One of my dogs, Ruby, is afraid of my stethoscope. She doesn't like it when I'm holding it and she stays away from it if it's laying on a table or chair. She tried to bite the vet when he put the stethoscope on her chest, even had to be muzzled to have her last exam.
I try to tell her that the stethoscope is not dangerous, it can't hurt her.
Then I remember coming in to work to a night nurse holding an incident report for me.
Yes, she had leaned over an elderly patient the night before and her stethoscope had hit the woman in the eye and the poor lady developed quite the shiner.