Possums are easy prey. We don't have many round here but when I was in the western ramparts I had a Boxer that did them in on a regular basis. Shrug, its better than they and their offspring making my home their own. (they breed almost as bad as mice if they find a cozy spot they can call a nest or a den)
Any ways, I said easy prey because they're better than some of the alternate relatively common pests like raccoons (they can tear the hell out of an unwise dog), or porcupine ( had to put down a nice gun dog once because of those damnable critters) or (spend just one night with a bucket of bloody water and pliers pulling quills and you'll know what I mean), or last but not least for reasons rather self explanatory if you ever have to deal with it is the skunk (he probably won't kill it, but you'll know he found one crossing within his reach. And I haven't found any 'real' recipe to eliminate the odor other than time)
Possum? Some chicken that finds enough lift to fly over a fence? it won't make that mistake again. A bird? must of been one stupid bird. A hedge hog? Good dog, now you don't have to go out and murder it yourself because it made your home or garden his.
I'd worry more bout my neighbor throwing 'stuff' over the fence for my dog.
Scratch behind the ears from me to Black.
Ogoun