A friend of mine, Rob, lives out in the middle of nowhere on a nice chunk of land, and he takes care of animals he finds or who wander into his yard. He's had quite a few dogs that he's cared for over the years, and most all of them live long and happy lives. This dog he had got sick, and while Rob was away working two 12 hour shifts, the dog died, and he found the bones a few days later. He said it didn't feel right to bury him, so he graciously gave the bones to me!
The bones were amazingly clean for only being outside three days. They had no tissues left, so I just soaked them in soapy water in my kitchen sink overnight.
Turns out I have an almost complete dog skeleton! I am only missing the tiny bones from the feet, a few tiny tail bones, the axis, and one lumbar vertebra, which were likely taken by small animals. Wild animals like rabbits and squirrels have front teeth that grow forever, so they have to have things to chew on to file them down, and bone perfect for this.
(Here's an example of what can happen to a squirrels teeth if they do not have appropriate things to chew on. Not fun! People who keep animals with teeth that grow as pets have many options for things their pets can chew on, both store bought and natural. Example from www.na2ure.com)
I put the bones together like a giant 3D puzzle, which was actually really fun, I think I could get into skeletal articulation! I'm thinking about wiring them together, but for now they're still layed out like this on my living room floor.