Testicular tumors are especially prevalent in older dogs and are the second most common tumor in male dogs. Prostatic enlargement predisposes a dog to prostate and urinary-tract infections , which can make urinating difficult and painful. If an infection leads to an abscess, the abscess must be surgically drained. Common consequences of the surgery include system wide infection and shock or sometimes death. Because prostatic enlargement is caused by the male hormone testosterone, and testosterone is produced by the testicles.
Neutering acts as both a preventative measure and a cure .
Additionally, by eliminating the sexual drive that can cause a dog to bolt from the yard or house, neutering helps protect dogs from injuries associated with roaming , such as being hit by a car or infections transmitted by other animals. As with unneutered male dogs, an urge to mate increases the chances that a male cat will slip out of the house and suffer fight wounds or traffic injuries . The resulting wounds frequently develop into abscesses that must be surgically drained and treated with antibiotics. FIV and Feline Leukemia can cause fatal failure of the immune system in some cats. Spaying prevents irritability and aggressiveness that some dogs show while in heat.