Nowadays, most pets adopted from rescues are spayed or neutered before adoption. But 30 years ago this wasn’t the case. So, what’s changed? Well, the main driving factor behind encouraging sterilization is the accumulation of data regarding how it affects pets’ health and behavior, as well as increased efforts to control population numbers (remember Bob Barker’s daily plug to “spay or neuter your pets” on The Price is Right?).
So what are the health and behavior benefits of spaying or neutering your pet? Spaying a female dog before her first heat lowers the chances she will develop mammary tumors later in life to almost zero. Compare that to a 25% chance of developing tumors for an unspayed dog (50% of which will be malignant).
Spaying eliminates the chances of a female dog developing pyometra — a potentially life-threatening infection of the uterus that often occurs in middle-aged, unspayed females. Neutering a male dog virtually eliminates the incidence of prostate disease, and prevents certain types of tumors. Spaying and neutering before a pet is sexually mature can help to reduce or avoid many hormone-driven behaviors, such as aggression, roaming, fighting and urine marking.