Afterward I talked with the vet a bit about it. I was worried because that is what I do and she was not. She pointed out that her gut sounds remained a loud and clear A in all four quadrants throughout and with her amazing CRIs, there was no way she was that dehydrated. But still....
I believe that she started out slightly dehydrated (reason she began drinking at mile 4 versus her typical mile 10-12) but the question is why and what could I do differently?
I think the first mistake I made was when I loaded her up. It was early and she hadn't had breakfast, so I fed her at the trailer prior to loading. I do this frequently so that she has something in her stomach for the acid to work on during the trip. But then we went 5 hours and she refused the bucket when I stopped to pee and again when I stopped for gas. She drank fairly well at camp, but not nearly enough.
I had always used Finish Line electrolyte paste in the past. With her history of not eating well, top dressing them on her grain isn't a good idea. Lately, however I have been giving her Grand Vite and she eats the powder readily. When I went to Biltmore in July I looked at the ingredients and it had everything the Finish Line did, in larger quantities, minus sodium. For that ride, in much sunnier and hotter conditions, I added table salt and mixed with homemade applesauce giving her a scoop morning, hold and after. Her hydration stayed at an A for all parameters all day with much less water available, not eating during the hold and at a much slower pace (5 1/2 hours for 25 miles). With that as my prior experience, I planned to do the same for this ride. Only it didn't seem to do her any good. In fact, when she didn't drink the entire second 20 mile loop, I bought some new stuff from Running Bear at the second hold. It was too late though since pretty much hydration is determined in the first 25 miles of exertion and she was already depleted.
Finally, I fed dry grain. I know everyone feeds a wet mash, but I had never had any success getting her to eat period. When we did the first 20 mile conditioning ride and got lost for 5 hours, the light bulb went on for her and she ate readily at the trailer. Ever since when we ride and she gets offered grain, she eats it. But it also has to do with the grain itself. I've always fed her a high protein low starch grain, mostly Strategy or the generic form of it, but this new barn feeds a sweet feed I've never heard of. It is still a 12% feed, similar to Stategy, but is covered in molasses and man does Gem love it. She has never refused it yet.
So what am I thinking of changing? A lot. Scientifically I know that you should change one thing at a time, replicating all other variables, so that you can hone in on the one ingredient that changes it all. But I'm not going to follow that rule. I'd rather change a lot and never know what is essential as long as something is working. Of course, keep in mind I also really really love keeping things as absolutely simple as possible.
- Wet the hay. She chomps down during the entire ride and will empty her hay bag given enough time. If I get her used to wet hay, this will give her some water during transportation, but since it isn't a super long drive or a ton of hay the risk of mold is pretty nonexistent as long as I always remember to fully dump the bag.
- Go back to Finish Line paste. It has always worked for me in the past. Is endurance friendly without bicarbonate, and easy to give. I can still use the Grand Vit as a top dressing the night before and after the ride to make sure she gets all her vitamins in. As an aside, she doesn't get any on a daily basis due to being fed in the pasture with others and playing musical bowls (the reason she doesn't get different grain as well), but I always give it to her when I ride and the entire week leading up to a ride.
- Using the paste also makes carrying it with me on trail a heck of a lot easier. The applesauce is messy and gets everywhere. If I had any on me, I would have given her some on trail around mile 10/30 or so when I started getting nervous about her lack of drinking. I'm against electrolyting when I'm uncertain how much water is available. The thought of shoving sodium down her throat and then leaving her without water for an hour makes my stomach turn. But this was the same portion as the first loop and I knew there was plenty of water for her. Even had she not drank then, it might have kicked in at the hold and made the last loop better.
- I'm going to spend the winter getting her mash friendly. She isn't incredibly picky, but isn't going to gobble down something just because it is in front of her either. I don't intend to make it as soupy as some I've seen where it is more water than grain because I still have a lingering concern over her not eating, but even damp is better than dry.
Hopefully the vet is right and her skin and cap refill were inconsequential in the grander scheme of her hydration status. I don't want to take any risks though. The next ride I can even try to make is in February, so I have plenty of time to make the above changes.