Telephone calls, “Being Difficult”, “Grabbing Money”, Speaking German and Taxes.
by Ben Sturgoen, BSc, BVM&S, Cert EP, MRCVS
A vet’s first priority is to treat his or her patient with the drugs that have proven to be the most effective. However a vet must also make sure the drugs are available and affordable to the owner. Many times antibiotics are administered even if an infection is not severe. This tactic ensures that the patient has the safest possible outcome, and it is difficult to argue with this strategy. Vets are doing what is best for their patient at the time. However, developing antimicrobial resistance is a problem that must be considered.
In a talk I gave last week, on dental disease, I discussed the Butterfly Effect or the sensitive dependence on initial conditions, where a small change at one place in a deterministic nonlinear system can result in large differences to a later state. The audience, perhaps not unexpectantly, fell quiet, I began to sweat until I highlighted the effect of a Petri dish on the outcome of the Second World War. With Flemming’s accidental discovery, after a two week break in the sun, clinical trials of penicillin began in 1934 and ultimately resulted in a death rate of 1 in 25 of Allied forces compared to 1 in 6 of German, importantly allowing the Allies to maintain effective fighting strength at the front line. Small accident, big result because I can’t speak a word of German.
It seems now we are on the brink of the Tsunami of the, even then, butterfly flapping its wings with the momentousness of that discovery. In just a couple of generations, what once appeared to be miracle medicines have been beaten into ineffectiveness by the bacteria they were designed to knock out. Once, scientists hailed the end of infectious diseases. Now, the post-antibiotic apocalypse is within sight.
Courtesy of England’s Chief Medical Officer (CMO), Ms Davies warned that “global action is needed to tackle the catastrophic effect of antimicrobial resistance, which in 20 years time could see any one of us dying following minor surgery.” Our horses will be no different.
Whilst over the last 50 years we have seen a wide armoury of vaccines and drugs effective against infection, antimicrobials are losing their effectiveness and the next 50 years could paint a very different picture. The CMO added “we face a prospect of a future where we have far fewer options in the treatment of diseases that, previously easy to control, will become much more significant threats to (human) health.” Imagine the prospect of the emergence of antibiotic resistance, it is the most eloquent example of Darwin’s principle of evolution and we all have to face up to it.
Consider that Escherichia coli, the ubiquitous bacteria causing a sometimes fatal diarrhea is being recorded as resistant in our UK horses and also that this bacteria is zoonotic, or can infect people. Consider that Streptococcus equi zooepidemicus, a very common bacteria causing eye ulcers, skin disease and respiratory infections is being recorded as resistant and also zoonotic. Consider that Pseudomonas aeruginosa, also zoonotic, causing keratitis is also becoming resistant.
Consider whether you have contributed? Have you noticed a decrease in your horse’ symptoms and sometimes stopped administering a drug? Many times, if you stop administering the drug before the prescribed time, there is a good chance that the entire pathogen has not yet been eliminated. Circumstances such as this create ideal conditions that select for drug-resistant organisms. Bacteria that are susceptible to an antimicrobial are killed or put at a competitive disadvantage, while bacteria that have the ability to resist the antimicrobial survive and multiply. Additionally, “bacteria can become resistant when resistance genes are passed from a resistant bacterium to a sensitive one. Therefore, antibiotics may increase the prevalence of resistant bacteria among both target pathogens and normal bacterial flora. Money is also cause for concern. Many clients do not have the resources to pay for more expensive antibiotics or follow up treatment or tests to check for resistance that will ultimately alter the health of their animal. Vets depend on antibiotics to treat but as more organisms become resistant to more antimicrobials, the problem of treatment becomes more complex. With no change in our present course of action, treatment will eventually become impossible.
Some telephone calls result in exasperation. Many people call to request a medicine as a precautionary measure for a horse with a cut leg or cough or skin infection and are often offended by my reluctance to dispense the stipulated. It is right and proper that the people discuss the condition with a trained person, for if antibiotics are deemed necessary then an educated guess as to the likeliest bacteria present and so the most appropriate antibiotic required can be given. However, I have often been accused of being “money grabbing” (by suggesting visiting and examining the animal to confirm the picture and apparent necessity) or of “simply being difficult” because I cannot see any reason why the drugs are needed other than to appease the owner.
What we do know is that selection for resistance will occur where antimicrobial usage is highest and least controlled, that best practice is critical with correct dosages for the weight of the patient and observance of treatment duration paramount. It is perhaps no surprise that populations around foreign pig farms have high levels of antibiotic resistance and that cheap (read counterfeit) pharmacy imports are creating another opportunity for resistance because of their largely unknown efficacy.
Whilst a recent symposium highlighted current evidence suggesting veterinary practices are not a major cause of resistance in bacteria that affect human health, it is a “loop hole” for its development. What I and we do not want to do is end up with restrictions or the removal from our shelves of drugs we presently consider or have considered the norm. Whilst there are obvious differences between a hospital situation, farm or production animal situation and the individual companion animal that is our horses, it has been shown that it is possible to reduce antimicrobial levels without detriment to health or productivity in both human and animal fields. It has even been touted that antibiotics may levy a tax, akin to fuel tax, in an attempt to conserve the range and life span of current antibiotics. Carbon trading was dreamed up to try to conserve oil and reduce its pollutant effects and there have now been a couple of interesting papers suggesting a Pigouvian tax – defined as one levied on an agent causing an environmental problem as an incentive to mitigate that problem. For antibiotics the cost of drug resistance is not reflected in the price of the drug. If you consider antibiotic sensitivity as a resource like oil, you may want to maintain that by introducing a tax! So if you think I’m still being money grabbing, please think again, we all need to think again.