Dog & cat health · Vet-reviewed guide

Cat Skin Infection (Pyoderma): Signs and Treatment

By the time a cat has a true skin infection, something else usually started it — an allergy, a wound, a parasite. Treating the infection without the cause just invites it back.

Quick answer: A cat skin infection usually means bacterial pyoderma — a Staphylococcus infection of the skin — and the important thing to know is that it is almost always secondary to another problem rather than a disease that appears on its own.

It shows up as red, inflamed skin, pus-filled bumps or pimples, crusts, and sometimes hair loss and a bad smell, and cats often make it worse by scratching or over-grooming. Because it is bacterial, it is different from ringworm (which is fungal) and from mites (which are parasites), and it responds to antibacterial treatment, not antifungal or antiparasitic. But here is the part: mild cases are usually treated with topical antibacterial shampoos or sprays rather than oral antibiotics, oral antibiotics are reserved for more severe or deep infections, and none of it lasts unless the underlying cause, often an allergy or parasites, is treated too. This guide covers the signs, why cause matters, and when to see a vet.

What a bacterial skin infection looks like

• Red, inflamed skin
• Pus-filled bumps, pimples, or pustules
• Crusting, scaling, and sometimes a bad odor
• Hair loss over the affected area
• Itching, with the cat scratching or over-grooming the spot²

Why it's almost always secondary

Healthy cat skin resists infection well, so when bacteria overgrow there is usually a reason the skin barrier broke down first.¹ The common triggers are allergies (flea, food, environmental), parasites, and over-grooming or wounds. This is the key to not having it come back: treat the infection and the underlying cause, or the pyoderma returns once treatment stops.

How it differs from ringworm and mites

This matters because the treatments do not overlap. Pyoderma is bacterial and needs antibacterial treatment; ringworm is fungal and needs antifungal treatment; mites are parasites and need an antiparasitic.² They can look similar, and a cat can have more than one at once, so a vet confirms the cause with a skin sample under the microscope rather than treating by appearance.

How it's treated

Treatment is matched to severity. Mild, surface infections are often handled with topical antibacterial shampoos, sprays, or wipes; more severe or deep infections may need a course of oral antibiotics, sometimes for several weeks.¹ Alongside that, the vet addresses the underlying cause. Antibiotics are used only when a bacterial infection is confirmed and warranted, not as a default for any skin problem, and the drug and dose must be chosen by a vet. If your cat needs a prescription, our licensed veterinarians can review your cat and issue one when appropriate. See how our vet prescription service works.

When to see a vet

See a vet if the area is spreading, oozing pus, very red or painful, or not improving, or if your cat is lethargic or off its food.² Do not use human antibiotic creams a cat will lick off, and do not give leftover antibiotics. For the wider map of cat skin issues, see our cat skin problems guide.