By the Pethocyn editorial team. Published October 28, 2026. Updated November 2, 2026. Sources are listed at the end of the article.

Pyoderma means a bacterial infection of the skin. In cats it is usually not a disease on its own: something else, such as an allergy, damages the skin first and bacteria take advantage. [1][4] This guide covers the triggers, what it looks like, how vets find it and why treatment has to be finished. For dogs, see pyoderma in dogs.

How common is it?

Cats get bacterial skin infections less often than dogs do, but a University of Minnesota dermatology handbook warns vets not to overlook them. One possible reason they are rarer: in lab tests, staphylococcal bacteria stuck far less well to cat skin cells than to dog or human skin cells. [1] One study suggests it may be seen more often than once thought: among 52 cats seen at a dermatology referral clinic, the authors put the prevalence of superficial pyoderma at 20%, higher than earlier reports. [2] That is a group of cats already referred for skin disease, so it does not tell you how common it is in cats in general.

The infection cats see most often in practice is a different kind: abscesses and cellulitis from fight wounds, when teeth or claws push bacteria deep under the skin. [1] See minor wound care for dogs and cats for bites and scratches.

What triggers it

Vets treat a skin infection as a secondary problem until proven otherwise. It only takes hold once the skin’s own defences have been weakened. [4] Common triggers include:

  • Allergies, including flea allergy. In the 52-cat study, allergies (hypersensitivities) were confirmed in 60% of cats and suspected in another 19%, and atopic dermatitis alone was confirmed in 48%. These were the most frequent underlying skin diseases. [2][4]
  • Parasites such as fleas or mites, which vets look for with skin scrapings. [4]
  • Chin acne, where a bacterial infection can set in on the chin and lips. [5]
  • Fight wounds, which carry mouth and claw bacteria deep into the skin. [1]

Anything that makes a cat lick, chew or scratch can break down the skin surface and open the door to infection. [4]

Related guides: itchy cat and overgrooming causes, mange in cats and cat chin acne.

What it looks like

In the 52-cat study, lesions were usually in several places, most often the face (62%), neck (37%), legs (33%) and belly (29%). Crusting (83%), hair loss (67%), sores or raw patches (54%) and redness (46%) were common, and itching was reported in 92% of cats. [2]

Deeper infections look different. A fight-wound abscess forms a swelling at the bite or scratch, most often on the face, legs, neck, shoulders or base of the tail. It may burst and leak thick pus, and the cat may be in pain, run a fever, stop eating or seem dull. [1] On the chin, infected acne can show as crusted bumps, swelling and larger lumps. [5]

How vets diagnose it

In the 52-cat study, the diagnosis was based on cytology: the vet presses a slide or tape on the skin and finds infection-fighting white cells with bacteria inside them under the microscope. [2] Because pyoderma usually has a trigger, the vet will also look for the underlying cause, for example with skin scrapings for mites. [4] For a draining wound, a smear of the discharge shows the bacteria involved, and the vet will ask about outdoor access and other cats in the home. [1]

Culture can matter for treatment. In a study of 41 cats in Italy with allergic skin disease and superficial pyoderma, staphylococcal bacteria were grown from 36 cats, and 15 of the 39 bacterial isolates (38.4%) were resistant to several antibiotic classes. The authors suggested that antibiotic sensitivity testing should be done routinely. [3] The Minnesota handbook advises a culture and sensitivity test when an infection keeps coming back, when new sores appear during treatment, when the infection is deep or when treatment is not working. [4]

How it is treated

  • Medicine your vet chooses. Ideally the antibiotic is chosen from culture and sensitivity results. Abscesses usually need to be opened, drained and flushed by a vet, and that alone is enough in some cats. [1]
  • Treat until it is truly gone. Treatment carries on until the signs have cleared, and the vet rechecks the cat before it stops. Too short a course is a common reason a skin infection does not clear. [1][4]
  • Yeast as well. Yeast (Malassezia) can overgrow alongside bacteria, which is why vets check skin samples for both, although in allergic cats both are less common than in dogs. [5][6]
  • Clipping. Your vet may clip the hair over affected skin and remove matted hair so treatment can reach it. Follow your vet’s grooming instructions carefully. [4][5]
  • Treat the trigger. Allergies, fleas or mites need their own treatment, or the infection is likely to come back. [4]

Why it comes back

Skin infections tend to recur when the underlying problem is not found and managed, and when treatment is stopped too early, so it is important to follow your vet’s instructions for any medicine to the end. [4] In the 52-cat study, the infection came back, or was thought to have come back, in 42% of cats. [2]

When a cat’s skin infection does not respond, vets also test for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV), and consider less common infections such as atypical mycobacteria or fungi. [1]

When to see your vet

  • Crusts, hair loss, redness or raw patches on the skin, especially with itching [2]
  • A swelling, abscess or draining wound, or a cat that seems in pain, feverish or off food [1]
  • A skin infection that comes back after treatment [2][4]
  • Skin sores that do not heal [1]

FAQ

Does my cat’s skin infection mean something else is wrong?
Often, yes. Vets treat pyoderma as a sign of an underlying problem, most often an allergy, until proven otherwise. [2][4]

Can I stop the antibiotics when the skin looks better?
Follow your vet’s instructions. Stopping too early is a common reason a skin infection does not clear or comes back, so let your vet recheck your cat first. [1][4]

The bottom line

Pyoderma in cats is a bacterial skin infection that is usually set off by something else, most often an allergy, but also parasites, chin acne or fight wounds. It tends to show up as crusts, hair loss and raw patches on the face, neck, legs or belly. Treatment is guided by your vet, ideally with a culture, and it goes on until the skin has healed. Finding and treating the trigger is what keeps it from coming back.

This article is for general information and is not a substitute for veterinary advice. If your cat has crusts, scabs or sores on the skin, please see your veterinarian.

Sources

  1. Torres SMF. 1.2 Feline Pyodermas. Small and Large Animal Dermatology Handbook, Vol. 1. University of Minnesota, 2025 (CC BY 4.0). https://open.lib.umn.edu/animaldermatology/chapter/feline-pyodermas/
  2. Yu HW, Vogelnest LJ. Feline superficial pyoderma: a retrospective study of 52 cases (2001-2011). Vet Dermatol. 2012;23(5):448-e86. PMID 22900753. https://pubmed.ncbi.nlm.nih.gov/22900753/
  3. Cavana P, Robino P, Stella MC, Bellato A, Crosaz O, Fiora SR, Nebbia P. Staphylococci isolated from cats in Italy with superficial pyoderma and allergic dermatitis: characterisation of isolates and their resistance to antimicrobials. Vet Dermatol. 2023;34(1):14-21. PMID 36221849. https://pubmed.ncbi.nlm.nih.gov/36221849/
  4. Torres SMF. 1.1 Canine Pyodermas. Small and Large Animal Dermatology Handbook, Vol. 1. University of Minnesota, 2025 (CC BY 4.0). https://open.lib.umn.edu/animaldermatology/chapter/canine-pyodermas/
  5. Torres SMF. Feline Acne. Small and Large Animal Dermatology Handbook, Vol. 2. University of Minnesota, 2025 (CC BY 4.0). https://open.lib.umn.edu/animaldermatology2/chapter/idiopathic-keratinization-disorders-feline-acne/
  6. Torres SMF. 2.2 Atopic Skin Syndrome: Feline. Small and Large Animal Dermatology Handbook, Vol. 1. University of Minnesota, 2025 (CC BY 4.0). https://open.lib.umn.edu/animaldermatology/chapter/atopic-skin-syndrome-feline/