I have a 20-year old Thoroughbred gelding that has recently been diagnosed with hyperthyroid.  All other blood work is normal.  His symptoms include lack of energy, weakness, weight loss, dull, dry coat, slow shedding of his winter coat.  He does have a golf-ball sized benign growth on his thyroid gland, which could be over-stimulating his thyroid gland.  Because of his age he is not a candidate for surgery.  My vet is perplexed as far as treatment goes, all his research seems to indicate that hyper-thyroid is very rare in horses. 

Are there any recommendations for treatment to help this guy?

 

Thank you,

Catherine