Karla, 10 is just not old for a Lab (and she looks like a Lab or mix to me). What does your vet save about improving her appetite?
Our Molly (also black Lab) is 14 years old and eats everything in sight. (although she is on prescription dog food for her heart) She has some trouble getting around and only one eye (other gone to cancer) and her "good" eye has cataracts but is doing well despite her age. Her spirit is amazing! (I think her cognitive ability has declined, too, but is comfortable in familiar surroundings and loves her "routine".)
I wouldn't give up on your baby. Have they done blood work and thoroughly checked everything out? Susie is a sweetie. Do look further into it.
(Molly is our 3rd Lab, the other three lived to 13! We feel lucky)