Food allergies or Adverse Food Reactions (AFR) in cats and dogs are blamed for a host of clinical signs ranging from itchy skin to loose stool. AFR is a convenient diagnosis as the treatment is avoidance of the offending dietary allergen, however, it is rarely that simple. While it is possible that a component of a pet’s food could be contributing to these symptoms it is important to consider other concurrent allergies as well.
It is estimated that AFR accounts for 15-46% of inflammatory skin lesions in dogs and 10-23% in cats. If you notice these are pretty wide ranges, which tell me that most of the time we really don’t know what the pet was allergic to. For many suspected allergic conditions a diet change may improve overall clinical signs but it is unlikely that the food is the only allergy that pet has. Allergies to environmental components like pollens, molds and dust mites as well as flea allergy dermatitis are far more common than a true food allergy alone.
4 common pet food allergy symptoms are:
- Recurrent ear infections – Dogs and cats with food allergies will often present with chronic ear infections. They are allergic to something in the food that creates an inflammatory reaction and makes their ears itchy. When they itch they disrupt the normal skin barrier, this allows the yeast and bacteria that normally live on the skin to go crazy. The warm, damp ear canal is the perfect environment for a yeast infection so this organism is especially proliferative.
- Anal gland issues – Whenever I have a dog or cat present with an itchy rear end that is causing the pet to lick or scoot I immediately think of a food allergy. Another common clinical sign with anal gland inflammation is an intermittent, extremely stinky, fishy smell as the irritated anal glands are producing a lot of their “juice” and it leaks a bit.
- Feline Eosinophillic Granuloma Complex (ECG) – If a cat comes in with a swollen, ulcerated lip or raised, red skin sores I am suspicious of ECG. Cats with allergic disease can break with these characteristic lesions and a food allergy is commonly to blame.
- Inflammatory Bowel Disease (IBD) – This allergic condition occurs when the gastrointestinal tract becomes inflamed resulting in weight loss, vomiting, diarrhea or loose stool and decreased appetite.
With any of the above conditions one must always treat all infections that are present. Even if a food allergy is the primary cause of the clinical signs, you must clear up the infection with an antibiotic and/or antifungal as well as reduce inflammation with a steroid. Now that you know more about AFR in dogs and cats you may be interested in switching your pet’s diet. Next week I will write more about the hypoallergenic diet options that are available and how to perform a true food trial.
Ashley Gallagher, DVM