The urethra is the tube leading from the bladder, through which urine flows out of the body. Any obstruction in this part of the urinary tract is a serious problem, because if the cat cannot pass urine, then the bladder is ultimately likely to rupture — a life-threatening condition. If you suspect that your cat is suffering from feline urological syndrome (PUS), then you must seek veterinary advice without delay.
Male cats are especially prone to urinary problems because they have a longer urethra than females. Check that your cat is urinating regularly and without pain or difficulty.
When dry cat foods first went on sale, it was thought that they could lead to FUS because they contained high levels of magnesium. This mineral is always found in the material causing the blockage. Manufacturers have since lowered the levels of magnesium.
Another feature of dry food is its very low water content, compared with canned foods. Studies have shown that cats eating dry food may not drink enough to maintain water intake.
Increased water passing through the kidneys and bladder makes the urine less concentrated so that salts are less likely to crystallise and create an obstruction in the urinary tract.
One of the most significant signs of FUS is a change in posture when the cat urinates. Instead of squatting down normally, the cat will rest with its back arched, and will appear to be uncomfortable or in pain. The cat will also lick repeatedly at its urethral opening, and any urine that is passed may be bloodstained. The cause of the problem is likely to be crystalline material, resembling gritty sand, which may have been washed out of the bladder. Urgent treatment is needed to remove the obstruction. Under anaesthetic, a flexible tube called a catheter has to be passed up through the urethral opening, in the direction of the bladder, to restore the urine flow. There may be an underlying infection, which will require antibiotic therapy, and if the cat is dehydrated fluids have to be given.
Unfortunately, in spite of the best veterinary care, FUS does have a tendency to recur, and under these circumstances, there is no long term solution. In some cases though, especially with male cats who have suffered from recurring FUS, surgery may be required to remove the narrow terminal part of the urethra.
It is still unclear why some cats seem more vulnerable to this problem than others, or what triggers the disorder. Dietary factors may be involved, and infection or irritation in the urinary tract may also be involved.
- FUS is sometimes known as urolithasis, which describes the presence of the grit that causes the blockage in the urinary tract.
- Adding several pinches of salt to a cat’s food can help to prevent recurrence of FUS: it increases thirst, encouraging the cat to drink more water.
- Cats that are kept indoors for long periods without a litter tray may be more susceptible to FUS because they cannot empty their bladders as often as normal.