Methicillin-resistant Staphylococcus aureus (MRSA) is a bacteria that is commonly found in the nasal passages and skin of humans and multiple animals. When this bacteria overgrows, it can cause serious infection that is usually resistant to commonly prescribed beta lactam antibiotics. Although MRSA is commonly found in people, animals may also be infected, particularly those who are nutritionally or immune compromised, as well as in weaker geriatric animals. The bacteria may infect a variety of species including dogs and cats, and in some of these animals there is no history of antibiotic usage, which means that the most likely source of infection in many of these cases is from human to animals.
Direct skin to skin contact is the most common avenue of transfer; however, MRSA may also be transmitted by contaminated surfaces and objects. Many animals and people may carry MRSA on their skin, ear and nasal passages, yet show no signs of infection. In that situation, these animals/humans are not a risk to other individuals. Symptoms of MRSA depend upon where overgrowth of the bacteria has occurred, but typical skin signs may include a non-healing wound with pus, red, warmth and fever often present. Occasionally, secondary blood and distant organ infection may also occur.
MRSA is diagnosed by a swab taken of the affected area, which is then cultured at an outside laboratory. Treatment may vary depending upon severity, and may include topical antibiotic and flushing solutions, as well as several weeks of oral antibiotic therapy, based on the results of initial swab cultures. With early detection and treatment, prognosis is usually excellent for full recovery. Given the role that a weakened immune system plays in infection, I will always preventatively recommend more species-appropriate natural, and if possible raw meat-based diets, as well as nutritional supplements and herbs to boost the immune system and keep the pet healthier in the future.