I realy hate to argue and i realy think opinion is so divided that people will have to agree to dissagree. I dont want to cause offence but must say that IMO most cats scratch to communicate there is a problem and they are unhappy. I can pet our cats without fear of being scratched. My neighbours cat however who is in our house more often than not is the type who will lash out and scratch. When stroking her we watch out for the signs. I know some cats are feisty , some scratch, some bite but we cant remove their teeth.
As for de barking Dogs (something i have only just become aware of on the forum) why on earth would anyone want to do this.
Maybe my views are idealistic but i do believe animals should be left as nature intended if at all possible
If your neighbor has a cat that cannot be trusted to be petted w/out scratching or biting, they have a bigger issue than to declaw or not.