Pilonidal sinus—also called a pilonidal cyst—is a skin infection that occurs in or around the crease of your buttocks. This condition happens when hair, skin cells, and dirt clog a hair follicle, ...

Explore causes, treatments, and prevention strategies for dog cysts. Reviewed by Jennifer Coates Tumors, growths, and cysts are common in dogs, particularly in older ones, and should be promptly ...