What is a Novel Protein Anyway, Or, Why is Chicken Bad for My Pet?

 Recently I've had a spate of owners claiming that they've been told that chicken is bad for their dog or cat. Well……yes and no.

Like the game we played in grade school – Rumor – the real story has been lost in the re-telling, such that when it reaches me from the owner in my hospital, chicken has become the enemy.

It is not.  So let’s talk about food allergy.

Food allergy is believed by many to be a common cause of allergic skin disease.  It is not – environmental  allergies are by far the most cause of skin allergy.  However, changing dietary ingredients may help  improve the itching from environmental allergy.

Food allergy is more likely to cause GI problems – intermittent or persistent loose stool, diarrhea, reflux, vomiting, gas, and noisy stomach.  And just to return to skin allergy for a second, I usually expect that GI signs will accompany skin signs if food allergy is the cause.

Food allergy is a problem for animals who are genetically predisposed to it, or for animals who have had an insult to the gut resulting in inflammation.  That inflammation can lead to a breakdown in the normal gut barrier, leading to absorption of substances into the body that would otherwise be kept safely inside the gut ultimately to be eliminated. This situation has a name – Leaky Gut.

When a leaky gut is present, the immune system gains abnormal access to food molecules, bacteria, and other protein-containing substances that lead to the development of immune response to “fight” this “foreign invader” that the immune system has never  seen before.

The good news is that leaky gut is often treatable using a combination of diet changes, probiotics, and anti-inflammatory herbs, nutraceuticals or drugs. For even more good news, some of these food allergy cases turn out not to be permanent.

Food allergy, if the conditions are right, develops because of exposure to that particular food ingredient.  Chicken just happens to be the most common meat ingredient in the pet food industry, so…..

So, if an animal does in fact develop a sensitivity* to chicken, a change in dietary ingredients is certainly warranted, but that doesn’t mean that chicken is forbidden forever.  In fact, it is not possible to definitively diagnose a food allergy in any way except for elimination and then challenging with that food ingredient.  If a challenge test using chicken meat results in a reaction (GI OR skin), well, food allergy is usually the answer.  But what we usually find is that on challenge testing, chicken is no longer a problem (or never was).

By the way, this reminds me of the whole corn story from 10 or 15 years ago.  Many dog owners were claiming that their pets were allergic to corn simply because they changed from corn-containing diets to diets that had none. There are many great reasons for significant clinical improvements to occur when we change diets, so I believed these owners. However, a true allergy to corn is even less rare than a true allergy to chicken.  There was something else at work there.    

Bottom line – if your pet is itchy or has ear problems, it’s usually fair to try and change the dietary ingredients.  But if your pet improves, we just can’t conclude that food allergy was the reason.  Food changes are powerful for many reasons.