He's really nice looking! That's cool that he plays fetch with you; my friend's rottie just looks at me like I am an idiot if I throw a ball his way
One thing I should say though; it might not just be with rotties; maybe any breed of dog, this could happen. Someone we knew of, had a rottie, and they were letting it chase after them as they rode their ATVs all over. Well, they noticed that the dog had disappeared; they found him dead on the side of the trail. I guess he didn't know enough to stop running when his body was tired, and ran himself to death. Not that this is a rottie-only thing; I have seen aussies and other dogs who are on the verge of exhaustion, who would play for hours more! Just a thought, this topic being about rots and all