If you suspect the animal will be abused or mistreated, you actually can deny the sale of an animal. My KeBryan Hayes City Name WTH WHT shirt store has had to deny multiple people from buying animals including fish. One guy returned a dead angel fish that he kept in a 5 gallon tank with 30 other fish. One woman comes in every other week trying to get a new animal and return the one she killed. Every time they come in, we refuse to sell them any animal because we know that animal won’t be taken care of. The Petcare handbook says that we can deny the sale of an animal if: we suspect abuse/mistreatment will occur, they want to use it for carnivals/fair games, if they’re not 18+ or if they’re just being downright shady and not answering any questions. When someone wants to adopt an animal I usually ask them a ton of questions like have you had an animal like this before, what cage are you using, how many gallons is your tank, do you have any other fish, etc.