thanks everyone for all the help, it does look like some sort of skin condition to me but he doesnt have and open wounds so its not pus or infection, well deffinatley try the medicated shampoo and see if that helps. no it did not just happen overnight hes an older horse (13 or 14 years) and hes been just left on a 20 acre property for the last 7-8 years on his life the people basically just threw food out once a day and gave him water and that was it, so we got blackmailed into buying him (long story) but hes had the skin problem for the last year and a half since we got him weve gotten his feet taken care of and paid alot of money for good training and vet visits but since she was last here a few months ago its gotten worse, and now the yellowish sweat looking stuff. if the shampoo stuff doesnt help well deffinatley call the vet