Just two nights ago, my around 30-year-old senior mare colicked. My vet administered some Banamine, and she's fine now, but he said she's slightly dehydrated. I've been trying to get her to drink more. Although I'm not watching her 24/7, I know for sure she drinks very little--when I separate her from the herd and give her some water, it's usually hardly touched in the morning, if she touched it at all.
She has plenty of salt. I had provided her with a salt block, and I'm looking for a container to put some loose salt in. She gets 2 tablespoons of salt thrown over her feed, morning and evening. It doesn't seem to be working.
I tried two methods I found on the Internet, one was squirt a mixture of applesauce and salt in her mouth and she should drink within a few minutes, and the other was squirt some corn syrup (or in my case, vegetable oil) into her mouth and she should drink within a few minutes. Of course, neither of them worked.
My mare's water is the cleanest water I think I've ever seen, and I scrub it out twice a day. I am trying to find my water heater so I can offer her warm water in one bucket and cold water in another, but since I am having trouble finding it, I try and offer her warm water after each meal. None of this is working. My other three horses drink gallons and gallons of water a day, so I know it's not poor quality water she just doesn't like. She's the leader of the herd (amazingly), so I also know she can get all the water she wants if she decides to. The water is very easy to get to. It's somewhere around 100 feet from the big round bale she's usually eating at, so it's not too far either.
The only other option I can think of is to manually squirt water into her mouth with my 2 ounce syringe, but in order to get 8 gallons into her (about 1 percent of her body weight) I would have to squirt 170 syringes full of water into her mouth, three times a day. Although I'll do just about anything to get my mare her water, I don't really have time to do this.