I didn't want to highjack the other girl's thread. I have a horse with loose stool too!
I bought a new horse at the end of October and she always has soft stool. Sort of soft and ploppy, firmer than cow patties, but not as solid as my other horses. It comes out looking normal but kinda goes "plop" and softens out as it hits the ground. She also seems to pee a lot.
When I saw her, she had a foal at her side which didn't come with her, so I thought maybe it had something to do with the fact she was still producing milk, or that the feed was switched, stress of moving, etc. But it's been about 3 months now and her poop is the same.
She has been dewormed twice, once with Ivermectin, once with something else (Safeguard I believe).
She seems happy and healthy otherwise, and I don't think she is under too much stress. The roads and trails have been so muddy and slushy that I hardly get to ride her.
I had the vet out to pregnancy check her, because she was out with a stud when I bought her, but the vet didn't think she was in foal. I didn't ask about the poop at the time because I thought she was still adjusting to her new home and feed and thought it would go away.
Do some horses just have softer stool, or is it something I should worry about?