It's interesting to speculate how clients and customers would react if they heard a dog barking in the background. I haven't seen any studies on this, though I have seen articles about how some employers are allowing employees to bring their pets to the office - the traditional office, that is. The goal is to make the office a more friendly place and to help employees feel better about working for this employer. If that's what's happening in the office, I suppose it could happen just as well in a home office.

I would have two concerns, however: first, it depends on how loud and distracting your dog is when it barks, and how annoying it might be to the other person on the phone. A few barks might be okay, but an extended period of loud and constant barking is something else. Second, you can probably get an indication of how your clients react by listening carefully to what they say when your dog starts barking. If they sound even the least bit annoyed by the interruption, then I think it's best for your dog to spend the day somewhere out of range of your phone while you're working at home.