I have the domain PetNeighbourhood.com which I bought to do a similar site which I never got around to.
Feel free to pm me an offer if you want it
Dave
EDIT// I should probably explain that I used the word neighbourhood as it is a friendly local term and I planned to let the friends have "buddies" so essentially the owners played the part of their pet on the site and helped them explore.
Using one of the "role play game" mods I was going to take this further to allow games and tasks to take place which would earn points as discount in a store or to win entries into competitions for physical products etc.
There were lots of other ideas too but this domain covered everything, was specific enough to let people know what the site is about but is broad enough to allow you to do pretty much anything related to pets. If one day you decided to make it just a 100% shop, the name would still suit. I always choose my names with future proofing built in
Just a shame I never get around to building half the sites lol