Interesting thread. I think there are many factors; Our family had three dogs very close in age. Benny is 2 1/2, Jake, DH's Borzoi will be 2 in a few weeks and Annie. our adult sons Pit is also 2 !/2. We are all dog lovers so I don't consider myself having three dogs. We each have our own dog for which we are responsible. We often go on outings together and sometimes train together.

It is also easy because the dogs are so different. Jake is a couch potato ( as long as he gets to run a bit each day) Annie is very submissive and also a bit of a couch potato while Benny is needs lots of exercise, training, a job to do.The three have really bonded as a pack. It would be hard if all three were like Benny!

For me adding a new pup is more an issue of time. I can't wait to retire or at least be able to work part time so I can spend more time with a pup.

I am hoping to add another GSD pup this spring or next when Benny turns 3 -4. I will be 58 ( yikes) but have lots of energy and also plan to be just working part time and have more time to devote to Benny and a new pup.

Here is Benny trying to be a couch potato!

Personally I would rather have 6 puppies at once than have 1 puppy and 2 seniors!!! (Or even a puppy and one senior.)

Never again will I have a baby and a senior! It just makes that much more work having to ride herd on the puppy to keep it from driving the old dogs crazy. And it was just due to the seniors age, they were fine with a puppy crawling on them when they were younger. But as they got older, they just didn't want to be bothered.

I think AT LEAST 2 years between is ok, but I think 4 or 5 years is even better.

Personally, I would say that I put age requirements on when I feel it's appropriate for me. If I offer an opinion to someone else , it's just an opinion or another point of view for consideration. I would not presume to say that my choice is right for everyone, just for me.