Shelties generally will live for 12-16 years.
Rescue dogs come in all ages. Many people want young dogs, but PLEASE consider opening your heart to an older dog. They most often are the best behaved. Full grown, seasoned dogs, need homes just as much, if not more, than the younger dogs.
First year – Young Shelties will chew indiscriminately. They may not be completely house-trained, and requires a lot of attention and training. It is not good for the puppy to be left unattended for long periods of time.
1-3 yrs – Still very puppy-ish, hopefully house-trained, but may make mistakes, and will still chews on whatever is available. Very Young Shelties still need a lot of playtime to burn off energy (walks will help). They will chew or dig and bark from boredom if being left alone a lot. A very young Sheltie MIGHT work for someone who is gone only PART of the day.
3-5 yrs – For short times, may be trusted alone in the house and will sleep. Still young, this Sheltie still needs several hours of playtime each day. S/He enjoys walks. These young dogs become bored easily and will chew or dig from boredom if not exercised.
5+ yrs — YES! The perfect dog! No more chewing, reliably house-trained, content to sleep while you are gone, will want to play for a few hours, but will be ready to sleep again after playtime. Best choice if you are gone a lot.