It's believed that VetSurgeon.org and VetNurse.co.uk, which run on a platform that predates Facebook, may be the first online communities to require good manners.
Under the new policy, anyone who posts anything in the forums which is sarcastic, belittling, snide, rude or unkind towards another member will face immediate removal from the website.
This marks a very radical change to the previous policy in which members were free to say pretty much what they wanted.
VetSurgeon.org Publisher Arlo Guthrie said: "For years, I felt the right to free speech trumped all, and would rarely intervene.
"When I did, the worst anyone faced was a temporary suspension.
"As time has passed, I've realised the limitations of the written word, especially the short-form, hastily-written word, which can cause real distress.
"We all moderate our language offline, it's just a question of realising that we need a different set of standards online, to account for the lack of facial expression and immediacy of reply, and the public nature of the discussion.
Some people have questioned the new policy, and whether it will stifle proper debate.
Arlo added: "I believe not. It is perfectly possible and OK to disagree with someone, and express that disagreement forcefully, without being sarcastic.
"On the contrary, I think that allowing bad manners has a far more chilling effect on free speech, because it scares off opinions from the majority of more moderate members"
Others have asked whether this new policy is the consequence of the new partnership with Improve International, or proposed new laws surrounding social media.
Arlo said: "Again, no. It was a very personal decision I reached after years of wrestling with the problem. It was precipitated by a series of unkind posts and I just thought 'enough's enough'.
"That said, I am really excited about the prospect of working with Improve to grow the community as somewhere its members can come for high quality clinical content and authoritative opinion, which for sure would be hard to achieve if we don't have a friendly, collaborative atmosphere."
Another issue raised about zero tolerance is whether it is fair that there may be no second chance.
Arlo said: "I've tried loads of things over the years. Warnings. Red cards. Suspensions. None of them work. People just push the boundaries.
"But the moment I said 'zero tolerance', it seems people get the message and moderate themselves accordingly."
"I'm delighted. I want people to think of VetSurgeon.org as somewhere everyone can come for authoritative advice and support, confident of a friendly welcome and the highest standards of online behaviour."
PS: Whilst you're here, take a moment to see our latest job opportunities for vets.
You just may get more people not bother commenting . Some criticism is valid but taken badly but it's the powers that be who decide and can block arbitrarily. Witness the comments section of The Times where this happens.
Paul Kensington - Interesting thought, but I think you’re missing the difference between the ‘bekind’ movement, which is sometimes used to shut down debate or stifle criticism, and this ‘begoodmannered’ alternative. As far as I am concerned, its fine to be disagree or criticise, as long as it is delivered politely (on social media).