How does an elimination diet work?

We use an elimination diet when we think a dog has either a gastrointestinal or a skin problem related to its diet. When dogs have an allergy or a hypersensitivity to food, it's generally the protein, the beef, the chicken.

And of course, the most common protein that we feed dogs sometimes is milk protein. It's not ever very often a grain that’s causing you hypersensitivity. So a hypoallergenic food or elimination food is picking a food that has a single protein, and probably one that you've never been on before.

So if you're always feeding chicken, we might try a lamb food and also a single carbohydrate source so we can eliminate all the other possibilities. Then we feed them that for about 12 weeks, during which time your dog's GI problems or skin issues are hopefully better.

Then you can then slowly add back a few things. And if the dog does well on them, then that is not something they were allergic to. So that's how we do that.

We use elimination diets if we're trying to figure out if your pet is sensitive to a specific protein. So you often hear this as a food allergy. And so, what we're trying to do with an elimination diet is figure out what specific protein your pet is allergic to. So it may be that we have you take out all of the things with chicken, or maybe we have you take out all the things with beef. Your vet may recommend a completely hypoallergenic diet that has a plant-based protein like soy. But the best thing to do is get strict guidance from your veterinarian, and they can walk you through how to work that elimination diet step by step.

Elimination diets are used to diagnose and treat food allergic disease or food intolerance. What that means is we eliminate everything that the dog is currently eating or has eaten and offer what's called a hydrolyzed protein diet, which is food that has been modified at a low molecular weight so the dog's immune system won't pick up the microscopic food particles. Either that or what's called a novel protein and a novel carbohydrate diet like rabbit and pea or duck and potato will be recommended. There's a bunch of them out there. You feed that and only that for one to three months. If the dog's signs, which include vomiting and diarrhea intermittently as well as skin itching, go away, it helps us to form a diagnosis such as a food allergy or food intolerance. We can then refeed items to see which ones trigger the response again. The only way to diagnose food allergies is with an elimination diet trial. There are no accurate blood tests.

It's hard for owners, but they have to stick with that food and nothing else. I'll give a list of certain treat-type items that are acceptable in food trials and won't cause an immune response, but you have to be very diligent. Everybody in the household has to be on board with the plan because if you feed for a month and then somebody offers them a hamburger, you have to start over. So that's important. Once we get the signs under control, those diets are meant for long-term feeding as well. Most owners don't want to re-introduce foods that cause signs again.

Good question. That gets more into food allergies, and food allergies are a whole other subject. I will mention a couple of things about food allergies. I'm passionate about dermatology and its effects on dogs' skin health, and food allergies can be a big part of that. When we're dealing with a food elimination diet, what we're doing is we're trying to eliminate things that we think are causing intestinal distress or skin problems, biting, scratching, licking, itching, and chewing. So what we can do is go to an entirely different protein. We can introduce the new food the same way we mentioned a few minutes ago, by gradually introducing a new food with each meal you give less and less of the current diet.

That's an appropriate way to introduce a different protein or diet into your dog's routine. But just so you know, when it comes to food allergies, I'll speak to it very quickly. Do I ever do anything quickly? Probably not. When it comes to food allergies, chicken and beef are the two primary causes, followed by lamb and dairy, followed by pork, brown rice, wheat, soy, and corn. So if we suspect your dog has a food allergy, we want to get them off whatever the primary protein is, which is usually chicken or beef. We want to get them off that and get them onto an appropriate or a different protein that's significantly less likely to cause an adverse reaction. We can switch to salmon, whitefish, trout, venison, goat, kangaroo, or ostrich. So we've got several choices available to us. Essentially, that's what an elimination diet is all about. When we suspect food allergies, we're trying to eliminate the different proteins they were getting exposed to through their diet previously and get them onto something entirely different.

An elimination diet is generally a prescription diet that is a strict diet focused on taking out all of the high allergic triggers. These diets need to be followed to the T of veterinarian recommendations, making sure they're not getting any other outside food sources into their system. This will allow us to monitor to see if any of the previously ill symptoms we were looking to get rid of start going away once they are on the elimination diet. From there, your veterinarian may decide to gradually introduce other foods to see which triggers those allergic responses again so we can take that out of the equation, or we have some pets that just right off the bat do so well that they stay on that allergenic specific diet.

That's a big question because we use elimination diets to find food intolerances and food allergies. An elimination diet's a big process that usually takes a minimum of six weeks, classically 12 weeks of feeding something that's very specific.