Double dipping is not okay, but what about sharing food with your pets?

A pint of Ben & Jerry's ice cream

Laura Conway (3PM Micro) loves eating on the couch with her dog and cat. She is interested whether it’s a good idea to have a spoonful of Ben and Jerry’s after Zeus and Minnie have theirs. An article from the Journal of Clinical Microbiology sheds some light on the normal oral microbiology of dogs, and whether those organisms pose a risk to humans if we eat after them. Here is Laura’s summary (additional kudos for working with a primary research article!):

As a pet lover and enthusiast I cannot resist sharing with my Yorkie-Chihuahua, Zeus, or my Lilac-point Siamese, Minnie, when they sit quietly and patiently while I eat. I’ve had them both since they were a couple weeks old, so they have grown to understand I will share my food with them, so begging has never been necessary. The sharing is not limited to letting them clean dinner plates though, they will lick my ice cream cones, I will let them take food off of my fork, and so on. Accepting your pet as a family member is not an uncommon trend in the US, but how far is too far? Well, the Journal of Clinical Microbiology must have been wondering the same thing, because they performed a study on the cultivable oral microbiota of a domestic dog. The study focuses on how to improve canine oral health, so scientists collected dental plaque and saliva of fourteen dogs to get a better understand of what was growing inside of our lovable pets mouths. The dogs tested had not received antibiotics within the three months prior to the study, and were housed in environmentally enriched facilities. Saliva samples were collected in two ways: playing with a ball causing the dog to salivate, or by using salivates – then utilizing a syringe to collect saliva. Plaque samples were collected by using a curette or dental probe, from the gingival margin, but when a periodontal pocket was present, the sample was taken from the base of the pocket.

So the results? A total of 339 bacterial isolates were recovered from the cultures. Based on literature research, 28% of the bacterial isolates are considered indigenous oral microbiota of humans. 11.6% of the plaque microbiota collected, and 25.5% of the saliva microbiota belonged to the speciesActinomyces, a gram positive, rod-shaped, facultatively anaerobic or strictly anaerobic. Actinomyces lives harmlessly in the mouth, throat, and GI of humans. If tissue in any of these areas becomes damaged the bacteria may become pathogenic, causing inflammation and pus-filled abscesses. Granulicatella and Streptococcus species were found abundantly in the saliva, and Porphyromonas and Neisseria species were found in the plaque samples.

In four of the cases, the closest human origin match for bacteria were Micrococcus luteus (normal flora of mammalian skin), Dialister invisus (found commonly in the oral cavity of humans), Propionibacterium acnes (another microbiota normal to our bodies, but in opportunistic conditions causes acne, or infections), and Wolinella succinogenes (which is normal flora found in cows, but is also known to cause GI infections in humans). In conclusion, the collected data shows that the cultivable oral microbiota of dogs differs significantly from the oral microbiota of humans. While some of the bacteria that was collected may be normal inhabitants of human bodies, placement is key. Bacteria can be residents in one area of the body where they do no harm, but when introduced to new territory, the bacteria often become pathogenic. So for now… I’ll take my chances, but I would definitely not suggest immunocompromised patients to share their fork with Fido.


About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on April 29, 2013, in Guest Post, The more you know, You are what you eat. Bookmark the permalink. 1 Comment.

  1. This is a great! I have never shared a frozen treat with Apollo (can dogs have dairy?), but I think it is mostly because Great Danes are droolers when they eat. I do let him eat off of our plates and wash his bowls in the dishwasher. Some people think it’s gross or unsanitary, but now I have this article to fall back on. Thank you!

%d bloggers like this: