Is prozac helpful for dogs?

I have a 3 year old hound mix (mixed with a bunch of breeds) She has become more and more controlling with the 2 other dogs. She started guarding the doorway, water bowls, couch, etc. It’s not all the time, just sometimes. She also has this behavior where she nibbles (cobs) on the middle dog’s neck and face 1.5 any time there’s a higher level of excitement. That could be just walking across the house, when we come home or let her out of her crate.

She recently got into a fight with the middle dog. They were playing and she became too aroused and couldn’t calm down. They fought for about 30 seconds and stopped on their own.

We saw a behaviorist and they suggested Reconcile (fluoextine/prozac).

I guess I didn’t consider that her behavior was anxiety based? He said she definitely has anxiety.

Has anyone had dogs improve with Prozac? Any risks I should be worried about? Thank you!