What is Dermoid Sinus in Dogs?

Kate Barrington
by Kate Barrington
An inherited condition, dermoid sinus can affect any dog breed. With symptoms that range from skin infections to nerve damage, here’s what you need to know about this disease.

Though many of the health problems that affect dogs are related to diet and other environmental factors, some of the most serious issues are inherited. Genetic disorders can be tricky because sometimes a dog can be a carrier for a disease without showing any symptoms. When that dog is bred, then, it passes along the gene as well as the risk for developing the disease. One inherited condition that is particularly troubling is called dermoid sinus. Keep reading to learn more.

What is Dermoid Sinus, Anyway?

Also known as a pilonidal sinus, a dermoid sinus is simply a tubular skin defect that forms a tubular indentation in the skin near the spine. These tunnels form deep in the underlying tissue but they can still be felt and seen in many cases. In cases when the indentation itself is not obvious, you may still see signs such as a swirling hair pattern at the sight or an area of slight discharge. These tubes exist to drain dead cells, tissue, and hair but when they form incorrectly it can lead to infection and abscess.

Related: What is Chronic Sesamoiditis in Dogs?

Depending where the dermoid sinus is located, this condition can produce a variety of symptoms which may include the following:

  • Visible opening along the back
  • Swirling hair pattern
  • Feeling a tube under the skin
  • Mild discharge
  • Formation of abscess
  • Infection
  • Neurological problems

There are technically five different types of dermoid sinus determined by the severity of the tube. Diagnosis can be tricky because you cannot always see the tube and because many veterinarians are undereducated in this area. A physical examination and history of symptoms will be required along with tests to explore the cavity and scans to gauge its size and severity.

Related: What is Ventral Comedo Syndrome in Dogs?

What Else Do You Need to Know?

The exact cause for dermoid sinus is not known, except for the fact that it seems to be hereditary. Researchers have determined that the condition can be inherited from one or both parents and that it is usually present at birth, though it may not be detectable until 3 to 5 weeks of age. It is also known that this condition tends to affect some breeds more than others, especially the Rhodesian Ridgeback.

In terms of treatment, there are two primary options – medications and treatment. If the dermoid sinus becomes repeatedly infected, antibiotic medications may be recommended before any other course of treatment is explored. In more severe cases, surgical removal of the dermoid sinus is an option but only as long as it has not attached to or wrapped itself around the spinal cord. Recovery may take anywhere from 10 to 14 days, assuming there are no complications along the way.

If you feel a strange indentation along your dog’s spine or notice a swirling pattern of hair, take him to the vet immediately. Your vet will either be able to diagnose and treat the condition, or he can refer you to a vet who is more educated about dermoid sinus.

Kate Barrington
Kate Barrington

Kate Barrington is the loving owner of two cats (Bagel and Munchkin) and a noisy herd of guinea pigs. Having grown up with golden retrievers, Kate has a great deal of experience with dogs but labels herself a lover of all pets. Having received a Bachelor's degree in English, Kate has combined her love for pets and her passion for writing to create her own freelance writing business, specializing in the pet niche.

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