I was interested to see that there are only two known contagious cancers. One is in Tasmanian devils and the other, surprisingly to me, is in dogs and wolves.
The idea of cancer being contagious is mind-bendingly scary. Thank goodness it's a rare occurrence.
Here's an encouraging little clip about the steps being taken to try to prevent the extinction of the Tasmanian devil.
Science Daily says this type of cancer is less likely to be fatal in dogs than in Tasmanian devils. (Sadly, it's always fatal in devils.)