Adrenal Steroid Hormone Concentrations in Dogs with Hair Cycle Arrest (Alopecia X) Before and During Treatment with Melatonin and Mitotane

In a study from 2004, 29 neutered dogs with hair cycle arrest (Alopecia X) were treated with melatonin and, in some cases, mitotane to evaluate the effect on hair re-growth and intermediate adrenal steroid hormones (ISH) levels. The dogs, which included 23 Pomeranians, 3 Keeshonds, 2 Miniature Poodles, and 1 Siberian Husky, were given an initial melatonin dose of 3–6 mg every 12 hours. The treatment was adjusted based on clinical progression. Results showed that 14 out of 23 Pomeranians experienced partial to complete hair re-growth, as did all 3 Keeshonds and 1 of the 2 Poodles, while the Siberian Husky saw no re-growth. Mitotane led to partial to complete re-growth in 4 out of 6 dogs. Overall, 62% of the dogs had partial to complete hair re-growth. However, hair re-growth was not consistently associated with normal ISH levels, as androstenedione, progesterone, and 17-hydroxyprogesterone remained above reference ranges in 21%, 64%, and 36% of dogs, respectively. The study concluded that while a majority of the dogs experienced hair re-growth, this was not necessarily linked to normalized sex hormone concentrations.