Philosopher E.J. Lowe states that
There is a clear difference between saying something like ‘Rover is a dog’, in which we assign Rover, a particular animal, to a certain natural kind or species, and saying something like ‘Rover is brown’, in which we attribute a certain property or quality to Rover. Modern first-order predicate logic completely obliterates this distinction, representing both sentences as having the logical form ‘Fa’.
However it is not so clear to me what the difference is between property ("brownness") and kind ("dog"). Couldn't we consider "dogginess" as property and "brown" as a kind? What is the difference ontologically?