Funny you should mention that, one of my dad's dog's died from a rattlesnake bite a few years back (he was bit on the nose). The vet said that rattlesnake bites don't usually kill dogs (at least not big dogs like Reuben was, flatcoated retriever/spaniel mx) but Reuben's system was weak because he had JUST finished his whole round of heartworm treatments (he was positive), and had just been diagnosed heartworm free. It was so sad, my dad put so much effort into Reuben, and he died just afterwards by something not even related. This is the same man who took my childhood cat, TinkerBell, in for brain surgury to remove a brain tumor (she was 13 at the time), she died a month later, the surgury was well into the upper hundreds. His love had no price.... He has a sheep that he bottle fed, and that slept in bed with him and my step-mom for several months.... He raises sheep also, but this one is just a pet, it runs with the dogs more than with the other sheep. I believe he named him Joshua, and had him neutered and everything. I've never met the sheep, but he sends me pics occasionally....
