I take my pups to dog classes, not to interact with other dogs, but to interact with me in the presence of other dogs who are controlled by their owners.
I do not go out of my way to socialize dogs to cats. Generally if a pup is homed in a house with a resident cat, they are fine. They can be fine with pets and not fine with invading cats in the yard. I don't expect my dogs to be walking down the street and experience someone's pet cat walking with its owner. If they see a stray cat it is the same as a squirrel or bird or rabbit, a quick, Eh! and With Me, or Leave It, ought to do the trick.
Bear Cub, Hepsi-Pepsi
Cujo2, Karma Chameleon
Ramona the Pest, Kojak -- who loves you baby?
Tiny Tinnie, Susie's Uzzi, Kaiah -- The Baby Monster.