Melatonin is a hormone produced by the pineal gland that helps regulate hormones and the body’s circadian rhythm. It is being used in veterinary medicine as a natural treatment for coat loss in dogs, cats and ferrets. Researchers are not exactly sure how melatonin helps thicken and regrow fur. Some researchers think it may be the relationship between melatonin, sunlight, and the body’s circadian rhythm. Other’s feel that melatonin’s antioxidant properties help promote hair growth. Melatonin has also been shown to help a pet gain back weight after surgery, stress or illness and help with anxiety, insomnia, and noise phobias. Mink farmers have been known to use melatonin to promote thick coats in the winter.
I don’t think it is overgrooming (psychogenic alopecia) because these are hard to get to spots to groom or impossible to get to. It may be due to a hormone deficiency. Hyperthyroidism can cause alopecia. The hair pulls out easily. I don’t want to speculate. Also hyperthyroidism causes cats to have increased appetite and you have not mentioned that. Can you feel a small lump under the chin (feeling gently)? It might be a mange. Demodectic manage causes hair loss around the eyes and eyelids, however. It is not common. I think a vet check is in order to be honest to check out any underlying health issues.
Sometimes the hair loss is hormonal.
On the other hand, sometimes there just isn’t any hair. Your dog is not itching or uncomfortable or pulling his own hair out. He is just losing his hair because of a larger problem. This type of hair loss is often the result of a hormonal disorder. Hypothyroidism (abnormally low thyroid hormone levels), adrenal gland dysfunction (Hyperadrenocorticism or Cushing’s Disease ), sex hormone imbalances , and another hormone-like pattern of hair loss termed Alopecia X can all cause-varying degrees of hair loss and alopecia. Your dog’s age, breed and the distribution of the hair loss along with any other clinical symptoms may make one or another of these conditions more likely. Your veterinarian will want to do specific diagnostic tests to know for sure. Blood test and even skin biopsies may be necessary in order to arrive at the definitive diagnosis.