What happens if I don’t spay or neuter my cat?
Expert Answer
An unspayed or unneutered cat enters heat irregularly; male cats spray urine to mark territory, and female cats may howl day and night and become unusually clingy. In addition, a cat in heat may run away from home, a female may mate and become pregnant outdoors, and a male may fight other cats and easily catch diseases.
Finally, unaltered cats are prone to reproductive-system diseases such as testicular cancer and prostatitis in males, and ovarian cysts, pyometra, and breast cancer in females.
I kept my first cat intact longer than I should and the heat behavior was chaos, yowling, spraying, the works, and the article's right about the disease risks too, pyometra and breast cancer in females, testicular issues in males. Once I neutered him the spraying stopped and he chilled out, and I stopped worrying about roaming and fights that spread disease. If you're not breeding responsibly, the health and behavior case for fixing is strong. The cancers alone convinced me, get them done, it's the kinder long-term call, talk it over with your vet.