Crabby Pooch

For the life of me I cannot figure out why my sister's new dog does not like me! 'Guero' the grouchy chihuahua, pictured shown last week, growls at me sometimes. What the hheck, I love dogs and have always treated him nicely. He gets along fairly well with my dog, but when I get close to him and try to cuddle him he growls slightly. I can't help but feel somewhat hurt :( That doesn't stop me though, I still pick him up and rub his little head. He is such a cutie, even though I know he's a crab!