Urinary incontinence in spayed bitches. Part 1: significance, clinical features and aetiopathology

Risk factors and characteristics of incontinence affecting spayed bitches

source: S. Arnold European
Journal of Companion Animal Practice, vol IX(2) October 1999
starts p125, 5 pages long

Spayed bitches have had their ovaries, and normally their uterus removed. The risk of mammary tumours drops to some 0.5%, though side effects can include poorer coat quality, weight gain, and incontinence. Bitches that become incontinent usually do so within three years of surgery, though they may not be affected until some years later. Incontinence tends to affect bitches when they are asleep.

Larger dogs are more vulnerable than smaller dogs. Boxers appear to be especially vulnerable, Dobermanns and Giant Schnauzers appear to have a higher than average risk, while one study reported no cases among Bernese Mountain Dogs and Spaniels. The removal of the uterus does not appear to increase risk significantly. An English study reported incontinence in three of 14 bitches spayed before puberty, and only one case in 180 bitches spayed after puberty, or 21% compared with 0.5%. However, a US study reported 12 of 73 bitches spayed before puberty becoming incontinent, or 16%, compared with six of 23 spayed after puberty, or 26%. Oestrogen deficiency may contribute to the problem, since many bitches can be successfully treated using oestrogen therapy. Oestrogen deficiency is not the only cause, however; around 25% of affected bitches do not respond to oestrogen, and intact bitches treated with gestagens, which lower their oestrogen levels, are unaffected. The problem appears to be linked to urethral sphincter incompetence, and there seems to be a link between urethral closure and ovarian function.
DO,IN