To start, and just to be absolutely clear: To "spay" your "bitch" means to "sterilize your female dog" through a surgical procedure whereby your veterinarian removes her uterus and both ovaries, making her unable to "come into season" or to ever have puppies.
The general wisdom is that you should spay your female dog if you're really not certain about her having puppies - and to spay early, in fact, before the first oestrus (heat) cycle, as this reduces the risk of mammary cancer to almost zero percent. It is thought that approximately one in four bitches who are not spayed and who experience more than one oestrus cycle will developmammary tumors - not good odds, so we do urge you to take this issue seriously. In fact, the only time it is recommended to wait even for one heat cycle before spaying is if your dog suffers from puppy vaginitis (vaginal infection) or if she is going to be a competitive agility dog. Furthermore, by being spayed there are the advantages that your pet will not be exposed to the risk of the serious condition called "pyometra" (uterine infection), nor the development of cysts in the uterus or ovaries. Oh, and of course there's also the benefit that she will no longer be attracting every male in sight, and won't be leaving blood stains around the house. (Phew!)
Downside? Yes. Urinary incontinence can develop in spayed dogs. However, the statistical possibility of her developing mammary cancer is far higher if you do not spay her than it is of her developing urinary incontinence if you do. The procedure requires a general anaesthetic which, of course, carries some risk, but if your veterinarian does a thorough pre-anaesthetic check, and if the correct modern anesthetic techniques are practiced, this risk truly is minimal.
There is also the "fat factor" - spayed dogs certainly do tend to pile on the pounds. At the end of the day, though, if you take responsibility for a healthy, restricted diet, there is no reason why your now spayed pooch should not remain a lean, mean, healthy machine.
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