It's okay to feel taken aback when a dog, particularly your dog, growls at you or a child. But please don't punish the dog for the warning instead thank them.
A growl is a warning from your dog that they are not comfortable - fearful, threatened or aggressive. It's saying back off I'm not happy with this situation. It's a critical part of the behaviours that have been built into dogs to try and keep social harmony and stop fights that could kill or maim.
It's a warning - an important one to heed and do something about. But what? Well firstly remove the tension from the situation by getting out of the immediate situation before someone does get bitten. Now think about what was happening that your dog was so uncomfortable about. It might be something obvious that he wasn't happy about like being cornered under the bed with a tissue with no escape route and an irate human trying to reclaim the treasure (what is it with dogs and tissues and how important they become to humans when dogs have them?). It could also be something less obvious.
Here's an analogy thanks to Robyn Hood from the TTouch world that might help: Think of a cauldron of water sitting on top of a bunch of candles of different sizes. When the water boils over a bite is far more likely to happen. Now let's take one dog's candles. One candle (a medium size one) is a fear of children. Another candle is a dislike of strangers (a large candle). Another is loud noises and yet another smaller candle is being uncomfortable when people are around his food bow. Now on a particular day when the dog is not feeling all that happy (yes they have bad days too) you have visitors over and a child is running around the house. The child is a stranger to the dog and making lots of noise as she plays. When the child enters the laundry where the dog is eating his meal the dog growls at the child. Lot's of candles here that you need to identify and work on reducing so that the incident doesn't recur. You also might need to have better management skills in the meantime (or perhaps for life).
Take the emotion (the scare, the humiliation, the disbelief) out of the situation and consider what caused the growl and how to deal with the issues so that the dog doesn't feel so threatened by the situation.
But whatever you do don't punish the dog for the growl. Why not? Well as already mentioned the growl is part of an escalating set of behaviours on the way to a bite or multiple bites and dogs are smart at figuring out what behaviours work and which ones don't.
If you punish the growl out of the dog there goes a major warning system - next time the leap may be from dog body language that you and others don't recognise to a full on bite - and no one wants to go there.
More on some of those more subtle messages in later posts. And I am not advocating doing nothing about growls but rather thanking your dog for giving you the warning and then coming up with a plan (perhaps with professional help) to work through the issues that contributed to the situation so that confrontation and bites can be avoided.
For more information check out the following as a start:
- Off-Leash Dog Play. A Complete Guide to Safety and Fun by Robin Bennet and Susan Briggs