MRSA

MRSA is the abbreviation for methicillin-resistant Staphylococcus aureus. Staphylococcus aureus is a type of bacteria primarily found in people and may also be called Staph aureus, S. aureus, or a staph infection. Methicillin is a type of antibiotic that was created in the late 1950s to combat Staphylococcus aureus bacteria that had become resistant to penicillin. For bacteria that are resistant to an antibiotic, that means the antibiotic, which should normally be able to kill the bacteria, is not strong enough to kill it. In other words, those antibiotics no longer work. In the early 1960s it was discovered that some S. aureus bacteria had also become resistant to methicillin. Thus, MRSA became the new name for this type of bacteria.

Even though methicillin is no longer used today, the name remains because MRSA, and its veterinary counterpart MRSP, remain resistant to many types of antibiotics (referred to as a multi-drug resistant bacteria), making it extremely hard to kill. Even more concerning is that MRSA is quick to adapt, or change, to its current environment, so it is able to become resistant to new drugs and treatments and avoid being removed by the immune system. This limits the options of what can be used to treat infections caused by MRSA.

MRSP

MRSP stands for methicillin-resistant Staphylococcus pseudointermedius (S. pseudointermedius). Unlike S. aureus, S. pseudointermedius is more commonly found on dogs, and less commonly cats, than people. It too is resistant to numerous drugs and adapts quickly to the immune system, so it is a big concern for veterinary patients.

Where Do MRSA and MRSP Come from?

MRSA can be contracted by people from their environment, such as the community where they live and work, or in a hospital or nursing home setting. Any person can get MRSA. Risk for infection is increased with crowded areas, skin to skin contact with an infected person, and sharing equipment or supplies (e.g. medical equipment, towels, shaving razors). Open wounds, such as a scratch, are a common site for infection. One study found that 5% of people hospitalized in the United States carry MRSA in their nose or on their skin, even if they do not show symptoms. MRSP can be contracted from the environment as well, but may be more likely to come from a veterinary hospital setting.

What Does MRSA or MRSP Look Like?

Common MRSA infections include pneumonia, skin, bloodstream (sepsis), or surgical site infections. Common sites of infection for MRSP are the skin, open wounds, and surgical sites. MRSP can also occur from skin infections that the pet already had. Pets with skin infections caused by a different bacteria or microbe can actually develop MRSP before the first infection has healed.

It is important to understand that you cannot tell by looking at infected skin or wounds what type of infection it is. See a veterinarian for your pet, or a physician for you or your family members, if you suspect an infection so it can be checked out thoroughly and handled appropriately.

Can I Get MRSA or MRSP from My Pet?

Technically, all people and pets can develop MRSA and MRSP infections. However, MRSA does not thrive well on animals because it has become so well adapted to living on people. Dogs and cats can develop MRSA infections, but if they are healthy, the bacteria won’t be able to grow and multiply as well as it would on a human being. Many healthy pets’ immune systems can beat the infection within a few weeks. While MRSA can potentially be transmitted between pets and people, it is much more likely for people to transmit MRSA to pets rather than pets infecting people. Of further importance, research has shown that there is no need to test pets for MRSA if a human becomes infected.

MRSP infections in people are uncommon, and the risk of transmission from an infected pet to humans is low. This is because, like MRSA, MRSP has adapted itself to live more easily on pets. In fact, it is extremely difficult to get rid of once it has started growing and multiplying. Dogs could potentially have MRSP for months to years, and in some cases, for life. Although transmission of MRSP from pets to humans is not common, transmission from pets to other pets is a concern, so care should be taken to prevent bacterial spread if possible.

How Do I Prevent MRSA/MRSP?

Good hygiene, such as frequent hand washing and regularly bathing, are great ways to help prevent spread of infection. Wash bedding and towels regularly. Cover any open or healing wounds with a bandage, making sure to change it regularly. Finally, if you or your pet are prescribed antibiotics, make sure to take or give them exactly as prescribed and finish all of them.