Don't feed them.

Lately there have been a few people hell bent on causing trouble in the group chat. They come in and talk about how their clover is passing it's coat or eyes, or come in demanding "priority support" because they have a "rare" coat.

These people are just looking to stir up controversy. They most likely thrive on it. What upsets them the most? When no one reacts.

Yes, it's difficult, but try not to engage them. You're just giving them exactly what they want.