How did my dog get roundworms?
Roundworms (Toxocara canis) are common in dogs, especially young puppies. Roundworm eggs are found in the soil, where they can survive for years. The life cycle of the roundworm seems unnecessarily difficult. The dog swallows the eggs from nosing around on the ground or picking something up in her mouth. The eggs hatch into larvae, ride through the bloodstream to the lungs and from there up the windpipe, where they’re swallowed again, return to the intestine, and become mature adult worms. Roundworm larvae can also be passed from mother to puppies through the placenta (the pups are actually born with roundworms) or through the mother’s milk. Adult dogs can carry roundworms without much in the way of symptoms. But puppies with a load of them may vomit, have diarrhea, and lose weight. They have a noticeable pot belly (more than the usual “puppy tummy”), their coats are dull, and they don’t thrive like other pups. Occasionally, a dog may pass some of the worms in her stool. These worms lo
