Change starts at home: summary of the 2023 inaugural Small Animal Antimicrobial Stewardship Workshop for US Veterinary Schools.

Small animal antimicrobial stewardship (AS) is emerging as a priority area in the global battle against antimicrobial resistance. Veterinary practices have limited support for implementation of AS programs, and even within veterinary schools, efforts are largely siloed and often limited in scope. Increased collaboration is needed to support and unify AS and infection prevention and control efforts, and to identify priorities for continued research. To address this, a 2-day in-person small animal AS workshop was held in August 2023. Delegates representing 23 US veterinary schools and 4 corporations/government agencies gathered for a series of lightning talks and focused group discussions in 3 domains: implementation of clinical AS programs, research opportunities and needs, and education. The workshop's goal was to identify and propose solutions for AS challenges. Meeting discussion identified a lack of resources and training as the greatest barriers to hospital AS program advancement and suggested creating standards for AS programs and a road map to support program development. Assessing antimicrobial treatment effects and performing studies to establish necessary treatment durations were considered the highest research priorities. Integrated educational practices were recommended to support unified messaging of AS concepts between preclinical and clinical training. The development of strategies to implement these suggestions was delegated to working groups with a goal to continue meeting biennially as a large group. Sharing news of these efforts is considered integral to heightening awareness and promoting implementation of AS practices moving forward in academic, specialty, and primary care settings.

A survey of US and Caribbean veterinary schools reveals strengths and opportunities in antimicrobial stewardship and infection prevention and control activities.

OBJECTIVE: To understand antimicrobial stewardship (AS) and infection prevention and control (IPC) activities in veterinary schools. METHODS: An online survey was completed by representatives from American Association of Veterinary Medical Colleges-accredited veterinary schools in the US and Caribbean prior to attending the Inaugural Small Animal Antimicrobial Stewardship Workshop for US Veterinary Schools. Responses were examined to identify patterns among AS and IPC activities and adherence to the AVMA core principles. RESULTS: Half (12 of 24) of the surveyed schools had an AS committee and most (79% [19 of 24]) had an IPC committee. Lack of dedicated staff time was a common barrier to AS (88% [21 of 24]) and IPC (75% [18 of 24]) reported by schools both with and without AS and IPC committees. Eleven of 24 schools (46%) reported performing at least 1 activity focused on each of the AVMA's 5 core principles of AS. Although 79% (19 of 24) of schools incorporate AS into preclinical curricula, training of clinical faculty (17% [4 of 24]), veterinary technicians and support staff (21% [5 of 24]), and house officers (42% [10 of 24]) is less common, despite these individuals engaging in teaching clinical-year veterinary students. CONCLUSIONS: Veterinary schools varied in established AS education and AS and IPC practices, though financial and human resources were a common barrier. CLINICAL RELEVANCE: A collaborative and cohesive approach to AS and IPC among schools to create sustainable frameworks for practice improvement will help combat the global threat of antimicrobial resistance. This is a critical action for settings where future veterinarians are trained.

ACVIM consensus statement on the treatment of immune thrombocytopenia in dogs and cats.

Management of immune thrombocytopenia (ITP) in dogs and cats is evolving, but there are no evidence-based guidelines to assist clinicians with treatment decisions. Likewise, the overall goals for treatment of ITP have not been established. Immunosuppressive doses of glucocorticoids are the first line treatment, but optimal treatment regimens beyond glucocorticoids remain uncertain. Additional options include secondary immunosuppressive drugs such as azathioprine, modified cyclosporine, and mycophenolate mofetil, usually selected based on clinician preference. Vincristine, human IV immunoglobulin (hIVIg), and transfusion of platelet or red blood cell-containing products are often used in more severe cases. Splenectomy and thrombopoietin receptor agonists are usually reserved for refractory cases, but when and in which patient these modalities should be employed is under debate. To develop evidence-based guidelines for individualized treatment of ITP patients, we asked 20 Population Intervention Comparison Outcome (PICO) format questions. These were addressed by 17 evidence evaluators using a literature pool of 288 articles identified by a structured search strategy. Evidence evaluators, using panel-designed templates and data extraction tools, summarized evidence and created guideline recommendations. These were integrated by treatment domain chairs and then refined by iterative Delphi survey review to reach consensus on the final guidelines. In addition, 19 non-PICO questions covering scenarios in which evidence was lacking or of low quality were answered by expert opinion using iterative Delphi surveys with panelist integration and refinement. Commentary was solicited from multiple relevant professional organizations before finalizing the consensus. The rigorous consensus process identified few comparative treatment studies, highlighting many areas of ITP treatment requiring additional studies. This statement is a companion manuscript to the ACVIM Consensus Statement on the Diagnosis of Immune Thrombocytopenia in Dogs and Cats.

Impact of antimicrobial use in dogs on antimicrobial resistance and shared flora with human owners.

