Current British veterinary attitudes to the use of perioperative antimicrobials in small animal surgery

Antimicrobial prophylaxis in companion animal surgery: A scoping review for European Network for Optimization of Antimicrobial Therapy (ENOVAT) guidelines

Surgical antimicrobial prophylaxis (SAP) is widely used to reduce the risk of surgical site infections (SSI), but there is uncertainty as to what the proportion of SSI reduction is. Therefore, it is difficult for surgeons to properly weigh the costs, risks and benefits for individual patients when deciding on the use of SAP, making it challenging to promote antimicrobial stewardship in primary practice settings. The objective of this study was to map the veterinary evidence focused on assessing the effect of SAP on SSI development and in order to identify surgical procedures with some research evidence and possible knowledge gaps. In October 2021 and December 2022, Scopus, CAB Abstracts, Web of Science Core Collection, Embase and MEDLINE were systematically searched. Double blinded screening of records was performed to identify studies in companion animals that reported on the use of SAP and SSI rates. Comparative data were available from 34 out of 39123 records screened including: eight randomised controlled trials (RCT), 23 cohort studies (seven prospective and 16 retrospective) and three retrospective case series representing 12476 dogs and cats in total. Extracted data described peri- or post-operative SAP in nine, and 25 studies, respectively. In the eight RCTs evaluating SAP in companion animals, surgical procedure coverage was skewed towards orthopaedic stifle surgeries in referral settings and there was large variation in SAP protocols, SSI definitions and follow-up periods. More standardized data collection and agreement of SSI definitions is needed to build stronger evidence for optimized patient care.

Patient weight has diverse effects on the prescribing of different antibiotics to dogs

Introduction

Various factors including body weight-associated treatment cost may influence the probability of dispensing antibiotics to dogs in first-opinion practice, but their effect on specific drug choice remains unclear.

Methods

Multiple membership regression modeling was used to investigate the probability of dispensing 12 different antibiotics to dogs of different weights in the context of various disease presentations, using anonymized data obtained from electronic health records of 18 clinics between 2020 and 2022. Data from 14,259 dogs were analyzed.

Results

Treatment choice varied significantly with animal weight. Higher body weight was associated with an increased likelihood of dispensing lower cost antimicrobials such as amoxicillin and trimethoprim sulfonamide, while use of higher cost antimicrobials such as cefovecin was strongly biased to smaller animals. However, these effects were limited when restricted treatment options were available for the target condition.

Conclusion

This work demonstrates that anticipated financial costs may result in different treatment choices for canine patients depending on their body weight. Further work is needed to understand the impact of financial pressures on veterinarians' treatment choices, and the implications for the optimization of antimicrobial stewardship in first opinion practice.

A multinational survey of companion animal veterinary clinicians: How can antimicrobial stewardship guidelines be optimised for the target stakeholder?

Antimicrobial stewardship initiatives are widely regarded as a cornerstone for ameliorating the global health impact of antimicrobial resistance. Within companion animal health, such efforts have largely focused on development and dissemination of antimicrobial stewardship guidelines (ASGs). However, there have been few attempts to understand veterinarian attitudes towards and knowledge of ASGs or to determine how awareness regarding ASGs might best be increased. An online survey regarding ASGs was formulated for veterinarians who treat companion animals. The survey was distributed across 46 European and associated countries between 12 January and 30 June, 2022. In total, 2271 surveys were completed, with 64.9% of respondents (n = 1474) reporting awareness and usage of at least one ASG. Respondents from countries with greater awareness of ASGs tended to report more appropriate use of antimicrobials (Spearman's rank coefficient = 0.6084, P ≤ 0.001), with respondents from countries with country-specific ASGs tending to score highest across both awareness and appropriate use domains. Respondents prioritised guidance around antimicrobial choice (82.0%, n = 1863), duration of treatment (66.0%, n = 1499), and dosage (51.9%, n = 1179) for inclusion in future ASGs, with 78.0% (n = 1776) of respondents preferring ASGs to be integrated into their patient management system. Awareness of ASGs and their use in companion animal veterinary practice appears to be greater than previously reported, with respondents tending to report antimicrobial prescription decision making broadly in line with current clinical recommendations. However, further initiatives aimed at maximising accessibility to ASGs both within countries and individual veterinary practices are recommended.

