Elimination diet for dogs: a step-by-step guide

An elimination diet is the boring, slow thing that works when a test can’t settle the question. It’s how vets figure out whether food is behind the itching and the gut trouble, and it takes patience and a very strict household.

I’m Jessica, a certified professional canine nutritionist and holistic pet health coach. This is how a trial works, where people trip up, and where I fit in. Wellness education, not medical advice. Start any trial with your veterinarian on board.

Who this is for

If your dog is itchy, chewing their paws, dealing with gunky ears, or living with loose stools and gas, food is one of the first places I look. Not the only place. Itching and gut trouble can come from a lot of directions, which is why I look at diet and environment together. But food is the one thing you control three times a day, so it’s the easiest lever to pull and the easiest to get wrong.

What an elimination diet is

You feed your dog a diet built from ingredients they haven’t eaten before, or proteins broken down small enough that the immune system doesn’t recognize them. Nothing else goes in. If the symptoms subside, you add foods back one at a time to see which ones, if any, bring the problem back.

At-home tests can give you clues. They can’t confirm a food reaction, and that’s the job of the trial. Think of a test as a map with half the roads missing. The trial is you actually driving it. Check my at-home test collection if you want a place to start looking for clues.

>>>>> Download your elimination diet workbook (no email required)

Step by step

1. Talk to your vet. Itching and loose stools have plenty of causes, and you want the other ones checked before you spend two months on a diet. Medications can quiet symptoms for a while, but they don’t tell us why your dog is reacting. That’s the question we’re after.

2. Write down everything your dog has eaten. Brands, proteins, chews, snacks, the bit of cheese that goes with the pill. The diet you pick depends on what’s already been in the bowl.

3. Pick the diet. There are two main routes. A novel protein diet uses one protein and one carbohydrate your dog has never had. Many veterinarians will recommend a hydrolyzed protein recipe, which can work for a short period of time but is not a long-term solution. We still need to address the underlying cause. More on choosing a protein below.

4. Lock down everything else. Snacks, rawhide, supplements, toothpaste and flavored medications often carry protein flavoring and other nasty ingredients. One sneaky chew can invalidate the trial and start the clock over. Tell everyone in the house, including the neighbor who feeds your dog over the fence.

5. Switch gradually, then stay with it. Don’t swap the whole bowl overnight. Dr. Judy Morgan suggests about a quarter new food for two days, then half for a few days, then three quarters, then all new after about a week. Then give it time. Eight weeks is my minimum. Whole Dog Journal and NutriScan both land on 8 to 12 weeks, and Dr. Morgan works with about six on a single novel protein, longer for dogs coming off years of kibble. Some dogs, especially those with gut signs, look better sooner. Don’t mistake an early win for the finish line.

6. Keep a log. Score the itching, stool, ears and energy once a day. Don’t rely on your memory. We need a log to better understand everything going on. There’s a simple way to do it below.

7. Challenge one food at a time. If your dog improves, add back one protein and watch. Reactions can show up within hours or take longer. You know your dog best, and in my experience you’ll usually know within the first day if something is triggering them.

8. Build the long-term bowl. The trial isn’t the finish line. It tells you what to leave out when you plan what to put in. The goal is to build at least three recipes using the ingredients your dog is tolerating well so you can rotate them while also supporting the gut. Over time, when everyone is ready, the ideal situation is to reintroduce foods that were once excluded.

Choosing your novel protein

Dr. Morgan puts it simply: “a novel protein is any protein that your pet hasn’t eaten yet.” Beef and chicken are in nearly everything, and lamb is common enough now that it may not count as new for your dog. Rabbit, venison, duck, bison and smaller fish like herring are examples of proteins many dogs haven’t met.

A few things worth knowing:

Read labels closely. Some leave out meat sources, so a “novel” food may not be.
Pick a single-protein food that’s raw or gently cooked and balanced. Dr. Morgan notes that a novel-protein kibble is no better than regular kibble.
If your dog has eaten kibble for years, start slower. Toppers are a good first step.
Homemade diets have to be balanced. This is the step where I see the most well-meaning trouble.

What a simple log looks like

You don’t need an app. A notebook on the counter works. Though, I have tried to make it easier for you with a free (no email required) workbook to track your progress. Every day, give each of these a score from 0 to 5:

Itching
Ears
Stool
Energy

Then jot down what your dog ate, anything new in the house, weather, baths, and new products. After a couple of weeks you’ll see patterns that your memory would have smoothed over. The log is also what we’ll look at together if you book a consult.

Supporting the gut along the way

Switching foods is a big deal for the gut, so go slowly and keep things boring. Dr. Morgan notes that a probiotic without fillers or animal digest may help during the transition. I carry a few options in my gut health and probiotics collection, and my itchy skin support collection is there if skin is the main event.

Mistakes I see

Quitting at week three because it’s hard
Changing two things at once, then not knowing which one helped
A home-cooked diet that isn’t balanced, so you fix one problem and create another
Only feeding one food, or one recipe
“Just a little” of the old food

If your dog doesn’t improve on the first diet, we try again. Every animal is an individual and they all respond differently to what goes into them. That’s okay. We keep trying.

Where I come in

Elimination diets are a lot of rules and not much hand-holding. A single consultation is $77 and we’ll look at your dog’s diet history and environment together. If you’ve done the Wild Wellness bioenergetic scan, the recorded report review is a quick way to turn the results into a plan. When you’re ready to plan what comes after the trial, take a look at my ReWild feeding approach.

Questions I get about elimination diets

How long does an elimination diet take?
Plan on at least eight weeks for the elimination phase, plus the time it takes to add foods back. It’s a long game, and it’s worth it.

What’s a novel protein?
One your dog hasn’t eaten before. What counts as novel depends on your dog, so the food diary in step 2 does the heavy lifting.

Can I do a raw or home-cooked elimination diet?
It can be done, but it has to be balanced and strictly limited to what you’re testing. That’s where a nutritionist earns their fee.

Can a test replace this?
No. Tests can point you in a direction. A trial is how you find out if the direction was right.

What about hydrolyzed diets?
Many vets recommend them, and they can work for a short stretch. I don’t see them as a long-term answer, because the goal is to understand what’s behind the reaction, not just keep it quiet.

Can my dog have snacks during the trial?
Not unless it’s the exact protein you’re feeding with nothing else on the label. When in doubt, skip it for now.

How do I know if it’s working?
Your log will show you. Look for the trend over weeks, not one good or bad day.

My dog is picky. Now what?
Go slower, and use a topper to bridge from the old food to the new one. Patience usually wins this one.

What if nothing changes?
It may not be food. Go back to your vet. Workshop things with your pet health coach. They may suggest a different diet or look elsewhere.

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