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.