Roundworms are the most common internal parasite found in dogs and cats. Nearly every dog or cat will have roundworms at some point in their life, usually puppy-hood. Adult roundworms live in the intestines and with small infection loads no symptoms maybe present. As the infection load increases things like diarrhea, vomiting, weight loss, pot-belly appearance and even a dull coat maybe noticed. Diagnosis is confirmed by looking at a fecal sample under the microscope and identifying roundworm eggs. Typically, this is performed at each monthly puppy/kitten exam and annually with wellness exams on adults. There are medications that are given by mouth to treat for roundworms. However, most of the monthly heartworm preventatives have a dewormer in them that treats for roundworms as well.