Some breeds are more vulnerable to particular types of tumour, such as Bernese Mountain Dogs, more vulnerable to sarcomas, and Dachshunds, more vulnerable to mammary gland cancers, though their overall rates are not very different. Further research on breeds and tumours will be published in due course. DO,CN Top of page Urinary incontinence in spayed bitches. 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. Oestrogen deficiency may contribute to the problem, since many bitches can be successfully treated using oestrogen therapy. 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 Top of page Urinary incontinence in spayed bitches.