We just added a now 4 month old pup to our household which had an 8 year old stud dog (he makes baby guide dogs for the blind) and 2 cats. It's been a month and it has been great. They get along very well. There is a lot more action inside and outside the house. They always want to wrestle and play fight. The older dog has not been quite as "alpha" as I would expect, especially as he is a stud, but he has always been VERY mellow. Some of the growling and not wanting to share food is perfectly normal and they need to sort it out on their own to some extent. Separating them while they eat is also a good idea.

I set up a separate fence within the stud's yard so that he and the pup can be "together but separate" during the day while I work. I am starting to let the pup spend time in the yard itself, but wanted to have a slow-ish introduction. The pup really can be a pain in the neck - he can be relentless.

Good luck!