Neutering is a routine procedure that most cat owners opt for. Removal of the testicles is recommended when the cat is very young, even before he becomes sexually mature.
So, chances are good that your cat will be his old self shortly after surgery, and will regain his energy. You will also see the clear benefits of sterilization – the reduction of aggressive behavior, and your cat will stop looking for females in heat to mate with.
However, every surgical procedure carries a certain risk. It would be very useful if you know how to recognize if complications occur after sterilization of your cat.
Let’s look at the 9 most common signs of infection after neutering cat.
Swelling in the area of the incision isn’t unusual. Actually, it’s even expected for your cat’s incision to be swollen, especially on the first and the second day after neutering.
In these first days, you can apply an ice pack on your cat’s incision to reduce swelling. Of course, you shouldn’t put it directly on the incision, but rather wrap it in a towel.
Still, if this doesn’t seem to help, and if the swelling is not getting any better in the following days, this could be a sign of an infection in your neutered cat.
2. Cat Seems To Be In Pain
Cats will not easily show they’re in pain. This has to do with their life in the wild, where they never showed pain so as to not seem vulnerable to predators.
Of course, male cats are likely to show decreased energy levels and less desire for socialization right after neutering.
But, most cats will soon get back to their normal routine – some might even seem unusually active quickly after neutering!
North Boulder Companion Animal Hospital explains how it’s expected for a cat to recover from neutering in 5 to 7 days.
If even after this period your kitten continues to be lethargic, wants to be alone, and seems completely uninterested in the activities he’s usually crazy about, this could indicate he’s in pain.
A neutered cat shouldn’t be in pain for this long after the procedure. If this is the case with your cat, he might have an infected incision.
3. Refusing To Eat
Many cats will have a decreased appetite right after sterilization.
But, this should change soon, and your cat should be eating normally for about 24 up to 48 hours maximum after neutering.
If you notice your cat still refusing to eat even 2 to 3 days after the procedure, this could also be a sign of infection that’s making your cat feel bad and not have the strength even to eat his favorite food.
Cats can’t go without food for too long – even 48 hours without any food can seriously impair their health.
So, you shouldn’t ignore your cat’s refusal to eat, since this could be an important sign that something is wrong with his incision.
4. Unable To Pee
It’s perfectly normal for a neutered cat not to be able to pee for the first 24 to 48 hours.
But, if 72 hours have passed since the procedure, or even longer, and you notice your cat still hasn’t defecated, this is another warning sign of an infection.
Cats shouldn’t go without peeing longer than 48 hours, since this can be very bad for their health in general.
According to petMD, if the urine cannot be emptied from the cat’s bladder, this will not only make the cat very sick, but can even become fatal.
5. Excess Bleeding
Noticing a bit of blood around your cat’s incision in the first 24 hours after the procedure isn’t an instant alarm for panicking.
However, there shouldn’t be any blood after the first 24 hours have passed. If you still notice it in the following days, this will require an immediate call to your veterinarian.
Excess bleeding can also be a symptom of infection after your cat’s neutering procedure.
Please beware that increased activity or movement soon after the surgery can greatly increase the chances of bleeding in your cat.
You should make sure he isn’t running or jumping in the first days after neutering. He should be resting in a calm environment, without other animals and many people around him if possible.
6. Discharge Or Pus
A yellow, green, or discharge in any other color coming out from your cat’s incision isn’t a good sign.
Moreover, this is one of the most common signs of infection. According to VCA Animal Hospitals, any discharge from the incision site is abnormal.
You might also notice your cat is excessively licking or scratching the incision area to relieve his pain.
Julie Flood  explains how infection is the cause of fever in most felines.
Cats with fever will usually have a body temperature between 103 and 106°F.
It’s very important to observe your cat’s temperature for a couple of days after neutering. As soon as you notice any increase in temperature, you should take your kitten to a vet clinic immediately.
8. Gastrointestinal Problems
Some cats could deal with vomiting or diarrhea on the first day of recovery after sterilization. But, this shouldn’t last for too long.
If your cat continues to show gastrointestinal problems in the following days, this could also be a sign of an infection.
Excess vomiting or diarrhea can cause dehydration in felines, so, you should consult your veterinarian on whether it’s necessary to take your cat for an observation.
9. A Bad Odor
If your neutered cat’s incision is healing as it should, there shouldn’t be any bad odor coming from it.
So, if you notice a rather unpleasant smell coming from your cat’s incision area, this might indicate an infection.
To notice this sign, as well as all other potential symptoms of infection in your cat, you need to observe his incision carefully and often.
If you notice any unusual smell in your cat, contact your vet right away.
Neutering is a routine surgery that veterinarians normally recommend to cat parents. Infections after this procedure aren’t so common, but they might happen.
And, they can be dangerous for your pet’s health, so, it’s essential that all you know how to recognize signs of infection after neutering cat.
The only thing you should do after noticing potential signs of infection in your kitten is to take him to the veterinarian.
Most infections are easily treatable, and your cat should recover quickly. It’s important you make sure your cat is resting, and that he doesn’t get involved in activities such as running or jumping at least 10 to 15 days after the surgery.
Make sure you follow the vet’s instructions, and don’t make any decisions related to your cat’s health on your own.
 Flood J. The diagnostic approach to fever of unknown origin in cats. Compend Contin Educ Vet. 2009 Jan;31(1):26-31; DOI, Retrieved June 13, 2023.