Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
What Are the Most Common Causes of Diarrhea in Cats?
What Are the Most Common Causes of Diarrhea in Cats?
Introduction: Why Cat Diarrhea Should Not Be Ignored
As a cat owner, you are likely used to seeing your cat’s habits and knowing what is normal for them. When you notice a change in their litter box—specifically, loose or liquid stools—it can be alarming. While diarrhea in cats is a very common problem, it should never be ignored. Diarrhea can be a sign that something is wrong with your cat’s health, from a simple stomach upset to a very serious illness.1 Knowing the causes of cat diarrhea is the first step to helping your feline friend feel better. This guide will help you understand why your cat might have an upset stomach, what to look out for, and when it is time to call the vet.
Understanding Cat Digestion
To understand why a cat gets diarrhea, it helps to know how a healthy cat’s digestive system works.
How a Healthy Cat’s Digestive System Works
A healthy cat’s digestive system is designed to break down meat and absorb a lot of protein.2 When a cat eats, the food travels from their stomach to their small intestine, where most of the nutrients are absorbed.3 The rest of the food and water move to the large intestine. The large intestine’s main job is to absorb water and turn the food waste into firm, well-formed stool.4 This whole process usually takes about 12 to 24 hours.
What Happens During Diarrhea
When a cat has diarrhea, the food and waste move through their large intestine too fast. The large intestine does not have enough time to absorb the water, which results in watery or very loose stool. This can be caused by a lot of things, like bacteria, a virus, or even just a stress-filled day.
The Most Common Causes of Diarrhea in Cats
There are many reasons why a cat might have diarrhea. Some are easy to fix, and others can be very serious.5
1. Sudden Diet Changes
This is the most common cause of a mild case of diarrhea in cats. Cats have very sensitive stomachs.6 If you change your cat’s food too quickly—from one brand to another, or from dry food to wet food—it can shock their digestive system and cause an upset stomach.7 It is always best to change their food slowly over a week or more.
2. Food Intolerance or Allergies
Just like people, cats can have a hard time digesting certain foods or can have a food allergy.8 A cat with a food intolerance might not be able to break down a certain ingredient, like a type of grain or dairy. A cat with a food allergy will have a bad reaction to a certain protein, like beef, chicken, or fish.9 This can cause feline diarrhea as well as skin problems.
3. Eating Spoiled or Toxic Foods
Cats are curious creatures and might get into the trash or eat food that has gone bad.10 Eating spoiled food can cause a cat to get a stomach bug, which will lead to vomiting and diarrhea. They can also get very sick from eating things that are toxic to cats, like certain plants, chocolate, or some human medications.11
4. Parasites (Worms, Giardia, Coccidia)12
Parasites are a very common cause of cat diarrhea, especially in young kittens or cats that spend time outdoors.13 Intestinal parasites like roundworms, hookworms, Giardia, and Coccidia live in a cat’s gut and can cause a lot of digestive problems. A cat with parasites might also lose weight and have a dull coat.14
5. Bacterial Infections
A cat can get a bacterial infection from eating contaminated food or from coming into contact with another animal that is sick.15 Bacteria like Salmonella or E. coli can get into a cat’s digestive system and cause severe diarrhea, vomiting, and a fever.16
6. Viral Infections (Feline Parvovirus, FIV, FeLV)
Viruses can also cause a cat to get diarrhea.17 A very serious virus called Feline Parvovirus can cause a very bad case of diarrhea that is often bloody.18 Other viruses, like Feline Immunodeficiency Virus (FIV) or Feline Leukemia Virus (FeLV), can make a cat’s immune system so weak that they can’t fight off other infections that cause diarrhea.19
7. Stress and Anxiety
A cat’s digestive system is very sensitive to stress.20 A cat that is very anxious or scared can get an upset stomach.21 Moving to a new home, a new pet in the house, or a change in a cat’s daily routine can all cause stress and lead to a temporary case of diarrhea in cats.22
8. Inflammatory Bowel Disease (IBD)
Inflammatory Bowel Disease (IBD) is a serious, long-term condition that causes a cat’s digestive system to get inflamed.23 This makes it hard for their body to digest food and absorb nutrients. A cat with IBD will have chronic or long-term feline diarrhea and may also vomit or lose weight.24
9. Hyperthyroidism
Hyperthyroidism is a condition that is very common in older cats.25 It happens when a cat’s thyroid gland makes too much of a certain hormone.26 This can make their metabolism go into overdrive, which causes a lot of problems, including a very fast digestive system.27 A cat with diarrhea and a big appetite might have hyperthyroidism.28
10. Cancer and Other Serious Diseases
In some cases, chronic diarrhea can be a sign of a very serious disease, like cancer or a tumor in the gut.29 These diseases can affect the cat’s ability to digest food and can cause long-term digestive problems.
Other Factors That Can Trigger Diarrhea
Beyond the most common causes, a few other things can cause a cat to get diarrhea.30
Medication Side Effects
If your cat has recently started a new medicine, a side effect of the medicine could be making their stomach upset.31 This is why it is always important to talk to your vet about the side effects of any medicine your cat is taking.
