Overview of Canine Dermoid Sinus
A dermoid sinus is a cyst-like structure that lies below the skin along the back and is sometimes connected to the spine. As the puppy embryo develops during pregnancy, the neural tube that forms the spine should separate completely from the skin. When this separation fails to take place, a dermoid sinus develops. Once the puppy is born, the sinus may remain connected to the spinal canal or may end in a blind sac.
Dermoid sinuses occur as inherited, autosomal recessive traits in Rhodesian ridgebacks or ridgeback-crosses, and they are occasionally seen in other breeds of dogs, such as the Shih tzu and the boxer. With recessive genetic traits the condition only becomes apparent when the puppy receives one defective gene from both parents. A dermoid sinus develops when two defective genes are present together. When only one defective gene occurs, the dog is a carrier of the condition, but does not show any signs of a dermoid sinus.
Young animals are most commonly affected. Affected individuals may be asymptomatic (have no clinical signs) early in the disease process. Signs resulting from a dermoid sinus depend on its location.
What to Watch For
Signs of a Dermoid Sinus in Dogs may include;
Additionally, clinical signs of meningitis (inflammation of the covering of the brain and spinal cord) or myelitis (inflammation of the spinal cord) including spinal pain, rigidity, and fever may be seen as a result of extension of a deep infection.
Diagnosis of Dermoid Sinus in Dogs
Your veterinarian may recommend the following tests:
Treatment of Dermoid Sinus in Dogs
If there are no clinical signs associated with the lesion and the site is not draining or connected to the spinal canal, then your veterinarian may recommend the site just be observed. If any clinical signs are present or the lesion has an open connection to the spinal canal, then surgical excision is the treatment of choice. If neurologic signs are present by the time of diagnosis, the dog may be left with permanent changes despite corrective surgery.
Antibiotic therapy may be indicated, especially in cases associated with meningitis or myelitis. Dermoid sinuses complicated by infections of the spinal canal or spinal cord carry a very poor prognosis.
Administer all medications as directed by your veterinarian. If any change is noted in your pet’s condition, notify your veterinarian immediately.
There is no prevention available for a dermoid sinus. Affected animals should be neutered, and the parents and littermates of affected animals should not be used for breeding.