Laura Y. Hardefeldt

A Multicenter Retrospective Study of 151 Renal Biopsies in Horses

BACKGROUND Renal biopsies are uncommonly performed in horses and little is known about their diagnostic utility and associated complication rate. OBJECTIVE To describe the techniques, the complication rate, risk factors, and histopathology results; as well as evaluate the safety and diagnostic utility of renal biopsy in the horse. ANIMALS One hundred and forty-six horses from which 151 renal biopsies were obtained. Animals ranged in age from 48 hours to 30 years. METHODS Multicenter retrospective study, with participation of 14 institutions (1983-2009). RESULTS Renal biopsy in horses was associated with a similar rate of complications (11.3%) to that occurring in humans and companion animals. Complications were generally associated with hemorrhage or signs of colic, and required treatment in 3% of cases. Fatality rate was low (1/151; 0.7%). Biopsy specimens yielded sufficient tissue for a histopathologic diagnosis in most cases (94%) but diagnoses had only fair (72%) agreement with postmortem findings. Risk factors for complications included biopsy specimens of the left kidney (P = .030), a diagnosis of neoplasia (P = .004), and low urine specific gravity (P = .030). No association with complications was found for age, sex, breed, institution, presenting complaint, other initial clinicopathologic data, biopsy instrument, needle size, or use of ultrasonographic guidance. CONCLUSIONS AND CLINICAL IMPORTANCE Renal biopsy in horses has low morbidity and results in a morphological histopathologic diagnosis in 94% of cases. However, this procedure might result in serious complications and should only be used when information obtained would be likely to impact decisions regarding patient management and prognosis.

Incidence of transfusion reactions to commercial equine plasma.

OBJECTIVE To report on the incidence of transfusion reactions to commercial equine plasma in a hospital-based population of horses, to characterize these reactions and report on outcome. DESIGN Retrospective study. SETTING University teaching hospital. ANIMALS Client-owned horses referred to the University of Wisconsin. INTERVENTIONS Intravenous administration of 2 commercial equine plasma products when clinically indicated. MEASUREMENTS AND MAIN RESULTS Medical records of 107 horses that received plasma transfusions between 2003 and 2008 were evaluated. Transfusion reactions were recorded in 6 of 107 transfusions. All individuals were administered plasma from 1 commercial source. Foals <30 days of age received a hypergammaglobulinemic product and all adults received a lower IgG concentration product. No reactions were recorded in adults. In foals (<30 d) reactions were recorded in 6 of 69 cases (8.7%), all of which occurred in neonates <7 days of age (6/62; [9.7%]). The most frequent reactions were fever (4/6), tachycardia (2/6), tachypnea (2/6), and colic (2/6). All affected foals survived the reaction. There were no statistically significant differences (P<0.05) in any of the variables examined between those foals that did and those that did not experience transfusion reactions. CONCLUSION The incidence of transfusion reactions was 8.7% in foals and 0% in adult horses in our referral population. Five of 6 foals responded to medical therapy and eventually received the clinically indicated transfusion. No transfusion related mortality occurred.

Antimicrobials used for surgical prophylaxis by companion animal veterinarians in Australia

Antimicrobials are widely used in veterinary practices, but there has been no investigation into the classes of antimicrobials used or the appropriateness of their use in surgical prophylaxis. Antimicrobial usage guidelines were published by the Australian Infectious Disease Advisory Panel (AIDAP) in 2013, but there has been no investigation of compliance with them. This study aimed to investigate antimicrobial use for surgical prophylaxis in companion animal practice and assess compliance with AIDAP guidelines for selected conditions by conducting a cross-sectional study of antimicrobial usage patterns of Australian veterinarians using an online questionnaire. Information solicited included: details of the respondent, the frequency with which antimicrobials were used for specific surgical conditions (including dose and duration) and practice antimicrobial use policies and sources of information about antimicrobial drugs and their uses. A total of 886 members of the Australian veterinary profession completed the survey. Few (22%) reported that their practice that had an antimicrobial use policy. Generally, the choice of antimicrobial drug was appropriate for the given surgical conditions. There was poor compliance with AIDAP guidelines for non-use of antimicrobials for routine neutering. Veterinarians caring solely for companion animals had higher odds of optimal compliance with guidelines than veterinarians in mixed species practices (OR 1.4, 95%CI 1.1-1.9). Recent graduates (>2011) had lower odds of compliance than older graduates (OR 0.8, 95%CI 0.6-0.9). The findings suggest that antimicrobial use guidelines need to be expanded and promoted to improve the responsible use of antimicrobials in small animal practice in Australia.

