My colt seems to be having very loose stools. Not really diarrhea, but just a blob. He is 8 weeks and has started to eat a little of the Mare & Foal grain I give mom. Could that be doing it? Also...what about fly spray. Could he be mouthing one of the other horses and getting sick from it? It's been 2 days. Is a loose stool an issue? How long should I let it go until I call the vet out?