at wit's end

During Bobby's first hospital visit, Linus's collar was discovered in three pieces in the yard. I haven't had time to replace it, so they've both been in the pen. Tonight I go to feed them, and Lucy's collar is chewed in pieces with the plastic clasp totally missing. It was partially buried.

We have put in an electric fence. It quit working. We bailed them out of the pound. And again. We then called a professional company and had a new electric fence installed, and then had it repaired. Now the dogs refuse to wear their collars. I'm at my wit's end. Any suggestions for my vagabond wanderers?