Urinary tract disorder a threat to cats

Press, 23 February 1989, Page 10

Urinary tract disorder a threat to cats

BY DR JOHN INGLES Northlands Veterinary Clinic Feline urologic syndrome (F.U.S.) is a term used by veterinarians to cover a variety of conditions that affect the lower urinary tract of the cat; the most important of these is urethral blockage in the male cat which is potentially a lifethreatening situation. It is generally accepted that F.U.S. is a condition caused by a number of factors which possibly interact to lead to the disease. A number of surveys have shown that a cat with F.U.S. is more likely to be: • Less than three years of age. • Neutered. • Overweight. • Have reduced physical activity. • Drink less water than “average.” • Have dry cat food making up a major part of its diet. The problem occurs in

both males and females, but because the. urethra of males is narrower than that of females, it is more likely to become blocked, hence, the manifestations of the disease are seen much more often in males. The blockage is caused by minute crystals of a mineral called strurite which forms in the bladder of cats plugging up the urethra. The earliest sign of the problem is for a housetrained cat to start to urinate in inappropriate places, usually inside. (This should not be confused with spraying which is a behavioural problem; an urinating cat squats, a spraying cat stands with an erect quivering tail.) Usually, urination increases in freqency, but decreases in amount passed; the male licking at his penis. The urine is usually blood-tinged. As the condition progresses, the cat strains, arching its back, and the abdomen is

painful when touched. At this juncture the penis is usually blocked.

Owners often confuse this situation with constipation and administer a laxative, such as paraffin, which is of no value in this condition. Cats with an obstructed penis need immediate veterinary attention, for the condition can be lifethreatening. Your veterinarian will be able to see the obstruction and administer further appropriate therapy to correct the immediate problem. He will also advise you how to assist in the prevention of a recurrence of F.U.S. It was noted some time ago in Britain that there appeared to be an association between F.U.S. and the feeding of dry cat food, while in the United States it was felt a diet high in magnesium was involved. Recently, emphasis has shifted from dietary magnesium to urinary pH (the acidity of the urine).

Research in New Zealand at the Veterinary School has shown that there is a direct relationship between pH and the production of the crystals that cause the blockage problem. A urine pH less than 6.4 significantly reduces the formation of crystals.

Cats were fed a nutritionally balanced canned diet, or one of a number of commercially available dry foods. The canned diet and two of the dry food brands produced a urine pH of 6.4 or less. Cats fed on these diets also produced no crystals in their urine and no blockages occurred during the trial period. To prevent F.U.S., cats should be fed a diet which results in a urine pH of 6.4 or less, and be low in magnesium. Your vet can advise you on the best brands of dry food to help prevent the problem. If your cat is very fussy and only eats one brand of food, a dietary acidifier

can be added to maintain urinary pH of lessthan 6.4

Increasing the water consumption of cats also helps in this condition. It has a flushing effect by increasing the amount of urine produced, and hence passed. Increased water intake can be induced by the addition of 0.25 to Ig of salt per cat per day; cats appear to readily accept a high salt diet.

If dietary management and/or urine acidification fails to prevent the problem, a surgical procedure can be carried out to create a wider urethral opening. This allows easy passage of the crystals which cause the problem. As a footnote, it has been noted above that the incidence of urethral blockage is higher in castrated male cats. This should not be a reason for not castrating tom cats. The advantages far outweigh this one "supposed” disadvantage.