first of all if ur going to race him and he is afraid of other dogs he might win every time because he is so scared he;s running for his life ,, i would try get better ground to work him on becaues horse paddocks is usally full of hidden objects ,, iwould stop wit the hunting for awhile [summer] and get him more socialised wit people and other dogs [parks playgrounds game fairs ect ] and then get back to hunting and make sure the dog knows the ground he running so there s no more mishaps good luck in the future mate