Two Easy Ways to Start Earning Rewards!
Become a member today!
Members-only pricing and offers, personalized care notifications, Vital Care points back on every purchase and more!
Already a member? Sign in
Become a credit card member today!
Earn 2X Pals Rewards points at Petco
when you use Petco Pay!
APPLY NOW
Learn More About Petco Pay Benefits

Why did grain food give my dog diarrhea? Is grain intolerance common?

Updated on September 23rd, 2025

Pet's info: Dog | Cavalier King Charles Spaniel | Female | spayed | 5 years and 1 month old | 17 lbs

How common are grain intolerances in dogs? I have a Cavalier King Charles spaniel and I tried her on a food with grains and she had really bad diarrhea. is this common among spaniels or just dogs in general? Thanks!

3 Answers

Most Helpful Answer

Answered By Sara Farmer, DVM

Veterinarian

Published on August 2nd, 2017

Any change in diet can trigger diarrhea, and a food intolerance can be seen to any protein in the diet, including those from meats, grains, egg or dairy. I can't find a study that gives the incidence of food intolerance to different grains, but In my experience it is not as common as food intolerance to meats like chicken or dairy. That being said, I always say if a dog is not doing well on a new diet, switch back to the previous diet! Spaniels in general do tend to have a higher incidence of allergies

1Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Dr. Macartney, BVet Med, MRCVS
Veterinarian
Published on August 23rd, 2017
At this stage I would not be able to conclude that Chloe is intolerant to grains. It could be the transition from one food to a new food that caused the diarrhoea. If Chloe is well in her self I would continue with the new food for a week. If the diarrhoea continues I would post another question here so that We can continue to advise and support you.
1Pet Parents found this answer helpful
Answered By Lauren Jones VMD
Veterinarian
Published on August 17th, 2017
It is quite rare for a dog to actually have a sensitivity or intolerance to grains, despite what many food manufacturers claim in their marketing campaigns. Instead, the protein sources in foods (particularly chicken, beef, and lamb since these are among the most common protein sources) tend to be the cause of food sensitivities or allergies. Consider looking at the two foods that you have fed Chloe and determine if they have any differences in the protein sources. If she tolerated one of the foods well, it would be fine to continue feeding it, but do not feel that you need to stick with a grain free diet since they do not provide any superior nutritional benefits. Grain free foods can also be more dense calorically since potatoes and lentils are often used for the carbohydrate sources rather than grains, so you have to more closely regulate portions with these types of foods. Just remember than anytime you change Chloe's food to do so gradually by mixing the old and new foods together over 5-7 days. I hope this helps and that all goes well! :-)
1Pet Parents found this answer helpful

Smart Picks for Smart Questions

Related Questions

Food & Nutrition

Switching grain-free dog to grain food? How to spot grain intolerance?

No. Most dogs handle grains very well. In fact most food allergies are to a protein source such as beef or chicken. If you dog does a food allergy if some kind, it typically shows up with itching and hair loss. A small percentage can have GI symptoms but that is the minority

Updated on September 23rd, 2025

Food & Nutrition

My dog has diarrhea and vomiting. Is his rice-based food the cause?

Food intolerances are not very common for dogs to get and it would be even more rare for rice to be the cause. Food intolerances are due to certain proteins which are usually animal proteins (beef, pork, dairy, etc.). To find the actual protein Max is allergic to, you would have to do an elimination trial. Here is a link to a good article that explains how to do the diet: http://communityvet.net/2010/03/diy-elimination-diet-for-the-dog-an-cat/ Keep in mind that your diet trial will cease to work if he is getting any treats or table scraps. Make sure that there is no possibility of this happening - especially if there are kids in the house. As always, it's best to do these things in consultation with your vet. They can also ensure that nothing else is responsible for the diarrhea. It is definitely possible that the vomiting and diarrhea is due to a long-standing infection. If Max has any of the following, the he should see a vet as soon as possible: 1) Blood in diarrhea 2) Very watery diarrhea 3) Dog starts acting very depressed 4) Dog stops eating or drinking for longer than 24 hours. I hope that helps and Max gets better soon.

Updated on September 23rd, 2025

Health & Wellness

Grain-free food causes puppy diarrhea. Why does Ol' Roy firm poop?

Hello, and thanks for your question. The grain free foods tend to be very rich; diarrhea is actually pretty common. I do not recommend grain free food - there is no science to back up any benefits of going grain free in dogs, and there are actually concerns that it is harmful (if you want further information, look into the connection between grain free and dilated cardiomyopathy heart disease). I recommend Purina, Hills Science Diet, Royal Canin, or Iam’s Eukanuba puppy food. Ol’ Roy would not be my preference, but I would still recommend it over grain free, especially since Freya clearly tolerates it better!

Updated on September 23rd, 2025

Food & Nutrition

My dog has diarrhea from new grain-free food. Is a vet test needed?

It wouldn't hurt to have a fecal done just to make sure that isn't the case. If the fecal exam checks out healthy, I would be concerned there is an ingredient in the new diet that may be causing some GI distress. If you suspect that is the case, your vet may be able to work with you on an elimination diet to narrow down the cause so it can be eliminated.

Updated on September 23rd, 2025

Food & Nutrition

Is it normal for my dog to have loose stools on grain-inclusive food?

Thanks for using Petco Pet Education Center, formerly Petcoach! This is not normal or expected or common. Having grains in a diet is not a reason to suspect diarrhea or loose stools so I would think that the loose stools are due to something else. This can be observed with conditions such as colitis, gastroenteritis, dietary indiscretion, intestinal parasites, among many other possibilities. If this continues, I recommend that you have Chloe evaluated by your veterinarian for further assessment and treatment. They may choose to check for parasites and to start medications for diarrhea depending on the results. Good luck! Hoping for a speedy recovery!

Updated on September 23rd, 2025

Health & Wellness

Why does my dog have diarrhea after switching to high protein adult food?

That is quite a high protein content for food, the recommended percent of protein in an adult dog's diet is 18-25%. It may be the switch in food to this higher protein could be the cause of his diarrhea. Since you have seen the vet and everything has come back normal, you might want to consider putting him on a diet with less protein. Sometimes certain brands of food do not agree with a dog's system, so you can look into a different brand. Brands I recommend include Royal Canin, Hill's Science Diet, Purina ProPlan, and Iams. I personally do not recommend grain free diets unless the dog has a diagnosed grain allergy, which is actually very rare. In dogs who suffer from allergies, only 10% have food allergies, and the majority of those are protein related. Grains really are beneficial to dogs, providing a lasting source of energy and fiber. In addition, recent studies have show that diets who use lentils instead of grains negatively affects the dog's absorption of taurine. This has lead to taurine deficient dilated cardiomyopathy later in life. If you really want to stay with grain free food, maybe try one with a different source of protein because chicken is the most common protein allergy. Best of luck, I hope this helps!

Updated on September 23rd, 2025

Food & Nutrition

Why is my dog hungry and sick after switching to grain-free food?

All brands have different feeding guidelines and some dogs can differ by up to 10% from the 'normal, recommended' amount to I recommend you check the bag carefully to see how much she should be expected to need daily. Grain free food does not suit all dogs, many domestic dogs digest processed cereals quite well and some do better on these than grain free brands. Sudden diet changes can cause mild gastrointestinal upset also, so if it is not settling over 5-7days I would return to her previous or a sensitive diet formula to see if it resolves again

Updated on September 23rd, 2025

Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Share