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 and the Thai 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. 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.

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.

Do they grow later in life?

No, 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.

Are they genetic?

Yes, a breeder could conceivably breed four litters using the same sire and dam and have no Dermoids yet a fifth breeding of the same dogs could produce one or more puppies who have a Dermoid.

Does it hurt?

Not unless it is infected.

Are they born with them?


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 receommended 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.

What happens if you leave it in the dog?

It is likely to become infected time and time again. With chronic abscesses, the dog is likely to be in a lot of discomfort.

How do the dogs get them?

No one knows the true cause of the Dermoid. It is safe to say that it is a polygenic condition and inherited from one or both parents who carry those genes.

How are they removed?

Many Dermoids are fairly simple to remove and the prognosis is good with a rapid recovery. Surgical removal can be complex and difficult however, and it is best to find a trusted veterinarian who is knowledgeable about this health issue or a veterinarian who is willing to consult more experienced peers.

Is that risky?

There is always a risk with anesthesia. As one cannot foretell the type of Dermoid, how deep it goes nor how complex the Dermoid is, it is impossible to know much about the individual Dermoid until the veterinarian/surgeon has opened the dog and is following the thread of the Dermoid. Only then will the veterinarian be able to know what to expect.

What is the cost of such a surgery?

Surgery could be as low as $125.00 and as high as $1,500.00. The cost depends on the area in which you live, the complexity of the surgery, and the usual and customary veterinary fees of your doctor.

Who could do the surgery?

Any veterinarian who is experienced with this type of surgery. It does not have to be performed by a Board Certified Veterinarian or a Diplomate in Veterinary Medicine.

How long is the recovery?

The younger the dog  when surgery is performed, the more rapid the recovery. Typically the recovery is about 12 to 14 days if there are no complications or seromas. Although it is hard to keep the puppies quiet, it can also be hard to deal with an adult dog who is in some pain and discomfort. Crate rest is recommended with supervised free time until the sutures are out.

What is a seroma?

A pocket of fluid filled skin at the site of the surgical incision. The seroma is usually due to the dog being allowed to be too active. It is highly receommended to leave the seroma alone and NOT to allow the veterinarian to drain it using a penrose drain or a needle.

Will the dog always be scarred?

Not necessarily. Some scars fade away, for the most part, the incision is usually small enough that there is little scarring.