Retrospective Study: Incidence of transfusion reactions to commercial equine plasma

OBJECTIVE To report on the incidence of transfusion reactions to commercial equine plasma in a hospital-based population of horses, to characterize these reactions and report on outcome. DESIGN Retrospective study. SETTING University teaching hospital. ANIMALS Client-owned horses referred to the University of Wisconsin. INTERVENTIONS Intravenous administration of 2 commercial equine plasma products when clinically indicated. MEASUREMENTS AND MAIN RESULTS Medical records of 107 horses that received plasma transfusions between 2003 and 2008 were evaluated. Transfusion reactions were recorded in 6 of 107 transfusions. All individuals were administered plasma from 1 commercial source. Foals <30 days of age received a hypergammaglobulinemic product and all adults received a lower IgG concentration product. No reactions were recorded in adults. In foals (<30 d) reactions were recorded in 6 of 69 cases (8.7%), all of which occurred in neonates <7 days of age (6/62; [9.7%]). The most frequent reactions were fever (4/6), tachycardia (2/6), tachypnea (2/6), and colic (2/6). All affected foals survived the reaction. There were no statistically significant differences (P<0.05) in any of the variables examined between those foals that did and those that did not experience transfusion reactions. CONCLUSION The incidence of transfusion reactions was 8.7% in foals and 0% in adult horses in our referral population. Five of 6 foals responded to medical therapy and eventually received the clinically indicated transfusion. No transfusion related mortality occurred.

Antimicrobial Prescribing in Dogs and Cats in Australia: Results of the Australasian Infectious Disease Advisory Panel Survey

Background Investigations of antimicrobial use in companion animals are limited. With the growing recognition of the need for improved antimicrobial stewardship, there is urgent need for more detailed understanding of the patterns of antimicrobial use in this sector. Objectives To investigate antimicrobial use for medical and surgical conditions in dogs and cats by Australian veterinarians. Methods A cross‐sectional study was performed over 4 months in 2011. Respondents were asked about their choices of antimicrobials for empirical therapy of diseases in dogs and cats, duration of therapy, and selection based on culture and susceptibility testing, for common conditions framed as case scenarios: 11 medical, 2 surgical, and 8 dermatological. Results A total of 892 of the 1,029 members of the Australian veterinary profession that completed the survey satisfied the selection criteria. Empirical antimicrobial therapy was more common for acute conditions (76%) than chronic conditions (24%). Overall, the most common antimicrobial classes were potentiated aminopenicillins (36%), fluoroquinolones (15%), first‐ and second‐generation cephalosporins (14%), and tetracyclines (11%). Third‐generation cephalosporins were more frequently used in cats (16%) compared to dogs (2%). Agreement with Australasian Infectious Disease Advisory Panel (AIDAP) guidelines (generated subsequently) was variable ranging from 0 to 69% between conditions. Conclusions and Clinical Importance Choice of antimicrobials by Australian veterinary practitioners was generally appropriate, with relatively low use of drugs of high importance, except for the empirical use of fluoroquinolones in dogs, particularly for otitis externa and 3rd‐generation cephalosporins in cats. Future surveys will determine whether introduction of the 2013 AIDAP therapeutic guidelines has influenced prescribing habits.

Barriers to and enablers of implementing antimicrobial stewardship programs in veterinary practices

Background Antimicrobial stewardship (AMS) programs are yet to be widely implemented in veterinary practice and medical programs are unlikely to be directly applicable to veterinary settings. Objective To gain an in‐depth understanding of the factors that influence effective AMS in veterinary practices in Australia. Methods A concurrent explanatory mixed methods design was used. The quantitative phase of the study consisted of an online questionnaire to assess veterinarians’ attitudes to antimicrobial resistance (AMR) and antimicrobial use in animals, and the extent to which AMS currently is implemented (knowingly or unknowingly). The qualitative phase used semi‐structured interviews to gain an understanding of the barriers to and enablers of AMS in veterinary practices. Data were collected and entered into NVivo v.11, openly coded and analyzed according to mixed methods data analysis principles. Results Companion animal, equine, and bovine veterinarians participated in the study. Veterinary practices rarely had antimicrobial prescribing policies. The key barriers were a lack of AMS governance structures, client expectations and competition between practices, cost of microbiological testing, and lack of access to education, training and AMS resources. The enablers were concern for the role of veterinary antimicrobial use in development of AMR in humans, a sense of pride in the service provided, and preparedness to change prescribing practices. Conclusion and Clinical Importance Our study can guide development and establishment of AMS programs in veterinary practices by defining the major issues that influence the prescribing behavior of veterinarians.

