopy- American Cocker
	Cutaneous asthenia- English Springer
	Food Allergy
	Hypothyroidism
	Idiopathic onychodystrophy- Springer
	Lip fold intertrigo
	Malassezia dermatitis
	Otitis Externa (especially proliferative)
	Psoriasiform-lichenoid dermatosis- English Springer
	Seborrhea, primary
	Vitamin A responsive dermatosis- Cocker
St. Bernard	Acral lick dermatitis
	Folliculitis and furunculosis, bacterial
	Pyotraumatic dermatitis
Terriers:
Cairn	Atopy
	Sertoli cell syndrome
Irish	Hereditary footpad hyperkeratosis
Jack Russell	Atopy
	Demodicosis
	Dermatophytosis (Trichophyton mentagrophytes, var. erinacei)
	Vasculitis
Kerry Blue	Footpad keratoses (corns)
	Otitis Externa
	Spiculosis
Scottish	Atopy
	Demodicosis
	Folliculitis and furunculosis, bacterial
	Hereditary nasal pyogranuloma and vasculitis
West Highland White	Atopy
	Demodicosis
	Epidermal dysplasia
	Ichthyosis
	Malassezia dermatitis
	Seborrhea, primary
Wire-haired fox	Atopy
Yorkshire (Yorkipoo)	Color dilution alopecia
	Dermatophytosis (m. canis)
	Injection reactions
	Melanoderma and alopecia
	Traction alopecia
Visla	Sebaceous adenitis
Weimeraner	Demodicosis
	Muzzle furunculosis
	Sertoli cell syndrome
	Sterile pyogranuloma syndrome
Whippet	Idiopathic onychodystrophy

Autoimmune & Immune- Mediated Skin Disorders

• Pemphigus Fopaceous (PF)

• Pemphigus Erythematous (PE)

• Pemphigus Vulgaris (PV)

• Bullous Pemhigoid

• Discoid Lupus Erythematous (DLE)

• Systemic Lupus Erythematous (SLE)

• Vesicular Cutaneous Lupus Erythematous (VCLE)

• Sterile Modular Pannicuptis

• Idiopathic Sterile Granuloma and Pyogranuloma

• Cutaneous Vascuptis

• Erythema Multiforme (EM) and Toxic Epidermal Necrolysis (TEN)

• Cutaneous Drug Reactions (Drug Eruption)

These diseases are uncommon or rare, but are seen fairly frequently by dermatologists. The most common are Discoid Lupus Erythematous (DLE) and Pemphigus Fopaceous (PF).

Pemphigus Fopaceous

PF can look identical to skin infection. It’s lesions include pimples (pustules) and scabs (crusts) which don’t respond to antibiotics. These lesions are created by the dogs immune system attacking it’s own skin. The distribution includes the ears, paws and entire body.

Discoid Lupus Erythematous

DLE causes nasal depigmentation, inflammation, scapng, erosion, ulceration and scabs (crusting). This disease is usually restricted to front and top of the nose. More severe cases may become secondarily infected.

Mast Cell Tumor

The most common malignant tumor of the skin. Affecting the mast cells of the dermis. Breeds predisposed include, Boxers, Pugs, Boston Terriers, Labradors, Weimaraners, Beagles, Chinese Sharpeis and Golden Retrievers. The tumors are usually found on the trunk, perineum and limbs.

Epitheliotropic Lymphoma (Mycosis Fungoides)

MF is a malignant cancer arising from T lymphocytes. Highest incidence in older animals, Scottish terriers and Golden Retrievers are predisposed. Initially most cases show large areas of scaling, red skin which is itchy. It can involve the areas in and around the mouth, nose, anus and genitalia. It will usually slowly progress into plaques and nodules (tumors).

Cutaneous Histiocytosis (CH)

Ch is a rare begin proliferative disease of histiocytic cells of the skin. Multiple nodules occur in a group on the head, neck, perineum, scrotum and extremitites. The nodules may wax and wane and regress and reappear in new areas. Only affects the skin.

Systemic Histiocytosis (SH)

SH is a proliferative disorder that affects the skin and internal organs. The highest incidence is in Bernese Mountain dogs. The multifocal areas are papules, plaques and nodules which are haired, hairless or ulcerated. Lesions occur on the eyelids, muzzle, planum nasale, extremities and scrotum. Lesions may develop in the lung, lymphnode, spleen, liver, bone marrow and nasal cavity.

Malignant Histiocytosis (MH)

MH is a malignant cause of histocytes. The highest incidence occurs in Bernese Mountain dogs. Other predisposed breeds include Labradors, Rottweilers, Golden Retrievers and Flat Coated retrievers. Skin lesions are uncommon but when present are characterized by multiple firm nodules which may have hair loss and ulcerated. The spleen, lymphnodes, lung and bone marrow are primarily affected and then spreads to liver, central nervous system and kidneys. MH is a highly malignant rapidly progressive and fatal disease.