Dermoid Sinus in the Rhodesian Ridgeback

What is a Dermoid Sinus?

A Dermoid Sinus is a neural tube defect found in the Rhodesian Ridgeback dog. Although there have been cases of Dermoids seen in several other dogs of various breeds, it is primarily found in the Rhodesian Ridgeback, the Thai Ridgeback Dog and the Phu Quoc Ridgeback.

Is there a difference between a Dermoid Sinus and a Dermoid Cyst?

Yes, the Dermoid cyst is encapsulated and often contains hair, or other material. It does not have the thread-like tube extending down into tissue or bone. The Dermoid Sinus is a tube-like opening which actually grows up from where it began in the embryonic stage. The tube can be of different lengths: thin as a piece of thread or thick as in spaghetti or cooked macaroni. The tube also is seen with hair, sebaceous glands and often debris from the outside world. Several different names are used to describe the condition: Dermoid Sinus, polynoidal cyst, or Africa cyst

Where are they found?

A Dermoid can occur anywhere along the dorsal line of the dog. They have been found in and around the tail, in front of an ear, on the side of the face but most often in the neck area between the occipital bone and the start of the ridge.

Are they life threatening?

Not necessarily. Should the Dermoid be connected to the spinal cord it could certainly cause meningitis, encephalitis or myelitis. It could lead to the death of the dog through infection. Many Dermoids are surgically removed with no residual effects,

Is it painful for the dog?

Not unless it is infected.

Are they born with them or do they grow later in life?

The Dermoid is present at birth. It may be so minute that it is not detected until the pup is older, but if a pup is found to have a Dermoid, that pup was born with it.

Do all dogs have them?

No, not all Ridgebacks have them and according to several articles and Ridgeback sources, a very few have been seen in other breeds, such as a Pit bull, Boxer, Golden Retriever, Siberian Husky, Shih Tzu, American Cocker Spaniel, English Springier Spaniel, Yorkshire Terrier, Chow Chow, Boerboel, Great Pyrenees, Kerry Blue Terrier and  Lhasa Apso.

What do they look like?

Generally, one can only see them once they have been removed from the dog. Once removed, they can look like a narrow tube, or a noodle. Inside the tube, if you open it, you will find sebaceous glands, hair and all that is generally found on the outer skin of the dog.

How would you know if a dog had one?

As you cannot tell by looking at the dog, it is recommended that you have a knowledgeable breeder or veterinarian check the puppy or adult dog for a Dermoid. Not everyone knows what they are, not every breeder has seen or felt one and definitely not every veterinarian has been exposed to more than a chapter in a text book while in school.