Food allergy has been recognized in animals for many years. Allergy to food can be from raw, cooked or processed food. There are specific foods associated with food allergy as well. However, it can be difficult to determine exactly which food that is.
The number one sign that your pet has a food allergy is itching. This is non seasonal and always present. Dogs typically scratch their face, ears, legs, feet, armpits, and hind end. Cats more commonly scratch their head, neck, ears, and eyes.
Other common signs are ear infection, skin infections, a change in hair coat, or change in pigment of their skin and seborrhea/ flaky skin. Cats will commonly have self induced areas of hair loss, as well.
These same pets can have gastrointestinal signs, too. These signs can be non specific and intermittent such as vomiting, diarrhea, increased frequency of bowel movements and belly pain.
The most common foods dogs are allergic to are: beef, chicken, corn, dairy, egg, soy and wheat. As for cats, the foods are: beef, dairy and fish.
A diagnosis of food allergy requires a food elimination diet trial. This is a two step process. First, the pet is fed an elimination diet. This is a limited ingredient diet that has a novel (new) protein or hydrolyzed (broken down) protein that the pet has never been fed. If the clinical signs resolve, then the second step is to feed individual foods, such as chicken, beef or corn, one at a time to see if signs recur. Most animals will develop clinical signs in 1-2 weeks when fed the allergenic food. The hardest part of these diet trials is owner compliance. Owners need to understand that their pet can only be fed the specific diet and absolutely nothing else. This means no treats, snacks, rawhides, pig ears, human food or flavored tablets/supplements.
There are serum (blood) tests available to diagnose food allergy but these are very unreliable. These yield many false positive and false negative results.
Most diets clients need to feed their pets are novel protein or hydrolyzed diets. These require a prescription and can only be distributed through your veterinarian. Novel protein diet examples are rabbit, venison, duck or kangaroo based. This is because most commercial diets do not contain these ingredients. Hydrolyzed diets, such as Hill's z/d, as not novel. Rather, they break up the proteins into such small sizes that the animal will not be allergic. Examples are soy, chicken and chicken liver.
Dogs and cats with true food allergy will respond within 6-12 weeks. Som skin related issues may occur intermittently but many of these pets have confounding factors such as environmental allergies.
If you feel your pet is exhibiting any of the aforementioned signs, please schedule an appointment or give us a call us at Eagle Animal Hospital. We look forward to helping you and your pet. We serve Chester Springs, Exton, Downingtown, Glenmoore and surrounding areas.
Written by Jennifer Granite, VMD