This is my first hand experience with snake bites and dogs. Here in my area, there can be copperheads, but hey are rare. The prairie rattlers are a little more common. On at least four occassions I have found them right by my house, front door, back door etc. That is just too close for comfort. (usually it's at that point the poor things pass away
I've had three different dogs get snake bitten. I've never seen the actually occurance, but I've seen the end results. The first time it happened, I was allarmed, and panick stricken. It was my black lab, and he was probably about 40 lbs at the time. (he's not a big dog, at 10 years old he's only 50lbs now) They tend to have HUGE localized swelling around the site of the bite. Now I'm only guessing but I would guess that each time it was a rattle snake bite. (simply because I've seen them, and I haven't seen any copperheads around here first hand)
I called the vet, and their advice to me was, determine the bite location. That can have a significant part of the severity. The nose and the throat can really be a problem. Make sure he's comfortable, and is breathing well. I said that my lab was bitten on the side of the nose, and it was about the size of a football. They asked if he was breathing well, and I told them that he was. They said you can bring him in for us to look at him, but I'm guessing he will be alright.
I was really concerned, so I took him in. I was supprised that they didn't say "bring him in STAT!" I was supprised that they didn't run a battery of tests on him, and administer anti-venom. But that's not standard procedure in this vet clinic, for this area. They said without knowing the species and the amount of venom, it was really a crap shoot, and dogs can matabolize a dose of rattle snake venom that would be leathal to humans. So I just kept him comfortable, and he recoverd just fine in about a week, swelling went back down and now he's a fully recovered and a wiser dog. (he won't go anywhere near a snake, and when I find a snake skin he acts really skiddish around it untill he figures out it's just a skin, then he goes crazy with the KILL IT mode!)
I had a blue heeler get bit a few years later, about the same area. It seems that if a snake bites a dog, it's most likely going to be around the muzzel area somewhere, as dogs are enquisitive and are constantly sticking their noses places. I just loosened up her collar to insure she wouldn't have any pressure from the swelling there, and she was fine in about a week.
The last dog to have this happen was my current female PYR. I took some pictures of her.
She looks like a bull terrior in this photo. That's the swelling in the nose. I don't think she swelled up as much as the other two dogs did. Probably because of her weight and her matobilisim. (pyrs have a slower matobilisim than other breeds do)
This shot doesn't show the swelling quite as much. I would assume that the amount of venom injected could also have something to do with how much swelling occures.
Here she is a couple months later, no swelling.
I do recomend a vet visit if your dog gets snake bit. I would assume that a smaller dog is more in danger than a larger dog. I would assume that a rattle snake may not be as leathal as some other breeds of snakes, so it could well depend on what species of snake that bit the dog, what actions need to be taken. For me, and my three examples, I took one in, and they didnt give it anything, not even an asprin.
Now to prevent snake bites..... you can do like some people and just never let your dogs outside.