GI Upset in Cats and Dogs

[dog looking guilty]

Consistent Diet May Help Prevent the Problem

The two most common symptoms seen in a small animal general practice are vomiting and diarrhea, referred to as “GI [gastrointestinal] upset.” These symptoms can range from mild to more severe and affect dogs and cats. Dr. Drew Sullivan, the medical director at the University of Illinois Medical District Veterinary Clinic in Chicago, sees these cases every day.

What Happened?

“There are numerous things that can cause vomiting and diarrhea in our pets. These include dietary indiscretion, stress, parasites, metabolic disease, and even cancer,” Dr. Sullivan explains.

The most common cause of GI upset among all ages of dogs is dietary indiscretion. That’s a fancy way of saying that the dog has eaten something unusual, such as garbage, foreign objects, human food scraps, or rabbit poop. Dogs are more likely than cats to eat something they shouldn’t. If something the dog ate is causing the GI upset, the problem is often difficult to diagnose unless the owner saw what the pet ate.

In kittens and puppies with GI upset, intestinal parasites are common and likely the cause.

“It is possible that stress can lead to GI signs,” Dr. Sullivan says. Stress is more likely to cause diarrhea, but vomiting can also be seen. It just depends on the animal.

Vomiting and diarrhea seen in an older patient could indicate cancer. The veterinarian will consider age and health history when deciding what tests to run to help determine a diagnosis.

Seek Help

It is important to take a sick pet to the veterinarian, but it can be hard to know exactly how soon the pet should be seen. Dr. Sullivan explains that “a single episode of vomit is typically not too concerning if the pet is acting normal otherwise.” How the pet is acting and whether they want to eat provides important evidence for the severity of the problem. Dr. Sullivan becomes more concerned when the pet refuses to eat.

“In general, vomiting can indicate more concern for an emergency. Diarrhea is rarely a true emergency,” Dr. Sullivan says. If the pet shows interest in eating and doesn’t vomit, then the pet should contact their regular veterinarian. Diarrhea alone is not typically a need for an emergency clinic visit. If the regular veterinarian doesn’t have appointments available and believes the pet should be seen, the client may be directed to an ER to avoid delaying care.

“A pet will need to be seen immediately at the ER if they are not keeping any food or water down,” Dr. Sullivan explains, “In addition, if they are retching but unable to vomit, this is a true emergency.” Retching without producing vomit suggests that the animal could have a blockage in the GI tract and must be seen right away by a veterinarian.

In cats, if they are trying to vomit and also unable to urinate, this could indicate a urinary obstruction. “These are very life-threatening cases and must be seen right away by a veterinarian,” Dr. Sullivan reiterates.

Dr. Sullivan advises, “Whenever a pet owner is concerned about signs they are seeing in their pet, I recommend having the pet evaluated by a veterinarian right away, whether at their regular veterinarian or an emergency clinic. It is better to be safe and have the pet seen than to wait and have a potential bad outcome.”

Diagnosis and Treatment

“In order to diagnose the cause of the symptoms, a number of different tests may be recommended,” Dr. Sullivan says. “I always warn owners that these tests may not provide the answer, but at least will narrow down the options.”

Some of the more common tests recommended are a fecal float to screen for intestinal parasites, bloodwork screening for metabolic conditions, and x-rays to look for foreign material. These diagnostics give the veterinarian a better idea of what might be going on with the internal organ function of the animal.

Treatment for GI upset depends on the cause itself, but supportive care is often given to help the pet feel better quickly. Supportive care for most pets includes administering fluids under the skin, medications to decrease nausea and diarrhea, and implementation of a probiotic and bland diet.

“In most cases, vomiting will resolve after a single dose of medication, and diarrhea will likely improve within 48 hours of supportive care,” Dr. Sullivan explains. Owner’s should keep their veterinarian updated with how the pet is doing and call if symptoms worsen.

“If the pet doesn’t improve with supportive care, then I suggest more advanced diagnostics,” Dr. Sullivan says. Options include abdominal ultrasound, a GI panel to look for malabsorption or maldigestion within the small intestines, or a GI scope to collect biopsies of the intestines. Some of these options may require referral to another specialty veterinarian that has the knowledge and equipment to perform these tests. This can become a long process of trial and error, if the case is complex.


Although some causes of GI upset cannot be prevented, owners can take steps to reduce the chance it will occur. “Feed a strict diet of only dog or cat food with occasional treats. Keep the diet consistent, avoid giving table scraps, and pet-proof the house to prevent the animal from getting into garbage or chewing up things they shouldn’t,” advises Dr. Sullivan.

All pets should have regular wellness check-ups with their veterinarian once a year and regular bloodwork screenings as needed, especially in older animals. These regular examinations will help to catch the more insidious causes of vomiting or diarrhea.

If you have questions about vomiting or diarrhea in your pet, contact your local veterinarian.

By Beth Mueller

Image by Fotografbee from Pixabay