I'm a new horse mom and I have a 8 1/2 month old baby Friesian. I've had her since she was almost 5 months old. I've wormed her every month with Ivermectin. I read that I should stick with the same wormer for a while, and this I was told that Ivermectin is a good broad wormer. If there were any sings that she had worms, I missed them. She is looking great, in fact she is a bit overweight. This month I decided to change the wormer to Pyrantel. For two days she eliminated an enormous amount of roundworms. They were huge and I can't even put it in words how many she had. I'm horrified. I could see something like this coming out of a neglected horse, not out of my baby. Do I need to do a fecal every month? I did look at her poop before and she had one little worm in her stool once, when she was 5 months old, it was dead and I didn't think it was something to worry about. I'm so lucky that she didn't colic. I feel like I failed her. My sister-in law is an experienced horse person, and she didn't see anything wrong with her. She was also seen by two vets, on three occasions(for general check up and shots) and besides telling me to take her off the pasture, the vet didn't see anything wrong with her either.
And what should I do now to get rid of worms that may be on the ground? I do pick up poop several times a day, but I can't remove 100% of fecal material.
Should I give her another dose of wormer in 10 days? What kind? I'm totally freaking out.
What else am I screwing up?
Thanks in advance for your help!