A Spanish Survey on the Perioperative Use of Antimicrobials in Small Animals

Appropriate use of perioperative antimicrobials can significantly reduce the risk of post-operative infections. However, inappropriate antimicrobial use can result in the creation of multidrug-resistant bacteria, increased costs, host flora disruption, side effects and increased risk of hospital-acquired infections. This survey evaluated the current perioperative use of antimicrobials in small animals by Spanish veterinarians using a web-based questionnaire. Responses were represented using descriptive statistics and a statistical analysis of the association between demographic data and perioperative antimicrobial use was performed. Pre-operative antimicrobials were administered in clean surgery by up to 68.3% of participants, 81.0% in clean-contaminated surgery and 71.3% in dirty surgery, while in the post-operative period, antimicrobials were administered by up to 86.3% of participants in clean surgery, 93.2% in clean-contaminated surgery and 87.5% in dirty surgery. Factors considered "very important" for antimicrobial selection were the degree of wound contamination, patient immunosuppression and use of prosthesis. The most frequently used antimicrobial was beta-lactamase-resistant (or potentiated) penicillin. Post-operative antimicrobial use was associated with participants without specific surgical postgraduate training. This study highlights an overuse of antimicrobials in perioperative procedures in small animal surgery in Spain. Therefore, evidence-based guidelines and further education regarding the correct use of antimicrobial prophylaxis are recommended.

Rate of surgical site and urinary tract infections in dogs after cessation of antibiotics following spinal surgery

BACKGROUND

Excessive use of antimicrobials and the increasing occurrence of antimicrobial resistance are major challenges in both human and veterinary medicine. The role of prophylactic antimicrobial therapy in orthopaedic and neurosurgeries in dogs can be questioned. The aim of this study was to evaluate the rate of surgical site infections (SSI) and urinary tract infections (UTI) in dogs after cessation of antibiotics following spinal surgery.

METHODS

Electronic patient records from January 2018 to December 2019 were retrospectively reviewed to identify dogs that underwent spinal surgery (n = 158). Antimicrobial drug use and the presence of SSI and UTI were recorded.

RESULTS

Overall, SSI developed in 1.3% of dogs that underwent spinal surgery, while UTI developed in 8.2%. Multidrug-resistant (MDR) bacteria were detected in 5.1% of dogs. The rates of SSI, UTI and MDR did not differ significantly between dogs that received postoperative antimicrobial therapy and those that did not.

LIMITATIONS

The main limitation of this study was its retrospective design.

CONCLUSION

Overall, the SSI rate in this study was low. Cessation of postoperative antimicrobial use in dogs following spinal surgery did not have a negative effect on either SSI development or the occurrence of UTI.

How animal agriculture stakeholders define, perceive, and are impacted by antimicrobial resistance: challenging the Wellcome Trust's Reframing Resistance principles

Humans, animals, and the environment face a universal crisis: antimicrobial resistance (AR). Addressing AR and its multi-disciplinary causes across many sectors including in human and veterinary medicine remains underdeveloped. One barrier to AR efforts is an inconsistent process to incorporate the plenitude of stakeholders about what AR is and how to stifle its development and spread-especially stakeholders from the animal agriculture sector, one of the largest purchasers of antimicrobial drugs. In 2019, The Wellcome Trust released Reframing Resistance: How to communicate about antimicrobial resistance effectively (Reframing Resistance), which proposed the need to establish a consistent and harmonized messaging effort that describes the AR crisis and its global implications for health and wellbeing across all stakeholders. Yet, Reframing Resistance does not specifically engage the animal agriculture community. This study investigates the gap between two principles recommended by Reframing Resistance and animal agriculture stakeholders. For this analysis, the research group conducted 31 semi-structured interviews with a diverse group of United States animal agriculture stakeholders. Participants reported attitudes, beliefs, and practices about a variety of issues, including how they defined AR and what entities the AR crisis impacts most. Exploration of Reframing Resistance's Principle 2, "explain the fundamentals succinctly" and Principle 3, "emphasis that this is universal issue; it can affect anyone, including you" reveals disagreement in both the fundamentals of AR and consensus of "who" the AR crisis impacts. Principle 2 may do better to acknowledge that animal agriculture stakeholders espouse a complex array of perspectives that cannot be summed up in a single perspective or principle. As a primary tool to combat AR, behavior change must be accomplished first through outreach to stakeholder groups and understanding their perspectives.

