Ok... 3 questions, 3 answers.

1. How do your actions lead to less senseless dog killing?- by rehoming one instead of buying one that's been manufactured for profit. every time a puppy is bought or sold, a breeder is encouraged to repeat the exercise. If there was no market, they would stop.

2. Yes different dogs have different characteristics. That's why you get them assessed by professionals before re-homing them... oh no, my mistake, nobody does that do they.. they often give less thought to the 10 + years of commitment than they do to buying a toaster.

3. 'Mental scarring'. The only non-human animals with any evidence for abstract thinking is the higher primates, re: tool-making in a very minor way. There is zero evidence of abstract thought in dogs.

What happens in dogs is Input A + Input B = Output C (behaviour). Lets take the above example- a dog afraid of a bin liner. Input A= presence of bin liner. Input B= pain/fear. Output C = Hide, act scared. That is how the dog learns Output C. There is no evidence to suggest it has any memory of what happened in the past, but now, Input A leads to Output C. If we change Input B to something pleasant for the dog, lets say a biscuit, and repeat enough times, we get output D- relaxed, happy behaviour in response to bin liner. This is obviously a simple example, but you get the drift.

What happens in human minds is very different. The reason why rescue homes say things like 'no kids', 'scared of traffic' etc is threefold. One- fear of litigation. Two- not all of them are very knowledgable, however well-meaning. Three- if they had to convince every prospective owner of the above before rehoming a dog, they'd never be able to do anything. It's simpler and quicker to just say what they say and then the dog has a home and the next one takes its place. And so the public never learns and the cycle goes on.. but what else can you do? A mass cull of all surplus dogs and compulsory exams for dog owners (it happens in Switzerland...).