FUS is an inflammation or obstruction of the urinary tract (the bladder and urethra) caused by crystals that form in the bladder. The mineral crystals form as a result of high levels of magnesium, and a high level of alkalinity in the urine, leading to a blockage of the urethra. These crystals, or struvite stones, are the result, not the cause, of the problem. Cats that are less active due to reduced physical activity and cats that eat foods high in magnesium are most susceptible to FUS.
The main cause of FUS seems to be the diet, but there are other factors that could contribute to the formation of these mineral crystals in the bladder.
A high level of alkalinity in the urine is primarily caused by the type of food the cat eats. There are some warning signs to look for when you suspect your cat has FUS: bloody urine, the cat urinates in locations other than the litter pan, the cat remains in a squatting position for extended periods of time, the cat strains while urinating, or a distended bladder that is painful to the touch. Other signs that might indicate FUS are vomiting or fatigue.
FUS is severe enough to be fatal if left untreated. Poisonous wastes and urine build up in the system because the kidney cannot eliminate them. It can be fatal in as little as 12 hours. If you suspect that your pet has FUS, take him to the vet as quickly as possible. Prompt attention could save your cat needless suffering and save you expensive vet bills.
Maintenance at home includes:
Many low ash cat foods are available and can help with this problem. Ash is the mineral content that is left after the cat food has been burned. The minerals present in ash are magnesium, potassium, calcium and phosphorous. A food low in ash is usually helpful, but a low ash cat food COULD contain levels of magnesium that would lead to FUS. Make sure you read to label before purchasing a low ash cat food.