Whipworms are very nasty intestinal worms. They are the ones that are most difficult to get rid of. They too are passed on when a dog eats infected soil, feces, or tends to step into stools or mud containing the worms. When it licks it paws, the worms get transferred into the intestines. They cause bloody stools, unusual appetite, bloating, abdominal cramps, a dull coat, anemia, weight loss, and loss of energy in the animal.