To know if a dog has parasites, watch for symptoms such as coughing, vomiting, a pot-bellied or bloated appearance, diarrhea (sometimes with blood), itching or skin irritation, weight loss, and changes in appetite. Visible worms in stool or around the dog’s rear end, scooting or rubbing the rear on the ground, and a dull coat can also indicate parasites. Some dogs may show fatigue, weakness, increased appetite without gaining weight, or a distended belly especially in puppies. Respiratory issues and malnutrition are also possible signs. A definitive diagnosis requires a visit to a veterinarian who may conduct fecal tests or other diagnostics to identify parasite eggs or proteins. Early detection and treatment are key, as untreated parasites can lead to serious health problems. Regular preventive care and fecal exams help catch infestations early.