Understanding Antibiotic Use in Companion Animals: A Literature Review Identifying Avenues for Future Efforts

Addressing antibiotic use is essential to tackle antimicrobial resistance, a major human and animal health challenge. This review seeks to inform stewardship efforts in companion animals by collating research insights regarding antibiotic use in this group and identifying overlooked avenues for future research and stewardship efforts. The development of population-based methods has established that antibiotics are frequently used in companion animal care. Research insights are also contributing toward an in-depth comprehension of the contexts to antibiotic use. Qualitative approaches, for example, have enabled a nuanced understanding in four key areas: interactions with owners, clinical and financial risk management, time pressures, and clinic dynamics. This review identifies that much of the existing research frames antibiotic use as the result of choices made by the individuals at the interface of their use. Future research and policy endeavours could look beyond the moment of prescribing to consider the societal structures and networks in which companion animal antibiotic use is entangled. A diversification in research approaches and frameworks through which antibiotic use is understood will facilitate the identification of additional targets for stewardship initiatives beyond providing information and awareness campaigns.

Infection rate treating radial and ulnar fractures using bone plate fixation without antibiotic prophylaxis

OBJECTIVES

To evaluate the effectiveness and complication rate of a 1.5- and 2.0-mm titanium locking plate for the treatment of radial and ulnar fractures in small dog breeds and cats without peri-operative antibiotic prophylaxis in a prospective case series.

MATERIALS AND METHODS

Medical records and radiographs of closed radial and ulnar fractures treated using internal fixation with a 1.5- or 2.0-mm titanium locking plate without antibiotic prophylaxis were collected prospectively. Patients were clinically followed up until radiographical fracture healing was complete.

RESULTS

Thirty-two fractures in small breed dogs and cats with an average bodyweight of 3.9 kg met the inclusion criteria. The follow-up time radiographically and clinically was 4-35 weeks. All fractures showed radiographical fracture union, and all patients had a good clinical outcome. The superficial infection rate in this case series was 0%; the deep infection rate involving the implant/bone was 3.1%.

CLINICAL SIGNIFICANCE

The novel 1.5- and 2.0-mm titanium locking plate system was successfully used to treat simple closed radial and ulnar fractures in small breed dogs and cats without peri-operative antibiotic prophylaxis, resulting in good clinical outcome and a low infection rate.

Antimicrobial Prescribing Practices in Dogs and Cats by Colombian Veterinarians in the City of Medellin

This study surveyed the prescribing behavior of Colombian companion animal veterinarians and compared the responses to the current guidelines of the International Society for Companion Animals on Infectious Diseases (ISCAID). A convenience sample of 100 primary-care veterinary practitioners was selected from the city of Medellin. A questionnaire was designed to present hypothetical clinical scenarios regarding prescription choices for systemic antimicrobials. The numbers of veterinarians empirically prescribing a course of systemic antimicrobials for each scenario were-perioperative elective surgeries (86%), superficial pyoderma (90%), lower urinary tract disease (52%), acute hemorrhagic diarrhea (50%), and kennel cough (46%). For urinary tract disease, cultures and susceptibility testing were only performed by half of the respondents, suggesting lower diagnostic standards. In superficial pyoderma cases, cytology was performed in the following percent of cases-0% (24), 20% (30), 40% (17), 60% (11), 80% (8), and 100% (10). Antimicrobials were over-prescribed relative to emerging standard for elective surgeries (86%), kennel cough (46%), and acute hemorrhagic diarrhea (50%). Critically important antimicrobials, such as fluoroquinolones, were applied commonly for superficial pyoderma (18%), kennel cough (12%), and lower urinary tract disease in dogs (20%) and cats (26%). In conclusion, antimicrobial prescribing behavior was inconsistent with current guidelines, and antimicrobial use could be improved by appropriate diagnostic steps allowing choice of an optimal antimicrobial drug. Overall, we documented the widespread use of antimicrobials for the treatment of these four common disease conditions.

