You'd know if it was the weasels. They go POP! You don't want to get the weasels. German weasels is the worst. I recommend the weasels vaccine. An ounce of prevention.
Thanks for the replies. I looked at pics of the prickly pear, and that could have been it. I still think it fell from outer space. Or a weasel threw it at my poor dog. I hear they're pretty mean.