Here’s a popular subject in my place of employ: For every single one of my patients diagnosed with allergies, I’ll recommend a “food trial.”

Here’s when we ask you, the pet owner, to either purchase ungodly-expensive bags and cans of foods...or to spend inordinate amounts of your time (and maybe even more of your money) whipping up pet cuisine at home. 

Have you ever received such a recommendation? Did you look at your veterinarian as if she might have confused you for a zillionaire?...or someone who has better things to do with his time than cook for his pet? 

That’s the look I usually get. It’s the one that says, “You mean for me to spend all this money just because his ears get dirty? Seriously?”

Let me back up and explain, now that I’ve broached the subject at its weakest point:

Pets get allergies altogether too frequently. It’s a common trait in many breeds and they boast a wide array of manifestations. Though most commonly evidenced by skin troubles (foot licking, head shaking, smelly ears, itchy underarms, skin rashes, butt rubbing, hair loss, etc.), gastrointestinal concerns can also be related to an animal’s reaction to proteins and carbohydrates found in certain foods.

That means your pet may be allergic to one or more proteins like milk, eggs, beef, chicken, lamb, soy, turkey, duck...and/or to one or more of any number of carbs like wheat, corn, potatoes, sweet potatoes, rice, peas, carrots, etc. 

Though fleas and contact allergies––along with inhalants and other environmental allergens––can also be at play, food allergies affect a sizable enough percentage of allergic animals to make their specific diagnosis (yea or nay) a necessary part of any allergic pet’s veterinary work-up.

Because the standard skin and blood tests for these ingested proteins and carbohydrates aren’t exactly the most specific kind of allergy tests we have in our arsenal, a feeding trial is undoubtedly the best method for diagnosing a food-related allergy. That means we eliminate all of the proteins and carbohydrate we believe your allergic cat or dog may have been exposed to and very strictly offer them only new ones. 

This kind of food trial is called an “elimination diet.” It’s best employed in conjunction with other allergy tests and strict ectoparasite (i.e., flea) control, but can work very well as a standalone starting point for allergy determination––as long as you’re careful to rule out any and all possible ingestion of anything but the new proteins and carbs.

Yes, the key is to strictly manage the pet’s diet so that even tiny beef treats, carrot nibblers, backyard lizards and even meat-flavored medications and supplements are left out of the deal. Must give heartworm meds? Move over to Revolution for the duration so no possibility of protein or carb contamination will wreak havoc with your approach. (Yes, even teeny-tiny amounts of allergens can get the allergic ball rolling again.)

So you want my pet on this horrifically restrictive new diet for life? No treats forever?

No, not for life. Eight to twelve weeks is usually all we ask. If you’re careful about doing it right you may just find that your pet gets the relief he needs. And treats can always be fashioned out of the new diet’s ingredients. 

Now for the sticky part: The foods veterinarians recommend run the gamut. Here’s a list of common recommendations:

  • Some veterinarians recommend a simple change from one diet to any other that does not contain the same carbohydrates and proteins the last food did. This can work, but requires an owner’s thorough understanding of all the ingredients the pet has received in the past and which foods on the market don’t carry them. Though it can be done with some diligence and simple research, that can get tricky.
  • Many veterinarians counsel owners to try diets with proteins and carbs rarely present in other foods. Kangaroo, rabbit, salmon, barley, beans and brown rice might sound nice, but if you’re accustomed to feeding your pets super-premium foods, be aware that your past diets may have contained some of these fancy ingredients. In that case, the new foods, “hypoallergenic” as they may be labeled, may be no match for your pet’s well-prepared immune system. 
  • Cooking is commonly recommended. That allows you to use just a couple of ingredients you know your pet’s never been exposed to. Sure, it can get expensive to feed scallops and quinoa for eight weeks but heck, you gotta do what you gotta do, right?
  • Hydrolyzed protein diets are all the rage. Hill’s Z/D is the king of these foods and, frankly, I have most success with it. The idea is that the hydrolyzed proteins in the diet are no longer recognizable as those occurring in nature––therefore the immune system will not respond to this non-allergen. Wheat is also omitted, which Hill's considers the number one carbohydrate allergen. Still, consider that if your pet is allergic to other carbs, this diet may not be for you.

The idea with all these diets is to consider their implementation a diagnostic tool. Should a pet owner meet with success with these food trials (AKA, elimination diets), the goal now becomes checking to see which proteins and carbs are at fault. Adding one in every month is my preferred tack. 

Sure, the trials and tribulations of food allergy diagnosis can be frustrating, but how many other tests do you know of with [almost] no side effects AND the ability to treat your pet’s disease along the way?