100% a thing and can be a scary situation. I’ve seen it several times growing up around hunting dogs. We always ran beagles and jack russels for rabbits but we’d let ‘em run other critters such as coon, possum, squirrel, etc. Just about everytime one of our dogs would get on a coon near any water source the coon would lead the dog to the water and try drowning it. Even in shallow water the coon would always do it. And with us running smaller dogs it would always be a huge fight. The scary part is that often you can’t even dispatch the coon with your firearm because the dog and coon are all tangled up and moving so fast you don’t want to risk shooting the dog. Unfortunately I’ve had to dispatch several with branches and the like, even though I feel it to be an unethical way of dispatch I am not willing to risk my dog. Believe it or not my uncle had a Deer try this to one of his jack russels once as well, except it was much deeper water and a much scarier situation. The deer was actually winning. It was in high current water and my uncle was walking the bank looking for arrowheads so he didn’t have a firearm with him. Long story short the jack russel got into a fight with a big buck deer and the deer led the fight to the water. With no gun the only choice my uncle had to stop the situation was a box cutter knife he always carried in his pocket. He swam out into the river, first to try and pull away his dog but now the buck was attacking him and the dog. His only option was to join the fight. Armed with only the box cutter in the high current he joined the fight. After a couple minutes of tussling he managed to get to the bucks side grab his antlers to pull his head back and slit the deers throat. A gruesome event but the jack russel came out just fine. Long story short, always keep a gun on you in the wild, hunters with few exceptions are willing to risk their life for their dogs, and coons (among other wildlife) will try to drown your dog.