Companion animals are increasingly recognized as potential reservoirs of antimicrobial-resistant (AMR) bacteria, yet the frequency of sharing between pets and their owners remains unclear. We conducted a systematic review and meta-analysis to estimate household-level co-occurrence ('sharing') of AMR pathogens. We searched PubMed, Embase, and Web of Science for studies sampling pets and owners from the same household and assessing genetic or phenotypic relatedness of AMR bacteria. Random-effects generalized linear mixed models were used to estimate pooled prevalences, with subgroup and sensitivity analyses by host health status, pathogen group, typing method, and study design. Across 152 studies, the pooled prevalence of household-level sharing was 3.8% (95% CI: 2.7%-5.1%). Sharing was similarly low among households when pets and owners were healthy or when the pet or owner had an illness unrelated to the pathogen (3.0% in both cases), but higher when a pet or owner had a confirmed infection (9.0%, 95% CI: 5.0%-16.0%). Estimates were comparable for Staphylococci and Enterobacterales. Studies using phenotypic methods alone reported higher prevalences than those using molecular typing, consistent with lower discriminatory resolution. Substantial heterogeneity was observed, but findings were robust across study design, geography, and quality. Household sharing of AMR bacteria between pets and owners appears relatively uncommon under typical conditions and is more strongly associated with infection or active shedding than routine cohabitation.

BACKGROUND:The human oral and gut microbiomes play critical roles in maintaining overall health. Although systemic antibiotics are frequently prescribed perioperatively in dental procedures, their impact on microbiota composition and diversity remains inadequately understood. The authors' objective was to characterize the evolution of the gut and oral microbiomes after a course of antibiotics administered for dental surgeries. The authors hypothesized that the microbiome would experience disruption but eventually recover to baseline levels and that patient-related factors would influence the extent of disruption and recovery. METHODS:Saliva and stool samples were collected from patients undergoing dental surgeries and receiving prophylactic antibiotics (n = 64) at baseline and then at 3, 10, 30, and 90 days after surgery. Microbial diversity and composition were assessed using 16S ribosomal RNA sequencing. Shotgun metagenomics sequencing was applied to a subset of samples to evaluate changes in antimicrobial resistance genes. RESULTS:Significant (P < .01) declines in alpha diversity were observed in both oral and fecal microbiomes, most notably at days 3 and 10, with near recovery at day 90. The oral microbiome exhibited greater disruption than the gut microbiome, suggesting higher susceptibility to postoperative disturbance. Patient-level factors including sex, race, gastroesophageal reflux disease, and antibiotic type influenced baseline diversity, disruption, and recovery. Results of taxonomic analyses revealed that key health-associated genera were substantially altered postsurgery. Some antimicrobial resistance genes increased in relative abundance over time, consistent with potential long-term ecological consequences of antibiotic use. CONCLUSIONS:The findings highlight the dynamic response of the human microbiome to antibiotic exposure and oral surgery and underscore the importance of antibiotic stewardship in practice. Further research on functional outcomes and host-microbiome interactions is warranted to optimize perioperative care in dentistry. PRACTICAL IMPLICATIONS:Consideration of patient factors is essential to minimize unnecessary disruption of the microbiome and mitigate the risk of developing resistance.

BACKGROUND:Commensal populations of coagulase-positive Staphylococcus spp. (CoPS) in healthy horses are not well-defined. OBJECTIVE:To determine the point prevalence, anatomical distribution, antimicrobial susceptibility and genomic characteristics of CoPS in healthy horses. ANIMALS:One-hundred and fifty privately owned, systemically healthy horses from seven facilities were enrolled in this study. MATERIALS AND METHODS:Horses were sampled from the nares, buccal mucosa and three skin sites. Isolates were identified using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry, and antimicrobial susceptibility testing was performed by gradient diffusion. Whole-genome sequencing with multilocus sequence typing (MLST) characterised Staphylococcus aureus lineages. In silico PCR differentiated Group A and Group B Staphylococcus delphini. Sampling site sensitivity was calculated using a multisite composite reference. Mixed-effects logistic regression evaluated associations between demographic factors and carriage. RESULTS:Carriage of any staphylococcal species occurred in 111 of 150 (74%) horses: S. aureus 28 of 150 horses (18.7%) and S. delphini 23 of 150 horses (15.3%). Increasing age was associated with decreased odds of CoPS isolation (odds ratio 0.92/year; 95% confidence interval 0.86-0.98). The nares were the most sensitive single sampling site, whereas multisite sampling improved detection. Meticillin-resistance was absent in all CoPS isolates, and S. delphini isolates were fully susceptible to all antimicrobials tested. MLST revealed multiple S. aureus sequence types, some of which were shared across multiple horses at some boarding facilities. Both groups of S. delphini lineage were identified, although many isolates were nontypable. CONCLUSIONS AND CLINICAL RELEVANCE:Healthy horses harbour S. aureus and S. delphini, with minimal antimicrobial resistance. Shared S. aureus sequence types within facilities suggest possible lateral transmission.

