THE PET HEALTH LIBRARY By Wendy C. Brooks, DVM, DipABVP Educational Director, VeterinaryPartner.com

Alopecia is the medical term for baldness. A particular type of baldness has been described in the Nordic or double-coated breeds whereby the dog develops symmetrical coat loss on the trunk as well darkly pigmented skin in the bald areas. This pattern of baldness is commonly called endocrine alopecia as it is common in several types of hormone imbalances (in particular, Cushing's disease and hypothyroidism.)

The condition we call Alopecia X, however, is not associated with the hormone imbalances that normally create endocrine alopecia. The causes remain mysterious, hence the name Alopecia X. Given that there are numerous therapies that work for some cases and not for others, and many of these therapies seem to be in complete opposition, it may be that Alopecia X is not one disease but several and we simply do not know how to distinguish them.

Alopecia X goes by many names:

• Black skin disease
 
• Growth hormone responsive alopecia
 
• Castration responsive alopecia
 
• The coat funk
 
• Pseudo-Cushing syndrome
 
• Biopsy responsive alopecia
 
• Follicular dysplasia of the Siberian husky
 
• Post-clipping alopecia
 
• Adrenal sex hormone alopecia
 
• Hair cycle arrest

This articles attempts to update what is currently believed about this confusing condition.

The Typical Patient    

The typical Alopecia X patient is a Spitz or Nordic breed such as a Chow Chow, Pomeranian, Alaskan Malamute, Elkhound, or similar. Poodles have also been over-represented. Hair loss begins in early adulthood, usually by age 3 years. First the long primary hairs go, leaving a fuzzy puppy-like coat but eventually that goes, too. The bald skin pigments are not itchy, and usually do not get infected.

Part of the problem is that all hormone-based hair losses can look exactly like this so some testing is needed to determine which of several conditions are occurring.
Expect your veterinarian to begin with:

• A blood panel
 
• A urinalysis
 
• Some kind of thyroid testing
 
• Some kind of adrenal hormone testing
 
• A skin biopsy

The purpose of this rather broad testing is to rule out diseases that look like Alopecia X but for which well-defined treatment protocols exist. This means that two conditions must absolutely be ruled out before proceeding with the trial and error process of Alopecia X treatment.

• Cushing's disease
 
• Hypothyroidism

Step Two: Sterilization
 
This is the same dog as seen at the top of the page, but after being neutered.

Alopecia X seems to be a sex hormone imbalance in at least some cases and did not earn the name castration-responsive alopecia for nothing. For this reason, the first step in treatment is to sterilize the patient; unspayed females should be spayed, intact males should be neutered. There are health benefits to sterilization regardless of whether or not there is a hair loss issue and many animals will grow their hair back (though possibly not permanently) so this is where we start rather than investing in complex and confusing diagnostics.

Step Two for Animals Already Sterilized

What if the pet is already neutered or if several months have gone by after altering and no hair has regrown? The next simple therapy to try is oral melatonin.

Melatonin can be obtained in 3 mg tablets at most health food stores or vitamin retail outlets. Approximately 50% of dogs will show some response within 6 to 8 weeks. Give the medication for at least 2 or 3 months before giving up but if hair regrowth occurs, continue the medication until hair growth seems to have plateaued. After maximal hair regrowth has been achieved, gradually taper down the dose over several months to a weekly dose. Some dogs can ultimately be discontinued but understand that if the melatonin is discontinued and the hair falls out again, the condition may not be responsive to melatonin a second time.

• Melatonin has been used as a sleep aide. Some owners ind the sedating side effect to be unacceptable.
  
  
• Since melatonin is a nutritional supplement and not a prescription medication, the FDA does not insist on the same quality control it does for drugs. There may be tremendous differences in the amount of melatonin contained in different brands. At this time a specific brand has not been recommended.

If neither sterilization nor melatonin has been fruitful and we know the dog does not have Cushing's disease or hypothyroidism, then one should realize that the therapies left to still try have potential harmful side effects. One should consider this:
Alopecia X is a cosmetic condition.

It may make the dog look funny, but it does not cause harm.

One will need to weigh the potential side effects of therapy against the appearance of the pet. That said, there are other therapies that can be attempted.

The University of Tennessee Hormone Profile

One option in the pursuit effective Alopecia X therapy is the Adrenal Sex Hormone panel available at the University of Tennessee. This test is done by drawing a baseline blood panel, administering a pituitary hormone called ACTH and an hour later drawing a second blood sample to compare. Samples are shipped to Tennessee for evaluation for numerous adrenal sex hormones. The results show not only what hormones respond abnormally but the University will make suggestions as to which therapy might be likely to work.

Testing is not inexpensive and results can take several weeks to obtain but may help in selecting what therapy makes sense to try next.

Methyltestosterone Therapy

If melatonin fails, methyltestosterone supplementation is the next step. One has presumably done a baseline blood panel when ruling out Cushing's disease and hypothyroidism, and while the dog is on testosterone supplementation the chemistry panel should periodically be monitored as this hormone can be toxic to the liver. The medication is typically given once a day and can lead to an increase in aggressive behavior.

Another Alternative: Lysodren

Lysodren (also called mitotane or OP'ddd) is normally used to treat Cushing's diseasem which is an excess production of cortisone-type hormones by the adrenal gland. Lysodren acts by eroding the outer layers of the adrenal gland to control cortisone produced by these layers. If the adrenal gland is over-eroded, problems with electrolyte imbalance can occur and potentially these problems can be permanent (though they are treatable). Lysodren helps with Alopecia X because the adrenal gland also produces sex hormones and Lysodren is able to stop the production of these hormones by eroding the part of the adrenal gland that produces them.

It is important to realize that dogs with Alopecia X do not have Cushing's disease and thus do not have an excess of cortisone. Treating these dogs with Lysodren can lead to a cortisone deficiency or, more seriously, the adrenal steroid deficiency called Addison's disease. Signs of Lysodren reaction include: listlessness, vomiting, and diarrhea. One should expect periodic blood testing to monitor the cortisone levels being maintained by the patient on Lysodren.

Trilostane is another medication used in the treatment of Cushing's disease. It has also been successful in treating Alopecia X if the adrenal gland called hyperplasia is present.

Growth Hormone

There was a time when this condition was believed to represent a deficiency of growth hormone. Growth hormone is not effective unless given as an injection. It is a genetically engineered product, which is often not commercially available but may be obtained through academic sources. Administration can cause diabetes, so blood sugars must be monitored. A 6-week course of therapy may produce results that last several years.

There are other drugs that have influence on adrenal hormones and they have been used in the treatment of Alopecia X with mixed results. These other options include: prednisone, Anipryl, ketoconazole , leuprolide, and cimetidine. Alopecia X is a frustrating condition and will remain frustrating for years to come. Research is on-going and progress comes gradually.

Date Published: 7/27/2003 11:43:00 AM
Date Reviewed/Revised: 01/11/2010