Problems of the bladder and urethra are all too common in pet cats. The lower urinary tract can be a site for inflammation, infection, stones, and obstructions. Together, these conditions are referred to as Feline Urological Syndrome (FUS) or Feline Lower Urinary Tract Disease (FLUTD). Signs that your cat may have lower urinary tract disease include difficulty urinating, blood in the urine, or urinating in inappropriate locations.
Cystitis means inflammation of the bladder. In dogs, its often due to an infection. Although infection does occur in cats, up to 60% of cases of feline cystitis are idiopathic, meaning the cause is unknown. Possible causes such as viruses and stress are being researched by major veterinary colleges.
Cats with cystitis urinate frequently, producing small amounts of blood-tinged urine. They may cry or appear to be in pain when urinating. Cats with any of these signs should see the veterinarian for a physical examination and urinalysis. The urinalysis can detect infection and other problems. If an infection is found, a urine culture will help identify the best antibiotic to treat it. In cases of chronic or recurrent cystitis, x-rays may be taken to get more information about the condition of the bladder.
Infections of the bladder are treated with antibiotics. Unfortunately, there is no specific treatment for idiopathic cystitis. Changing the diet so that the cat takes in more water and alters the urine pH is often helpful. Reducing stress is also a good idea. Medications are often given to ease discomfort and manage secondary infections. Most cats recover from idiopathic cystitis within a week or so, but recurrence is common.
Urinary stones (uroliths) can be a serious, even life-threatening, problem. Uroliths are composed of crystallized minerals, such as struvite, oxalate, urate, or cystine. They can be found anywhere in the urinary tract. In the bladder, they cause irritation, increasing the likelihood of cystitis or bacterial infections. In the urethra, they can cause an obstruction, making urination impossible. The resulting accumulation of urine in the bladder prevents the kidneys from continuing to cleanse the blood. Death can result within days. Male and female cats get uroliths with equal frequency, but urethral obstruction is more common in males due to their narrower urethras.
Cats suffering from uroliths have signs similar to cystitis. However, cats that are obstructed also strain to urinate, without producing urine. It may appear as though the cat is constipated. As time goes on, the cat may vomit, have a tender abdomen, and become comatose. A cat straining to urinate but producing no urine should be seen by your veterinarian immediately.
Diagnosis of urolithiasis is based on a physical exam and urinalysis. X-rays, ultrasound and blood tests may also be beneficial. For proper treatment, the veterinarian must identify the mineral content of the stones, either by finding crystals on the urinalysis or by collecting stones via urinary catheterization or surgery.
Some stones can be dissolved with special diets or flushed out of the bladder through a urinary catheter, but others require surgical removal. Urethral obstruction is an emergency condition requiring hospitalization. A surgery called a perineal urethrostomy is sometimes recommended for male cats that become obstructed repeatedly. This surgery widens the cats urethra, making blockage less likely.
Around 60% of uroliths in cats are composed of struvite. Cats with a history of struvite urolithiasis should be fed diets that are low in magnesium and that create urine with an acid pH. No other foods or treats should be given. The second most common type of urolith is calcium oxalate. Cats with a history of oxalate urolithiasis are fed diets with reduced levels of protein and oxalate. These diets create urine that is less acidic.
It is also a good idea to encourage cats to urinate regularly by providing adequate numbers of clean litter boxes.