It doesn’t sound like Cushings. Cushings usually comes on quite a bit later, i.e. in early to mid 20s and has symptoms such as failure to shed winter coat, repeated abcesses and infections as well as lethargy. My older boy was recently diagnosed though he showed symptoms for about 2 yrs before the test came back positive for Cushings. Cushings is also common to have in addition to Insulin Resistance. I agree this horse sounds more like he has a thryroid issue instead. For Cushings though, thank God there is now Prascend, which is easy to administer and is consistent in the amount of pergolide as compared to compounded pergolide. My guy is doing great right now, so by no means is Cushings a death sentance, just something that needs to be managed in our older equine friends.