Sores and Bald Patches on Your Cat: Top Reasons & What to Do

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  • Does your cat have patches of fur missing and sores on its skin? As vets we see this surprisingly often – but the good news is it’s often very treatable. Read on to learn about the most common causes and what you can do to help.

    What are the top reasons for sores and bald patches in cats?

    1. Fleas

    Fleas are the most common cause of bald patches and sores, usually across cats’ backs and near the base of the tail. Though many cats can tolerate a few fleas, others are hypersensitive to flea saliva and develop dermatitis. With only a couple of bites, your cat may become intensely itchy and develop patchy scabs and hair loss called miliary dermatitis.

    miliary dermatitis on cat

    dermatology disease at the cat scin with lots of red acne

    Effective flea control is essential to treat this – over the counter products can be used but prescription products may be more effective. You’ll need to treat all in contact pets for at least 3 consecutive months to fully eliminate fleas. Your vet may also recommend a short course of steroids to help relieve itching.

    Other parasites like mites can also cause itching, so if your cat’s case is severe or doesn’t respond to flea treatment, it’s worth seeing your vet. Read more about treating fleas in cats.

    2. Ringworm

    Ringworm is a fungal infection that causes circular areas of crusty, scaly and intensely itchy skin to develop, often with fur loss. It’s very contagious to other animals and humans, so be careful! Diagnosis may be based on clinical signs or further testing including fungal cultures. Treatment depends on the severity of the case and may involve topical bathing and/or oral medications – cats usually respond well and symptoms resolve over a few weeks, although fur can take a little longer to grow back! See more photos of ringworm in cats.

    ringworm scabs on a cat's head near ears and neck

    3. Allergies

    Although less common in cats than dogs, allergies can cause hair loss and itchy, red, sore areas of skin. They most frequently affect the head and belly. Cats can develop allergies to environmental allergens like pollen and dust mites or dietary allergens. Diagnosing and managing allergies in cats can be tricky so it’s important to work closely with your vet to try to get to the bottom of things. Find out more about allergies in cats.

    4. Dermatitis

    Bacterial infections can cause red, irritated skin, pustules, sores and areas of fur loss. Again, these are less common in cats than dogs, but if you suspect a possible infection you should see your vet quickly as it’s likely to need veterinary treatment to prevent it spreading and getting worse. Find out more about skin infections in cats.

    pyoderma skin infection on cat's skin

    5. Trauma

    If your cat only has one or two localized sore areas or patches of missing fur, it may be the result of a fight or other trauma. It’s worth getting any wounds checked by a vet as cats can easily develop severe infections and abscesses if wounded by another cat.

    6. Overgrooming

    In some cats, visible skin irritation is the result of overgrooming, not the cause of it. Cats overgroom for a range of reasons including pain (e.g. osteoarthritis) and behavioural issues like anxiety. If you notice your cat overgrooming a specific area and causing skin changes, you should see your vet to try to get to the bottom of what’s going on. Learn more about overgrooming in cats.

    7. Autoimmune diseases

    Less commonly, conditions like pemphigus and eosinophilic granuloma complex can cause skin changes including reddened, sore areas and missing fur.

    What can I do at home?

    If your cat has severe skin changes, is very distressed or is showing other symptoms, you should take them to the vet as soon as possible to be assessed. Otherwise, there are a couple of things you can try first.

    • First, keep your cat up to date with flea treatment, especially if they go outdoors. Consider using one that also treats mites.
    • Secondly, consider a buster collar to prevent scratching. Cats have sharp claws and can cause a lot of damage scratching themselves! This should be a temporary measure while you try to treat the cause.
    • Finally, if your cat has sores that are oozing discharge, whilst waiting for a vet appointment you can bathe the area with dilute salt water to keep them clean and reduce the risk of infection.


    • Dr. Moss, Veterinarian

      Dr. Primrose Moss graduated from the University of Cambridge with a Bachelor's of Veterinary Medicine. She is currently a veterinary surgeon at Avonvale Veterinary Centres in the UK.