Both male and female cats spray, but it is most common in unneutered male cats. (cathealth.com)
(Over 80 percent of unneutered male dogs develop some form of prostate disease.) (animalbehaviorcollege.com)
A related disorder, stud tail, occurs around the base of the cat's tail and gets its name because it's most common in unneutered male cats. (everydayhealth.com)