The British Small Animal Veterinary Association (BSAVA) has updated its practice guidelines for management of MRSA and MRSP.

Overall, there’s good information in the document with an emphasis on routine infection control as the key measure to reduce the impact of MRSP and MRSA. I’d like to see more emphasis on developing an overall infection control program, but the emphasis on basic principles such as hygiene is good.

Like any guideline document, there will be some disagreements in recommendations. I agree with the majority of what’s written, although there are some recommendations that I wouldn’t make, and some additional areas that I’d address. That’s not surprising since most of the recommendations are based on opinion rather than evidence because we don’t have solid evidence for most areas, and there isn’t necessarily a single "right" answer to many questions at this point.

Typically, guidelines assess and report the level of evidence on which recommendations are based, but that’s not done here. Letting people know the evidence (or here, the relative lack of evidence) is a useful part of guidelines. How the recommendations are worded can also play a role. Here, they perhaps overstate the strength of evidence through use of wording such as saying something "will" have an impact, when we really should say it "might." In the absence of evidence, good common sense measures can be recommended and implemented, however we need to remember that we have major limitations in our knowledge. We need to figure out which infection control practices are effective.

I have a major problem with one recommendation: "Colonised animals should be treated with a chlorhexidine shampoo and intranasal fusidic acid or mupirocin once daily." There is simple no evidence supporting the use of active measures to eliminate MRSA and MRSP.

  • For MRSA, there is reasonably good evidence that dogs and cats eliminate it on their own in a reasonably short period of time.
  • For MRSP, we simply don’t know how long they can be carriers. I suspect that long-term carriage can happen in some animals, so decolonization might be attractive, but we don’t know what to do yet.
  • There is absolutely no evidence that intranasal antibiotics are effective in dogs and cats. I have serious doubts that someone can adequately administer a topical antibiotic to the nasal passages of a dog, and particularly a cat.
  • If this recommendation is adopted and widely used in the UK, I suspect the country will be an international leader in fusidic acid- and mupirocin-resistant bacteria.

Overall, there are some good recommendations in the guidelines, including the general infection control sections. We need to improve our baseline level of infection control and hygiene to reduce the impact of MRSA, MRSP and a variety of other concerning microorganisms. At the same time, we need to acknowledge our limited knowledge in a lot of areas and the fact that we are really working based on common sense and extrapolation from human medicine, with little direct evidence from veterinary medicine. Much more research is necessary, a major limitation of which is the limited priority given to companion animal infection control by research funding agencies.  This has to change to help control the impact of bugs like MRSA and MRSP on both animals and people.