Whipworms also live in the intestine and also lay microscopic eggs that are passed in the feces.  Like hookworms, whipworms can cause diarrhea in their hosts, but are less likely to cause the same severe symptoms present with hookworms. 

Unlike their relatives, whipworms do not always lay eggs and are therefore less likely to be properly diagnosed.  Fecal tests can come up negative for whipworms even though your pet may be infected with these parasites.  Because of this, all dogs should be dewormed regularly for intestinal parasites and even more frequently as puppies.  Severely infected individuals can have more serious symptoms including bloody diarrhea and even death.

Like the other parasites, dogs can be infected through ingesting eggs in their environment, usually through items dropped on the grass or soil.  Like other parasites, these can also infect humans so be sure to clean up all areas with feces. 

Whipworms can be easily treated by a veterinarian.