My dog - 9 year old german shepherd / lab mix spayed female. The last 2 years she has slowed down and gained some weight. I noticed her doing something weird recently - when she wakes up from sleeping she sticks her tongue out and pulls it back in (almost like if she were drinking water) and when she pulls her tongue back in, sometimes her jaw shakes (like when we shiver).
She's just been slowing down gradually over the last 2 years and it is hard for me to say "ok now we need to worry" because nothing drastically changed with her. However, from 3 years ago to now she went from acting like a hyper dog to laying around all the time - like humans going from 20 years old to 90 in 10 years?

The average lifespan for labs and shepherds is 10 to 13 years. So, it is possible that she is just getting older and slowing down. Maybe not 90 yet, but up in her 60s or 70s.

I agree with froggy she is getting older. When is the last check up she has had. My shephard turns ten in two weeks . My last shephard lived until ten and a half . Mine is much slower than before but still alert and happy. Somedays he is more active than others and after a lot of playtime the next few days he takes it easy. If yoou think there is abig change get her checked out. Other wise just relise like humans as we age we slow down.

Just a general note: dogs age faster than humans do. That's why vets will often recommend bringing older pets in twice a year (or more). Going more often allows the vet to notice changes earlier.