Schnauzer comedo syndrome

What is ... ?: 

Dogs with this syndrome have multiple comedones on their backs. These plugs of keratin and sebum block the hair follicles, and are commonly called "blackheads."

How is ... inherited?: 

The mode of inheritance is unknown.

What does ... mean to your dog & you?: 

Animals with this syndrome have bumps, scabs and blackheads on their backs, which may only be noticed when the hair is clipped. These usually do not bother the dog unless a secondary bacterial skin infection develops, causing some pain and itching.
The dog's general health is not affected.

How is ... diagnosed?: 

The diagnosis is readily made based on finding comedones or blackheads along the back of a miniature schnauzer. Your veterinarian may take a skin biopsy to confirm the diagnosis. This is a simple procedure done with local anesthetic, in which your veterinarian removes a small sample of your dog's skin for examination by a veterinary pathologist.

How is ... treated?: 

This condition can not be cured but it can be controlled. Mild cases need no treatment. In other cases or where there are repeated infections, regular cleaning with acne cleaning products or mild anti-seborrheic shampoos will be required. Your veterinarian will work with you to find a regime suitable for your dog.
If a secondary bacterial infection develops, your dog will need to take antibiotics for 3 or 4 weeks.
For the veterinarian: Refractory cases may respond to retinoid therapy.

Breeding advice: 

It is preferable not to breed affected dogs, in order to reduce the occurrence of this common disorder in miniature schnauzers.


Scott, D.W., Miller, W.H., Griffin, C.E. 1995. Muller and Kirk's Small Animal Dermatology. p. 752  W.B. Saunders Co., Toronto.

Campbell, K.L. 1997. Diagnosis and management of keratinization disorders in dogs. ACVIM- Proceedings of the 15th Annual Veterinary Medical Forum. p 220-222.

What breeds are affected by ... ?