Fearful Terrier-mix gets muzzled at apartments!

I wrote to get advice about my dog "Jr." He is a Terrier mix, and seems to bark at nothing, except when I have him on lead. The rest of the family find he barks almost non-stop! Others find this aggressive, and I dont blame them.
He has nipped at people, while on lead. He also was present when my Corgi was attacked by two pit bulls on Mothers day! That seems to have made things worse.
The advice I got, was what I had guessed already, Id need professional help to get both dogs into a better, calmer place not only on "The walk" as someone on T. V. calls it.
I will see what happens if I can afford the special training.

DeeEzBee about PetCoach by Petco