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“What should I do for diarrhea after neutering my cat? I brought him home yesterday and he’s been in and out of his litterbox with runny diarrhea several times already. Is this normal?”

–Shelley P.

Dear Shelley,

Thanks for the note! I’m sorry to hear you’re dealing with diarrhea after neutering your cat. Let’s talk about why your kitty might have loose stools, when to worry and what to do next…

Male domestic cats have an instinct to spray urine on horizontal surfaces as a way of communicating with other cats. That’s great when they live outside, but most people aren’t willing to deal with a cat spraying urine in their house for 12-15 years.

Cat neutering is very standard for male pet cats in the United States.

Neutering male cats before they reach physical maturity significantly reduces urine spraying behavior. Neutering also prevents unwanted cat reproduction and decreases wandering and fighting with other male cats. (3)

Neutering male cats is a relatively simple surgery but cats can experience problems (including diarrhea) after they come home. 


  • Neuter surgery can be physically and mentally stressful to a cat.
  • Stress can lead to a temporary change of bowel habits including diarrhea.
  • Diarrhea that lasts longer than 48 hours or is accompanied by other symptoms should be reported to your veterinarian.

What to Expect After Neutering a Cat

Cats have variable responses to neuter surgery. I’ve seen many who return home and act as if nothing happened. Some act weird for about half a day while the anesthetics drugs wear off. A few kitties experience more serious problems like diarrhea, lethargy and poor appetite

Cat Neutering Can Be Stressful

Even though neutering a male cat is a less intensive surgery than spaying a female cat, it’s still a big deal for the cat. They experience stress from multiple sources in the few days around their surgery. 

First, they may be restricted from eating breakfast on the day of their surgery. Then they might not feel like eating for 24 hours after surgery. So that’s 1-2 days without food or eating less than normal. 

Second, they have to be transported to the vet clinic. Being put into a carrier and riding in the car is quite stressful for many cats. 

Third, they’re held in the vet clinic before and after the surgery for a period of time. Being confined to a cage is bad enough. Add to that the noises and strangers that are common in vet clinics and you’ve got a legitimate source of stress.

Fourth, your cat will receive several different kinds of drugs. Anesthetic agents and pain medication are given to most male cats undergoing neuter surgery. These are very helpful for preventing pain, but they can mess up the normal physiology of your cat’s guts for a couple of days. 

Finally, especially if your cat stays overnight at the vet clinic, he may be fed unfamiliar food. That is an extremely common trigger for diarrhea.

litterbox with diarrhea after neutering cat
Sticky, loose stool in the litterbox is an unwelcomed surprise.

What to Do for Diarrhea After Neutering Your Cat

As mentioned above, there are many sources of psychological and physical stress to a cat during and after a neuter procedure. 

If your kitten has sudden diarrhea after neutering, don’t panic. Most cats’ bowel habits return to normal within a day or two.

You can try offering a bland highly digestible food such as Gerber chicken baby food or plain, cooked chicken breast meat for a couple of days. Chicken broth offered alongside her regular water dish may encourage her to take in more liquids. 

If you have access to pet probiotics like Forti-Flora, you can sprinkle that on the food. It has been clinically shown to improve certain types of diarrhea in cats and is quite safe to use. (1,2)

Purina Pro Plan FortiFlora is a probiotic sprinkle that cats love eating and it can help resolve diarrhea.

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Watch for other symptoms like poor appetite, lethargy, vomiting, etc. If you notice these in addition to diarrhea, your cat needs to see a vet right away. 

If your cat doesn’t have any other symptoms but still has diarrhea 48 hours after his procedure, he might need treatment. Contact your vet for help. 

Other Common Cat Problems After Neutering Surgery

Now let’s go over some of the most common problems cat owners ask about after having their cat neutered. 

Can I Feed My Cat After Neutering?

In most cases, your vet will keep your cat in the clinic until they’ve fully recovered from anesthesia. Most cats will be cleared to eat within 8 hours after the procedure. 

Ask your vet what time you can feed him. If in doubt, offer about ¼ of his normal meal and don’t get too worried if he doesn’t want to eat it right away. 

