Hyperthyroid Corgie Pomeranian Mix

My sister has a small dog (possible corgie/pomeranian mix) that she adopted from a shelter. He is now about 12 yrs old and has been diagnosed as hyperthyroid by the conventional veterinarians. Her monetary budget is tight and the vet bills are difficult. I was hoping that there would be a homeopathic solution.
He is a very bright, energetic, and intelligent dog. His hair is falling out around his neck and rear haunches. His eyes have a very slight bulge common in thyroid imbalance. He weighs approximately 20 pounds. Other wise he does not seem to have symptoms.

I am assuming that as of yet, the dog is not on any medications from the veterinarian or otherwise. Diet can often play a part in regulating thyroid levels so the first thing your sister might want to do is to look at the work of Richard Pitcairn, "Natural Health for Dogs and Cats", "The Complete Herbal Handbook for the Dog and Cat" by Juliette de Bairacli Levy and "The Barf Diet" by Ian Billinghurst for further information and recipes to make up a good, homemade diet. In addition, foods such as broccoli, cabbage, cauliflower, turnip, Brussels sprouts and kale tend to have depressive effect on the thyroid and may help if the dog will eat some of these foods as part of its diet.
Herbs often used in cases of hyperthyroidism include Bugleweed (Lycopus virginicus), Hawthorn (Crataegus oxycanthus), Motherwort (Leonurus cardiaca) and Passionflower (Passiflora incarnata). It would be best if your sister worked with a qualified professional in her area as thyroid levels would need to be monitored if using these herbs so the right balance may be achieved.
As for homeopathics, the choice of a remedy in this case would depend on taking a full case history as hyperthyroidism is a constitutional issue. It is not possible to do this via email. Your sister may find someone in her area to by looking for a practitioner through the Academy of Veterinary Homeopathy (https://www.theavh.org/). Should she be interested in finding a herbal practitioner she could also look at the website of the Veterinary Botanical Medicine Association (www.vbma.org).