Responsible antibiotic usage: Twelve Top Tips in Small Animal General Practice
This article is not intended as a lecture about the importance of responsible antibiotic usage - you’d have to live under a rock not to have an inkling that mitigating the development of antimicrobial resistance is a critical matter of global “one health” concern! This is more of an acknowledgement that it’s one thing wanting to do something about it, or feeling like you “should”, and quite another to actually make that change, especially when you think about all the factors involved in that decision in general practice. As a GP myself (small animal but hopefully lots of this is applicable to equine and farm animal practice too), I’m only too aware that antibiotic prescribing habits vary widely and I’m passionate that there are lots of smaller ways in which we can help to drive change.
1. Start by talking about it with your colleagues - Practise evidence-based veterinary medicine (EBVM), and appoint or volunteer to be the practice “antimicrobial guardian”. Use a vet meeting or two to revise or create protocols for common presentations. Consult free useful resources including CEVA’s Gram initiative, BSAVA’s “PROTECT ME”, Clinician’s Brief/VIN articles and friendly specialists for case advice. Set an example but don’t be judgemental - you might be expecting colleagues to change the habits of a professional lifetime.
2. Educate yourself and your clients - Expect to have the same conversation more than once. It is to our advantage that in recent years responsible antimicrobial use and resistance has had national news coverage through NHS campaigns. Also remember that antibiotics are often comparatively expensive, and multiple “trial” courses without confirming a bacterial cause could mean funds that might be put to better use, or even illness that would have resolved without antibiotics and only symptomatic treatment. Beyond the more easily identifiable infections (e.g. abscesses, urinary tract infections and infected wounds) seen in general practice, in study populations referred for pyrexia, the majority of patients didn’t have a bacterial cause - only 18% of cats (1) and 16-19% (2,3) of dogs had confirmed bacterial infections when assessed for persistent pyrexia, this figure rose to 27.2% for dogs in which pyrexia was acute (3). This is a good reminder that the bodies’ responses of fever and neutrophilia are not specific for bacterial infection. Many cases of self limiting fever from viruses resolve within a short period of time (with or without antibiotics) and so wouldn’t have made it into these studies.
3. The microscope is your friend! - and so are your nurses. Could you build time into “first ear/skin consults” for cytology and ensure reception/first line staff ask owners to bring a urine sample to any urinary consults?
4. Avoid defensive or unnecessary prophylactic prescribing - Prescribing systemic antibiotics is not a benign action; it may make cases harder to diagnose (if antibiotics are given before samples for culture are obtained), promote resistance, have long-lasting consequences for commensal populations or result in side effects, ranging from mild gastrointestinal (GI) signs to more serious immune reactions.
5. Consider delayed prescribing - There’s nothing stopping you from prescribing antibiotics later if your patient deteriorates or if you get diagnostic results back that confirm that they are required.
6. Consider how you administer them - For superficial disease (skin, ears and eyes), topical application will obtain far higher concentrations than systemic agents at the target site. For dehydrated patients, or those with poor perfusion, subcutaneous absorption may be impaired whereas intravenous administration results in instant increases in serum concentration of the drug.
7. Encourage rechecks - Thus avoiding excessively long antibiotic courses and confirming resolution of cases, or the need for further diagnostics where appropriate.
8. Longer is not necessarily better - Numerous studies demonstrate non-inferiority of shorter antibiotic courses in human medicine, even for very severe diseases like pneumonia, bacteraemia and septic peritonitis. (4,5)
"An antibiotic’s job is not to kill every last bacteria, the immune system is designed for that!"
Clean surgeries under 90 minutes don’t require perioperative agents (with some exceptions such as orthopaedic implant placement), and clean contaminated procedures (such as GI surgery without spillage or existing peritonitis) may actually have increased risk of resistant surgical site infections if perioperative antibiotics are continued past 24 hours post-operatively. (6)
9. Preserve those important antibiotics - “Bigger gun” agents (fluoroquinolones, 3rd (and above) generation cephalosporins e.g. cefovecin) would ideally be used only based on culture results when other less important antibiotics are not an option.
