You should call the vet when your cat has diarrhea lasting more than one or two days, if the diarrhea is dark and bloody, or if it’s accompanied by a fever, vomiting, or loss of appetite.



Cat Diarrhea



Should I Take My Cat to the Vet for Diarrhea?


Cats are no strangers to upset stomachs and diarrhea. They love to eat things they shouldn’t like plants and plastic, get hairballs, and overeat if given the opportunity. 


Occasional cat diarrhea should not cause panic, but several circumstances warrant calling the vet and scheduling an appointment. Prolonged diarrhea in your cat lasting for more than 24 to 48 hours, regardless of age, can be dangerous to your cat’s health. Additionally, cat diarrhea that appears dark and bloody are signs of a more serious internal problem such as bleeding or parasites.


If you’re unsure that you should make an appointment, call the vet anyway. It’s always better to be on the safe side. The veterinarian or their assistant will listen to your cat’s symptoms and tell you whether or not you should make an appointment or visit an emergency vet



Cat Diarrhea



Cat Diarrhea Causes

Cat diarrhea is not a disease or sickness that exists in isolation. Instead, it’s a symptom that something else could be wrong. Why does my cat have runny poop? Diarrhea can be caused by several causes, from diet changes to internal parasites. 


Here are some of the leading causes that can lead to cat diarrhea:


  • Changes to their diet
  • Food intolerance or allergies
  • Medications or antibiotics
  • Viral or bacterial infections
  • Inflammatory bowel disease
  • Cancer
  • Worms or other internal parasites
  • Thyroid imbalance


Why Does My Cat Have Diarrhea After Changing Their Food?

Cats actually have very sensitive stomachs. If your cat tries new food, acclimates to a new diet or gets ahold of “people food,” this can cause diarrhea. Eating anything foreign can cause diarrhea as well, such as birds or rodents. If a cat’s food changes suddenly, they might get sick or stop eating entirely—you may notice vomiting as well.

Your vet will be instrumental in determining the cause of your cat’s diarrhea, but you can also do some investigation at home. Have you recently changed the brand or flavor of their food? Is your cat eating more or less than their usual amount? You should bring a list of the food you feed your cat to the vet, alongside any medications, vitamins, or supplements they receive daily.



Cat Diarrhea

Can Antibiotics Give Cats Diarrhea?

Some antibiotics and other medications can give your cat diarrhea. If you notice that your cat has diarrhea after they begin their conditional medications, let your veterinarian know. They may recommend a different antibiotic or medication.

Can Canned Cat Food Cause Cat Diarrhea?

Wet food is not the direct cause for diarrhea in your cat, though any changes to a cat’s diet might give them diarrhea. Cats have sensitive stomachs, and often do not respond well to abrupt nutritional changes.

It can take some time for your cat’s system to become used to any new food or diet alterations, including quantity of food. If you’ve recently changed your cat’s diet in any way, don’t fret if their feces changes in consistency for a couple of days.

Can Cats Get Diarrhea from Stress?

Stress can cause physical ailments in cats, just like humans, and diarrhea is one symptom. Anxiety does a number on anyone’s stomach, including your beloved kitten.

When to Be Worried


Diarrhea happens when the intestinal tract cannot absorb the normal amount of water from the stool before a bowel movement, which can stem from a number of causes, some of which are listed above. 


Prolonged diarrhea causes dehydration. Diarrhea lasting anywhere from 24 to 48 hours should not be a cause for concern unless you have diarrhea in a kitten or elderly cat.


If you’re wondering, “When should I take my cat to the vet for diarrhea?”, the answer depends on a few factors.


Regardless of the time span, if your cat’s diarrhea accompanies a fever, vomiting, or loss of appetite, you should contact your vet as soon as possible.




It can be difficult to determine if your cat has a fever. A common myth is that you can tell if they have a fever by feeling for a dry, warm nose, but this is false. The only way to know if your cat has a fever is to take its temperature using a rectal thermometer. 


Watch for these signs that your cat has a fever:


  • Lack of energy or activity, depression
  • Loss of appetite
  • Decrease in drinking
  • Decrease in grooming
  • Shivering
  • Rapid breathing
  • Vomiting


And, of course, diarrhea. A fever develops to fight off a sickness or disease and will typically measure around 102.5º F, but anything higher than 106º F risks damage to internal organs. 


Cats have an extremely low risk of contracting Coronavirus, but symptoms to watch for of COVID-19 in your cat include coughing, fever, and diarrhea.



Cat Diarrhea





There are two types of vomiting in cats: chronic and acute. 


If you’ve had a cat for any amount of time, you’re probably familiar with acute vomiting. Acute cat vomiting happens infrequently and usually follows when your cat overeats, consumes something toxic or harmful, or simply has an upset stomach. Chronic vomiting occurs when your cat throwing up occurs regularly and can be a symptom of an ongoing digestive problem.


