Strep Throat – Is my dog the carrier?
At least once a winter I get a client requesting their dog get a throat culture for strep throat, not because the dog is sick, but because the family can’t shake it off, after cycle after cycle of medication. Most often the pediatrician is requesting testing and treatment of the dog. Is it possible? The quick and dirty answer is yes – theoretically. Dogs and people can pass it back and forth, but it is HIGHLY unlikely.
Strep throat is caused in people by Lancefield’s Group A B-hemolytic Streptococci (Streptococcus pyogenes). The primary host is humans and it is passed by airborne droplets that are mostly inhaled. Contamination of food and possibly water is also possible. Dogs and cattle are susceptible to infection mostly by people, but cows used to pass strep in epidemic proportions to people via unpasteurized milk. The cow would develop a mastitis, strep would pass into the milk, someone would swallow it – you get the picture. Most chronic strep’s are usually due to a virus colonizing the tonsils, with periodic secondary strep infections.
Many pediatricians recall a paper published in Postgrad Med. 1983 titled: “Recurrent pharyngitis in family of four. Household pet as reservoir of group A streptococci.” In this paper, numerous attempts using conventional methods of treatment failed to permanently rid the family of strep throat. Their pet dog was finally discovered to be a carrier of group A streptococci and was treated. This paper is now considered irrelevant because the methodology they used would not differentiate group A strep (the one that causes strep in people) from group G strep (canine cause). Most likely, the dog got strep from a human family member, just like the rest of the family!
My recommendation is to save your money and not test the dog for strep. I have agreed to treat a dog with antibiotics, just in case, to ease a client’s mind, but along that path I feel the pediatrician should insist all human family members go on antibiotics too!