Cystitis is the medical term for a bladder infection. Bladder infections are more common in female dogs and cats than in male dogs and cats due to the shorter, larger urethra. Clinical signs of dogs with cystitis include having accidents in the house, frequent squatting and attempting to urinate when outside, excessive licking at the vulva, and occasionally increased thirst and urination. Cats with cystitis also have accidents outside their litter pan, will have frequent visits to the litter pan, will also lick excessively at their vulva and on occasion, will vomit, presumably from lower abdominal pain. Causes of bladder infections can vary, but the two most common are incomplete bladder emptying and bladder crystals or stones that irritate the lining of the bladder. Because a dog or cat can flush the bladder to help reduce infections by frequent urination, many of these clinical signs don’t appear until the infection has been present for several days or even weeks.
Cystitis is diagnosed from testing the urine by what is called a urinalysis. The urine is screened for blood, protein, pH, ketones, glucose, bilirubin, and urobilinogen, and is examined under the microscope for red and white blood cells, bacteria, crystals, epithelial cells, casts, and any abnormality that may be present.
Once diagnosed, bladder infections are treated with antibiotics given for a minimum of 2 weeks, after which a follow-up sample of urine should be checked to confirm that the problems are gone. If there are underlying problems that lead to bladder infections, such as bladder stones or bladder tumors, it may be necessary to take x-rays to evaluate the bladder for these problems.