Dog allergies

The most common cause of itching, scratching and licking in dogs is allergies. The most common cause of skin, paw and ear infections in dogs is allergies.  Allergies can be tough to correctly diagnose.  Veterinary dermatologists have the advanced training, knowledge and experience to correctly diagnose the specific allergy. If one does not diagnose the specific allergy then the client can only treat the symptoms (itching) with drugs such as Apoquel or Cytopoint which can be expensive as you will likely be on them indefinitely. If you know what the allergy is then you can specifically treat the allergy and not just the symptoms. Veterinary dermatologists know which tests to run, how to run these tests and very importantly how to interpret them correctly as the allergy tests can give wrong and misleading results in addition to “good” results. Filtering the correct information from the incorrect test results are what experienced Veterinary dermatologists are very good at. At least 50 % of allergy dogs have food allergies.  Around 50 % of allergy dogs have environmental allergies, while approximately 20-30% can have both allergies.

Common environmental allergies such as House dust mite allergies can be treated by controlling, what the dog sleeps on. Pollen and mold allergies can be treated and sometimes cured by Allergy Immunotherapy (“Allergy shots”). This is very similar to the allergy treatment done by human allergists. If the allergy tests can identify the correct allergy triggers (pollens and molds) then these are put into either in injectable or orally administered preparation which is administered by the owner over the next number of years. This essentially desensitizes the allergy patient to those allergens. This can be very effective in at least 75% of the dogs with allergies. After 2-3 years some of these dogs can be cured. This either eliminates or reduces the dependency on drugs such as Apoquel or Cytopoint to control the itching licking and scratching. Omega three fatty acids such as fish oil will help around 50% of dogs with environmental allergies, and can help reduce the Apoquel dosage by half in some patients, thus reducing the cost of this drug. Currently we are treating many of our allergy dogs with probiotics to see if they can benefit by decreasing their allergies, reduce food allergy dogs from developing more food allergies in the future or have a better response to the allergy immunotherapy vaccine that the owner will be administering. Over the years, working with human allergists, we have learnt which grass, tree, and weed pollens as well as mold spores are the most important in Vancouver.

Veterinary dermatologists need to diagnose and treat the most difficult skin, paw, external and middle ear infections. Hair loss can be due to hair follicle infections with bacteria, fungi or parasites. Hormonal conditions can also result in hair loss that can be diagnosed and treated.

Lumps and bumps due tumours and cysts can be diagnosed and treated. Nail disorders, autoimmune and immune mediated disorders are all are also areas of expertise of veterinary dermatologists.

Hot spots (Acute Moist Dermatitis)

There are two main types of “hot Spots”. The first one is usually located on the back end or back legs. These are usually due to self trauma, and if the dog is prevented from licking the area they quickly heal. These hot spots are usually treated with corticosteroids and the “cone of shame”. The second type of “Hot Spot” is located on the head usually the cheek area. These are usually deep infections requiring 4-6 weeks of antibiotics.

Skin Infections

The majority of skin infections in dogs are caused by a bacteria caused by Staphylococcus. The second most common is a yeast called Malassezia. The majority of infections are caused by underlying allergies.

Parasites

Fleas are the most common parasite and are usually found on the back 1/3 of the dog. Often hard to find but leave traces of “flea dirt” (flea poop). Fleas are rare now because of the improvement in very effective flea control products.

Demodex mites in hair follicles result in hair loss and infections, are mostly seen in puppies but also occasionally in adult dogs. Not contagious. Diagnosed with a skin scrape to see many mites under the microscope.

Scabies mites or sarcoptic mange is very contagious and extremely itchy. Any recent exposure to other dogs such as in dog groomers, dogy day care, boarding kennels and dog shelters can suggest this diagnosis.

The diagnosis of scabies can be difficult and is often misdiagnosed as just another dog with allergies. There is usually very few mites and thus difficult to find. Response to therapy is a very good way to help confirm the diagnosis.

Ticks are usually obvious on examination. Ticks are usually found in forests where there are deer. Vancouver Island, Gulph Islands, or Squamish are known areas.

Alopecia (hair loss)

Alopecia is most commonly due to follicular infections caused by bacteria, fungus or demodectic mites. Itching due to allergies or parasites can also remove the hairs. Hormonal diseases such hypothyroid or Hyperadrenocorticism (Cushing’s) can cause lack of hair growth. More rare diseases and less well understood hair loss diseases include Alopecia x in Pomeranians, Alaskan Malamutes, Keeshonds, Samoyeds, chow chows and miniature poodles. Recurrent flank alopecia occurs in English Bulldogs, Boxers, Airedales and Schnauzers. Follicular Dysplasia and Alopecia Area are other rare diseases that can cause Hair loss.

Dermatitis and Rashes

These are non specific terms that would describe any skin disease that causes inflammation of the skin. The most common wound be infections or allergies and parasites. The Autoimmune diseases Pemphigus foliaceus and Discoid Lupus will also result in inflammation.