Does anyone have any ideas with what is wrong with my 22 yr old highland mare. She has been really itchy since around October. We have taken her off all hard feed - she now only gets enough happy hoof to put her Bute and Cortaflex in. She had no signs of any parasites, lice or anything but we have treated her for these anway just to rule them out. She has had blood tests to check her Kidneys... and liver - these came back clear. She has been tested for Cushings - this also came back clear. She lives out 24/7 and is not rugged up. She is itchy everywhere and is just about demented with it. The vet is puzzled and is now talking to a dermatologist. Any of come across anything like this before?