1 of 3 horses on farm parasitic

[sassy]

Anyone have any experience with this? We have three horses, and recently did fecals on all of them. One came back heavily parasitic and the other two were negative. The two that were negative are old retirees and don’t leave the property. The positive one is a young show horse who goes places fairly frequently.

The two old guys go out together, and the younger one is on solo turnout. They rotate fields and have all been out in the same field at some point (not all together) so we don’t think it’s related to the farm or a certain field. All on the same deworming schedule. Is it as simple as the one may have gotten exposed to parasites at a horse show? It’s a bit of a head scratcher for us. If anything I would have guessed the old guys with weaker immune systems would be more vulnerable but

[JB]

Not atypical at all, especially for a young horse (how old?) who also goes places (stress)

How high was his FEC?

[SusanO]

And some horses have a natural immunity that others do not have. My two older ones never had anything show up on a fecal despite being in a smaller pasture. The younger one was a high shedder (2,000) when I got her. Naturally she is hard to worm with a paste wormer. She is in a large (15 acre pasture ) by herself so you would think she would not have high counts now. The last few times I did a count she was about 500 before I wormed her. She just does not have as high an immunity as the other two. Otherwise she is very healthy. It happens.

[JB]

Roughly 80% of horses take care of strongyles on their own once they’re 2, at least by 3 (which is as long as it takes to self-control ascarids). These guys need 1, but usually 2 dewormings a year to control bots and tapeworms. The once a year is for those where botflies and grass aren’t an issue, or where Winter is spent entirely off grass and it’s cold enough.

The other 20% - most need 1 additional deworming, and a small % need 4 dewormings a year

I wouldn’t assume this young horse will always need additional help, but it will be good to do regular FECs on him for a while to see what his trend is

What is your deworming schedule?

[PaddockWood]

I got an 8yo 4 years ago, who tested 2100 in his FEC and I have picked my fields ever since. Also went through a course of several types of dewormers as he’s a mustang so I had a theory that he might not be resistant? He now tests low consistently. He isn’t travelling though or stressed so there is that.