backhoe...
Funny you should mention those two species...several years back, I had a self-described 'educator', who was an internet goat 'guru'...stalking me about veterinarians misdiagnosing barberpole worm (H.contortus) infection as a leading cause of death in small ruminants, with her contention that it was really liver flukes, and that veterinarians couldn't tell the two eggs apart.
She was WRONG, of course. If you look at photos of the eggs of those two parasites, they really don't look that much alike - other than being sort of oval in outline. Haemonchus has a little morula of developing cells inside, and the fluke eggs have a prominent operculum (trap door) at one end. That, and if you have(and you really need one!) an ocular micrometer so that you can measure egg size, you'd find that the fluke eggs are at least twice as big as the Haemonchus eggs.
In 30+ years of practice and diagnostic pathology in AL, TN, MO, KY - I have seen exactly ONE liver fluke in an animal(elk) - but hundreds, if not thousands, of goats/sheep that died due to Haemonchus infection. In some areas of the country, liver flukes ARE a problem - but not anywhere I've been...
Hook, if you're gonna undertake it, read up on McMasters or Modified Wisconsin counting techniques for quantifying how many eggs/gram of feces are present. Again, an ocular micrometer is very helpful if you're gonna be trying to definitively ID specific ova, larvae, or coccidia oocysts. If you can't measure it, how do you know how big it is?
