The primary reason to have your pet spayed or neutered is to control the domestic animal population. A single unaltered animal can produce multiple litters of offspring during their lifetime, with each female offspring able to reproduce in a short time. This can result in hundreds or even thousands of unwanted strays that are subject, to injury, illness, and starvation.
There are other reasons why it is best to spay or neuter your pet. These include:
When a female dog or cat is in estrus, or "heat", their hormones will cause to them to attempt to escape your home at the first opportunity. Male dogs and cats will fight for the attention of a female, which can result in serious injuries or infections. Sometimes, animals will run directly into traffic while they affected by this condition.
If you have an intact female, you run the risk of pregnancy or communicable diseases if she escapes to mate. A male dog or cat may also be subject to disease from mating with a female stray in estrus, in addition to injury or death from fighting or being hit by cars.
Animals that haven't been spayed or neutered can be troublesome even if you are able to keep them indoors. An intact male dog or cat will often be much more aggressive, because they still produce testosterone, which causes them to be less submissive and in some cases challenge their owners for dominance. Intact males will also be more territorial, and use urine to mark their territory. Male dogs will urinate in diverse places, while male cats will spray urine mixed with a pungent secretion on furniture and other places where it is difficult to remove.
Intact female dogs will go into estrus (heat) periodically, often two or three times per year, depending on the breed. They will often exhibit behavior such as excitability or whining, and a bloody discharge may appear. This may last for two or three weeks, during which time you may experience a few intact males who will loiter outside your home, drawn by the female's scent, fighting and being obnoxious.
Female cats will go into estrus and cry out continuously, rubbing their hindquarters against anything stationary, and may spray a secretion similar to that of male cats.Worse, if female cats are not spayed or mated, they can go into an almost continuous state of estrus, with every nearby intact male cat spraying and fighting outside your home.
Do yourself a favor. Unless you intend to breed your pet, go to a veterinarian and have it spayed or neutered. You and your pet will both be happier.