Earlier quoted context omitted.
It's not capitalism because a licensing cartel artificially keeps the supply of vets low by keeping out qualified PAs and nurses who could handle easy cases.
It's exactly capitalism because concentrations of capital form and end up with a critical mass that controls various aspects of society - in this case licensing. It's also something that's literally happening under capitalism, right now, in very capitalist America.
It’s actually very surprising we trust doctors so much (have inelastic demand for them) because for most of history doctors were more likely to kill you than not.