She needs immune support for whatever reason, imho. Get her right back on the probiotic as soon as the course of antibiotics is done, she needs to reestablish beneficial flora in her gut that is being killed off. No reason to discontinue the Omegas either, not that I can see, but your veterinarian brother would be the expert on the matter.
She hasn't been off her probiotics and omega 3. She gets them every day and she thinks it's her treat. Next week the ferns that I suspect are causing all the dogs skin problems are going to get a dose of Round Up. I wanted to wait until we are gone and the dogs are at the boarding kennel so they won't get into the Round Up while it is working. I'll plant something else on that slope.