We've had a few Beagles bitten, and one GSD. We have timber rattlers. One of the beagles lost his eyesight, but he was bitten on the brow. I'm really surprised he survived the bite. There were five pups that got on a snake when out hunting and all came back with bite marks on the face and throat. Don't know what kind of snake, could have been a moccasin. I watched a tiny rattler bite one of the beagles in the kennel before I could get in to kill it. She survived. The GSD has a large deformed paw where he was bitten that never healed right. He was bitten again about a year later on the neck. I'm sure that that snake had just used up his venom, as he was over five foot long, and Ben didn't have near the reaction as the first time. Other than the dogs seem to develop a hate for snakes (and some of the scars can be nasty) I've not seen a lasting reaction. Or I guess I should say that I've not recognized a lasting reaction.