My 14 year old quarter horse is losing weight and I'm not sure why. I need some suggestions. He had is yearly shots in April, about 2 months ago and the vet said he was at a good weight and made it through the winter great. Now that his summer coat is coming in I can see his ribs. I've never had a problem with his weight. He will eat anything. When he came to me about 2 years ago he was actually a bit overweight. I have him on sweet feed 12%, a scoop in the am and pm (probably about 3/4 of a lb per scoop) and 2 flakes of hay. He has always been fed this way since I've had him and hes done just fine. But hes losing weight. I notcied that him and my other horse has a bit of diareha and I'm not sure why. Could it be the change of seasons? Nothing in their diet has changed. I wormed him about a month ago with invermiticn. I also noticed that he's rubbing is butt. I havent seen him do it but the top of his tail is a little messed up. And with the weather getting nicer he is getting ridden more often, maybe 3-5 times a week for 30 min to an hour and a half. Sorry for being so long, but I'm trying to cover all the bases! So, what do you all think?