Transmission of bacteria between animals and humans in domestic households is increasingly recognized. We evaluated the presence of antimicrobial-resistant fecal bacteria in 8 dog-owner-dog pairs before and after the dog received amoxicillin-clavulanate. The study identified shared flora in the humans and dogs that were affected by antimicrobial administration.

Demonstrating the importance of local culture and susceptibility data: antibiograms from dogs at a veterinary tertiary care center.

OBJECTIVE: To create antibiograms for commonly cultured organisms in a small animal tertiary care hospital following Clinical and Laboratory Standards Institute guidelines and to compare these local resistance patterns to published first-tier antimicrobial recommendations. SAMPLE: Urine (n = 429), respiratory (41), and skin (75) isolates cultured from dogs between January 1, 2019, and December 31, 2020, at the Tufts University Foster Hospital for Small Animals. PROCEDURES: MIC and susceptibility interpretations were recorded for multiple sites for 2 years. Sites with greater than 30 isolates for at least 1 organism were included. Urinary, respiratory, and skin antibiograms were created using Clinical and Laboratory Standards Institute breakpoints and guidelines. RESULTS: Urinary Escherichia coli had a higher susceptibility percentage for amoxicillin-clavulanate (80% [221/275]) than amoxicillin alone (64% [175/275]). Respiratory E coli were greater than 80% susceptible to only 2 antimicrobials (imipenem, amikacin). Of skin Staphylococcus pseudintermedius isolates, 40% (30/75) were methicillin-resistant and frequently also displayed resistance to non-beta lactam antimicrobials. Susceptibility to recommended first-line antimicrobials varied and was greatest for gram-negative urinary isolates and lowest for methicillin-resistant S pseudintermedius skin isolates and respiratory E coli. CLINICAL RELEVANCE: Local antibiogram creation identified frequent resistance that may preclude the use of guideline-recommended first-line therapy. High levels of resistance identified in methicillin-resistant S pseudintermedius isolates supports growing concern for methicillin-resistant staphylococci in veterinary patients. This project highlights the need for population-specific resistance profiles to be used in conjunction with national guidelines.

Multi-institutional retrospective study investigating blood culture protocols and test positivity in 701 dogs.

Objectives: (i) To determine the influence of specimen collection protocol (timing and specimen quantity), primary disease process, and pre-existing antimicrobial or immunosuppressive therapy on blood culture (BC) positivity and (ii) To determine agreement between urine culture and BC results. Animals: 701 client-owned dogs. Methods: Multi-institutional retrospective study (2019-2022). Mixed-effect logistic regression was used to determine whether primary disease process, the number of BCs, or the timing of specimen collection was associated with BC positivity. Prediction plots were generated. Associations between urine culture and BC results were performed using logistic regression. Results: Dogs with a positive urine culture were more likely to have a positive BC (OR: 4.36, 95% CI: 2.12-8.97, p = 0.003). Dogs that had three BC specimens had the greatest odds of obtaining a positive BC result (adjusted predictive value: 0.44, 95% CI: 0.21-0.70), although this was not significant. Isolates from 38.5% of dogs with a positive BC had resistance to ≥3 antimicrobial classes. The timing between specimen collection had no significant association with BC positivity. Pre-existing antibiotic or immunosuppressive therapy had no significant association with BC positivity. Clinical relevance: Dogs with a positive urine culture were more likely to have a positive BC result.

Prevalence of antibiotic use for dogs and cats in United States veterinary teaching hospitals, August 2020.

BACKGROUND: Awareness of prescribing practices helps identify opportunities to improve antibiotic use (AU). OBJECTIVES: To estimate AU prevalence in dogs and cats in U.S. veterinary teaching hospitals (VTHs) and identify antibiotic drugs commonly prescribed, indications for use, and evidence of bacterial infection. ANIMALS: Medical record data were collected from dogs and cats examined at 14 VTHs. METHODS: Data were collected from VTH medical records of dogs and cats examined by primary care, urgent care, emergency and critical care, internal medicine, and surgery services on a single day during August 13-September 3, 2020. Data included signalment; clinical service; inpatient or outpatient status; clinical conditions; diagnostic tests; evidence of bacterial infection; intended reason for AU; name and route of antibiotics prescribed. RESULTS: Of 883 dogs and cats, 322 (36.5%) were prescribed at least 1 antibiotic. Among 285 antibiotics administered systemically intended for treatment of infection, 10.9% were prescribed without evidence of infection. The most common class of antibiotics presribed for systemic administration was potentiated penicillin for dogs (115/346, 33.3%) and cats (27/80, 33.8%). For dogs and cats, first-generation cephalosporins (93/346, 26.9% and 11/80, 13.8%, respectively) and fluoroquinolones (51/346, 14.7% and 19/80, 23.8%, respectively) was second or third most-prescribed. Common AU indications included skin, respiratory, and urinary conditions, and perioperative use. CONCLUSIONS AND CLINICAL IMPORTANCE: Collaborative data collection provides a sustainable methodology to generate national AU prevalence estimates and bring attention to areas requiring additional research and detailed data collection. These efforts can also identify practice improvement opportunities in settings where future veterinarians are trained.

