MRSA in Pets

Veterinarian Talks About Pets with MRSA

As CA-MRSA – community-acquired MRSA increases, the number of documented MRSA colonization in domestic animals increase. There is a direct link of staph aureus infection from animals to the pet owners. Horses, cats and dogs seem to be the most affected and these animals are considered a reservoir of infection. Pets may be carriers of MRSA in their nose or on their skin and have no outward sign of illness or infection, but are carriers.

There can be complications from pet bite or wounds, such as sepsis. Bite wounds are a major cause of injury in Europe and the U.S. with children and most often occur on the hands, arms, neck or head.

Pet infections can present in various forms and most often as skin infections. The skin infections are sometimes hard to detect because of thick fur. The infections can be transmitted to the pet owner. It is advised that pet owners do not allow the pet to sleep on the bed, but have their own bed on the floor.

Good sanitation is always the best prevention and pets that are diagnosed with a MRSA infection by a vet most often are given antibiotics after the culture results are available, but infections can also require surgery (incision and drainage) if more severe.

Wound care instructions should be followed from your vet and the following contact precautions and environmental cleaning should be performed as it is with human MRSA infections:

  • Keep all wounds, cut and scrapes clean and covered with dry, clean bandaging till healed.
  • After being in contact with your pet, wash hands thoroughly and frequently with warm, soapy water or use an alcohol-based sanitizer.
  • Wear disposable gloves when touching the pet’s bedding or other items or objects of the pet and after removing the gloves, wash hands thoroughly again.
  • Clean pet items with hot water and bleach and machine dry when possible. Household chlorine bleach that is diluted 1:10 can be used on surfaces.
  • Pets with MRSA colonization may never get an infection and those who have an infection in most incidences, can be treated successfully and there is no need to remove the pet from the home or give the pet away.

MRSA In Farm Animals

Livestock (cattle, pigs and chickens) has been identified as a new reservoir of MRSA. Pigs carry the strain ST398 and it has shown to transfer from pigs to pig farmers and their families. Colonization has also been found in veterinarians. In addition to vets, animal workers and farmers and the risk to the general population has increased and it also includes petting zoos.

In Europe and in Asia, MRSA has been detected in retail meats and the strain of MRSA was ST398. The first link to pig farming with MRSA occurred in 2004 in Holland when it was discovered that a 6 month old infant was found to be a carrier of this strain. MRSA had been rare in Holland as doctors had been screening patients who enter their healthcare facilities for MRSA for decades and have less than <1.00% prevalence. ST398 have also been found in Belgium, Denmark and Germany. Other strains of MRSA have been found in Austrian livestock.

In the 2009, the first research study conducted in the U.S. on livestock; researchers found that MRSA was highly prevalent in swine (49%) and 45% colonization in swine workers in commercial operations in Illinois and Iowa. All were the MRSA ST398 strain.

In 2007 a study conducted with Canadian farms found half of the total of pig farms, 1-in-4 pigs tested positive, 1-in-5 pig farmers were colonized with MRSA and 80% tested had the ST398 strain. Canada is the leading exporter of pigs and pork to the U.S.

Overuse of antibiotics in livestock in the U.S., Canada and Europe are a significant contributing factor for the emergence and spread of MRSA in livestock. In the U.S. large quantities of antibiotics are added to livestock feed, not just given to sick or ill animals, but to all livestock. Animals are in overcrowded and stressful conditions which can create illness. Continued exposure to antibiotics in farm settings is creating antimicrobial resistance that effects the human population.

Besides MRSA, Salmonella, Campylobacter, Escherichia coli, Enterococcus, Clostridium difficile and Klebsiella pneuminiae have been found to cause food borne illnesses.

National Institute for Public Health and the Environment – the Netherlands
Risk Profile on Antimicrobial resistance Transmissible from Food Animals to Humans


Veterinary clinics have been identified as an environment for transmission along with veterinarians and vet workers who can be colonized (carriers) and considered a high risk group. Others considered high risk are those previously colonized or infected with MRSA or coming from a farm with known colonization or infection. Veterinarians and vet workers can become ill or become asymptomatic carriers and simply pass the strain on to others, who might become ill.

According to the2009 European Food Safety Authority’s (EFSA) ‘Assessment of the Public Health significance of MRSA in animals and foods’, livestock-associated MRSA represent only a small proportion of the total number of reports of MRSA infections in the EU, however this proportion varies from each country. The panel recommended that intervention studies should be carried out in order to evaluate the effectiveness of control measures to reduce the transmission in MRSA in livestock.

In the U.S. more studies need to be conducted by the CDC and the USDA and mostly have been limited to the Midwest region. Identifying and controlling transmission of MRSA in the community is imperative for the public health of Americans. The CDC must be proactive, survey and conduct surveillance programs in rural hospitals and with farm workers to determine the source of MRSA and the strains that are prevalent. The U.S. and world food supply needs to be protected to reduce the rise in antimicrobial resistance.