Sebaceous Adenitis (SA) is a skin disease appearing most frequently in young adult dogs. For reasons currently unknown, sebaceous glands become inflamed and may eventually be destroyed leading to progressive loss of hair. SA has been diagnosed in the Akita, Collie, Dalmatian, Dachshund, German Shepherd, Golden Retriever, Irish Setter, Lhasa Apso, Maltese, Miniature Pinscher, Old English Sheepdog, Poodle (Toy, Miniature and Standard), Samoyed, Springer Spaniel, St. Bernard, Vizsla, Weimaraner, as well as mixed breeds.
WHAT DOES SA LOOK LIKE?
Describing the clinical appearance of SA is difficult. First, because the disease can look different in different breeds and second, be cause the disease can vary from so severe that owners legitimately consider euthanasia as an option to so mild that no clinical lesions are present, and diagnosis requires microscopic examination of a biopsy sample. In spite of the wide range of lesions that make up sebaceous adenitis, the lesions are all associated with excess dandruff (scaling) and/or hair loss.
In the Standard Poodle, the scaling is often silvery and tightly adherent to tufts of existing hair shafts. In severely affected animals, the hair loss and scale can be severe, is often accompanied by a musty odor, and secondary skin infections may occur.
Standard Poodles affected with subclinical SA have no outward signs of the disorder.
IT IS IMPORTANT TO TEST FOR SA ON NORMAL LOOKING STANDARD POODLES!
SA in Akitas can have a similar clinical appearance as Standard Poodle SA but systemic illness (weight loss and fever) appear to be more common. In Vizslas, the lesions are common on the head and hair loss is a much more common finding than scales.
Although in many breeds the head, muzzle, and ears are the sites first affected, in German Shepherd Dogs, it appears that lesions often start on the rump and advance to the head.
Because SA can look like so many other diseases (including hypothyroidism or an allergy), diagnosis requires microscopic examination of a skin biopsy by a veterinary pathologist. The procedure is safe and causes minimal discomfort to a dog. Basically, the veterinarian will shave the affected area (for dogs being biopsied for the purpose of registration, biopsies should be obtained from anterior dorsal skin between the top of the head and the withers). DO NOT SCRUB THE AREA. A local anesthetic (Lidocaine) will be injected into the site to be biopsied. When the skin is numb, a 6mm Baker’s Biopsy Punch is used to remove a tiny cylinder of tissue. The biopsy will then be lightly attached to a tongue depressor by gentle pressure, placed in formalin and sent to a pa- thologist for evaluation. Note that at this time, GDC registration can only be obtained for Standard Poodles and requires that two biopsy specimens be evaluated by a GDC approved veterinary pathologist. A list of approved pathologists may be obtained from GDC.
NOTE: UNLESS THE DOG IS EXTREMELY VICIOUS, THERE IS NO JUSTIFICATION TO PUT A DOG COMPLETELY UNDER ANESTHESIA FOR THE PROCEDURE.
TREATING THE SA AFFECTED DOG
Currently, there is no cure for SA. The disease seems to go in cycles. A dog will lose hair, regrow some–usually of a different texture– and then lose hair again. Antibiotics are necessary to control secondary skin infection. Except in Vizslas, there is serious doubt that retinoids (such as Accutane)have any beneficial effect on SA-affected dogs.
At best, what one can do to improve the dog’s appearance and to make it more comfortable is to bathe it frequently (weekly may be necessary at first) with a hypoallergenic dog shampoo to loosen and remove scaling and dead hair.
Oil baths have improved the appearance of many SA affected Standard Poodles. An inexpensive, non-perfumed baby oil or bath oil mixed half and half with water is sprayed onto the dog and rubbed into the skin until it is thoroughly saturated. Let the dog soak for one hour . Shampoo several times to get out all the oil. The water will run gray with loosened scales. A good dog creme rinse should follow the final shampoo.
Some dogs will have significant hair regrowth following this treatment. Others do not. However, there is no question that the additional bathing and oiling helps restore lubricants to the skin that are missing due to the absence of sebaceous glands.
SA is a cosmetic disorder. Most SA dogs are happy, healthy animals requiring the same love and attention from their owners that they did before they developed the disease.
SA in the Standard Poodle was identified in veterinary research in 1987. There is a misconception that it affects only certain colors of Standard Poodles. In reality, it has been diagnosed in every color. Through a test breeding funded by the Poodle Club of America and administered by Michigan State University, the mode of inheritence in this breed has proven to be simple (one gene) autosomal recessive.
Statistics show that perhaps as high as 50% of all Standard Poodles are SA carriers or affected. Therefore it is important that every Standard Poodle, whether used in a breeding program or not, be skin punched annually. This is the only current means of identifying subclinical SA in normal-looking animals. Anyone planning to purchase a Standard Poodle puppy is urged to request a written copy of the SA test results on the sire and dam.
Research continues to find an alternate, non invasive method of diagnosing SA
Published by the Institute for Genetic Disease
Control in Animals (June 1994)