Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: An abscess is a pocket of pus under the skin. In cats, it’s usually caused by a bite from another cat: the sharp teeth push bacteria deep into the skin, the tiny wound seals over, and an infected swelling develops 2–5 days later. Cats with abscesses often have a fever, hide, and stop eating. Most need a vet to drain the abscess and prescribe antibiotics and pain relief. Don’t try to lance it yourself.
Signs
- A warm, painful swelling, often on the face, neck, legs, base of the tail, or back
- A soft lump that may burst and drain foul-smelling pus
- Limping, if on a leg
- Hair loss or matted fur over the area
- Fever, lethargy, hiding, and poor appetite
Why it happens
Cat fights are the most common cause, especially in outdoor, unneutered males. Abscesses can also follow other puncture wounds, and some form around the teeth (tooth root abscesses) or in other body sites.
When to see a vet
See your vet if you notice a painful swelling, a draining wound, or your cat is lethargic or not eating. Go urgently if your cat is very weak, breathing fast, or the swelling is on the chest or belly.
How vets treat abscesses
- Clipping and cleaning the area, often with sedation or anesthesia
- Lancing and flushing the abscess to remove pus and debris
- A drain in some cases, to allow fluid to keep draining for a few days
- Antibiotics when needed, often for about a week
- Pain relief
- FeLV and FIV testing, since these viruses spread through bites. Testing is often repeated after about 2 months.
Home care
- Keep the wound clean: gently wipe away drainage with a clean cloth dampened with warm water, or a dilute antiseptic if your vet recommends one.
- Warm compresses (if your vet advises) a few times a day to help drainage.
- Prevent licking with a cone if needed.
- Keep your cat indoors while it heals.
- Give all medications as prescribed, including finishing antibiotics.
- Check the site daily. It should look better each day.
What to avoid
- Squeezing or lancing it yourself: painful, risky, and it can push infection deeper.
- Hydrogen peroxide and alcohol, which damage healing tissue.
- Tea tree oil and essential oils, which are toxic to cats.
- Human pain relievers, which can be deadly to cats.
- Leftover antibiotics from another pet or person.
Prevention
- Neutering reduces roaming and fighting.
- Keeping cats indoors, or supervising outdoor time, prevents most bite wounds.
- Check outdoor cats for small scabs or tender spots after fights.
- Keep FeLV vaccination up to date for cats at risk.
Frequently asked questions
Will a cat abscess heal on its own?
Some burst and drain, but they often heal poorly or come back without treatment, and cats can become quite sick. A vet visit is the safest option.
How long does healing take?
Most abscesses heal within 1–2 weeks after treatment.
Is a burst abscess an emergency?
It isn’t usually an emergency if your cat is otherwise alert, but it needs a vet within a day for cleaning and treatment.
Sources
- Merck Veterinary Manual: Abscesses in cats
- Cornell Feline Health Center: Abscesses
- Little SE, et al. 2020 AAFP Feline Retrovirus Testing and Management Guidelines. J Feline Med Surg. 2020
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.