Sebaceous Adenitis

Often referred to as "Alopecia"

What is Sebaceous Adenitis?

This is a perplexing condition in which the sebaceous glands in the skin become inflamed for unknown reasons, and are eventually destroyed. These glands normally produce sebum, a fatty secretion that helps prevent drying of the skin.

Clinical signs vary with the severity of the condition, and between different breeds.

What is Alopecia?

Alopecia is a general term to encompass any loss of hair.  Alopecia is used as a broad term and does not tell you WHAT MEDICAL ISSUE affects the dog.

How is sebaceous adenitis inherited?

It appears that the disorder is inherited as an autosomal recessive trait; however the wide variation in clinical signs suggests that inheritance is not straightforward, and breeding studies continue.  Being Autosomal recessive means that EACH parent MUST be or carry for the disease and each must give one of their affected genes to the offspring in order for the offspring to be affected.  A genetic disease of this type cannot be cured, but can be treated and most definitely can be bred away from.

What breeds are affected by sebaceous adenitis?

Sebaceous adenitis is most often seen in the Miniature Pinscher, Standard Poodle, Vizsla, Akita, Samoyed and in many other breeds as well.

For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have listed breeds for which there is a consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed.

Where did Sebaceous Adenitis come from?

This disease has been around since at least the 1960s, and carriers of the disease have been tracked to dogs in the 1950s. The disease affects all colors of the breed but is seen most often in the dilute colors of Blue and Fawn.

Sebaceous Adenitis was first described in the veterinary literature in 1987.  Most veterinarians have not had enough experience in the diagnosis of Sebaceous Adenitis in their clinical practice. For this reason, expensive bills can be run up experimenting with treatments that don't work as the dog's health deteriorates and it looks progressively more moth-eaten. However, effective treatment is relatively inexpensive once any secondary infection is controlled..

What does sebaceous adenitis mean to your dog & you?

Sebaceous adenitis is usually first noticed in young adult dogs (1 to 5 years of age). The condition can appear differently in different breeds, and there is also marked variability depending on the clinical severity.

One form of the disorder is seen in long-coated breeds - the Akita, Dachshund, Samoyed, and (most-studied) the standard poodle. Typically affected breeds have dry scaly skin with patches of hair loss along the top of the head, back of the neck, and back. Silvery scales tightly adhere to tufts of remaining hair. Very mildly ("sub-clinically") affected breeds have a normal hair-coat, but abnormalities typical of the condition are seen on microscopic examination of skin biopsies. More severely affected dogs will have areas of thickened skin ("hyperkeratosis"), extensive hair loss and often a musty or rancid odor. Secondary skin infections often occur as well.

The second form of sebaceous adenitis occurs in short-coated breeds such as the Miniature Pinscher, Dachshund & Vizsla. There is a moth-eaten appearance to the hair coat with mild scaling, affecting primarily the trunk, head, and ears.

Sebaceous adenitis is primarily a cosmetic disorder - that is it affects the appearance of the dog rather than his/her general health. The condition tends to be most severe in the Akita, resulting in chronic secondary bacterial infections, weight loss, and fever.

How is sebaceous adenitis diagnosed?

Symptoms of Sebaceous Adenitis can resemble allergies and can often go improperly diagnosed for some time. The most common symptoms are excessive dandruff (scaling) and hair loss which can be from moderate to severe.  The hair loss is usually patchy, giving a moth eaten look. Itchiness is not indicative of Sebaceous Adenitis but can accompany secondary skin infections, which can flare up and are often accompanied by a musty odor.

Your veterinarian may suspect this disorder based on your dog's clinical signs. To differentiate this condition from other skin disorders, many of which are also associated with increased scaling, a skin biopsy is necessary. 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. The biopsy will show changes in the skin consistent with this condition.

