As discussed during our conversation, it is possible that your cat has developed an abscess or infection.

Why do cats get abscesses?

Because of their tendency to solitary and territorial behaviour cats can frequently get into scraps with each other. This is particularly common with outdoor cats but can also happen with multi cat groups indoors.

If you move to a new area or a new cat moves into your area there can be sudden territorial disputes between cats and you may find your cat getting involved with fighting even if it has not seemed to be a problem in the past.

Cats are particularly prone to abscesses because they injure each other with their teeth or claws. Both teeth and claws carry bacteria that can easily cause infection. 

An abscess is a painful collection of pus in one area usually associated with bacterial infection

Because the teeth and claws are sharp they tend to make quite deep puncture wounds which then seal quite quickly, trapping the infectious bacteria deep within the tissues. Unable to drain or be cleaned by the cat, the infection may then build to form a hot painful swelling that may eventually burst releasing the pus.

What you may see

If your cat has just been in a fight it will not yet have had time for infection to develop but you may see wet areas on the coat or missing fur. It may just seem vaguely uncomfortable or lame just from the pain of the bite.

After a day the cat may improve as the soreness subsides only then to deteriorate again after a couple of days as the infection begins to build up under the skin.

Once infection (abscessation) is developing

Your cat may simply appear quiet, reluctant to go out, and less willing to move and play.

Frequently, if the cat is bitten on the limbs,a cat bite injury will appear as a lameness and this can develop into a very swollen foot or leg.

(N.B. infection or abscess is one of the few causes of lameness that will get worse over a period of days)

Injuries around the face are common so a swelling on the face may be an abscess particularly if it appears quite suddenly.

If a cat is trying to get away they are often bitten near the base of the tail. If this happens your cat may appear to be unable to raise its tail normally and may be very painful if you try to examine the tail.

The first thing you may see if your cat has not shown other signs is excessive licking and the blood stained and often very smelly pus in the coat when the abscess bursts. 

Abscesses and infections from cat bites and scratches are not usually dangerous but they can be very painful and cats may have a high temperature and be quite unwell. They may be more lethargic and have reduced appetite because of both the fever and the pain. The signs associated with a developing abscess or infection usually appear over a period of 1-5 days.

Treatment

Cat bite abscesses will be treated differently depending on the stage of development and the problems they are causing. They may require antibiotics and pain relief and in some cases they may require lancing to release trapped infection and this may involve sedation and admission to the clinic. Your vet will advise you on the best course after an examination.

There may also be some home care such as bathing or flushing the infected area if that is practical in your particular case.  

Cats that are most prone to fighting and therefore infections and abscesses are those with access to the outdoors. These cats are also at risk of much more serious trauma such as dog attacks or road accidents. Whilst injuries caused by other cats are very unlikely to pose an emergency (with the exception to injuries to the eyes) the signs that you see could be evidence of a more serious incident.

If your cat is suddenly unable to bear weight on a leg at all, or appears to be weak or has any breathing difficulties you should seek veterinary attention as an emergency.