I have just watched a really interesting episode of The Dog Whisperer and featured on the programme was Will Smiths wife Jada Pinkett, whose dog had an encounter with a rattle snake. The dog survived the attack, though he was very sick. He did die 6 weeks later, but he was 14.
They have snake therapy guys, who train dogs to keep away from Rattlesnakes, by using electric collars. Cesars Pitbull, Daddy, had the therapy and it worked amazingly.

I was wondering, we have a few people on this forum from America, Terry? and was wondering have you had this problem?

I have seen this episode a while ago - amazing! I lurve Daddy

I haven't seen the episode but I could do with that here with our Tiger and Copperhead snakes. Snakes are my biggest fear with the dogs as I know they will go for it if they see it but death comes very quickly from snake bites here. I'm sure the collar is very effective but I don't like the idea of using shock collars on my dogs.