An abscess is a localized pocket of pus usually due to a bacterial infection.An inflammatory response occurs, drawing huge amounts of white blood cells to the area and increasing regional blood flow. Pus forms, which is an accumulation of fluid, toxins, living and dead white blood cells, dead tissue and bacteria. As the bacteria kill the local cells and release toxins, the body responds by walling off the infection with a membrane (known as a 'pyogenic membrane') to prevent the infection from spreading. An inflammatory response occurs, drawing huge amounts of white blood cells to the area and increasing regional blood flow. Pus forms, which is an accumulation of fluid, toxins, living and dead white blood cells, dead tissue and bacteria. This area begins to grow, creating tension under the skin and further inflammation of the surrounding tissues.
As the abscess grows, the skin thins and weakens, eventually causing the abscess to rupture and the pus drains out.An abscess can form in any part of the body including under the skin, in the mouth (dental abscess) and in organs such as the liver and pancreas. This article relates to abscesses under the skin. The most common bacteria involved are staphylococci and streptococci.
Most abscesses are caused by a puncture wound which introduces and traps bacteria under the skin. The most common cause of a penetrating puncture leading to an abscess is from a cat bite, the oral cavity, including the teeth harbour a great number of bacteria which are injected into the skin during penetration.
Abscesses are seen more often in un-neutered male cats who are allowed to free roam as they are more territorial and therefore become involved in cat fights with neighbourhood cats. There is an increase in cats presenting with abscesses in spring as this is cat mating season.Other causes of abscesses include scratches and any penetrating object such as a thorn, splinter, grass seed or glass shard.
Abscesses are most frequently found around the head, neck, limbs and back and base of the tail. Not all cats will display symptoms.By the time you find the abscess, the skin may be sufficiently thin resulting in the abscess draining (this is known as 'pointing' and usually occurs when the abscess is close to the skin). If it has drained you may notice a thick, yellow and foul smelling discharge and a hole in the skin. If the abscess is located deeper under the skin, you may notice a an indentation (or a 'pit') when pressure is applied to the area of swelling.
Other common symptoms of an abscess include:
- Hot, swollen and painful area, possibly red and/or with missing fur.
- Loss of appetite.
- Lethargy - Sleeping more, reluctance to play or go outside.
- Lameness - Limping, reluctance to bear weight on affected limb.
- Listlessness - Can't seem to settle, loss of interest in activities he usually enjoys.
- Hunched over appearance.
An abscess isn't always visible, especially as the coat may hide the wound, so if your cat is acting off colour, appears to be in pain or displays any other symptoms above, it is advisable to seek veterinary advice.
Most abscesses can be diagnosed during a physical examination.Your veterinarian may take a sample of the discharge and culture it to determine the bacteria involved so that he can prescribe the best antibiotic for that particular bacteria.He may also recommend an FeLV (feline leukemia) and FIV (feline AIDS) blood test to rule out infection which is more common in outdoor entire cats who fight.
If the abscess hasn't drained, your veterinarian will clip the fur surrounding the abscess, lance it, drain the pus, remove any necrotic tissue flushed with antiseptic and/or antibiotic solution. This will either be done under heavy sedation or general anaesthetic. Your cat may need to stay in hospital for a day or two.
If the abscess has drained, your veterinarian will flush the wound with antiseptic and/or antibiotics.
If the abscess is large, a surgical drain may be required to assist with the removal of pus. A drain is a thin plastic tube which is inserted under the skin which will allow any pus to drain out. The drain will need to be flushed daily with antiseptics.
Your veterinarian will either administer a long acting antibiotic via injection or prescribe a course of oral antibiotics.
Warm compress applied several times a day may be beneficial to increase blood flow to the area which can hasten healing.
Follow your veterinarian's instructions carefully and administer any antibiotics as prescribed.
Your cat may be required to wear an Elizabethan collar, especially if he has a drain, this will prevent him from pulling it out.
Keep your cat indoors while he heals.
Watch for signs of infection including redness, oozing and swelling of the affected area.
Follow up with your veterinarian if required.
The best way to avoid abscesses in cats is to spay and neuter cats and prevent them from free roaming.
If your cat is involved in a cat fight, check him over for bites, scratches and wounds. Any wounds should be cleaned with antiseptic.
Keep a close eye on your cat over the next few days and if you notice any lumps, signs of pain, fever or general signs of illness, take him to a veterinarian. Despite what you may read on the Internet about treating an abscess at home, it is not recommended. An abscess can rupture into the bloodstream causing septicaemia (bacteria in the blood), which is often fatal.
While this won't prevent an abscess, keep your cat's vaccinations up to date, this is particularly important if your cat is free roaming.
It should be noted that people can develop abscesses too and it is not uncommon for veterinarians and vet nurses to develop them as a result of a scared or angry cat biting them. This is why it is extremely important for pet owners to be careful around sick, injured and agitated cats. Even the most placid cat can lash out if he is scared or in pain. If you are bitten or scratched by a cat, clean the wound immediately and as has been recommended above, keep a careful watch for signs of an abscess. If you do think you have one, seek medical attention immediately.