To understand food allergy, you first need to know how dogs’ allergies work. In a nutshell, an allergy is when an animal’s immune system identifies something that is harmless as a threat. The dog’s body then mounts a response to the perceived threat just as it would to a real one. Some molecules are more apt to cause this hyper-immunity than other— proteins are thought to be common offenders. Dogs suffering from food allergy may have skin itching, skin and ear infections and even vomiting and/or diarrhea.
A lot of GI issues are dubbed by pet owners as “food allergy,” but an actual allergy requires an immune response to the food. This category does not include food intolerance when a pet eats something he was not supposed to and becomes ill.
Usually true food allergies, also called Adverse Food Reaction (AFR), are caused by immune response to a main diet ingredient or something that is fed very frequently, not an incidental or occasional ingestion. It is important to remember that AFR is an actual medical diagnosis and not something you should decide is ongoing and try to manage yourself.
Dogs can be allergic to many things from inhaled allergens to dietary ones and can mount an allergic reaction to more than one allergen at a time.
How we can help
If your veterinarian suspects food allergy, they will probably recommend a dietary trial. The way this diagnostic tool works is by feeding the affected dog a diet that has been formulated to be very unlikely to incite AFR. Diets used for this role are “novel protein” source or hydrolyzed protein diets.
Novel protein sources mean that the protein molecules in the diet are completely new to your dog, so his immune system has not had an opportunity to develop a reaction to it. This is a challenge in today’s market when pet foods are in a race to be attractive to owners and dogs, so novel protein diets are available only by prescription. Choosing a pet store or grocery store option that says “hypoallergenic” is absolutely not a diet trial, so make sure that your veterinarian is supervising any diet trial.
Hydrolyzed protein diets have been modified in a laboratory to create no immune reaction and are an excellent choice for a diet trial. These too are available only from your veterinarian by prescription.
During the prescribed trial period, your dog must ingest absolutely nothing but the novel or hydrolyzed protein diet. No treats, people foods, flavored toothpaste or natural meat flavored medications can be offered at all. If the dog seems to respond favorably by the end of the trial, the original diet must be restored and the dog monitored for recurrence of signs. Only after the dog responded and then relapsed on the old food can a diagnosis of Adverse Food Reaction be made.
Remember AFR is a clinical diagnosis that can only be made by a veterinarian. There are other causes of itching and recurrent skin infections and these must also be ruled out or addressed. Our veterinary staff will help you know the steps toward confirming your dog’s diagnosis and treating his issue.
If you have any questions, please do not hesitate to contact us.Source: Kathryn Primm, DVM (dvm360)