Canine Skin Allergies

Skin Allergies in Dogs

DEFINITION

A skin allergy is the bodies’ ‘’hypersensitive’’ response to an allergen (e.g. pollen, dust, mould, mites etc). This presents as redness in the skin and itching behaviour.

Causes of itch (allergic and other)

• Atopic dermatitis; when your pet is ‘’hypersensitive’’ to these common allergens, as mentioned above. This is genetically inherited and occurs in 10% of dogs. This is seen on the ears, muzzle, around the eyes, paws, chest and flank
• Contact dermatitis; when your pet reacts to allergens (usually plants/grasses) they come into contact with, seen commonly on their stomach and paws.
• Food allergy; when your pet reacts to an allergen in the diet, this is most commonly beef or chicken protein.
• Flea allergy dermatitis; when your pet has an allergic reaction to the bites of the fleas.
• Parasites; Skin reaction to fleas, mites, lice, ticks.
• Bacterial or yeast infections: Commonly staphylococcus bacteria or malassezia yeast or ringworm.
• A combination of the above conditions.

Diagnosis

• History
• Physical examination
• Localisation of affected regions on the body
• Skin scrape for external parasites
• Food trial; hypoallergenic diet
• Blood test; todetect antibodies
• Intradermal test to look at the skin’s reaction to injected allergens

Treatments

• Avoidance of offending allergens; e.g. avoiding particular plants in the garden
• Corticosteroids; to quickly reduce the itch and inflammation. However there are side effects to their use, especially long term.
• Antihistamines; Can help control the itch but usually has a mild effect and may be best when used in conjunction with other treatments.
• Cyclosporine: a drug which modulates the immune system (as allergies are an excessive immune response). Particularly relevant for more severe cases when dogs have frequent flare-ups.
• JAK inhibitors: A new class of drug that targets the chemical messengers involved in itch and inflammation, soon to become available in Australia (mid 2016).
• Fatty acids (fish oil capsules); To reduce inflammation and put oil back into dry, scaly skin to build up its protective barrier.
• Emollients (oatmeal washes); To put moisture back into a dry, scaly coat. This provides only short term relief. This may also remove residual allergen from the skin i.e. the pollen of a plant the dog is allergic to. Medicated shampoos may treat particular pathogens involved.
• Topical treatments such as local anaesthetic/corticosteroid creams or sprays.
• Desensitisation/immunotherapy; Injections over a longer time period to desensitise the dog to the offending allergen.
• Diet modification: eliminating offending allergens, or providing additives such as fatty acids to build up the skin barrier.
• Specific treatments for pathogens suspected to be involved in the disease, such as anti-biotics, anti-fungals, or anti-parasitics.

Allergic skin disease is a lifelong condition, but we can help you determine what the best long term management plan is for your dog, to keep it under control.