People carry more drug-resistant strains of E. coli bacteria than their dogs, according to a study conducted in 2009 by Dr. Kate Stenske, a clinical research professor at the Kansas State University's College of Veterinary Medicine.
The study, published in the American Journal of Veterinary Research, looked at how disease could be spread between owners and their dogs.
The study focused on E. coli bacteria only, which is common in the gastrointestinal tracts of both humans and dogs and under normal circumstances does not cause illness. Results showed that in 10 percent of dog-human pairs, owners and their dogs shared the same E. coli strains, which had more resistance to antibiotics than expected.
The owners had more multiple drug-resistant strains than their dogs, indicating owners are more apt to transmit multiple-drug resistant E. coli to their dogs than vice versa.
Bonding behaviors between owners and their dogs appeared to have no bearing on bacteria transmission. However, there was an association between antibiotic-resistant E. coli and owners who didn't wash their hands after handling their dogs or before cooking meals.