Diseases in Cats That Create Skin Lesions

Wear gloves when examining skin lesions, as they could be contagious.
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Lesions are an itchy, painful and aggravating skin problem for your kitty. They develop when infections damage the upper layers of your cat's skin. Your pet can create lesions by scratching an area too much. Mites, allergic reactions and some forms of cancer are also associated with their development.


Mange mites are a pesky group of practically microscopic parasites that infest cats and other pets. They dig thin tunnels through the upper layers of your cat's epidermis and feed on biological substances created by his skin cells. Lesions develop as your pet scratches the already damaged skin repeatedly. Patches of crusted lesions first appear on your pet's head, chest or limbs. Skin damage and hair loss can progressively spread across your pet's body as the mites reproduce. Mites require animals to finish their life cycle. They can't truly infest a human, but they will bite you if they land on exposed skin.


Bacteria, fungi and viruses are always looking for an opportunity to infect a host. When your pet's skin is healthy, it keeps all these nasty pathogens from causing any damage. If your pet gets hurt, infections may set it in around the wound, even if it's just a scrape. An infection of staphylococcus bacteria can cause pyoderma, which produces painful lesions all over your cat's skin. The bacteria is usually present alongside a more serious health condition that suppresses the victim's immune system, according to Northern Virginia Community College Veterinary Technology Program. The parasitic fungus ringworm and yeast infections are other possible sources of your feline's skin infection.


Flea and mosquito bites are itchy, but it's way worse when your pet is also allergic to the insect's saliva. As unlikely as it sounds, cats can develop prominent skin lesions after being bitten by just one of these parasites. Lesions from mosquito hypersensitivity grow progressively worse, becoming crusted and very itchy, according to the Greater Saint Louis Veterinary Medical Association. Allergies to food ingredients, pollen or chemicals can also aggravating your cat's skin, leading to repetitive scratching and lesion development.


It's unpleasant to think about, but it is possible that your pet's lesions are related to cancerous growth. Squamous cell carcinoma (SCC) starts on the top layer of your pet's skin. The growth starts with only a few cells, but it spreads to surrounding tissue and eventually spreads throughout the body if it isn't treated, according to Cornell University College of Veterinary Medicine. This is why it's so important to take your pet to a vet for an official diagnosis if you find skin lesions. The chances of cancer are pretty low compared to other diseases or infestations, but catching cancer early vastly improves your pet's chances of a complete recovery.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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