Before you spend money on anti bark collars, electric shock collars, pinch collars, spray collars or spend small fortunes on books which may be very confusing, take a moment to consider how much value a professional dog behaviourist gives. A professional one will not advise the purchase of expensive articles like this which distress your dogs.
If you go down this route it is highly likely that you will end up contacting a professional in the end because of the damage you will do to your dog. Once E collars, prong collars and the like have been used, the damage done to dogs' emotionality is usually permanent! Electric shock collars cause aggression! You might suppress a signal of aggression (e.g barking or growling) but all you will have succeeded in doing is preventing your dog from actually warning. This then leads to BITES without warning as the warning signals will have been punished out. Aggression is usually fear based so E collars makes this worse not better!
There is also a trend to use prong and pinch collars too and trainers who recommend them are happy to say they cause no pain or fear. Just ask them to put one around their own neck and let you deliver a level 7 correction and I am sure they would not let you. These devices are as bad, if not worse than electric shock collars as users can inflict as much pain on them as they feel like doing at the time. When the electric shock collar is officially banned (and the government has already agreed they will be banned), more trainers will use these instead.
There appears to be an increase in the use of these products locally which I find VERY depressing indeed! It makes my job MUCH harder. This is why I feel the need to rant!
The Electric Shock collar is illegal in Wales. It has been agreed that England will also ban them, but this is yet to be written into law! Please see a recent study into dog welfare re the use of electric shock collars here.