You're enjoying a bonding moment with your kitty, and as you're petting her, you notice a lump on her skin. It may be small and your cat may seem fine, but even so, you should have a veterinarian check it out. There's no way for you to know what's going on by just feeling it. Your feline friend could have an infection, a parasite, or a more serious problem. These are the common causes of lumps on a cat's skin:A minor injury can cause a bump. It may heal on its own, but it could get infected. A cat that’s been given a shot may have a lump for a few days, too. But if it doesn’t go away after that, call the vet. An abscess is a pus-filled, swollen spot on the skin that sometimes forms where your cat has been bitten or scratched. They're often red and painful, so your cat may shy away from your touch. She might seem more tired than usual and may not be that interested in eating. A warm compress may bring her some relief. To treat the abscess, your vet may give your cat an antibiotic and an anti-imflammatory medication. He may also trim the hair around the bump to keep the wound clean. If the abscess is deep, she may need surgery. Fatty tumors, called lipomas, may show up anywhere on a cat’s body. They aren’t cancerous and don’t need to be removed unless they keep your cat from getting around well. They’re seen more often in older or overweight cats. To check a lump for cancer, your vet will use a needle to get a sample. If it’s just a fatty tumor, he may suggest to do nothing and watch the tumor. If it changes or gets bigger, he may suggest surgery. Mast cell tumors can also appear on the cat’s skin, usually on the head or neck. They may be itchy or red. About 10% of these tumors are cancerous. Fibrosarcomas are cancerous tumors that can appear anywhere on the body. Rarely, they happen as a side effect to any injection that is given. If your cat has a lump at the site of a recent shot, let your vet know. He may ask you to watch it for a few weeks and visit the office if it doesn't shrink away. Usually, these tumors happen long-after the vaccination. One of the most common types of cancer to affect cats is breast cancer, or mammary gland tumors. They appear on the underside of the cat, near her nipples, and often go unnoticed until they’re large. At the start, these tumors may feel like BB pellets. About 85% of these tumors are cancerous, so don't delay taking your cat to the vet to be examined if you notice something unusual. If you spay your cat before she goes into heat for the first time, you'll cut her breast cancer risk by about 90%. If your cat has any type of cancer, she will most likely need surgery to remove the tumor and the tissue around it. Your vet may refer you to a veterinary oncologist, who treats animals with cancer. For breast cancer, removing the whole mammary gland may be the best treatment. In some cases, the doctor may recommend radiation or chemo after surgery. Just like people, some cats have blackheads on their chin or face. These can feel like very small bumps under the surface of the skin. They may be easier to notice if they become infected. If your vet says that your cat has acne, he may ask you to use a special wash, wipe, or medicine on your cat’s face to remove extra oil. Plastic bowls for drinking and eating may also lead to cat acne. If your kitty stays inside, you may not think of this, but indoor cats can get ticks. The parasites can hitch a ride inside from dogs or humans who spend time outdoors. If a tick stays on your cat's skin long enough to embed itself, it can look and feel like a lump. If it’s a tick, your vet can safely remove it. You and your vet can then discuss how to proceed,Mosquitos, bees, wasps, spiders, and ants can cause bumps on cats, too. There may be redness and swelling at the site. The ears and nose may have worse reactions than other body parts. A cold compress may help ease pain. If your pet was stung, a vet may need to make sure the stinger is removed. The vet may want to use an antihistamine or steroid to reduce swelling. Some cats are sensitive to flea bites, but they’re more likely to get a rash or sore than a raised bump. Make sure to give your cat treatments to help control fleas. To avoid mosquito bites, keep your cat indoors at dusk and dawn during summer months. Get in a routine of grooming your cat. That way, you’ll know when something unusual first appears on her skin. It may be nothing serious, but if it is, the sooner you find out and seek treatment, the better.