Most young puppies are infested with ascarids. Other worm parasites may also be present, but they?re not as common. It is advisable to have your veterinarian check your puppy?s stool before deworming for ascarids, because if other worms are present, a broad-spectrum deworming agent may be recommended.

Puppies should be dewormed at 2 weeks of age (before ascarid eggs are passed in the stool) and again at 4, 6, and 8 weeks of age. Then, it's prudent to put them on a monthly heartworm preventive for life that also protects the dog against other parasites, or at least continue monthly deworming for six months. This schedule kills all ascarids, whether acquired in utero, through infected mother?s milk, or by ingesting the eggs. Pyrantel pamoate (Nemex or Strongid) is an excellent choice for ascarids and can be safely given to 2-week-old puppies. It is available as a liquid suspension or tablet.

Worm medications can be harmful to puppies that are ill from a respiratory infection, chilled, crowded in unsanitary surroundings or abruptly weaned from their mothers. Stressful conditions such as these should be corrected before administering the dewormer. Do not deworm a puppy who has diarrhea unless your veterinarian has determined that the diarrhea is caused by the parasite.