Usage patterns of carbapenem antimicrobials in dogs and cats at a veterinary tertiary care hospital.

BACKGROUND: Carbapenems are a class of antimicrobials reserved for resistant infections or systemically ill people, yet the extent and context in which they are prescribed in the small animals is understudied. HYPOTHESIS/OBJECTIVE: To describe cases in dogs and cats treated with carbapenems to establish baseline data regarding the types of infections, outcomes, and resistance profiles of target infections. We hypothesize that prescribing practices for carbapenems at a veterinary tertiary care hospital would not comply with the recommended use guidelines in human medicine. METHODS: Retrospective study of veterinary medical records from all dogs and cats prescribed carbapenems between May 1, 2016, and April 30, 2017. RESULTS: A total of 81 infections (71 in dogs and 10 in cats) representing 68 animals (58 dogs and 10 cats) involving carbapenem use were identified. Cultures were performed in 65/81 (80%) infections, and antimicrobial use was de-escalated or discontinued in 10/81 (12%) infections. The average duration of treatment was 27.5 days and ranged from 1 to 196 days. Resistance to more than 3 antimicrobial classes was present in 57/115 (50%) isolates. Resistance to carbapenems was found in 2/64 (3%) of the bacterial isolates with reported carbapenem susceptibility. CONCLUSIONS AND CLINICAL IMPORTANCE: The majority of carbapenem use at a veterinary tertiary care hospital was prescribed in conjunction with culture and sensitivity determination, with de-escalation performed in a minority of cases, and treatment durations longer than typically recommended in human medicine.

Effects of cyclosporine and dexamethasone on canine T cell expression of interleukin-2 and interferon-gamma.

Cyclosporine and glucocorticoids are powerful immunosuppressive agents used to treat many inflammatory diseases in dogs. Cyclosporine inhibits calcineurin-dependent pathways of T cell activation and resultant T cell cytokine production, and glucocorticoids directly inhibit genes coding for cytokines. Little work has been done comparing the effects of these agents on T cell cytokine production in dogs. Our study measured T cell interleukin-2 (IL-2) and interferon-gamma (IFN-γ) production using flow cytometry and T cell IL-2 and IFN-γ gene expression using quantitative reverse transcription polymerase chain reaction (qRT-PCR) in activated canine T cells incubated with cyclosporine and dexamethasone in vitro. For flow cytometric assays, diluted whole blood was cultured for 7 h in the presence of cyclosporine (10, 100, 500, and 1000 ng/mL) or dexamethasone (10 ng/mL, 100 ng/mL, 1 µg/mL, and 10 µg/mL). For qRT-PCR, whole blood was cultured for 5 h with the same drugs at the same concentrations, and RNA was then extracted from leukocytes. Flow cytometry and qRT-PCR both demonstrated inhibition of IL-2 and IFN-γ that was concentration-dependent in response to cyclosporine, and was more variable for dexamethasone. Quantitative RT-PCR but not flow cytometry documented significant reduction of IL-2 expression after dexamethasone treatment, while both methods showed concentration-dependent suppression of IFN-γ. Quantitative RT-PCR also revealed additional cytokine suppression at higher cyclosporine concentrations, an effect not found using flow cytometry, and may therefore be the preferred method for cytokine determination in dogs. Suppression of IL-2 and IFN-γ in activated T cells may have potential as an indicator of the efficacy of cyclosporine and glucocorticoids in suppressing canine T cell function in vivo, and may therefore be of value for characterizing the immunosuppression induced by these drugs in clinical patients.

ACVIM consensus statement on the treatment of immune-mediated hemolytic anemia in dogs.

Immune-mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence-based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.

ACVIM consensus statement on the diagnosis of immune-mediated hemolytic anemia in dogs and cats.

Immune-mediated hemolytic anemia (IMHA) is an important cause of morbidity and mortality in dogs. IMHA also occurs in cats, although less commonly. IMHA is considered secondary when it can be attributed to an underlying disease, and as primary (idiopathic) if no cause is found. Eliminating diseases that cause IMHA may attenuate or stop immune-mediated erythrocyte destruction, and adverse consequences of long-term immunosuppressive treatment can be avoided. Infections, cancer, drugs, vaccines, and inflammatory processes may be underlying causes of IMHA. Evidence for these comorbidities has not been systematically evaluated, rendering evidence-based decisions difficult. We identified and extracted data from studies published in the veterinary literature and developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria for IMHA, comorbidities, and causality. Succinct evidence summary statements were written, along with screening recommendations. Statements were refined by conducting 3 iterations of Delphi review with panel and task force members. Commentary was solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted. The resulting document is intended to provide clinical guidelines for diagnosis of, and underlying disease screening for, IMHA in dogs and cats. These should be implemented with consideration of animal, owner, and geographical factors.