There is an instance in the reference for ImageIdentify were a category is specified. Here it is:

ImageIdentify[Image, Entity["Species", "Infraspecies:CanisLupusFamiliaris"]]

It says dog (species specification). Not knowing this instance, how would I find this command?

Even though knowing this command from the reference I have no idea how to figure it out. I tried many things and at least found "Infraspecies" by using EntityClassList["Species"]. But how do I get further to the mentioned category?