Introduction

Urinary tract infections (UTIs) in cats are not common. When they do occur, they are painful and, if left untreated, can lead to severe damage to the kidneys and other parts of the urinary tract. They can cause systemic illness. Once a cat has been diagnosed with a urinary tract infection, it normally will be placed on an empirical course of antibiotic therapy while the precise cause of the infection is investigated.

Treating Urinary Tract Infections in Cats

The goal of treating feline UTIs is of course to eliminate the infection. In cats, an equally important therapeutic goal is to identify and address any predisposing medical or anatomical conditions. Cats diagnosed with what is thought to be an uncomplicated bacterial UTI normally are treated empirically with broad-spectrum antibiotics, initially without culturing the urine. The attending veterinarian will select one or a combination of several antibiotics depending upon the results of preliminary urine tests, including whether the infection is gram-positive or gram-negative. Obviously, these should be antibiotics with good penetration and distribution into the urine. It is extremely important that the owner give the antibiotics exactly as instructed by their veterinarian, and for the complete duration of the treatment course.

If the infection persists, or if it resolves but later returns after a complete course of antibiotic therapy, the urine should be cultured to identify the exact cause of infection so that the most effective medication can be prescribed. Underlying medical and/or anatomic conditions that predispose cats to develop UTIS must be identified and addressed to prevent persistent or recurrent infections. The results of initial blood and urine tests, combined with urine culture, appropriate antibiotic selection and administration, abdominal radiographs and ultrasound, will help the attending veterinarian identify the cause of the infection.

The prognosis for cats with uncomplicated bacterial urinary tract infections is excellent. Primary fungal infections, on the other hand, are extremely difficult to treat. The prognosis for cats whose UTI is caused by some predisposing condition is variable, depending upon correct identification of the causative infectious organism and identification and resolution of the predisposing disorder or disease.

Urinary tract infections in cats, if not successfully treated, are likely to persist or recur and progress into other, much more serious problems. In addition to the pain and discomfort caused by these infections, the bacterial or other contributing organisms can proliferate and infect areas in addition to the lower urinary tract, particularly the kidneys and ureters. Even more dangerous is the potential for systemic infection, which is called “sepsis” and is a life-threatening medical emergency. Chronic antibiotic use can contribute to allergic drug reactions and bacterial antibiotic resistance, which increasingly is a problem in both human and veterinary medicine. Certain antibiotics can be nephrotoxic with prolonged use as well, causing kidney damage.