Worms, or internal parasites, commonly found in pigs include Ascaris suum (roundworms), Trichuris suis (whipworms), and Oesophagostomum dentatum (nodular worms). These parasites can cause symptoms such as weight loss, poor growth rates, diarrhea, and even more severe health problems if left untreated. Understanding the life cycle of these worms is essential, as it can help farmers implement effective control measures.