There is a wide variety of conditions that can cause pus in cats. Pus is a liquid that is produced by the body in an infected area, including a wound created by a bite or puncture. Puncture wounds often lead to pus secretions from an infected site in cats, while splinters and other foreign objects can lead to infections with pus as well. Other common causes for pus in cats include tooth problems, acne, mosquito bites, and serious conditions such as thrush and urinary tract infections. Pus on the skin of a cat can sometimes be treated at home, but if the infection progresses it might need to be drained or otherwise surgically treated at a veterinarian’s office.
Bite wounds are a common cause for pus in cats. If the cat gets into fights with another cat or animal, it can be infected by bacteria found in the saliva the feline was bitten by. The infection can be prevented if the wounded is found and treated early, but otherwise can lead to an abscess in the infected area. In addition to a fight, a cat can step on something and get a splinter, which must be removed before the wound gets infected and possibly spreads to other parts of the cat’s body.
Tooth problems such as decay can also lead to pus in cats, which is often accompanied by a bad smell. By touching the cat’s gums, a pulsating feeling indicates that tooth decay might be present. A cat will usually go to touch its mouth if there is pain near a tooth, while symptoms for other problems causing pus can include red and swollen tissue, pain, fever, and a yellow to brown liquid at the infection site. Cats with an infection also lose their appetite and appear to lack energy.
Additional causes of pus can be more severe if it is produced internally. If pus is found in a cat’s urine, for example, this can indicate a kidney infection or stones, inflammation in the pelvic area, an immune problem, or a tumor. Infections and abnormalities in the urinary bladder and urethra are also causes of pus in cats, and a veterinarian typically needs to test, diagnose, and treat the cat before the infection spreads and can be potentially fatal. For any cause of pus in cats, medical help is necessary if the cat will not eat, is in extreme pain, or if an abscess with puss exceeds the size of a golf ball, or does not shrink in a couple of days.