Comet was our beloved GSD mix. He had unusual coloring for a GSD, with a reddish head and tip of his tail. He may have been 10% wolf - he certainly acted wild enough at times.
We acquired Comet for protection at a time when F.B., our black lab mix, was declining. Our daughters were still young and we had questionable neighbors. Stan and our older daughter picked Comet out at the local animal shelter in Sacramento. He had been placed there by his owners, and his name was "Diesel" at that time. He was about a year-and-a-half old.
He seemed very docile. After we took him to the vet for a checkup and neutering, we found out he had kennel cough and diarrhea. For the first ten days, he had to be confined to a bathroom, and followed around when he was outside so that the poop could be scooped up and no whipworms could get into the soil. He was very calm and seemed grateful to be in a home rather than the pound.
Once he felt better, however, there was a BIG behavior change. We let him out in the yard and he started charging around, coming at us at top speed, nipping at our feet, and barking loudly! He was scary - there seemed to be no way to control him at all. At that time we didn't know that this was his normal behavior after he had not been exercised for a day, let alone ten.
He was terrible on a leash, pulling like no get out. We were afraid to let him off leash since we weren't sure he'd come back. We took him to an obedience training class. He was so excitable in there that the teacher told us we would NEVER be able to let him off leash anywhere. Fortunately, that turned out to be an inaccurate statement.
We took him hiking in a place where there were no other people. He ran his heart out in all directions but came right back to us. We had one part of the problem solved, but we certainly couldn't take a two-hour drive every day, and we also didn't want to fire up a vehicle to take him to a dog park, especially when we had a few regular parks close by.