I wonder if maybe Dad is jealous of the attention his wife and daughter give the cat, men can be such big babies sometimes, is that a possibility?
I am very glad he does not hurt her in anyway, but cats are very sensitive creatures, she will indeed sense he does not like her.

Please don't give her up for adoption unless absolutely necessary, she has been with you for sometime and not all cats take kindly to being given away to a new home, especially if she is safe and loved and well taken care of by the rest of you.

Give it time, he may come around, sounds a bit like that, gosh it is hard to believe he was once a vet, and dislikes your cat, amazes me!!
Well good luck, just keep the cats well-being in mind, kitty has done nothing to deserve to be treated this way by anyone ok.