Hi all, I hope I've posted this in the right place...I have 4 geese, one which is acting a little strange and wiggles his neck back and forth quite a bit, not necessarily gaping his mouth, but also has some watery poops. I'm suspicious of worms but don't have a vet that will take a fecal sample from geese unfortunately. This guy also has been shivering off and on the last few days. I've seen him do this before on occasion, then he comes out of it. Strange. He's otherwise seemingly healthy, eating, drinking, etc, same with my other birds. I do have a bottle of ivermectin drench that I was able to get at a pharmacy, it's 0.8 mg ivermectin per mL, but labeled for sheep. I have no idea what dosage my geese should have. I also have a bag of piperazine powder. I have some 'stress-aid' electrolytes that I can give him in the meantime. An advice would be greatly appreciated, thank you 
