socialising an older dog, Nemo is 8

Everyone says puppies need socialising, but nobody talks about older dogs who only know one family. Nemo is 8 and very gentle, but he barked at every dog on our walks and I was embarrassed. We took him to meet other dogs slowly because he was never used to it. We started in the quiet park in Khlong Toei at 6am. Only one other dog at a time, and we walked side by side for 10 minutes before letting them sniff. After 3 weeks he could sit near a dog without barking. Don't force the greeting. If the dog is not calm, just walk away. Nemo still gets nervous with big dogs but now he has a few friends. He also loves our budgie Jelly, who sits on his bed for hours.