My Dancer lost a TON of weight right before Rain was born last June (long story, and it's already all over this forum). She gained quite a bit of it back in spite of nursing her chunky monkey. Separated Dancer and Rain on 03/19/11, and Dancer is still looking skinny.
Finally broke down and took her back to the vet - different one this time - he specializes in horses. He ran blood work (perfectly fine) and then did a fecal. It was essentially negative - no surpise there, as we had wormed Dancer just a couple of weeks before. He found one little egg floating around, then said something that floored me. The wormer (ivermectin) killed the adult worms, but doesn't affect subadults. While we do alternate between ivermectin and fenbendazole (fenbendazole kills larvae) the regularly available products like we use - that you can get from TSC or Jeffers - really only helps with control. On some horses, like Dancer, they can get so many encysted larvae that their digestion is affected. They will have negative fecal exams, but still have a major worm problem.
So, starting this week, or weekend at the latest, we are going to powerpak all of our horses, to the tune of $200. (Good thing Panacure is cheaper to get in bulk from the vet than it is to get from TSC or Jeffers!) There's no sense in just doing Dancer - they all probably need it. Even Rain, the filly, has a bit of a worm belly, and she's negative for worms.
Vet assures me that the powerpak will help my Dancer - and will help her gain the 50 pounds she still needs. I'd like her a little fluffier than that, but the vet says all she needs is 50 pounds, and getting rid of the worm belly will help her look less ribby. I hope he's right!
Plain Old Dee, horses Dancer and Rain I believe in dragons, unicorns, good men and other mythical creatures!