I am guilty of this, too, despite it being one of my training hobby horses!
I’m going to talk about “no” but everything applies equally to my “ah ah” or any other word or noise you may use when your dog does something you would prefer they did not.
One of my brilliant colleagues suggests experimenting with this on your human friends or family – when they start to speak, say “no” sharply. If they stop, ask them how they feel ! If they carry on, then your “no” wasn’t strong enough – try it on someone else, but louder.I suspect that the person won’t feel great about your experiment, and will think you are being very rude.
I ask my clients to describe what the behaviour “no” should look like – what should your dog do when you give this cue? That usually causes some furrowed brows and cogs turning in the brain.
Our dogs can’t give meaning to any words that we use, they are simply a sound (often attached to some body language from us or something being present in the environment) which they learn to associate with a particular behaviour and a particular outcome, which may be good or bad for our dog.
As humans, we tend to use “no” whenever our dog is doing something we would rather it didn’t. This doesn’t help the dog to learn what it SHOULD be doing, and so can be very frustrating for both human and dog, as the dog is likely to persist in the behaviour that we are finding objectionable. What we ought to do is ask ourselves “what would I like my dog to do instead of this behaviour?” and proactively teach them that ! And the ultimate goal should be that our dogs generally make good choices for the context they are in, when faced options for different behaviours.
If I had £1 for every time someone asks me “how do I stop my dog from . . .”, I could have retired somewhere very exotic by now ! My unpopular answer is always: firstly, don’t put your dog in the situation where they can practise this behaviour and secondly, teach them a behaviour which you would like to see instead.
“No” can serve at best, as an interrupter (allowing you to then ask your dog to do something else – there are very much better ways of doing this) or at worst as a punisher (your dog stops the behaviour in that moment). A punisher, in the scientific definition is something which decreases a behaviour. Only your dog can decide what effect “no” has on them, we can’t plan to use it in either of those ways, and it will largely depend on the circumstances where you are applying your “no”.
Modern, well educated trainers will avoid the deliberate and unintended (as far as possible) use of punishment as this risks so many unwanted consequences. We all have clients who have been to a trainer promising a “quick fix” for a behaviour which they find problematic (barking, perhaps). There is no denying that there are quick fixes, however what they haven’t been told is the risk of unwanted and unintended consequences. These are often very much more challenging to address ethically than the original issue.
This is why when working with puppies or “second hand” rescued dogs, good trainers will advise that you put in a great deal of management, so that dog’s choices of activities are limited to those that are safe and appropriate. Then, in a very controlled fashion, you can introduce them to circumstances (maybe some food on a coffee table as an example) and proactively teach the behaviour you would like to see in this circumstance. A much more fair and effective strategy than yelling “no” as your puppy seeks to help himself.