CVMA | Documents | Neutering of Male Dogs

Neutering of Male Dogs

October 23, 2012

Neutering (called castration when performed on male dogs) is recommended for all dogs, with the exception of those that are to be used for breeding purposes or in those cases where a veterinarian might advise against it. 

Neutering is beneficial to dogs for a variety of reasons. Dogs that have been neutered show a reduced sexual interest in females after approximately six to 12 months. Episodes of aggression towards other male dogs should also cease. In 60 per cent of cases, inter-male aggression is reduced, as is mounting of people. Roaming (i.e. running away from home) is also reduced in about 90 per cent of cases. Territorial urine marking in the house, if it occurs, is reduced in half the cases.

The health effects of castration are quite significant. There is a reduced incidence of perianal adenomas (i.e. tumours of the rectal area) and testicular tumours are completely eliminated. There is also a reduced incidence of perineal hernias.

With neutering, the incidence of many prostatic diseases, such a prostatic hyperplasia and prostatitis, are greatly reduced, as is the incidence of prostatic cancer. Without neutering, the incidence of these problems is quite high.

It is important to realize that castration does not change a dog's personality nor does it affect a working dog's ability to perform. Castration may contribute slightly to obesity (i.e. in about 10 per cent of cases) or reduced physical activity. Castration does not have any affect on the relationship between pet owners and their pets.