Oh no - the Koehler method is terrible
No offence to you or your dad, but you are so right, it is cruel. It's also not effective as the dog is repressed rather than obedient. I would rather not have a dog than have to train it this way.
Please, do go to Clickersolutions, I hope they may still be able to help you :)
Also try reading some modern up to date books such as Jean Donaldon's "The Culture Clash" and books by Ian Dunbar so that you can try to advise your father. He may just be ill advised and stuck in the dinosaur age, but treating a dog this way is unfair and usually makes things worse in the long run.
Re the halti, be careful she doesn't get her neck pulled if she lunges, don't let your dad hurt her with it as it could seriously injjure her skeletal structure.
Try giving her food treats when she has the halti on to help her feel better about it.
I believe actually, Jean Donaldons IS Canadian!! She has helped many a difficult dog, and knows what she is talking about. You may also find her book "Dogs are from Neptune" very good as she discusses dogs who are dog aggressive - it's better in some ways than her "Fight" which is a bit technical.
I feel so much for you and your dog :(
Lindsay
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