Dog Ticks the usual suspects
The most common tick found on dogs, cats and humans is the American Dog Tick (Dermacentor variables). American dog ticks are distributed east of the Rocky Mountains and can also be found in some areas of the Pacific Coast. Dogs, cats, medium-sized mammals and people are the preferred hosts of the adult ticks. The larvae and nymphs of this species feed on small rodents.
These ticks also cause Rocky Mountain spotted fever in humans.
Kill ticks without poison
Dog ticks can be killed without poison by using a product called Nomoflea™, check it out here.