I have been having discussions with some rather enthusiastic vegans who have a degree in philosophy, and they have been trying to convince me that it is a settled issue in ethics and philosophy that the debate is finished, that 'the experts' all consider veganism to be the correct course of action with no valid counter-arguments against it.

I am skeptical of these claims to be sure and I have not found any evidence to support that.

So, are these claims correct, or is veganism as much debated and discussed between philosophers and ethicists as it is among regular folk?