Remember a few years ago about the pig who was an emotional support animal?
Just because you may think it's a load of B.S., like others have said, there are dogs that can detect seizures before they happen. A few months ago I had a lady who appeared just fine. She looked normal, she talked normal, she ate everything on her plate like anyone else.
I inquired about her female Doberman at her feet and she then informed me that her dog was an Emotional Support Animal that detects her seizures. These animals are not listed on the FAs paperwork, which I really don't like because of instances such as the OPs.
I have written it up so many times that we need documentation for these animals incase they are to sit next to someone who is highly allergic. I did have one pax who was seated near a dog on a transcon. Fortunately, we found another seat for him and he was happy we has far from the animal.
I love animals, but we have people out there who don't pay the Animal fee and bring their pets onboard anyway...without thinking of those with possible allergies.
Sorry to hear about the rudeness of the FA in your case!