In Sebaceous Adenitis the sebaceous glands that adjoin the hair follicles become inflamed and gradually are destroyed. Accurate diagnosis requires punch biopsy. A local anesthetic is injected into the site to be biopsied (usually near the withers or affected area). When numb, a tiny 6mm BakerÌs Biopsy Punch is used to remove a tiny plug of skin, usually only one to two sutures are needed to close. The sample will then be gently placed (without squeezing) in formalin and sent for evaluation by a dermatopathologist. A parent may or may not show clinical symptoms, instead being what is known as subclinical affected meaning some inflammation may exist but hasn't progressed to destruction of the glands and the subsequent loss of hair or they may have been described as having some skin allergies. But they are carriers none the less.

 

How is Sebaceous Adenitis treated?

This disorder requires *long term management, which can be frustrating for both owners and veterinarians because the response to treatment is highly variable. There may be periods of spontaneous improvement or worsening of the condition, independent of treatment.

*Note - long term MANAGEMENT as there is NO cure at this time.  It is worth repeating "A genetic disease of this type cannot be cured, but can be treated and most definitely can be bred away from".

Your veterinarian will likely try a combination of approaches, to determine with you what will be most effective for your dog. Most important is the regular use of anti-seborrhea shampoos to remove scales and dead hair, together with fatty acid dietary supplements. This may be all that is required in mildly affected dogs. Additional treatments include spraying the dog with a mixture of propylene glycol and water to help restore lubricants to the skin and the use of oral essential fatty acids.

NO - NO - NO - NO - NO

Affected dogs are sometimes placed on thyroid medication without any determination of their thyroid level. This is because hair loss can be a symptom of thyroid deficiency, and the medication is cheaper than the test for thyroid level. However, thyroid medication will have NO effect on Sebaceous Adenitis, and may postpone prompt treatment to prevent or clear up secondary infection.

The suggested treatment is to treat secondary infection immediately with antibiotics. Then use baby oil baths to remove the scales. Although the baby oil can be used directly, many people have mixed the baby oil and water in a spray bottle. Shake well and spray the baby oil mixture on the dog, rubbing it in to thoroughly saturate the skin. Let the dog soak for one hour while standing in the tub. The baby oil is thought to expand and mechanically loosen the scales. After an hour, shampoo the dog with Palmolive dish washing detergent.

The rinse water will run gray with loosened hyperkeratosis scales. Be careful not to get any detergent in the eyes of the dog. It will take several rounds of shampooing with Palmolive liquid to cut the oil. The more hair, the more rounds. Then shampoo with any good dog shampoo to eliminate any traces of detergent. How many shampoos will it take to see improvement? Most dogs show immediate improvement in their skin. Most dogs treated with baby oil begin to grow hair at a normal rate, but this may take 5 or 6 months of regular oiling.   Many owners report a baby oil soak once very 3 or 4 weeks is sufficient to maintain the dog when the secondary infection has been controlled. Some users also spray their dogs every few days with propylene glycol to keep the skin soft.

Owners of one dog developed a comprehensive treatment using a variety of Redken Laboratories cosmetology products. This is described in the Spring 1992 issue of Progress in Sebaceous Adenitis Research.

Significant hair growth has been reported from these treatments in most cases, and owners are able to discontinue expensive medications and supplements without ill effect. There is no question that clinically affected Sebaceous Adenitis dogs require more maintenance than unaffected dogs, although the initial effort generally yields good results within a few months.

Breeding advice

Although the genetics have not been determined, the condition does appear to be inherited in those breeds studied. It is thus preferable to avoid breeding affected dogs of any breed, their siblings, and their parents.

The Institute for Genetic Disease Control in Animals (GDC) used to operate an open registry for sebaceous adenitis in the Standard Poodle and some other breeds.  That database was sadly turned over to the OFA.  All dogs that have been used or are intended to be used for breeding purposes, or any dog with a diagnosis of sebaceous adenitis, should be registered through an annual skin biopsy. Bear in mind that subclinical affected animals (meaning that they have no clinical signs, even though a skin biopsy shows that they have a mild form of the disorder) may produce clinically affected puppies.

