Lower urinary tract disease encompasses any disease involving the urinary bladder or urethra. Last week we discussed lower urinary tract disease (LUTD) in general and discussed bladder infections and bladder stones in both dogs and cats. Today we will focus in on feline lower urinary tract disease (FLUTD).

As we discussed last week, cats can form bladder stones and get bacterial infections (particularly diabetic cats), but for over half of the cats that present with LUTD, veterinarians can’t identify the cause of the inflammation. We call that Feline Idiopathic Cystitis (FIC).

FLUTD affects both male and female cats, but since the urethra is relatively narrow in male cats it can actually be life threatening for a male cat that is affected. The urethra can become obstructed (or “blocked”) with mucus, crystals, inflammatory cells or even stones. Any male cat who has repeated non-productive attempts to urinate needs veterinary care immediately. If noticed in the evening, this is not a situation that can wait until the next day when your regular veterinary clinic is open.

A pet owner won’t be able to identify the cause of LUTD signs based on the cat’s behavior. Tests (particularly a urinalysis) are required to better define why a cat is straining. Furthermore, a physical examination by the veterinarian will determine if the pet has obstructed which puts the kidneys at great risk. When I meet a cat with LUTD signs, I do the urinalysis in house rather than send it to an outside laboratory. As a urine sample sits, solutes may come out of solution and skew the results. I try to read a urine sample when it is still warm from the pet! If the cat has obstructed, it will necessitate mild sedation or anesthesia and the passage of a urinary catheter to reestablish urine flow. Additionally, IV fluids are instituted to lessen the damage to the kidneys and allow the body to normalize the electrolyte status. Your vet may take a lateral abdominal x-ray to look for bladder stones. It is clearly much better to address straining and signs of LUTD before a pet obstructs. If caught early, the immediate treatment may be as simple as an anti-inflammatory, pain medications and anti-spasmotics. If the cat has an infection, antibiotics will be used. As we discussed last week, only 1 to 2% of cats under 10 years of age with signs of LUTD actually have an infectious cause. As cats age and lose their ability to form concentrated urine that percentage climbs.

Risk factors:

Obesity and an indoor lifestyle (which tends a cat toward obesity) have both been linked to increased risk of FLUTD. From a vet’s perspective, it’s much easier to unblock a thin cat than a tubby cat. Secondly, eating only dry food increases incidence of FLUTD. In general, wet food has about 5 times the amount of water in it than dry food contains. Dilute urine greatly decreases the risk of FLUTD. Finally, stress increases the risk of FLUTD. While stress is not an easily measured nor tangible factor, it plays a role.


Increasing water intake is paramount to success. Years ago I went to a lecture on FLUTD and the specialist giving the lecture said, “Think of water as the most important drug for this disease.” Dilute urine decreases the chance of crystals and stones forming and decreases the concentration of any sloughed cellular debris from the bladder. When I diagnose FLUTD, I ask the pet owners to monitor the urine specific gravity (concentration). If you are able to catch urine while your cat is in the box you can take the sample to your vet to check the concentration. Otherwise, your vet likely has some nonabsorbent litter pellets that you can put in an empty pan and collect the urine once your cat urinates. Ideally we will achieve a dilute urine concentration of less than 1.025 specific gravity for a cat with FLUTD. While canned food will yield more dilute urine than dry food, that may not be enough. Owners may need to make the canned food into a slurry/gruel consistency or get a pet water fountain to encourage a cat to drink more. Again, the goal of dilute urine is to keep any solutes (crystals) in solution. Furthermore, any inflammatory mediators will have less contact time with the bladder wall if the pet is forming a larger volume of urine as the pet will void the bladder more often.

Do your best to identify and alleviate anything that may be a stressor to your cat. If all else fails, you might even speak with your vet about medication that can help.

If your water has a very high mineral content (as a few regions do), you might consider distilled water for your pet.

Diets have come a long way! In general, FLUTD diets have fewer of the minerals that the body uses as “building blocks” for crystals and stones. Many of the FLUTD diets contain omega 3 fatty acids for their anti-inflammatory effects. Finally, some FLUTD diets incorporate added salt to encourage drinking. Before embracing one of these salty FLUTD diets your veterinarian should make sure you cat doesn’t have hypertension, heart disease, ascites or kidney disease.

Realistic expectations are important. Particularly if your cat is one of the many FIC patients, there may be periodic flare ups. During these episodes your vet will likely arm you with analgesic pain medications and an anti-inflammatory.

NOTE: Consult your Veterinarian first to make sure my recommendations fit your special health needs.