Absolutely, spaying or neutering your pet when it reaches 6 months of age will prevent a number of health problems in the future. For example, if you spay your dog or cat before its first heat cycle, you dramatically reduce the probability of malignant mammary gland tumor development down the line. If you do it prior to the first heat, the probability is less than 1%. That probability increases with each heat cycle.
In addition, during a heat cycle, the uterus can develop cysts on the uterine wall, and fluid produced during the cycle begins to build up within the uterus. Over time, that fluid can become a breeding ground for bacteria, leading to an infectious condition called a pyometra, which is a surgical emergency. As for males, by neutering early, not only do you avoid the development of unwanted sexual characteristics like urine spraying/marking, aggression, wanderlust, and “humping” behaviors, but you help protect the prostate gland from enlargement and infection.
In older non-neutered males, the prostate, which wraps around the urethra, will enlarge, putting pressure on the urethra and causing urine leaking and straining to urinate. The enlarged prostate is also much more likely to develop prostate infections, which can be very painful. Finally, neutering can prevent the development of testicular tumors.