Each month, Plano veterinarian Dr. Shawn Messonnier will share his insights on topics of interest to our readers. If you have a concern you would like Dr. Shawn to address, email him at email@example.com.
Most readers have heard of MRSA (Methicillin-Resistant Staphylococcal Aureus.) This “superbug” has been in the human medical news a lot, as several reports of deaths (often among younger athletes who contracted the bacterium from work-out facilities) have been reported. Yet, it may surprise you that MRSA and related bacteria are increasing among pets as well. I’ve diagnosed this dangerous bacterium in a number of my patients with skin and ear infections. It’s time to get serious about fighting this infection before it harms or kills even more.
Staph aureus is a common human bacterium that can occur on pets. Methicillin is an antibiotic, but methicillin-resistant Staph are not killed by methiciliin or other antibiotics that typically are used to treat Staph. These methicillin-resistant Staph are considered “superbugs” because they can be hard to treat, take a long time to treat, often require treatment with very expensive antibiotics (and it’s become harder to find antibiotics that kill MRSA,) and as a result, they are more likely to be fatal then non-MRSA bugs. This means prevention, when possible, and early diagnosis and aggressive treatment are a must in order to protect your pet and yourself.
Staph aureus is a common human pathogen, and many people carry the bacterium harmlessly in their nasal cavities. Estimates are 33% of people carry Staph in their nasal passages and 2% carry MRSA. If the bacteria leave the nasal cavity and infect another part of the body (as through a cut in the skin), they can quickly invade the bloodstream and cause septicemia, a deadly and often fatal infection of the entire body. In people, this typically happens when hand-washing is not done properly, and the nasal MRSA is spread by touching another person or inanimate object that can then cause an infection when a susceptible person encounters the bacteria.
In pets, usually dogs, either Staph aureus (MRSA), or more commonly Staph intermedius (MRSI), infections can occur. Dogs and people can become infected through environmental contamination or by infecting each other (people can infect other people or dogs, and dogs can infect other dogs or people.)
Usually, MRSA presents as a skin infection manifested by small pustules (pimples.) Many dogs with Staph infections are itchy, and many have other diseases, such as allergies and thyroid or adrenal dysfunction. MRSA infections look just like “plain old” Staph infections, but there is an important difference. MRSA infections don’t get better when treated with antibiotics (or they improve but never really heal and continue to be present.) The only way to diagnose MRSA is through a skin culture. This can be done simply by swabbing the skin surface or through a skin biopsy. (A biopsy is recommended for chronic skin disease, skin disease that doesn’t look typical, or if a culture of a skin swab is negative and MRSA is still suspected.)
Because MRSA is a tough bug to kill, and because it often develops when inappropriate and long-term antibiotic treatment is used to treat any problem, specific antibiotics must be used, along with topical shampoos and herbal remedies to support the immune system. A sensitivity test, done alongside the skin culture, suggests which antibiotics might be helpful in killing MRSA. In general, most antibiotics that are routinely used in veterinary practice are ineffective against MRSA. MRSA is typically only sensitive to expensive “human” antibiotics that must be given for 1–2 months or longer. Because MRSA can be fatal, especially in humans, it is recommended to save the “newer” more aggressive antibiotics for life-threatening infections in people and not use them to treat skin infections in pets.
Treatment is continued until the skin looks normal and a repeat culture fails to identify the Staph bacterium. Ongoing care with regular bathing and herbs or homeopathics are used as dictated by each case.
The takeaway message is this: Treat skin infections early and aggressively without using antibiotics (overuse of antibiotics predisposes to MRSA), except for serious infections. If the infection is not better, the skin may need to be biopsied and cultured to confirm the diagnosis. Regardless of whether or not antibiotics are needed or are used, regular bathing and the use of immune-stimulating herbs and probiotics are essential.
Learn more about natural pet care at pawsandclawsanimalhospital.com.