First and foremost....EXERCISE EXERCISE EXERCISE! Lol. I agree with Szecsuani and Hockey's suggestions as well. Also, they're both quite young! This is puppyhood. When Zeke was a pup, he tested his limits with much older Rusty, who was 4-5 years old when I brought Zeke home. Rusty tolerated some things, and warned him when he was crossing the line. They learned how to act with each other, and how to interact with other dogs. It just takes time. The older your pups get, the more mature they will get, and therefore they will grow out of the hyperactive play(part of it). Let them play. They're pups! =) Just make sure that it never gets too rough, and I would actually discourage the jumping....if he learns to greet every dog by jumping on them, he may jump on the wrong dog someday. When he jumps, give a firm "Ah-ah!" This may or may not discourage him. If it does, praise him when he looks at you rather than jumping on the other dog.
I would also discourage the cat-chasing...it can turn into a habit, and the cat doesn't always enjoy it. Mud, being a Border Collie, needs something to do frequently. If she doesn't get enough physical/mental stimulation, she stalks my cat. Doesn't chase him, just follows him around obsessively...I fix this by saying, "Ah-ah!" in a firm tone, and offering a game of fetch instead. Simply telling the dog not to get rid of its boredom on the cat doesn't solve anything...so I give her something else to do rather than stalking the cat. Hope this helps! :dogsmile: