How to Tell if a Cat is Neutered

• Spot neutered male strays by looking for a notch missing from their ear, a tattoo on their ear, or a tattoo on their stomach.
• Unneutered male cats will still have their testicles. They will also have puffy cheeks and their urine will smell especially strong.
• Don’t assume you have a neutered male cat just because their testicles are gone—the cat may simply be female.

Check his ear for a missing notch.

The missing notch is a universal sign the cat is neutered. If you spot a stray cat with a triangular notch missing from his ear, that cat has been neutered by a humane society, local nonprofit, or city program. The “tipped” ear is the universal sign that a stray cat has been caught, neutered, and released back onto the street. Don’t worry! The cat was under anesthesia when his ear was clipped and it didn’t hurt him. Stray cats reproduce quickly, and too many cats can destroy a local ecosystem. That’s why it’s so important to neuter and spay stray cats. You can totally adopt a cat with a tipped ear! All the ear means is that a kitty spent some time on the street. They can still be a totally awesome pet and friend to you. The tipped ear prevents animal control and members of the public from wasting their time trying to catch a stray cat and take them in to be neutered/spayed.

Look for a tattoo in his ear.

Many organizations will tattoo cats instead of removing tissue. Some people are understandably uncomfortable with the practice of physically clipping a cat’s ear. As such, some nonprofits, programs, and adoption centers will tattoo a cat’s ear instead of removing tissue. The tattoo and the tipped ear mean the same thing—the cat is neutered or spayed. This tattoo is normally a squiggle near the top of the ear, although you may also see a straight line, circle, or dot. The tattoo ink is often bright blue, although it may be black or red.

Check his stomach for a tattoo.

Vets will put a mark on the stomach to show a cat is neutered. Most veterinarians and catch-and-release centers will tattoo a cat’s tummy after spaying or neutering them just so future vets and centers don’t perform unnecessary surgery. You may not be able to see this tattoo on a long-haired cat, but it should be visible on a short-haired kitty if you look closely. This tattoo is almost always bright blue; it’s usually a line just above a cat’s genitals. This kind of tattoo is more for vets and surgeons than it is for the general public. The last thing a surgeon does before opening a cat open to neuter or spay them is shave their tummy. That’s when a surgeon would see this marking and realize they don’t need to perform surgery. Don’t pick a stray cat up to look at their stomach if you don’t know how they’ll behave. They may be carrying disease or become aggressive when you pet them.

Look for testicles.

Gently lift the cat’s tail to see if he still has his genitals. When a cat gets neutered, his testicles are removed. An unneutered male cat will have testicles located below the tail and anus, but above the penis. If you see testicles, the cat is unneutered. If they’re missing, the cat is neutered. If you find one testicle, your cat has not been neutered. You may need to get someone to help you if you think your cat will squirm around while you do this. If a cat is very young, his testicles may not have descended yet, so you can’t rely on the presence of absence of testicles if you’ve got a kitten you need to sex.

Confirm the cat isn't female.

A female cat or kitten will have a vertical slit instead of a round penis. Your cat may still be capable of reproducing if you don’t see testicles—the cat might be female! If you lift the cat’s tail and you don’t see testicles but there’s a thin, vertical slit where you’d expect the testicles to be, she’s a girl. Take them to a vet to get fixed soon if you aren’t sure they’ve been spayed. Spaying a female cat is just as important as neutering male cats, so don’t take your time. If a kitten has a round opening or mound of fur below their anus instead of a slit, it’s a boy. Another sign you’ve got an unspayed female cat is that they go into heat once a month. A cat in heat will be really needy; they’ll want constant attention, meow frequently, and stick their backside up in the air at you.

Inspect his face for thin jowls.

An unneutered tomcat will typically have large, puffy cheeks. A mature, unneutered cat is known as a tomcat, and they’ll have a few secondary sexual characteristics, like penile barbs and dorsal glands. While those aren’t visible, the massive, fluffy jowls will be. If a male cat’s face is super round and puffy, he’s most likely unneutered. Male cats frequently fight in the wild to win over female cats, and it’s thought that they develop the puffy jowls to protect their face in a fight. Sexually mature and unneutered tomcats will also tend to vocalize more than other cats. They’ll often be more aggressive and tend to wander off, too.

See if his urine smells normal.

Especially nasty urine is a sign that a male cat is unneutered. Male cats who aren’t neutered will produce hormones that neutered cats won’t. These hormones mark their territory and let female cats know they’re around, but to humans, this urine is especially strong and smelly. If you’ve got a good nose and a male cat’s urine is uniquely unpleasant, he may be unneutered. A lot of people won’t be able to tell the difference between normal cat urine and unneutered male cat pee, so don’t rely on this test too heavily.

Take the cat to a vet.

A veterinarian will know if a cat has been neutered or spayed. If you have tried all other methods and are still not sure, you should ask your veterinarian if the cat has been neutered or spayed. They will be able to tell you immediately just by inspecting the cat’s body. If you find out that your cat isn't neutered, make an appointment to get it done as soon as possible. If you’ve picked up a stray, you should take them to the vet anyway to have them checked for diseases and get their vaccinations.

Read through the cat’s medical history and paperwork.

If you're buying or adopting a cat or kitten, ask if he’s neutered. There will be a certificate or letter from a vet to prove that the cat has been neutered. If the cat comes with a medical history, his reproductive status will be listed there. Don't be afraid to ask! It’s not a problematic question and this makes you more responsible as a potential owner.