Acute vomiting is not a cause for concern unless you notice blood or a coffee ground-like appearance in the vomit. Acute vomiting does become an issue, though, when a cat who typically doesn’t throw up begins puking multiple times in a short time span. 


Vomiting itself is a vague symptom, but it warrants a call to the vet if it accompanies diarrhea.



Loss of Appetite


A loss of appetite in cats can be indicative of some illnesses such as an infection or kidney failure, or it can be caused by something as simple as a toothache.


Either way, loss of appetite can be detrimental to your cat’s health. If they’re not eating, their body will begin to tap into their fat reserves. This can lead to a condition known as hepatic lipidosis, a precursor to liver failure.


If your cat has stopped eating and regularly drinking, accompanied by diarrhea, their body is heading towards dehydration and fatigue quickly and needs to be seen by the vet.



Cat Diarrhea


Blood In Cat Diarrhea?

There are some serious and not-so-serious reasons your cat might have blood in their stool. Diarrhea can cause bowel irritations, especially along the digestive tract, which causes bleeding. If you’ve noticed that your cat’s bowel movements have been more liquid, you may notice blood in their stool in the coming days.

Diarrhea is caused by stress, and any dietary changes or intolerances might cause a change in their bowel movements, including blood showing up in their feces. Your cat also may have become dehydrated, or they might have a growth they need removed. Since many different diseases and circumstances can cause problems in your cat’s gastrointestinal tract, consulting your veterinarian is the best idea.

Why Do All My Cats Have Diarrhea?

There are a number of factors that can cause diarrhea in cats—these can be bacteria, intestinal worms, viruses, other illnesses, internal irritation, or chemical toxins. Your cat may have consumed something they shouldn’t have, and may be suffering from some common inflammation. Many cats also have food allergies and intolerances. There are specific ingredients in certain cat foods that could cause diarrhea in your cats. Consult your veterinarian over your cat’s diet.

Cat Diarrhea And Lethargy?

If your cat has recently had soft stool but is still playful and happy, you should wait to check their next bowel movement. Red flags for diarrhea are when your cat loses appetite, becomes lethargic, or becomes depressed. If you notice decreased playfulness, consult your veterinarian.

Cat Diarrhea Treatment


The treatment for your cat’s diarrhea will vary based on the cause. Your vet may prescribe a medication or treatment, or you may have to tackle the problem at home by changing their food and providing fresh water.


What do vets give kittens or cats for diarrhea? Treatments include:


  • Switching their food. If you’ve recently changed their brand or flavor of food, an ingredient in the new food could be upsetting them. Consider switching back to their old food and phasing the new food in gradually, or switching them to a highly digestible diet.


  • Since diarrhea causes dehydration, make sure that your cat always has access to fresh, clean water. You can also mix water in with canned food to increase their hydration.


  • Some types of diarrhea will respond to fiber supplementation, such as canned pumpkin or Metamucil. Both can be mixed into your cat’s food.


  • If internal parasites are causing diarrhea, your vet will recommend a deworming medicine and schedule.


  • If your cat has irritable bowel disease, your vet will recommend treating it with a special diet, vitamins, or medication.


If your cat has diarrhea, it may just be the result of an upset stomach and will pass within a day. If you have a kitten, elderly cat, or witness diarrhea lasting longer than 24 to 48 hours, then you should call your vet, especially if it’s accompanied by fever, vomiting, or loss of appetite.


What Is The Best Medicine For A Cat With Diarrhea?

Is your cat suffering from diarrhea? In some cases, your vet may prescribe common antidiarrheal agents, probiotics, or dewormers. The medications metronidazole and tylosin (and their associated brand names) are often prescribed as anti-diarrhea agents to safely decrease any intestinal inflammation in your feline. Your vet may prescribe Fagyl, Tylan, Profender, or Drontal, depending on the animal, the need, and the situation.


Always err on the side of caution and call your vet if you’re unsure about your pet’s health.


Can Cats Take Imodium for Diarrhea?

Imodium is safe for cats to take, though there are certain precautions. You should consult your veterinarian when giving your cat Imodium, and make sure they know your cat is starting any additional anti-diarrhea medications.


Consider Joining the Paoli Vetcare Family


We invite you to meet Dr. Jay Rowan or Dr. Dawn Urioste—the best reviewed veterinarians on the Main Line—for a free physical exam or free second opinion. You can book an appointment online now. If you’d like to support our animal hospital, please shop for your pet food and medications through the Paoli Vetcare Online Pharmacy.



Cat Diarrhea

Dr. Erin Downes VMD

Dr. Erin Downes graduated valedictorian from the University of Pennsylvania School of Veterinary Medicine in 1992. She and her husband, Dr. Jay Rowan are the owners of Paoli Vetcare | Main Line Vet & Animal Hospital.