If your family is suffering from recurrent infections with group A Streptococcus (GAS), including strep throat, your physician may suggest the culprit is your family dog. That's not likely to be the case, and there's science to back that up.
From an article by J. Scott Weese, DVM, DVSc, DACVIM, a veterinary internist and microbiologist, chief of infection control at University of Guelph Ontario Veterinary College Health Sciences Centre, and Canada research chair in zoonotic diseases:
A few older studies implicating animals as potential sources of GAS infection in humans used culture methods that we now know do not differentiate GAS from group G streptococci (eg, the canine commensal S canis).2,3 More recent studies have not identified GAS in companion animals, including those living with children with recurrent GAS infection.4,5 In fact, Infectious Diseases Society of America (IDSA; idsociety.org) guidelines recommend only testing human household contacts in specific situations and assert that no credible evidence supports that pets have a role in recurrent human infection.6 Testing is not indicated in this situation; however, discussion with the physician is important to ensure that the reasons for not testing are clear, to educate the physician about the issue, and to foster better communication between veterinarian and physician.
Read more here, including how to work with a physician who has concerns about the family pets (free registration may be required).