has anyone ever heard of problems with Ivomec / Ivermectin

[localpigeon]

I have heard of birds dying after taking this medicine because it's so toxic. One cockatiel that I rescued died the day he had his Ivomec dose from the vet. He was already suffering from fatty liver disease. The vet guaranties it has nothing to do with the medicine but then she would said that. I have heard of a canary that died on the same day as taking Ivo as well.

Does anyone know more about how dangerous this can really be for birds?