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Why Does My Cat Have Bumps on Their Skin? 8 Common Reasons

It can be scary to notice a lump on your cat’s skin. Immediately, our minds tend to rush to the worst-case scenario—but don’t jump to conclusions quite yet! There are plenty of reasons that your cat may have a bump on his skin that is not related to cancer.

In this article, we will look over some common reasons your cat may have lumps on his skin. The categories that we will cover include trauma-related bumps, tumor-related bumps, and bumps due to bugs, parasites, or fungi.

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The 8 Most Common Reasons Why Cats Can Have Bumps on Their Skin


Bumps on your cat’s skin can be due to a previous physical trauma that occurred. If your cat got into a fight recently, it is possible that is the cause of the strange bump on his skin. Take a look at some of the possibilities and see if they might fit your cat’s circumstances.

1.  Injury

An injury may lead to lumps on this skin.1 This can include swollen wounds, blisters, sores, and more. Cats often hide their pain, so it may be difficult to tell whether or not they are injured from their behavior alone. If an injury is small and difficult to see past his fur, you may not notice it. However, if the injury becomes infected, there may be more clear signs. Signs that your cat has an infected injury include swelling, redness, warmth, and discharge.

Depending on the nature and severity of the injury, your veterinarian may recommend different treatment approaches. If you notice a wound on your cat’s skin, it is best to take your cat to the vet so that your vet can determine the seriousness of the matter and provide proper care.

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2. Abscesses

person scratching a senior cats head
Image Credit: MauriceDT, Unsplash

Abscesses are related to injuries because they often cause them. These areas of infection typically occur due to a bite or other puncture wound.2 Signs that your cat may have an abscess include swelling, fever, pain, and discharge. If the spot is located on one of your cat’s legs, you may notice him limping.

Your vet may sedate your cat for minor surgery to remove the abscess. Antibiotics will usually be prescribed, and at-home treatment will be necessary.

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Unfortunately, tumors also cause bumps on your cat’s skin. However, not all of these tumors are dangerous.

3. Fatty Tumors or Lipomas

Fatty tumors, or lipomas, are benign tumors.3 They are generally soft lumps that can be easily manipulated. When compared to dogs, these tumors are relatively rare in cats. These lumps are noncancerous and do not tend to be life-threatening, though they still need to be diagnosed in case treatment is necessary.

Usually, lipomas do not cause your cat pain, but that is not always the case. Often, your veterinarian will only recommend careful monitoring of the lipoma, but there may be instances where surgical removal is necessary.

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4. Mast Cells Tumors

Mast cells are a form of white blood cells that are present throughout your cat’s entire body. A mast cell tumor is formed when these cells rapidly replicate and divide. Mast cell tumors are the second most common type of skin tumor in cats.4

These tumors can develop over a long period and can be benign or malignant. Mast cell tumors on the skin are often benign, while mast cell tumors on other body parts tend to be malignant. When mast cell tumors develop on the skin, surgical removal is the most common treatment method.

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5. Fibrosarcoma

Fibrosarcomas are soft tissue sarcomas that can be highly invasive to other areas of the skin but generally do not spread to other organs. These lumps tend to grow slowly. Treatment of fibrosarcoma can be difficult, as it can be impossible to verify if all cancerous cells have been entirely removed due to their microscopic nature. Multiple surgeries and radiation therapy may be necessary.5

The prognosis heavily depends on the tumor’s severity, the growth’s location, and the treatment offered. Without aggressive treatment, some tumors will return.

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Bugs, Parasites, or Fungi

Injuries and illnesses are not the only possible causes of lumps on your cat’s skin. Bugs, parasites, and fungi may also lead to strange bumps.

6. Ticks

removed tick from cat
Image Credit: Ivan Popovych, Shutterstock

Ticks are pesky parasites that bother our animals far too often. If your cat has a strange lump on his skin, ticks could be the cause. Cats self-groom often, so it is not likely that you will find more than one or two ticks on his body. If you find several ticks, that may indicate a more serious illness since illnesses may lead cats to groom poorly.

If you spot a tick on your cat’s skin, you can take him to the vet or remove it yourself. After removing it, you will need to disinfect the area. Your cat will be more susceptible to infection after removing the tick, so thorough washing is necessary.

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7. Bug Bites or Stings

Like injuries, a previous bug bite or sting on your cat’s skin can leave a bump behind. If your cat has been bitten or stung by an insect, try to identify which insect left the lump. Depending on which insect it was, the bite or sting could lead to other serious health complications. Some signs that a bug bite or sting is dangerous include swelling, hives, drooling, and difficulty breathing.

Do what you can to minimize swelling and prevent your cat from licking or scratching the wound. If you are ever uncertain about the severity of the bug bite or sting, reach out to your veterinarian.

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8. Ringworm

Ringworm is a fungal infection that impacts your cat’s skin. The fungal infection has a round, red, raised appearance, which is where the name ringworm comes from. Ringworm is a zoonotic disease, meaning it can be passed from your cat to you, so be careful handling any cat that may have ringworm.

Cats infected with ringworm will be contagious for around 3 weeks. To treat the condition, you must be persistent in your methods. Depending on the case, your veterinarian may recommend oral or topical treatments.

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There are several common reasons that your cat’s skin may have developed odd lumps or bumps. Trauma or tumors may be the cause, although small creatures such as bugs, parasites, or fungi may also affect your cat’s skin. In any case, consult your vet about any odd lumps you notice on your cat’s skin. If there is any possibility that your cat may be suffering from something serious, it will be essential to diagnose the condition and provide treatment early.

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Featured Image Credit: rihaij, Pixabay