ABSTRACT Background Understanding antimicrobial use practices in goats is essential to ensuring appropriate antimicrobial stewardship. Objective To describe antimicrobial prescriptions in periparturient does admitted to veterinary teaching hospitals and to determine if any factors were associated with the administration of antimicrobials in general or ceftiofur in particular. Animals One hundred ninety‐eight periparturient does presented to nine university veterinary hospitals from October 2021 to June 2022. Methods A multicenter cross‐sectional study in a prospective design. Data were collected from questionnaire completed by admitting clinician. Results Out of 198 periparturient does included in the study, 153 (77%) received antimicrobials during hospitalization. Commonly administered antimicrobials included oxytetracycline (n = 44, 29%), ceftiofur sodium (n = 43, 28%), ceftiofur crystalline free acid (CCFA; n = 27, 18%), potassium penicillin G (n = 15, 10%), procaine penicillin G (n = 14, 9%), florfenicol (n = 14, 9%), tulathromycin (n = 9, 6%), ampicillin trihydrate (n = 4, 3%), and ampicillin sodium (n = 1, 1%). Cesarean section was associated with antimicrobial administration in general (OR = 5.89; 95% CI = 2.49–13.98, p < 0.01) and with ceftiofur administration (OR = 2.54, 95% CI = 1.25–5.17; p = 0.008). Significant variability in ceftiofur administration by hospital was observed (p < 0.001). Conclusions and Clinical Importance Marked heterogeneity was observed in the antimicrobial administration practices in periparturient goats between nine US veterinary teaching hospitals.

Objective:To identify risk factors for carbapenemase-producing, carbapenem-resistant Enterobacterales (CP-CRE) acquisition in dogs and cats during hospitalization. Methods:A retrospective case-control study evaluating risk factors for acquiring CP-CRE during hospitalization in dogs and cats admitted from June 1, 2021, through September 30, 2023, was performed. Cases consisted of patients testing negative for CP-CRE at admission and positive prior to discharge. Control patients testing negative at admission and throughout hospitalization were matched to cases with a 3:1 ratio by species, managing service, and date and number of hospitalized days of CP-CRE testing. Patient demographics and characteristics were extracted from the electronic medical record. Conditional logistic regression modeling was performed to assess the association between these variables and being a case. Results:46 case dogs and 4 case cats were investigated. Due to the small number of cats, risk factors were only analyzed for dogs. On multivariable analysis, the odds of CP-CRE acquisition were significantly greater for dogs receiving a β-lactam antimicrobial (OR, 4.71; 95% CI, 1.32 to 16.82) or metronidazole (OR, 6.38; 95% CI, 1.71 to 23.74). All 4 case cats had received a β-lactam antimicrobial, and the majority (3 of 4 case cats) had received acid suppressants, were admitted from the emergency service, and had a central venous catheter or peripheral sampling line. Conclusions:Receiving a β-lactam antimicrobial or metronidazole was an independent risk factor for CP-CRE acquisition in hospitalized dogs. Clinical Relevance:These findings highlight the importance of antimicrobial stewardship.

Zinc is an important trace element for animal health and physiology, and it is routinely provided as a supplement in livestock diets. High levels of dietary zinc have been found to be beneficial for weanling pigs in preventing diarrhea and improving growth. It has also been associated with better reproductive performance in gestating sows and survival of neonatal piglets. However, little is known about zinc’s effect on the microbiome of the gestating sow and her neonatal piglets. Even less is known about its effects on the sow and piglet resistome, which is important because dietary zinc can co-select for antimicrobial resistance. The goal of this randomized controlled dietary feeding trial was to assess the effect of high levels of dietary zinc in the last week of gestation on the microbiomes and resistomes of the gestating sow and her neonatal piglets. Seventy-three gestating sows were randomized to receive a diet with standard zinc levels (125 ppm) or high zinc levels (2500 ppm) approximately one week prior to their anticipated farrowing date. Fecal samples were collected from sows at enrollment and at farrowing and from piglets within 3 days of parturition. Fecal samples underwent 16sS rRNA gene sequencing, and a subset of samples underwent shotgun metagenomic sequencing. Statistically significant differences in richness, diversity and taxonomic composition were observed over time, and sows in the treatment group had significantly higher alpha diversity at farrowing (p = 0.04) and significantly altered levels of 3 taxa (Turicibacter, unclassified Clostridiaceae, and unclassified Christensenellaceae). Several antimicrobial resistance genes were significantly more abundant in the zinc group at farrowing compared to the control group, including tetracycline resistance genes [tet(O); tet(W); tet(32); tet(O/W)]; aminoglycoside resistance genes (APH(3’)-IIIa), macrolide-lincosamide-streptogramin (MLS) resistance genes (lsaB; macB); and others (kdpE, Pseudomonas aeruginosa CpxR). No significant differences were observed in the piglet microbiomes or resistomes across sow treatment groups. Overall, high levels of dietary zinc had modest effects on the sow microbiome during the feeding trial. Increases in antimicrobial resistance genes in zinc supplemented sows suggest that supranutritional levels of dietary zinc should be avoided in gestating sows.

