An exercise pool for animals having an entry thereto and an exit therefrom with a hollow island mounted centrally thereof and extending upwardly therefrom, a filtering area and a solids pit in the island with a screen disposed therebetween, a skimming gutter at the upper end of the island having an inlet at the surface of the pool of water and an outlet to the solids pit, a pump for pumping water from the pool through the solids pit and the filtering area and back into the pool through the lower portion of the island, water filtering mechanism in the filtering area for filtering the current of water flowing therethrough, water treatment mechanism for treating the water flowing through the island to maintain the chlorine content and the pH thereof within predetermined limits, and a main drain in the lower portion of the island to draw water from the pool and upwardly to the solids pit when the water level within the island falls to a predetermined level; there also is disclosed a self-contained island for mounting in animal exercise pools.