This is so weird. My husband and I were just this past minute talking about how old does our babies have to be to be labeled a senior. Zada is only 7 and he thought she was already and I said I think about 12 for the tiny dogs, but maybe 6 or 7 for the large breeds. With great care and health, they should live to be 18 years old or more, so maybe age for seniors isn't set in stone now days!