What is Causing My Cat's Skin Infections?

What is Causing My Cat's Skin Infections?

When we pet our cats, we expect their fur and skin to feel soft and smooth, so it can be very alarming to suddenly discover a rough, inflamed, bumpy or oozing section of skin.

Skin infections in cats aren’t all that common, but they can happen. Because cats are so good at keeping themselves clean, you’d think that skin infections would be next to impossible. However, there are a number of things that can lead to a skin infection.

Infections of the skin are typically caused by an overgrowth of bacteria or fungi. But this overgrowth is often a result of an underlying problem that you need to identify and address.

How to tell if your cat has a skin infection

Some skin infections can look different from others, depending on what is causing the infection. However, many infections have similar symptoms.

You might first notice the skin infection because of your cat consistently licking, scratching or biting at the area. Infections can become inflamed and itchy, and your cat may try to “clean” or soothe the symptoms day and night.

Upon examination, skin infections typically look red and inflamed and may have small bumps or lesions. The area may contain a pustule and be secreting yellow or white pus and/or blood, and the skin may appear dry, flaking or crusted.

Usually, the infected are will also have hair loss. This is usually due to the cat over grooming to soothe the infection, which can remove fur.

Common causes of skin infections

Bacterial infections, also known as pyoderma, on your cat’s skin are most commonly secondary infections. This means that an underlying problem has caused the skin to become a hospitable environment for bacteria.

Here are some of the most common underlying causes of skin infections in cats.

Environmental allergies

Cats can become allergic to things in their environments just like humans can. Seasonal allergens like mold and weeds, as well household things like perfume or cleaners and even food can affect your cat’s immune system, resulting in something called atopy: red, inflamed and itchy bumps on the skin.

When cats experience atopy, their first instinct is usually to over groom in an attempt to soothe the itch. When cats constantly lick or bite the skin, they can cause hair loss, hot spots and injury that leaves the skin susceptible to bacterial infections.


Fleas can also cause over grooming similar to allergic reactions. A flea infestation can cause your cat to itch and scratch as a result of their bites. Additionally, some cats can develop allergies to flea saliva, making them even more sensitive to the itchiness.

And, like with atopy, consistent itchiness can cause cats to over groom, bite and scratch, potentially injuring themselves or creating a hot spot where bacteria can settle in and cause an infection.

Bites and scrapes

Injuries like bites, scratches and scrapes on your cat’s body have a high risk of becoming infected, especially if you are unaware of them and can’t keep them clean.

This problem may affect cats that roam outdoors more, since they have a higher chance of encountering a wild animal. Cats that fight with each other in multi-animal households may also be susceptible.

If you notice an injury on your cat, you must make an effort to keep it clean and prevent infections from occurring.


Stress is another common underlying cause of bacterial infections. Unfortunately, it tends to be overlooked by owners looking for physical problem.

Sudden changes in routine, the addition or loss of a family member, changes in location and more can cause cats serious distress. Many cats use over grooming as a way to self-soothe, which can ultimately lead to problems of the skin. Many cats experience hair loss as a result of stress-related grooming, but unchecked or chronic stress may lead to the occurrence of an infection.


Ringworm is an extremely contagious fungal infection that can afflict cats, as well as other animals and humans. The infection causes hair loss and scaly lesions on the skin, but they are not always round like they are in humans.

The infection caused by ringworm is not usually itchy, but it can still cause problems for your cat’s skin and even lead to a secondary bacterial infection if left untreated.

Two-fold treatment

When your cat develops a skin infection, you’ll want to take it to the vet to have it examined. The vet will take samples of the infected area to examine and determine the specific cause.

This may require two-fold treatment: the first, to clear up the infection itself, and the second, to treat the underlying cause to prevent infections from occurring in the future.