Ivomectrin should not be used on Border Collies it absolutely causes siezures. We chose Advantage Multi based on research and advice from several other Border Collie owners. Our two year old Border Collie has had no problems with Advantage Multi.
I read on here that a women's Border Collie had seizures when her dog was on Heart Guard. I do not keep my Border Collie mix on Heart Guard year round. She has had three seizures that I have witnessed over the years. I went through her records and she was on Heart Guard at the time of all three seizures. I don't think I'll put her back on it and I'll be curious to see if she has anymore.