BackgroundThe study of the epidemiology of Clostridioides difficile in populations is greatly facilitated by the ability to isolate and further characterize individual organisms, which requires effective culture protocols. In cattle, where little is known about the epidemiology of C. difficile, no studies have assessed or compared the performance of different assays for detecting C. difficile.ObjectivesThis study compared two culture protocols for detecting C. difficile in bovine faeces from 121 gestating cows and 70 of their neonatal calves, while situating results obtained with each protocol relative to those obtained with shotgun metagenomic sequencing.MethodsProtocol 1 involved direct plating enrichment onto taurocholine-cycloserine-cefoxitin-fructose agar (TCCFA), while Protocol 2 included an ethanol shock step before plating on CCFA/ChromID agar. For both protocols, one aliquot underwent broth enrichment prior to plating, while the other aliquot did not.ResultsClostridioides difficile was detected following broth enrichment in two of the same calf samples using both protocols, and an additional cow sample was found to be positive with Protocol 2, though the difference in detection rates was not statistically significant (p = 1.0).ConclusionsThe detection of C. difficile in a much high number of these samples by shotgun metagenomics, albeit at low levels of relative abundance, suggests that neither of these culture protocols is sensitive when levels of abundance are low.

Zinc is an essential trace element required in the diet of all species. While the effects of zinc have been studied in growing calves, little is known about the effect of zinc on the microbiota of the gestating cow or her neonatal calf. Understanding factors that shape the gut health of neonatal animals and evaluating the effect of dietary supplements in adult gestating animals is important in promoting animal health and informing feeding practices. The aims of this study were to determine the effect of dietary zinc on the microbiota and resistome of the gestating cow and calf. Gestating cows received standard (40 ppm) or high (205 ppm) dietary zinc levels from dry off to calving. Fecal samples were collected from cows upon enrollment and at calving and from neonatal calves. Fecal samples underwent 16S rRNA sequencing and a subset also underwent shotgun metagenomic sequencing. The effect of zinc supplementation on the diversity and composition of the cow and calf microbiome and resistome was assessed. Alpha and beta diversity and composition of the microbiota were significantly altered over time but not by treatment in the cows, with alpha diversity decreasing and 14 genera found at significantly higher relative abundances at calving compared to enrollment. Levels of 27 antimicrobial resistance genes significantly increased over time. Only a small number of taxa were differentially expressed at calving in treatment and control groups, including Faecalibacterium, Bacteroides, Turicibacter, and Bifidobacterium pseudolongum. No effect of the dam’s treatment group was observed on the diversity or composition of the neonatal calf microbiota. The calf resistome, which was relatively rich and diverse compared to the cow, was also unaffected by the dam’s treatment group. The impact of high levels of dietary zinc thus appeared to be minimal, with no observed changes in alpha or beta diversity, and few changes in the relative abundance of a small number of taxa and antimicrobial resistance genes.

OBJECTIVE:To describe clinical and radiographic outcomes in dogs with uncomplicated pneumonia receiving a shorter (2-week) versus longer (4-week) duration of antimicrobial therapy. ANIMALS:30 client-owned dogs with radiographic evidence of pneumonia. METHODS:Dogs were randomly assigned to either a 2-week course of antimicrobials followed by a 2-week course of placebo medication (2-week group) or a 4-week course of antimicrobials (4-week group). All study investigators and owners were masked to the treatment group. Dogs were reevaluated at 12 ± 2 days and again at 28 ± 2 days for a physical examination and thoracic radiography. Standard documentation at visits included owner-reported clinical signs, nurse-acquired history, the clinician's physical examination, the number of affected lung lobe segments, and the global radiographic severity scores assigned. Outcomes investigated included the persistence of clinical and radiographic signs of pneumonia. RESULTS:28 dogs (93.3%) experienced complete resolution of clinical signs by the first visit, and no dogs in either group experienced relapse of clinical signs during the study period. Eighteen of 30 dogs (60%) and 25 of 30 dogs (83%) experienced complete resolution of radiographic lesions at the first and second study visits, respectively. The remaining 5 dogs (17%) had either stable (4 dogs) or continued (1 dog) improvement in radiographic lesions. CLINICAL RELEVANCE:Resolution of clinical and radiographic signs followed similar courses in dogs with uncomplicated pneumonia receiving a 2-week course of antimicrobials compared to a 4-week course. Clinical signs may be more useful for guiding discontinuation of antimicrobial therapy for pneumonia than radiographic signs.

