I noticed last night that the inside of my horses mouth, mainly underside of lips and tongue (not the gums though) were very red. Over the past 6wks or so his eating habits have changed and he's dropped some weight even. He has been taking a bite of hay, chewing it, twisting his head like he's choking and then spitting the hay out. He is eating his grain fine and grazing fine so it can't be choke or an obstruction. His teeth were floated recently enough that I know that wouldn't be affecting his chewing ability. I did notice that he urinated two times in about 30min which is very unusual.
We did get new hay (orchard - which he's had most of his 21 yrs of life) so I don't know if there is a strange weed in it that he doesn't like or if there is something else going on. I tried to give him some of the leftover hay from before that he was eating, and he's not really eating that either. I hate to call the vet out unless I have to because it just costs SO much money.
I'm thinking some sort of allergy? The excessive urination has me a little concerned though. He spends a lot of time (usually 8am-8pm) outside so it's hard to tell exactly how much he's urinating because he may be going outside and not in his stall.