This story is so strange. > her veterinarian recommended she purchase one Every small animal veterinarian I've ever met (probably dozens at this point) has said in no uncertain terms that no one should ever use flea collars on their pets. I wonder why this one said otherwise.
This is a vet I trust very much, and who has given my cats decades of excellent life. They do not sell it directly and do not make a profit on it.
I don't know what the difference is between my vet and the ones you know. Do your vets recommend the drops instead? I use the collar because one of my cats did not react well to the drops. (Nothing serious, but he had a bald patch.)
I've never had a problem with the Seresto collars. Which isn't to doubt the article; the incidence of problems is high enough to be of serious concern but low enough that it's not surprising that I would observe no issues. I trust my vet will keep me posted.