Cat Won’t Eat After Neuter Surgery

It’s not unusual for cats to have a poor appetite within the first 12-24 hours after any kind of anesthetic and surgical procedure. You can try tempting him with an extra delicious yet easy-to-digest meal of Gerber chicken baby food or plain, cooked chicken breast meat only. 

If your cat is still refusing food 36 hours after his neuter surgery, it is cause for concern. You should contact the vet clinic that performed the surgery and ask for their recommendation. If you can’t get in touch with them, call a 24-hour emergency vet clinic for advice.

spoon with chicken baby food
Chicken baby food tastes good to most cats and is easy to digest.

My Cat Is Very Active After Surgery

I’ve had many clients tell me their male cats didn’t seem phased at all by their neuter surgery. Kittens who were wild right before surgery might be just as wild after surgery!

Some cats act weird when they get home due to the effects of anesthetic drugs. It can make cats loopy, sleepy or sometimes even hyperactive. These effects are usually gone by the next day after the surgery.

Vet Didn’t Give Us a Cone After Cat’s Neuter Surgery

Many vets don’t send home a “cone” (a.k.a. Elizabethan collar or e-collar) with male cats after surgery. It’s not that common that male cats need a cone to keep them from licking their scrotal incisions excessively. And wearing a cone is stressful for cats so why use one if it’s not needed?

If you’re concerned about your cat licking the surgery site too much, call your vet or a 24-hour emergency vet clinic to see if they’ll sell you a cone. You can also buy them in pet stores like PetSmart or online from Amazon.com. 

It’s tough to make a homemade e-collar cone for a cat. Unlike dogs, they’re really good at removing a rolled-up towel from around their necks! 

I’ve seen people cut the bottom from a small plastic container, fit it over the cat’s head like an e-collar and rig it up so it’s tied to a regular collar around the cat’s neck. If you try this, keep a close eye on your cat in case he gets tangled up trying to remove it. 

Cat Is Vomiting After Neuter

The events surrounding a cat neutering surgery can affect their upper GI tract, too. It’s not unusual for a cat to vomit once or twice in the 24 hours after surgery from stress, medication, general anesthesia, etc. 

If your cat vomits more than a couple of times or is continuing to vomit 48 hours after surgery, contact your veterinarian for help. Cats with both vomiting and diarrhea should also receive treatment to prevent dehydration. 

If it’s after hours and you don’t have access to a 24-hour vet clinic, you can offer your kitty plain chicken broth or unflavored Pedialyte to stave off dehydration. But your vet will have a much more effective way to help your cat so get them into the clinic A.S.A.P.!

gray cat standing on hind legs
Some cats act weird for a while after anesthesia.

Cat Is Acting Weird After Neuter

Cats should be fully conscious when they come home after being neutered. But the effects of anesthetic drugs may cause them to act weird for 12 hours or so after surgery. 

Some cats act are hyperactive, some are just goofy. In any case, make sure they stay in a safe area so they can’t accidentally get injured. Don’t let them have access to swimming pools, outdoors or tall furniture. If you can’t confine them to a safe room, have them stay in a crate any time you can’t directly supervise their activity. 

If your cat is still acting weird 24 hours after their surgery, contact your vet for help.


Neuter surgery is a big deal to both the mind and body of a cat. Anesthesia and medication can cause changes in the GI tract that lead to diarrhea. Mild loose stool for 24 hours is not a cause for alarm. If you notice persistent diarrhea with other symptoms, your cat should be examined by a vet as soon as possible. Most cases are easily treated and feel better quickly. 

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Related Posts

  1. Bybee, S. N., Scorza, A. V., & Lappin, M. R. (2011). Effect of the probiotic Enterococcus faecium SF68 on presence of diarrhea in cats and dogs housed in an animal shelter. Journal of Veterinary Internal Medicine, 25(4), 856-860.
  2. Torres-Henderson, C., Summers, S., Suchodolski, J., & Lappin, M. R. (2017). Effect of Enterococcus faecium strain SF68 on gastrointestinal signs and fecal microbiome in cats administered amoxicillin-clavulanate. Topics in companion animal medicine, 32(3), 104-108.
  3. Knol, B. W., & Egberink‐Alink, S. T. (1989). Treatment of problem behaviour in dogs and cats by castration and progestagen administration: A review. Veterinary Quarterly, 11(2), 102-107.