Clinton Cotten, DVM
What is cystitis? Cystitis means inflammation of the bladder, and the term is used as a general description for any urinary problems.
What causes cystitis?
The most common cause of cystitis in dogs is an infection caused by bacteria. Other common causes include bladder stones, tumors or polyps in the bladder, and abnormal anatomy. Some dogs will experience interstitial or "sterile cystitis", a condition that causes inflammation and associated clinical signs without any infection.
What are the signs of cystitis?
The most common sign is blood in the urine. Cystitis causes discomfort and pain. Dogs with cystitis may spend several minutes squatting and straining to produce only a small amount of urine. Bacterial infections, bladder stones, and excessive amounts of crystalline minerals in the urine all cause irritation to the bladder wall. In severe cases, the bladder stones may block the urethra and obstruct the flow of urine, which is a potentially life-threatening condition. Tumors or polyps are usually not irritating to the bladder, but they can cause bleeding and straining to urinate. A urethral diverticulum is an abnormal anatomical defect consisting of a small pouch in the wall of the bladder or urethra. Bacteria can easily get into this protective pouch and set up an infection that is extremely difficult to treat without surgical removal of the pouch.
How is cystitis diagnosed?
The first group of tests includes urinalysis, urine culture, and feeling bladder for stones. A urinalysis consists of several tests to detect abnormalities in the urine and urine sediment. These are generally adequate to confirm cystitis, but they may not tell us the exact cause. A urine culture and sensitivity determines if bacteria are present and what antibiotics are likely to be effective in killing them. This is often indicated because bacteria cause most cases of cystitis in the dog and usually eliminated easily with the appropriate antibiotic.
Bladder radiographs (x-rays) the bladder for common types of bladder stones.
Ultrasound visualizes stones as well as some tumors and polyps.
If a dog shows other signs of illness, such as increased production of urine, fever, poor appetite, or lethargy, cystitis may be a symptom of a more serious problem. Biochemistry profile and complete blood count (CBC) should be performed to assess metabolic and organ function. The most common diseases that can cause cystitis as a secondary problem are diabetes mellitus, Cushing's disease, and kidney disease.
How is cystitis treated?
Bacterial infections are generally treated with antibiotics. Some bladder stones can be dissolved with special diets or surgical removal. Benign bladder polyps can usually be surgically removed, but malignant bladder tumors are difficult to treat successfully. Pain relief or anti-inflammatory medications to relieve discomfort and improve urine outflow.