I Googled rattle snake training and found several companies in the Phoenix area that provide this service.
I won't go into all the details. Basically the dog is placed in a situation where the dog safely gets to see and smell a snake, and as soon as this happens, the dog is stimulated, via a shock collar. This happens three times and whala - the dog is trained in snake aversion. Many of the sites recommend that the dogs get a refresher course every few years. The cost is $89.
Update on the cows:
We've not seen the cows again this week. Joe from APS, Arizona Power Services, knocked on Marilyn's door about 7:30am. He is out here with a crew to install a "cow barrier" on the property out back. He told me the cows are getting too close to the power station fence that is about 200 yards from Marilyn's backyard. Not sure if the barrier will stop them from visiting Missy. I will have to check with Marilyn.
Today we are going to the Verizon store to check on phone upgrades for Marilyn. We are going to see Nancy, the lady that does Marilyn's hair. And then we are going to see her CPA in Sedona.