Drinking Contaminated Water
If your cat gets to drink water from a dirty bowl, a toilet, or an old puddle, the water could be contaminated with bacteria or other germs that can make them sick and cause them to have diarrhea in cats.
Hairballs Passing Through the Gut
Cats are very clean animals and often get hairballs.32 Sometimes, when a cat is trying to pass a hairball, it can cause a temporary case of diarrhea.33
When to Worry: Warning Signs with Cat Diarrhea
If your cat has a mild case of diarrhea, you can often treat it at home. But if you see any of these warning signs, you need to get your cat to a vet right away.
Diarrhea with Blood or Mucus
If you see blood or a lot of mucus in your cat’s stool, it is a sign that there is a serious problem in their gut.34 This is a medical emergency and needs to be treated right away.
Diarrhea with Vomiting and Weakness
If your cat has diarrhea and is also vomiting, they can get dehydrated very quickly.35 If they also seem weak, are not moving much, or are not eating, you need to take them to the vet immediately. A cat not eating can be a sign of a serious problem.36
Persistent Diarrhea Lasting More Than 48 Hours
If your cat’s diarrhea lasts for more than a day or two, it is a sign that a simple stomach upset is not the cause.37 You should call your vet and get an appointment.
What to Do If Your Cat Has Diarrhea
If your cat has a mild case of diarrhea and is not showing any of the warning signs, you can try these things at home to help them feel better.
Step 1: Withhold Food Briefly (But Not Water)
For about 12 to 24 hours, do not give your cat any food. This will give their stomach a chance to rest. It is very important to make sure they have a lot of fresh, clean water. Do not limit their water intake.
Step 2: Offer a Bland Diet
After the fast, you can start giving them a bland diet. You can give them a small amount of plain, boiled, unseasoned chicken or white fish.38 A good bland diet can help their stomach get back to normal.
Step 3: Keep Your Cat Hydrated
Diarrhea can cause a cat to get dehydrated very quickly.39 Make sure your cat has a lot of fresh water to drink. You can try giving them a little bit of canned food to help them get more water.
Step 4: Call the Vet if Symptoms Continue
If your cat’s diarrhea does not get better after 48 hours, or if you see any of the warning signs, you need to call your vet. They will be able to help you figure out what is wrong and can give your cat the right treatment.
How Vets Diagnose the Cause of Diarrhea
When you take your cat to the vet, they will do a few things to figure out what is wrong.
Stool Tests
Your vet will likely ask you to bring a sample of your cat’s stool. They can test the stool for parasites, bacteria, and other things that can cause cat diarrhea.40
Blood Work
Blood tests can help a vet figure out if your cat has a serious medical problem, like hyperthyroidism or an infection.41
Imaging (X-Rays, Ultrasound)
If the vet thinks there is a more serious problem, they may want to take an X-ray or do an ultrasound to get a better look at your cat’s gut. This can help them find a tumor or a foreign object.
Treatment Options for Cat Diarrhea
The treatment for your cat will depend on what the vet finds.
Deworming and Parasite Control
If your cat has parasites, the vet will give them medicine to get rid of them.42 It is important to make sure your cat gets regular deworming to prevent this from happening again.
Antibiotics and Antivirals
If your cat has a bacterial or viral infection, your vet will give them medicine to help them fight it.
Special Diets for Sensitive Stomachs
If your cat has a food intolerance or IBD, your vet may recommend a special diet.43 These diets are made to be very easy to digest and can help a cat’s stomach get back to normal.
Long-Term Management for Chronic Conditions
If your cat has a long-term problem like IBD, the vet will give you a plan to help manage the disease with a special diet and medicine.44
Preventing Diarrhea in Cats
The best way to deal with cat diarrhea is to prevent it from happening in the first place.
Proper Diet and Slow Food Transitions
Always feed your cat a high-quality food. If you need to change their food, do it slowly over a week or more.
Clean Water and Litter Box Hygiene
Make sure your cat always has fresh, clean water to drink. Keep their litter box clean, and clean it every day. This can help prevent a lot of problems.
Reducing Stress at Home
Try to keep your cat’s life as calm and stress-free as possible. A consistent routine and a quiet home can help a lot.
FAQs About Cat Diarrhea
Should I give my cat human medicine for diarrhea?
No. Never give your cat human medicine. This can be very dangerous for them.
Why is my cat not eating but drinking?
A cat not eating can be a sign of a serious problem.45 If they are also drinking a lot, it could be a sign of a kidney problem. You should call your vet immediately.
What is a bland diet for a cat?
A bland diet is a simple diet of plain, boiled chicken or white fish.46 Do not use any salt or other seasonings.
What is the difference between soft stool and diarrhea?
Soft stool is just a little loose, while diarrhea is very watery or liquid. Both can be a sign of a problem.
Conclusion: Protecting Your Cat’s Digestive Health
Watching your cat have diarrhea can be a stressful thing. While it can be caused by something simple, it is always best to be safe and to get your cat the right help. By knowing the signs and what to do, you can help your cat feel better and protect their health. Your loving care and attention to their well-being can make a world of difference for your cat.
