Ebenezer wrote:Never worm anything over 3 YO old.
I don't think that is good advice if you have liver flukes.
The parasite/host relationship has been going on for over 3 billion years - give or take a couple billion. It is like an arms race, no one wins.
Mammals do develop defenses against parasites but that does not mean they do not suffer damage, illness and down time. The parasite has the advantage in numbers - they adapt much faster than a mammal.
If you have taken parasitology, medical parasitology, advanced graduate level Invertebrate Biology and Speciation, you know that in biological systems, the host has a high probability of survival but the host may not perform well. In nature, survival is all that is needed to perpetuate the species but in animal husbandry, we want the host animal to perform at a much higher level than in nature. If you want performance, not treating or preventing a fluke infestation of the liver and the resulting damage is not going to get you there .