The male and female cats suffer an inflammation of the bladder which can have serious consequences. The condition seems to be more commonly seen over recent years but as yet veterinarians are not able to provide a precise explanation.
In the male cat changes in the chemical composition of the urine can occur which lead to the formation of aggregations of crystals which build up within the bladder until they choke the urethral opening in the penis. The first sign of the obstruction to the flow of urine may not be noticed by the owner.
The cat takes longer and longer to pass its urine but it is not until almost complete obstruction occurs that the owner is alerted. The cat goes to its sand box or litter tray frequently, crouches for a long time, strains and often cries in pain. Sometimes the owner concludes that the cat is constipated and administers laxatives and valuable time is wasted before relieving a serious situation.
Examination at the surgery reveals a very depressed cat which resents handling of its abdomen, but with gentle palpation a very tightly distended bladder the size of an orange is obvious. The penis is often protruded and has dried blood at its end. Sometimes the cat is deeply shocked and almost comatose if the condition has been present for some time.
Treatment at this stage is aimed at relieving the pressure within the distended bladder before the organ ruptures.
The cat is given a light anesthetic and a pliable plastic tube is passed into the penile portion of the urethra. A warm slightly acidic solution is passed through the tube and this is continued until it is possible to gently push the tube into the bladder.
If the cat has been obstructed for some time the urine within the bladder contains blood. The more long-standing the condition the more blood is found in the bladder.
Fluids are given intravenously to correct the chemical imbalances that have occurred as a result of the obstruction and antibiotics are administered to combat bacterial infection in the damaged bladder or kidneys.
The precise reason why some cats develop these obstructive substances within their bladders is not understood.
Their chemical composition is complex and varied but all contain crystals of magnesium and ammonium phosphates. They are often bonded together in sand-like particles but can be in a soft cheese-like farm.
It is thought that cats are more susceptible to the formation of these obstructions if they are inactive and empty their bladders infrequently. Also these cats seem to drink less water than the average and therefore their urine is more concentrated.
The role of diet in the formation of these obstructions is not clear. Certainly some substances in the modern cats diet are very high in magnesium.
Fish foods, beef and dry cat foods contain high percentages of magnesium. Milk, rabbit and tinned cat foods not containing fish, are relatively low in magnesium. It is tempting to conclude that diets high in magnesium are the sole cause of the problem but groups of cats kept on these diets do not seem to suffer more urinary obstructions than control groups.
It seems that a combination of factors are involved and some research workers have suggested that viral infection may be necessary to trigger the reaction leading to the formation of crystals within the bladder of a susceptible cat.
Prevention of a recurrence of the condition once the animal is over the acute phase is not always successful.
Chemicals are given each day to acidify the urine, and an attempt is made to get the cat to drink more water. Cats get most of their fluids from their food, the average cat only drinking about one ounce to 30ml of water daily.
If the cat is fed dry food, it must drink about 7 times this amount. The most successful way to increase the water intake is to mix water into the food. Cats that have suffered a urinary obstruction should not be fed on high magnesium diets and certainly never dry food.
Female cats can develop similar chemical changes, in their urine but as the outlet of the bladder is much wider in the female, obstructions do not occur. Sometimes large masses or calculi are formed within the female bladder and these have to be removed surgically.
The most common urinary disorder in females is cystitis or inflammation of the bladder wall.
This causes the cat considerable pain and she attempts to relieve the discomfort by passing urine frequently. Small amounts only are passed which are frequently blood stained and the cat tends to lick the vaginal opening after each urination.
Antibiotics are administered to control infection in the bladder and attempts should be made to increase the water intake by adding water to the food as well as avoiding the feeding of dry food.