We are having dramatic weather changes here in Missouri. It is up to 80 one day and 40 the next. My 2 year old colt started having a runny nose a week ago, now my 2 1/2 year old colt is also having runny nose. The 2 year old colt does not have runny nose anymore. The 2 1/2 year old is showing more signs. He sounds funny when he whinnies. Also I got him out and he passed gas about 4 times with in the 40 minutes that I was with him. He doesn't seem sad and is eating, drinking and has regular bowels. Me and my son also have a sinus infection and wondering if he has the same thing. Should I worry or not? I had read the back posts and see that colds need to run its course. I would treat him as I do my kids, not take to the doctor yet and put on antibiotics, but let it runs its course, and if it doesn't get better then call the vet. This is the first time I have had a horse sick. Any advice?