10. Consider risk factors for multiple drug resistant organisms - In people, factors such as recent hospitalisation, prior antibiotic use, underlying disease state such as endocrinopathies or chronic disease, and indwelling devices such as urinary catheters are all known to increase the risk. Although we may not have such comprehensive evidence in companion animals, some risk factors such as prior antimicrobial use and urinary catheterisation remain the same. (7)
11. Provide the pathologist with as much information as you can and get to know the meaning of those culture and sensitivity results - Document previous antibiotic use/treatment, previous cultures, location of the swab - it may even help you to get faster results. How well do you understand that ssSirr on the lab report? Check out the Idexx guide to understanding MICs and culture/sensitivity results.
12. Re-think old thinking - Evidence suggests that most uncomplicated dentals (8), cats with uncomplicated feline lower urinary tract disease (FLUTD)/feline idiopathic cystitis (FIC), (9) self-limiting GI disease, subclinical bacteriuria (10) and even acute haemorrhagic diarrhoea syndrome (11) (unless they are showing signs of sepsis) can be managed without antimicrobial agents.
This is one field (of many!) where so much dogma exists - and so it is even more important to acknowledge the now rapidly growing body of evidence that is becoming accessible to us.
"Whilst it’s easy to focus on the harm we might be doing with inappropriate antimicrobial prescribing, we can be optimistic and look at all the things we can change."
Plus it’s really satisfying to see change in the right direction. There’s plenty of free CPD and education out there too, membership of British Society of Antimicrobial Chemotherapy (BSAC) is free, as are several online platforms with courses dedicated to the topic (listed below).
- Spencer SE, Knowles T, Ramsey IK, Tasker S., (2017), Pyrexia in cats: Retrospective analysis of signalment, clinical investigations, diagnosis and influence of prior treatment in 106 referred cases. Journal of Feline Medicine and Surgery, 19(11):1123-1130.
- Dunn KJ, Dunn JK., (1998), Diagnostic investigations in 101 dogs with pyrexia of unknown origin, Journal of Small Animal Practice, 39: 574-580.
- Battersby IA, Murphy KF, Tasker S, Papasouliotis K., (2006), Retrospective study of fever in dogs: laboratory testing, diagnoses and influence of prior treatment, Journal of Small Animal Practice, 47:370-376.
- Llewelyn MJ, Fitzpatrick JM, Darwin E, Tonkin-Crine S, Gorton C, Paul J, et al. (2017), The antibiotic course has had its day, British Medical Journal, 358:j3418
- Spellberg B,. (2018), The Maturing Antibiotic Mantra: “Shorter Is Still Better”. Journal of Hospital Medicine, 5;361-362.
- Willard MD, Schulz KS,. (2013), Surgical infections and antibiotic selection, In Fossum TW (Ed.), Small Animal Surgery 4th Edition (pp.84-94), Elsevier.
- Ogeer‐Gyles JS, Mathews KA, Boerlin P,. (2006), Nosocomial infections and antimicrobial resistance in critical care medicine, Journal of Veterinary Emergency and Critical Care, 16(1):1-18.
- Bellows J, Berg ML, Dennis S, Harvey R, Lobprise HB, Snyder CJ, Stone AES, Van de Wetering AG,. (2019), AAHA Dental Care Guidelines for Dogs and Cats. Journal of the American Animal Hospital Association, 55(2):49-69.
- Black, V., 2018. Approach to feline lower urinary tract disease, Companion Anim. 23(7):388-394.
- Weese JS, Blondeau JM, Boothe D, Breitschwerdt EB, Guardabassi L, et al. (2011), Antimicrobial Use Guidelines for Treatment of Urinary Tract Disease in Dogs and Cats: Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases, Veterinary Medicine International, 2011:263768.
- Unterer S, Strohmeyer K, Kruse B, Sauter‐Louis C, Hartmann K, (2011), Treatment of Aseptic Dogs with Hemorrhagic Gastroenteritis with Amoxicillin/Clavulanic Acid: A Prospective Blinded Study, Journal of Veterinary Internal Medicine, 25:973-979.