The drug Pergolide, although unsafe for humans treating Parkinson's, was used to treat horses with Cushing's Syndrome.

A drug used to treat humans with Parkinson's Disease has been pulled off of the market by the U.S. Food and Drug Administration. Now, horse owners who use the drug Pergolide say that it will leave them unable to treat their horses suffering from Cushing's Syndrome.

While the drug does not cure Cushings, it is known to reduce the symptoms and dramatically increase the quality of life for the animals. One veterinarian says that certain pharmacies have enough Pergolide on hand to meet demand until an alternative can be found, while another veterinarian says the removal will cause severe problems for horse owners nationwide. She and several others are now calling on the FDA to issue an exemption on the drug so that it may be used to treat sick horses.