"It sucks getting old!!!"
I agree for humans, but I honestly don't think that dogs realize the passage of time.
When our beagle crossed the Bridge at almost 16yo, I missed her so much, and still do for that matter, but as soon as the weather warmed up, I planted a dogwood tree in her memory. It took a few years to bloom, but now it does consistently every spring, right now in fact. I always feel that the blossoms are a gift and a visit from Kathy Beagle, and I spend time thinking about what a sweet little angel she was.