It's tough, but you have to stay rational and keep some perspective. No doubt everyone here offers their pet an excellent life and should have no regrets when the time is over. All the love in the world simply cannot turn back the clock.
10 days ago, we said goodbye to Goldie. Two days later, I left to pick up her ashes and got a call from my wife. She had a puppy that the girl across the street needed a home for. I arrived home with the ashes to a new puppy. We had already discussed what type of dog could possibly get alone with our other two, a male and female 60lbs and very dominate. It would need to be a puppy for the old girl dog to accept it and a female for the old male to accept. That's what this dog was, a perfect fit, 4 month old little female. She has an injured eye and it may not recover fully.
I think young dogs learn a lot from older ones, esp how to behave. So, it seems to make some sense to have a bit of overlap in your various dog's age. In this case, all of our 3 old dogs were about 14-16 years old. They keep each other company too. This played out in an odd way....
A day or two of being kind of bad, the male dog Kona taught the new puppy, Zooey some manners. Everything is going well, except my wife calls me again, a big mass on Twister the old girl's gum.
Went to the vet and it was a fiasco. Bottom line is that Twister's xrays show no body tomours and she is perky and healthy, so I'm not going to spend $1000s of dollars to cut her up. She's home and warming up to the puppy, at 16.5. I was upset, but going thru the Goldie thing made me stronger, and the puppy gives me hope. Life is cycle we cannot break.