Antimicrobials used for surgical prophylaxis by equine veterinary practitioners in Australia

BACKGROUND Antimicrobials are widely used in Australian veterinary practices, but no investigation into the classes of antimicrobials used, or the appropriateness of use in horses, has been conducted. OBJECTIVES The aim of the study was to describe antimicrobial use for surgical prophylaxis in equine practice in Australia. STUDY DESIGN Cross-sectional questionnaire survey. METHODS An online questionnaire was used to document antimicrobial usage patterns. Information solicited in the questionnaire included demographic details of the respondents, the frequency with which antimicrobials were used for specific surgical conditions (including the dose, timing and duration of therapy) and practice antimicrobial use policies and sources of information about antimicrobials and their uses. RESULTS A total of 337 members of the Australian veterinary profession completed the survey. Generally, the choice of antimicrobial was appropriate for the specified equine surgical condition, but the dose and duration of therapy varied greatly. While there was poor optimal compliance with British Equine Veterinary Association guidelines in all scenarios (range 1-15%), except removal of a nonulcerated dermal mass (42%), suboptimal compliance (compliant antimicrobial drug selection but inappropriate timing, dose or duration of therapy) was moderate for all scenarios (range 48-68%), except for an uninfected contaminated wound over the thorax, where both optimal and suboptimal compliance was very poor (1%). Veterinarians practicing at a university hospital had higher odds of compliance than general practice veterinarians (Odds ratio 3.2, 95% CI, 1.1-8.9, P = 0.03). MAIN LIMITATIONS Many survey responses were collected at conferences which may introduce selection bias, as veterinarians attending conferences may be more likely to have been exposed to contemporary antimicrobial prescribing recommendations. CONCLUSIONS Antimicrobial use guidelines need to be developed and promoted to improve the responsible use of antimicrobials in equine practice in Australia. An emphasis should be placed on antimicrobial therapy for wounds and appropriate dosing for procaine penicillin.

Antimicrobial susceptibility testing by Australian veterinary diagnostic laboratories: Antimicrobial susceptibility testing by Australian veterinary diagnostic laboratories

BACKGROUND The national strategy for tackling antimicrobial resistance highlights the need for antimicrobial stewardship in veterinary practice and for surveillance of antimicrobial susceptibility in veterinary pathogens. Diagnostic laboratories have an important role in facilitating both of these processes, but it is unclear whether data from veterinary diagnostic laboratories are similar enough to allow for compilation and if there is consistent promotion of appropriate antimicrobial use embedded in the approaches of different laboratories to susceptibility testing. METHODS A cross-sectional study of antimicrobial susceptibility testing and reporting procedures by Australian veterinary diagnostic laboratories was conducted in 2017 using an online questionnaire. All 18 veterinary diagnostic laboratories in Australia completed the questionnaire. RESULTS Kirby-Bauer disc diffusion was the method predominantly used for antimicrobial susceptibility testing and was used to evaluate 86% of all isolates, although two different protocols were used across the 18 laboratories (CLSI 15/18, CDS 3/18). Minimum inhibitory concentrations were never reported by 61% of laboratories. Common isolates were consistently reported on across all species, except for gram-negative isolates in pigs, for which there was some variation in the approach to reporting. There was considerable diversity in the panels of antimicrobials used for susceptibility testing on common isolates and no consistency was apparent between laboratories for any bacterial species. CONCLUSION We recommend that nationally agreed and consistent antimicrobial panels for routine susceptibility testing should be developed and a uniform set of guidelines should be adopted by veterinary diagnostic laboratories in Australia.

Cross-sectional study of antimicrobials used for surgical prophylaxis by bovine veterinary practitioners in Australia

Antimicrobials are widely used in veterinary practices, but there has been no investigation of antimicrobial classes used or the appropriateness of their use in bovine practice. This study investigated antimicrobial use for surgical prophylaxis in bovine practice in Australia. A cross-sectional study of veterinarian antimicrobial usage patterns was conducted using an online questionnaire. Information solicited included respondent’s details, the frequency with which antimicrobials were used for specific surgical conditions (including the dose, timing and duration of therapy) and details of practice antimicrobial use policies and sources of information about antimicrobials. In total, 212 members of the Australian veterinary profession working in bovine practice completed the survey. Antimicrobials were always or frequently used by more than 75 per cent of respondents in all scenarios. Generally, antimicrobial drug choice was appropriate for the reported surgical conditions. Procaine penicillin and oxytetracycline accounted for 93 per cent of use. However, there was a wide range of doses used, with underdosing and inappropriate timing of administration being common reasons for inappropriate prophylactic treatment. There was very low use of critically important antimicrobials (3.3 per cent of antimicrobials reported). Antimicrobial use guidelines need to be developed and promoted to improve the responsible use of antimicrobials in bovine practice.

Secondary renal tubular acidosis in a Hereford calf

A 3-month-old Hereford heifer calf was presented for lethargy. Blood gas analysis and plasma biochemical testing revealed severe metabolic acidosis, azotemia, hyponatremia, hyperchloremia, and normal anion gap. Results of a urinalysis were consistent with acute tubular necrosis with inadequate acidification of urine based on the degree of acidemia. Salmonella enterica serovar agona was cultured from both urine and feces. The calf was treated with intravenous polyionic fluids, bicarbonate, and antimicrobials. Acidosis and azotemia resolved, and 4 months following initial presentation the heifer was clinically normal.