Population Pharmacokinetic Study of Cefazolin Used Prophylactically in Canine Surgery for Susceptibility Testing Breakpoint Determination

This study aimed to determine the population pharmacokinetic (Pop PK) parameters of cefazolin administered prophylactically at 25 mg/kg intravenously (IV) 30 min before surgery in a canine population of 78 dogs and assess whether covariates, such as sex, age, body weight (BW), breed, health status, creatinine level, and surgery time, have an influence on cefazolin disposition. The ultimate goal was to compute PK/PD cut off values and subsequently establish a specific clinical breakpoint (CBP) for the development of an antimicrobial susceptibility test (AST) of cefazolin in dogs according to the VetCAST approach. Two to 11 blood samples were collected from each dog from 5 to 480 min after cefazolin administration. A two-compartment model was selected, and parameterization was in terms of serum clearance (CL), intercompartmental CL(s) (Q) and volume(s) of distribution (V). The percentage of cefazolin binding to serum protein was 36.2 ± 5.3%. Population primary parameter estimates V1, V2, CL, and Q were (typical value ± SE) 0.116 ± 0.013 L/kg, 0.177 ± 0.011 L/kg, 0.0037 ± 0.0002 L/kg/min, and 0.0103 ± 0.0013 L/kg/min, respectively. Cefazolin presented rapid distribution and elimination half-lives (mean ± SE) 4.17 ± 0.77 min and 57.93 ± 3.11 min, respectively. The overall between-subject variability (BSV) for estimated primary parameters ranged from 36 to 42%, and none of the seven explored covariates were able to reduce this variability by an amplitude clinically relevant. By Monte Carlo simulation, the probability of a PK/PD target attainment (here to achieve a free serum concentration exceeding the MIC for 50% of the dosing interval in 90% of dogs) was computed with a dosage of 25 mg/kg administered IV every 6 h for 4 administrations in 24 h. The computed PK/PD cut off value was 2 mg/L. In conclusion, cefazolin administered prophylactically in surgical dogs at 25 mg/kg IV every 6 h was deemed effective against pathogens with a MIC value ≤ 2 mg/L and from a PK/PD perspective, can be recommended in a wide range of canine patient populations with no necessary dose adjustment for special dog subpopulations.

Antibiotic prophylaxis in veterinary cancer chemotherapy: A review and recommendations

Bacterial infection following cancer chemotherapy-induced neutropenia is a serious cause of morbidity and mortality in human and veterinary patients. Antimicrobial prophylaxis is controversial in the human oncology field, as any decreased incidence in bacterial infections is countered by patient adverse effects and increased antimicrobial resistance. Comprehensive guidelines exist to aid human oncologists in prescribing antimicrobial prophylaxis but similar recommendations are not available in veterinary literature. As the veterinarian's role in antimicrobial stewardship is increasingly emphasized, it is vital that veterinary oncologists implement appropriate antimicrobial use. By considering the available human and veterinary literature we present an overview of current clinical practices and are able to suggest recommendations for prophylactic antimicrobial use in veterinary cancer chemotherapy patients.

Investigation of short-term surgical complications in a low-resource, high-volume dog sterilisation clinic in India

Background

Surgical sterilisation is currently the method of choice for controlling free-roaming dog populations. However, there are significant logistical challenges to neutering large numbers of dogs in low-resource clinics. The aim of this study was to investigate the incidence of short-term surgical complications in a low-resource sterilisation clinic which did not routinely administer post-operative antibiotics.

The medical records of all sterilisation surgeries performed in 2015 at the Worldwide Veterinary Service International Training Centre in Tamil Nadu, India were reviewed (group A) to assess immediate surgical complications. All animals in this group were monitored for at least 24 h post-surgery but were not released until assessed by a veterinarian as having uncomplicated wound healing. In the second part of this study from August to December 2015, 200 free-roaming dogs undergoing sterilisation surgery, were monitored for a minimum of 4-days post-surgery to further assess postoperative complications (group B).

Results

Surgery related complications were seen in 5.4% (95%CI, 4.5–6.5%) of the 1998 group A dogs monitored for at least 24 h, and in 7.0% (3.9–11.5%) of the 200 group B dogs monitored for 4 days. Major complications were classed as those requiring an intervention and resulted in increased morbidity or mortality. Major complications were seen in 2.8% (2.1–3.6%) and 1.5% (3.1–4.3%) of group A and B, respectively. Minor complications requiring little or no intervention were recorded for 2.6% (1.9–3.4%) for group A and 5.5% (2.8–9.6%) for group B. There was no evidence for a difference in complication rates between the two groups in a multivariate regression model.

