I understand it can hender the dogs performance, but wouldn't that be better than a dead or cut up dog? Sooner or later even a loose bay dog will be gutted and extremely expensive surgery will be the only option.
A dog that can't move and perform will get cut up. A bay vest won't stop a dog from getting gutted. A bay dog in a full catch vest is a disaster waiting to happen... can't move, heat stroke, getting hung up, drowning, etc...
My bay dogs only hit the ground with tracking collars on... i'll continue to "gamble".
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I run a 3 layer vest with 4 layers up front. It's Kevlar sandwiched between cordur, which is briar and water resistant. Also, it has a polyfelt chest plate. The dogs move and swim well with them. They rarely get caught up. These vest have never been cut through. I surely don't see a dog getting gutted anytime soon. Nothing seems to be pig proof though. I only hunt at night in the summer and those are usually the cooler nights after a good rain. Heat is never really an issue. Not saying it couldn't happen though.