Eating feces or soils
One of the common reasons and the easiest way to get (hookworms, roundworms or whipworms) is eating soils or feces coming from other animals, since this latter may contain parasites, worms or even worm’s eggs, that your dog may consume and that can lead him to have intestinal worms.
When those eggs or larvae get to the small intestine for roundworms or to the upper part of the large intestine for whipworms, they get to maturity, which can be developed to infections or some serious health problems.