Conclusion

This study demonstrated that high volume, low-resource sterilisation of dogs can be performed with a low incidence of surgical complications and low mortality.

Prospective, Randomized Comparison of the Effect of Two Antimicrobial Regimes on Surgical Site Infection Rate in Dogs Undergoing Orthopedic Implant Surgery

OBJECTIVES

To determine whether extending prophylactic antimicrobial administration into the postoperative period would decrease the surgical site infection (SSI) rate in clean canine orthopedic surgery associated with a metal implant.

STUDY DESIGN

Randomized prospective clinical study.

SAMPLE POPULATION

Consecutive procedures (n = 400) on dogs that had clean orthopedic surgery using a metal implant.

METHODS

Cases were randomly allocated to 1 of 2 groups. Group 1 was only administered perioperative antimicrobial drugs whereas group 2 was administered perioperative and 5 days of postoperative antimicrobial therapy. Owners were questioned or dogs were examined at 2 and 6 weeks after surgery to identify any SSI. Long term follow-up by questionnaire of the referring veterinary surgeon ≥1 year after surgery was obtained.

RESULTS

Ten of 191 dogs (5.24%) in group 1 developed SSI within 6 weeks compared with 7 of 198 (3.54%) in group 2; 7.22% of dogs in group 1 and 8.24% in group 2 developed infections more than 6 weeks after surgery.

CONCLUSIONS

SSI rates in this population of dogs were similar where antimicrobial prophylaxis was administered perioperatively over 3 hours or as a course continued for 6 days.

Qualitative study of factors associated with antimicrobial usage in seven small animal veterinary practices in the UK

Responsible use of antimicrobials by veterinarians is essential to contain antimicrobial resistance in pathogens relevant to public health. Inappropriate antimicrobial use has been previously described in practice. However, there is scarce information on factors influencing antimicrobial usage in dogs and cats. We investigated intrinsic and extrinsic factors influencing decision-making of antimicrobial usage in first opinion small animal practices in the UK through the application of qualitative research methods. Semi-structured interviews were conducted with 21 veterinarians from seven veterinary first opinion practices in the UK in 2010. Topics investigated included: a) criteria used for selection of antimicrobials, b) influences by colleagues, c) influences by clients, d) pet characteristics, e) sources of knowledge, f) awareness of guidelines and g) protocols implemented in practice that may affect antimicrobial usage by veterinarians. Hypothetical scenarios selected to assess appropriateness of antimicrobial usage were: a) vomiting in a Yorkshire Terrier due to dietary indiscretion, b) deep pyoderma in a Shar-Pei, c) Feline Lower Urinary Tract disease in an 7 year-old male neutered cat and d) neutering of a 6-months dog. Interviews were recorded and transcribed by the interviewer. Thematic analysis was used to analyse content of transcribed interviews. Data management and analysis was conducted with qualitative analysis software NVivo8 (QSR International Pty Ltd). Antimicrobial usage by participants was influenced by factors other than clinical evidence and scientific knowledge. Intrinsic factors included veterinarian's preference of substances and previous experience. Extrinsic factors influencing antimicrobial selection were; perceived efficacy, ease of administration of formulations, perceived compliance, willingness and ability to treat by pet owners, and animal characteristics. Cost of therapy was only perceived as an influential factor in low, mixed socioeconomic areas. Veterinarians had limited awareness of current recommendations for responsible use in small animal practice. Social norms, particularly verbally agreed protocols influenced veterinarians. Inappropriate antimicrobial usage was identified in the therapy of non-infectious diseases and prophylaxis of routine clean surgical procedures. Discussion of clinical cases with peers and effectiveness meetings in the workplace were useful to veterinarians to share scientific knowledge. Effectiveness meetings can be a common ground for veterinarians to discuss and agree protocols for clinical conditions and surgical procedures. Protocols should be evidence-based, follow current recommendations and take into account the resources available in the workplace. Targeted training of veterinarians in the workplace with peer support should be used to promote responsible antimicrobial usage.