Elimination diet for dogs: how to do a diet trial
What is an elimination diet
What can dogs eat on an elimination diet
How to do an elimination diet
What happens after the trial
Diet Trials for Dogs: Frequently Asked Questions
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Elimination diet for dogs: how to do a diet trial
An elimination diet, also called a diet or food trial, can help your vet determine whether your dog's food is contributing to their skin or digestive signs.
It may be recommended for dogs with symptoms such as constant chewing, licking, biting, recurrent ear infections or chronic loose stools. A diet trial usually lasts up to 8 to 12 weeks, so patience is needed, but it is an important step when investigating ongoing skin or digestive problems in dogs.
Blood and saliva “allergy tests” for food can produce both false-positive and false-negative results, so they are not considered reliable for diagnosing food allergies in dogs. A properly performed diet trial is the most reliable way to investigate whether your dog’s symptoms are caused by a food reaction.
What is a diet trial for dogs?
Why? A diet trial may be recommended if your dog has a suspected food allergy or intolerance. Possible signs include constant chewing, licking, biting, recurrent ear infections or chronic loose stools.
A diet trial means feeding a specific food for a set period, usually around 8 to 12 weeks, to see if symptoms improve. The trial needs to be continued for several weeks because it can take time for your dog’s symptoms to settle after a suspected food trigger is removed. Digestive symptoms often improve sooner, while skin symptoms can take much longer to improve.
Diet trials need to be done with strict supervision. No treats, table scraps, other foods, or extras should be given, as this can affect the results. During a diet trial, your dog should be fed food containing ingredients that they haven’t eaten before, using a novel diet or a hydrolysed diet.
What food to use for a diet trial
There are two main options for diet trials:
Novel protein diet: Using a food source that your dog has never been exposed to before. This usually means feeding a less commonly used protein such as kangaroo or venison, depending on your dog's previous diet.
Hydrolysed protein diet: Hydrolysed diets contain proteins that have been broken down into smaller pieces, making them less likely to trigger an immune response.
Home-cooked diets may be an option for some dogs, but these should be formulated by a veterinary nutritionist to make sure they provide all of the nutrients that your dog requires.
Veterinary diets commonly used for food trials
Your vet can discuss the best option for your dog, based on their lifestyle, age, diet preferences, previous diet, and any other health conditions.
This may include:
Hill’s Hydrolysed Protein Treats or ROYAL CANIN® Hypoallergenic Dog Treats may be suitable as treats during a diet trial. However, always check with your vet before giving your dog anything extra, as even small amounts of other foods can affect the results of the trial.
How to do a diet trial in dogs
Diet trials should be performed under veterinary supervision. This is important for selecting the correct food for your dog and carefully monitoring their symptoms. Your vet will usually rule out other conditions that can cause similar symptoms first, such as a flea allergy.
Select the appropriate food for your dog after discussing the options with your vet.
Transition your dog onto their diet trial food slowly, over 5 to 7 days, to reduce the risk of an upset tummy.
Feed the diet trial food exclusively for the period recommended by your vet (usually around 8 to 12 weeks).
Do not feed any treats, chews, or table scraps during the diet trial. Talk to your vet if your dog is taking flavoured medication, as this may affect the trial. Make sure all family members and visitors are aware of the rules. A small slip can cause a big setback.
Keep a diary of your dog’s symptoms, including the severity of their itching, stool quality, ear problems, and energy levels. This helps you and your vet track any changes.
If your dog’s symptoms improve during the trial, your vet may recommend reintroducing their previous food to see if the symptoms return. Your vet may also recommend adding individual ingredients one at a time, such as chicken then beef, for around 2 weeks each to help identify triggers.
If your dog’s symptoms return with previous foods or individual ingredients, this strongly suggests that your dog has a food reaction to these.
What happens after the diet trial?
If your dog’s symptoms improve during the trial and return with their previous food, this usually suggests that their food was contributing to their symptoms.
Once you know what foods your dog reacts to, you can choose a diet that avoids those ingredients. Dogs with food reactions usually need to avoid the triggers long term.
If your dog’s symptoms do not improve with an appropriately performed diet trial, your vet may start looking for other causes of their symptoms, such as environmental allergies.
Diet Trials for Dogs: Frequently Asked Questions
Q: Can my dog have dental chews during a diet trial?
No. Your dog should not have treats, chews, table scraps or any other foods during a trial unless your vet has approved them.
Q: What if my dog eats something they shouldn't during the diet trial?
A: Contact your vet and tell them what your dog ate and how much. They can advise if the trial needs to be restarted or not.
Q: How long does a diet trial take?
A: Most diet trials last 8 to 12 weeks. Digestive symptoms, such as loose stools, usually improve quickly, within 1-2 weeks. Skin symptoms, like itching and ear infections, can take much longer. Your vet will help guide you on this.
Q: How can I tell if a diet trial is working?
A: If your dog has a food allergy or intolerance, you may notice their symptoms gradually improve during a properly performed elimination diet. Keep a note of their symptoms throughout the trial so you can compare how they are doing before and during the diet.
Always work with your vet when changing your dog's diet. They'll make sure the food is safe and nutritionally complete.
Our Joii Vets are available 24/7 for advice.
