Hi All. While I have not taken the bar and I am not an attorney yet, and by no means am I giving legal advice, I am a third year law school student and I do have some insight to provide regarding defamation issues. The first thing to keep in mind, is that suing someone is very costly, unless you go to small claims court and do it yourself, thus the vast majority of lawsuits never reach the courtroom. Second, defamation is very hard to prove -- you would have to show that the posts here caused you to lose business and be able to prove that those people who chose not to buy from you because of the posts were in fact going to buy from you in the first place and did not buy from you solely due to what was in the posts (which would be hard because most people inquire about puppies regularly before firmly agreeing to purchase, so it would be hard to prove they weren't just making an inquiry with you about a puppy). Lastly, and more importantly, the truth is an affirmative defense to defamation. What that means is that the person being accused of defamation can simply claim that what they are saying is true and really happened and the lawsuit would likely be dismissed via a motion for summary judgment before the plaintiff and defendant even present their case. If something is embarrassing and/or shameful, but true, there is really not a whole lot you can do. That's why it is important to provide good quality when you are in a business in which reputation and word of mouth are very important. I don't mean to rant and rave, I just don't think it is right to try and threaten someone with a defamation suit for sharing the truth about their experiences with you because you don't like what they said or it hurt your reputation.
Okay, I'll get off my soapbox now.