After the only doctor in a small isolated village falls prey to a rising unsolvable disease–making the victim’s psyche that of farm animals–a vetenarian steps up to solve the mystery, only to discover a bigger conspiracy.

Agree with most of the previous comments. When I first read small isolated village for some reason I imagine it somewhere like Africa but I don't know whether this is correct. To me, the result of this spreading further has more of an impact if it's based somewhere highly populated. I think it would be good to have some idea what's at risk if it spreads. Would it drastically change the premise to have it based in Washington DC (or similar) where the risk of it getting into government could have global repercussions? Politicians and bullshit go hand-in-hand after all...

When the CDC doctor contracts a mysterious disease that make human behaves like animal, a misanthrope veterinarian must find a solution before the isolated village is permanently quarantined.

Agreed with most of what FreeWill wrote.

This sounds like a good twist on the infectious disease trope and has some wonderful human/animal nature theme elements built in. I think you need to rewrite the logline from the veterinarian's point of view and raise the stakes by making them personal.
For example:
After her brother contracts a mysterious virus that makes humans behave like animals, a xenophobe veterinarian is the only one who can save the isolated village he lives in.

It almost sounds like a black comedy instead of a thriller.