I recently went to a home with a sweet male terrier mix who barked all the time according to the owner. As I approached the front door I realized I was not feeling safe based on the body language and rapid barking which was being sent my way through the screen door.
I took a step back initially as the dog began to jump, bark, snap and lunge at the door, my presence was clearly a stressor. When I felt as though the dog may push the screen door open I raised my hand to brace the door just above the door knob. Instantly, the dogs bark changed from rapid to fierce with a show of teeth and higher lunging and snarling. I looked away from the door, but continued to hold it shut knowing quite well that this little dog and I were FREAKING each other out.
Dogs growl at people to warn them to go away, which is very normal dog behavior. I highly recommend you comply until you are able to earn the dogs trust. I would never recommend correcting a dog for growling at a human, or even a child, as the dog may not give a warning growl next time and simply bite as a way to make himself feel safer.
To avoid being bitten by a growling dog, it is best to rule yourself out as a threat. Help this dog see you as a person that brings yummy treats, avoids eye contact, avoids entering his personal space and he will soon settle in your presence. Be ready to toss treats again as you begin to move about as your movement may be seen as a threat to this dog.
My point here is to help you know what to do when you find yourself being barked at by a friend’s dog. Simply take some time to earn the dogs trust by taking some cheese or cooked chicken. I do not recommend you hand feed a snarling dog, but with the owner present and the dog behind a gate, toss a treat behind the dog and leave the area, repeat 8 or 9 times or until the dog begins to settle. Your friend may be embarrassed by his dogs reaction, but you can let him know you understand that this dog is simply afraid and it is nothing to be embarrassed about. Making an owner feel bad about the dog he or she loves is what you should not do.
It took me 20 minutes to make friends with the little terrier that acted like he was going to eat me when I arrived. By approaching the gate he was behind and tossing some chicken behind him and then walking away, repeating this 8 or 10 times using the phrase “find it”. I then sat down and they removed the gate and the little guy came and stared at me, so I continued to toss food behind him, then I proceeded by walking about the house while playing the “find it” game and eventually ended by playing “touch” and hand feeding the terrier. Only because I could read his body language, and am confident not to threaten him in any way, I was able to progress so quickly. There is no timeline for building a trusting relationship; safety is the most important focus! When the owners teared up at the sight of their dog being “normal”, I was thrilled to begin to work with this family and help their terrier become a happier dog.