Infected cat wounds – everything you need to know

Has your cat been fighting again?

Cats are territorial animals, and much like their wild cat ancestors, they prefer their own company. When they meet other cats, things can get tense. It’s not uncommon for disputes to boil over, even with cats who have lived together for a while. 

Cats use many tactics to avoid coming to physical blows, such as scent marking their territory and time-sharing resources. But sometimes fights will erupt, and cats can inflict some nasty injuries upon each other.

Two common medical outcomes of a cat fight are the development of abscesses and cellulitis. Here’s what you need to know about these painful conditions.

What is a cat bite abscess?

When a cat sinks their tiny razor-sharp teeth into another cat, they make a puncture wound in the skin that introduces bacteria from their mouth. Depending on how deep the bite was, this might push bacteria into the muscles or deeper tissues of the body. The skin rapidly heals over, but bacteria is left behind and this will set up an infection. 

The cat’s body will do all it can to get rid of the invading bacteria

There will be inflammation, which means white blood cells are sent to the area to destroy the bacteria. The diseased tissue and inflammatory cells liquefy into pus, which gets trapped in a pocket under the skin. 

This pocket of pus forms an abscess – a fairly unattractive, painfully infected wound that can swell up, cause a fever and burst, with very messy results! 

Common places for cat bite abscesses to appear are the cheeks, legs, and the base of the tail. These areas are usually the target zones for bites during a cat fight.

Your cat is likely to feel very tender, especially around the area where the bite was received. In the early stages, it may be difficult to spot where exactly they were bitten, as the skin injury often heals up so quickly. However, after a day or so, swelling may start to become noticeable. The skin over the abscess may be very tender and fragile. 

The fluid pocket may eventually rupture, releasing pus that will usually have quite a strong, foul odour.  

If you suspect your cat has been injured in a cat fight, it’s best to contact your vet

Sometimes, the area will heal on its own, once the pus has leaked away. However, these injuries are painful, so it’s always best to take your cat to the vet to be properly checked over and to get some pain relief administered.

If the abscess has already ruptured, you will probably smell it! After an abscess has ruptured, the skin around the wound can look quite raw. Your cat may spend some time licking the area, making the wound more visible, and potentially introducing more infection from their mouth that will hamper healing.

If the abscess has not yet ruptured, your cat may develop a high temperature and become quite poorly. Fevers are more likely to occur when the pus is not able to drain away. When your cat has a fever, they will often seem quieter than usual, be less energetic and may also lose their appetite. It can be tricky to find the exact entry wound for an abscess that hasn’t burst, and sometimes your vet will need to shave away some of the fur to see it.

Your vet may need to lance the abscess

This is often vital to get it to drain properly, if it hasn’t already ruptured on its own. They will use a sharp blade to pierce the skin over the top of the abscess, and then they will flush the area thoroughly to get rid of any pus and infected debris. Sometimes, cats will need to be placed under anaesthetic for this procedure, especially if the abscess is very large and painful, or when there is dead infected tissue that needs to be surgically removed. When an abscess is especially large or deep, the vet may opt to stitch a plastic rubber tube in the wound to act as a drain. This is usually left in place for a few days to ensure the pus keeps leaking out of the wound and doesn’t get trapped inside the body again. 

If the wound has drained nicely, and your cat does not have a fever, it may be possible to treat the abscess at home. You’ll need to care for your cat by giving them the pain relief prescribed by your vet, and by gently cleaning the area with cotton wool and salty water, two or three times a day. It’s important to wear disposable gloves and to wash your hands thoroughly before and after treating your cat.

However, in some cases your vet may feel a course of antibiotics is also necessary

This is usually the case when the wound doesn’t have great drainage, when it was a very deep wound, and if your cat is feeling persistently unwell with a high temperature. If your cat is prescribed antibiotics, it’s really important to give them as instructed and to finish the whole course, to reduce the chance of antimicrobial resistance developing.

Another aspect of cat fights to be aware of is their role in spreading contagious viral infections 

Common issues are viruses like feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV). Most outdoor cats are routinely vaccinated for FeLV in the UK, but there is no effective vaccine available for FIV. It can take a while for your cat to test positive for these viruses after exposure through a bite wound. Depending on your cat’s previous medical history, your vet may want to run a test to check for these infections. A positive test can impact your cat’s ability to heal. It may be best to keep positive cats indoors to protect them from further injuries and infections, as well as to protect other cats from contracting these viruses.

Fortunately, recovery from an abscess is usually swift

It usually takes about a week for an abscess to heal. If your cat has a big abscess, or if they are old, or already ill, it can take longer. It’s important to check with your vet how long they expect healing to take. If the abscess is not healing as anticipated, make sure you contact your vet again for advice.

What is cellulitis?

Cellulitis is an infection that has spread through the tissues under the skin. This type of infection differs from an abscess, where a more localised pocket of pus forms. 

With cellulitis, the infection is more widespread throughout the area

Cellulitis generally happens when a bacterial infection enters the skin from a cut, open wound, or through a bite wound. This means cellulitis is often a secondary medical issue; the first being the wound that breaks the skin. The initial wound does not have to be large, and often the break in the skin may go unnoticed until the cellulitis sets in.

Areas where the skin is looser will be more prone to forming an abscess following a cat bite, but if the location of the bite wound is in an area of tighter skin, it is more likely to lead to cellulitis. 

The most common bacteria causing cellulitis are Staphylococcus and Streptococcus. These bacteria are found commonly in the soil, water, and air, on humans and on other animals. An open wound is a perfect environment for these bacteria to thrive. 

Cellulitis is painful and causes a lot of inflammation

Cats with cellulitis may be very sensitive when the affected area is touched. The skin may feel hot and can look red and swollen. As cellulitis is painful, cats will often lick at the area, which can make the infection worse. If there is discharge from the wound, this may have an unpleasant smell. Sometimes the infection causes a fever, and if your cat has a high temperature, they may become lethargic, quieter than usual, and go off their food. 

If left untreated, cellulitis can become serious and can lead to tissue death (necrosis). In severe cases, the infection can be life-threatening. Do not attempt to treat the infection at home; a vet visit is essential. 

To treat cellulitis, your vet is likely to prescribe pain and antibiotic medication

Unlike an abscess, where the infection can often be drained away, the only way to treat the infection in a case of cellulitis is through antibiotic medication prescribed by your vet. 

Wound care is important, and you may be asked by your vet to clean the area with some salty water and cotton wool at home. As with treating an abscess, make sure you wear disposable gloves and wash your hands well before and after. 

In severe cases, the vet may want to perform a surgical procedure under a general anaesthetic to ‘debride’ the wound. This involves trimming away any dead tissues and flushing the wound thoroughly. After this type of surgery, the vet may place a piece of sterile tubing to act as a drain, which can be removed after a few days.

For wounds that are not healing as expected, your vet may take a swab of the area in order to grow the bacteria that have contaminated the wound in a specialist lab. This allows the type of bacterial infection to be identified, and a targeted antibiotic can then be selected. As always with any antibiotic, it’s important to administer the medication as directed, and to always complete the course.