Fido's Fre-Itch Flea Shampoo This pleasant smelling shampoo contains the biodegradable insecticide carbaryl. It is useful in the control of fleas and ticks on dogs and cats. Can be used weekly in hydrobaths. Active Constituents: Pyrethrins and Piperonyl Butoxide. This product controls fleas and lice on cats and dogs. Does not control paralysis ticks.