Food allergies are the third most common type of allergies seen in our pets, following airborne toxins and atopy (flea bites). Food allergies can be quite troublesome, difficult to diagnosis and may cause severe discomfort for your pet.
What causes food allergies? The simple explanation is that an allergic reaction to a certain food occurs when your pet’s immune system identifies a substance found in the food as harmful to them, something to be fought off and expelled, rather than something healthy or beneficial. Their body develops antibodies to fight off the ‘invader’ and this reaction can result the symptoms we normally equate with a food allergy – itchy skin, diarrhea, etc. If you want a more detailed and technical description of the what’s going on inside your pet’s body and immune system, here’s a good explanation from Modern Dog.
Allergies are typically genetic, but may also be environmental in nature. Since they are genetic, there are some breeds more prone to these allergies than others, specifically German Shepherds, Retrievers, Boxers, Cocker Spaniels and Dalmatians to name a few.
Currently, there is some innovative research going on to better understand (and maybe prevent) the development of these allergies. One school of thought is that they might be related to the use of antibiotics in a puppy or kitten. This early use may impact the development of the immune system and then impact immune related reactions later in life. It will be interesting to watch this research and any findings that may help our pets.
An allergy may also disguise itself as the more common food intolerance since some of the symptoms may be similar (vomiting, diarrhea). Think of it like a human who can’t eat spicy or greasy foods, it’s not an allergy, it’s just their digestive system staging a revolt because it has difficulty processing that particular food.
Food intolerances can develop slowly if a pet is fed the same foods every day for long time periods. Unfortunately, this is exactly what many pet parents do-- they choose a pet food and stick with it for years. Some experts, like Dr. Karen Becker, recommend switching up the pet’s food, and specifically, the primary protein sources in the foods, frequently. At a minimum, consider changing foods (focusing on the protein sources) every few months. This can help reduce the risk of your pet developing food intolerances to common pet food ingredients.
Both cats and dogs exhibit some of the same symptoms to a food allergy:
- Itchy skin affecting primarily on the face, neck and limbs. Possibly leading to skin lesions or even hair loss or ‘hot spots’.
- Chronic ear infections and scratching of the ears.
- Vomiting, possibly even food avoidance.
- Diarrhea or frequent bowel movements.
If you suspect your pet has a food related issue, your first stop should always be at your veterinarian’s office. Your pet’s issue may be food related (about 10% of all pet allergies are food related) or it could be caused by external (fleas) or internal parasites, yeast or bacterial infections or even sarcoptic mange.
Unfortunately, there is no definitive test to diagnose food allergies for your pet. Diagnosis is normally done through trial and error. Your vet will first test for and reject other potential causes of your pet’s symptoms. After other potential causes have been ruled out, the most commonly accepted approach to identify the culprit food is the “elimination diet”. Simply put, this diet eliminates each potential irritant to your pet one at a time until the culprit is identified.
We will cover the specifics of the elimination diet as well has ongoing treatment and prognosis for food allergies in our next post: Food Related Pet Allergies Part 2.