The difference in the GDC and the OFA is that the GDC was an OPEN registry database and the OFA is an OPTIONAL database.  With GDC the results were open to the public but with OFA you can opt to keep it secluded from the Open database.  What we need is an OPEN database so that results can not be hidden from those who NEED the information to improve their bloodlines and to breed away from diseases that are KNOWN by testing to be in the bloodline.  With an OPEN DATABASE a buyer of an affected puppy can have that puppy tested and submitted and the record will then show that an affected animal does exist in that bloodline when future searches are done on the bloodline.  The breeder can no longer hide behind no testing results and lies.

The OFA  provides registration forms, instructions for veterinarians regarding biopsies, and a list of participating pathologists. Registration requires evaluation of two 6-mm skin biopsies by a participating dermatopathologist, who will send the results to the submitting veterinarian and GDC for their computer files.

In sub-clinically affected dogs (those with a normal hair coat), histologic lesions consistent with sebaceous adenitis may not be evident in a particular biopsy sample. Thus a pathologist's report of "normal" does not guarantee that the dog is unaffected, but rather that the skin biopsies examined showed no evidence of the disorder. By having the animal in question biopsied and registered annually however, the owner has done all that they can to ensure the animal is suitable for breeding, and has contributed information to the registry to decrease the incidence of this disease in the breed.

How can breeders find "UNAFFECTED" breeding stock?
First we have to find enough concerned breeders who are willing to go to the expense and trouble to have their dogs tested and OPENLY submitted into the OFA database.  Not just one or two of their dogs or their suspected clear or non-clear ones but EVERY dog in their possession.  Through these efforts a complete database can be made and breeders from that point forward can breed away from those with confirmed affected diseases.  Contact OFA at (573) 875-5073 for SA and other forms. We highly recommend that you register with OFA (Orthopedic Foundation for Animals), and use the "choice" option to share the results of your dog's evaluations openly with other breeders through the OFA web site: www.offa.org

The owner wishing to breed a dog submits the names of candidate dogs to OFA for a n Open Report. . Information in the database if processed by the OFA computer and compiled into a report on the Sebaceous Adenitis phenotype and genotype information on file. . The strategy is to breed to low risk vs. high risk dogs.

The original database came from the GDC database who merged with the OFA in order to better serve the breeder.

How reliable is the information in the registry? First, the open registry contains information about dogs with a genetic history of Sebaceous Adenitis, as well as those that test normal at this time. Unlike closed registries that provide information only on normal animals, the breeder receives a more comprehensive vies of the data. The European open registry model has thus reduced the incidence of hip dysplasia, while the closed registry model has not significantly reduced hip dysplasia. Second, the more dogs registered, the more reliable are the data.

Can We Rid the Breed of Sebaceous Adenitis?
Time will tell. A recessive Malamute disease open registry was set up, and seven years later was discontinued because the disease had virtually disappeared. We do not know how long it will take to eliminate the risk of Sebaceous Adenitis, but if most breeders cooperate, it should be accomplished within a decade.

Additional research is being conducted to see if skin lipid levels can be measured to provide early warning of Sebaceous Adenitis. In the long range, mapping of the canine genome may reveal the location of the gene responsible for Sebaceous Adenitis. The success of this research may be many years away, but it could lead to a blood test screen for Sebaceous Adenitis and other hereditary diseases. In the meantime, our best hope is to breed away from Sebaceous Adenitis by wise selective breeding.

FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN.

Resources

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

Dunstan, R.W., Hargis, A.M. 1995.  The diagnosis of sebaceous adenitis in standard poodle dogs. In J.D. Bonagura and R.W. Kirk (eds.) Kirk's Current Veterinary Therapy XII Small Animal Practice. p 619-622.   W.B. Saunders Co., Toronto.

Genodermatosis Research Foundation (GRF), 1635 Grange Hall Road, Dayton, OH, 45432

The Institute for Genetic Disease Control in Animals

VetMed - UC Davis