Urinary Tract Infection

Bacterial urinary tract infection is relatively common in the dog and less so in the cat. Infection may occur anywhere in the urinary tract. The location of the infection impacts the clinical signs observed, the prognosis, the diagnostic plan and the treatment of the infection. A simple urinary tract infection is the first episode of urinary tract infection (usually of the bladder) without predisposing causes such as bladder stones, prostate disease or conformational abnormalities. Complex urinary tract infections include chronic and recurrent infections of the bladder. They may involve the kidneys or the prostate or both. There may be other complicating factors such as bladder or kidney stones, cancer, conformational abnormalities or decreased resistance. In the non-neutered male dog, all urinary tract infections are considered complex since the prostate gland is almost always involved.

Diagnosis is based upon clinical signs and laboratory tests. Most animals with urinary tract infection have a history of abnormal urination. There may be pain associated with urination. The animal may urinate in unusual places and there may be blood present in the urine. If there is history of urinary tract infection in the past, the infection is considered to be complex. Definitive diagnosis relies upon urinalysis and urine culture. Bacteria, abnormal cells, blood components including red blood cells, crystals and casts of tubules in the kidneys all give clues as to the nature of the infection. If the infection is complex, blood tests, urine culture and x-rays are also necessary.

Treatment of urinary tract infections varies with the cause and location of the infection. An injection of antibiotics and oral antibiotics are the cornerstone of treatment. In non-neutered male dogs, neutering is strongly recommended. If the infection is complex, hospitalization and surgery are often necessary to correct the predisposing factors.