Our dog is 7 months old. He's a border terrier cross and very excitable. We got him at 3 months but as he seems to go a bit over excited when meeting other dogs, we haven't taken him off the lead yet. There are no fenced off areas where we live and I'm bothered he'll run off if I let him off elsewhere. Any advice much appreciated please. We don't know anyone locally with a dog.. I know mixing him with other dogs would be beneficial but our friends have cats!