MRSA Infection and Pets

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MRSA Infection and Pets

Question:

I found out my friend's daughter has a sore on her back infected with MRSA. I had also noticed a sore on the head of one of their dogs, but only after I pet the dog. I don't believe I touched the sore on the dog and when I got home I washed my hands thoroughly. Should I be concerned?

Answer:

No, you should not be concerned. It is very unlikely that you picked up any form of dangerous bacteria from the dog. And you performed the best measure to decrease spread of all infections — washing your hands.

MRSA is short for methicillin resistant Staphylococcus aureus. Originally, all strains of Staph aureus bacteria were killed by good old penicillin. But then, many years ago, a strain of Staph became resistant to penicillin. A new antibiotic, methicillin, was developed as the "cure" for penicillin-resistant Staph.

Methicillin and similar drugs remained effective against almost all Staph infections for some time, but of course that didn't last. Now there are multiple strains of Staph that are resistant to penicillin, methicillin and a host of other antibiotics.

Staph aureus bacteria are all around us and reside on our skin and inside our nose. Horses also tend to carry a lot of Staph aureus, but dogs and cats are more likely to carry a different, less dangerous Staph species called Staph intermedius.

However, transmission of MRSA can definitely occur from human to pets and pets to humans. Petting a dog or cat that happens to have a small MRSA skin infection might pass the bacteria on to your hand. Washing your hands or cleaning them with an alcohol-based gel would stop MRSA from being carried to other parts of your skin or into your nose. But even if you didn't wash your hands immediately, the risk of MRSA or any bacteria getting under your skin and into your body is extremely small.

The greater concern is animal bites. High levels of MRSA can live in the mouths of cats and dogs; while this is not common, it is on the rise. Also, other bacteria, in addition to Staph, can live in animals' mouths. Some of these bacteria are also developing resistance to multiple types of antibiotics.

Last updated:	July 09, 2009