Dermoid sinus (DS) in dogs is an autosomal, recessively inherited, developmental anomaly that results in the dermoid sinus (tubular indentation) of the skin on the dorsal midline, usually along the center of the back of the dog.
Also called as also known as pilonidal sinus, Dermoid neural tubes can dig deep into underlying tissues and the affected animals are exposed to the risk of infections causing serious pain, and possibly developing an abscess and disease. The depth of this penetration into the tissue below varies between animals. The track may extend into the tissue just underneath the skin or may run deeper and attach to the dura mater (outer layer covering the spinal cord) or it is just a blind-ending sinus tract beneath the skin
Category IV sinuses pose a life-threatening risk as they connect with the spinal cord and pose a risk of infections to the delicate nervous tissues.
Dermoid sinus is a cyst-like condition that can be found at birth and can be typically found along the dog’s upper spine, tail, and neck. This is prevalent among Rhodesian ridgebacks or ridgeback-crosses and recently this has been found in other breeds as well. These tubes are intended to drain out hair, tissues, and dead cells. This is a developmental glitch that does not form during embryonic development correctly.
The affected region typically will not cause any pain to the pet unless they become inflamed or infected. Protruding hair, often in a swirl hair pattern at the site or any slight discharge in the area can be used to spot a DS.