Thats BS and sounds like another "advisement" to me. On what grounds? Especially after she already found that the guy lied the first time. If your dogs are licensed and have their shots you would have grounds to sue if they took and destroyed your property (which in the eyes of the law pets are).
PS-
It sounds like this deputy didn't make either side happy.
Having seen some of the "vicious dog" statutes around the country -- it could be possible. Some of them are pretty messed up, and "a history of attacks" is all it takes to initiate the proceedings. Bill would have the right to challenge it in court -- but that's time and money, versus complying with a simple seizure order.
From Bill's account, the deputy was an ***. I suspect he's had some problems with dogs himself, and has zero tolerance. On one level, I want to say it was like the guy I had to tell not to walk his dog in a park one night. We were chasing some kids out, and the guy comes up walking his dog. The kids asked "Isn't he trespassing, too?", and so I was stuck telling the guy essentially that he couldn't walk his dog in the park, or else. No, I didn't really care, and I wouldn't have said anything -- but the kids were still right there and had directly addressed the issue.