Are humans the only species that suffer baldness?
There are only a handful of animals that lose their hair naturally rather than to disease. Disorders like alopecia can affect animals, especially animals that live longer than their life expectancies. Guinea pigs can lose their hair when pregnant, just like some human females do when expecting.
Male chimps lose the hair on the top of their heads and could be more attractive to females because of this hair loss.
All stump-tailed macaques lose their hair with age, both males and females. The hair on their bodies is thin to begin with, and gradually falls out as the monkey gets older. Even some lions go bald, and scientists think that losing the mane could give an old lion the ultimate alpha status.
Image from www.flickr.com/photos/stuutje