Summary Orthopaedic infections, including synovial sepsis, osteomyelitis and infection of orthopaedic implants are common in equine medicine. Infections can be caused by haematogenous spread of pathogens, trauma or penetrating injuries, extension of local infections and iatrogenic causes such as surgery and synovial injections. Horses with orthopaedic infections are generally markedly lame and often require aggressive and prolonged therapy. Early diagnosis can greatly impact treatment outcomes and can be facilitated by careful physical examinations, haematology, diagnostic imaging and timely synovial fluid sampling. Concerted efforts should always be made to obtain a positive bacterial culture and sensitivity. Treatment is focused on antimicrobial therapy with local therapy, including intravenous regional limb perfusion and intrasynovial injections, being employed whenever possible; lavage and debridement; and analgesia and supportive care. Responsible use of antimicrobials and antimicrobial stewardship are critical when treating orthopaedic infections. Prognosis will depend on the source and severity of the infection, the causative agent and the time to intervention. Foals and horses can respond well to treatment and return to soundness with early, aggressive and targeted treatment.

Zinc is a crucial trace element that plays a vital role in various physiological functions, including immune function, growth, and reproduction in livestock. Zinc deficiency can lead to various health problems in livestock, such as decreased growth rates, impaired reproductive performance, and increased susceptibility to diseases. In contrast, supplementing livestock diets with zinc can promote health and enhance microbiome balance, leading to improved animal welfare and productivity. This review seeks to provide valuable information for researchers, veterinarians, and livestock producers on the effects of dietary zinc supplementation. Current knowledge on the importance of dietary zinc for livestock and microbiome health as well as mechanistic insights are discussed.

BACKGROUND:A core principle of antimicrobial stewardship (AMS) in veterinary settings is the need for engagement of all stakeholders; however, no studies have addressed the role of veterinary technicians in AMS specifically. The objective of this study was to qualitatively assess knowledge, opinions, and practices related to AMS among technicians. Semi-structured interviews were conducted with 33 veterinary technicians with varied backgrounds, experience and roles. Interviews centered on participants work experience and interactions with their employer, perceptions of antimicrobial resistance and overuse in veterinary medicine, observed application of AMS principles, opinions on potential opportunities for technicians to contribute to AMS and concomitant potential barriers to these opportunities. Transcripts of interviews were coded thematically by two authors, then organized into a hierarchical framework, and the characterization of codes was compared across different categories of respondents.RESULTS:Most veterinary technicians were knowledgeable about antimicrobial drugs but could not provide a complete definition of antimicrobial resistance or AMS. Most veterinary technicians could identify examples of antimicrobial misuse. Participants identified areas of client education and discussion with veterinarians as potential areas to contribute to AMS. Barriers identified included hierarchical structures of veterinary practices and time-constraints. Most participants expressed a personal interest in participating in AMS.CONCLUSIONS:There is a possible appetite among some veterinary technicians to participate in AMS and they already play applicable roles in practices. Barriers such as educational needs, hierarchical structures of veterinary practices and time constraints will need to be addressed if technicians are included in AMS efforts.

Companion animals have been shown to carry Clostridioides difficile strains that are similar or identical to strains found in people, and a small number of studies have shown that pets carry genetically identical C. difficile isolates as their owners, suggesting inter-species transmission. However, the directionality of transmission is ultimately unknown, and the frequency with which animals acquire C. difficile following their owners' infection is unclear. The goal of this study was to assess how often pets belonging to people with C. difficile infection carry genetically related C. difficile isolates. We enrolled pet owners from two medical institutions (University of Pennsylvania Health System (UPHS) and The Ohio State University Wexner Medical Center (OSUWMC)) who had diarrhoea with or without positive C. difficile assays and tested their faeces and their pets' faeces for C. difficile using both anaerobic culture and PCR assays. When microorganisms were obtained from both the owner and pet and had the same toxin profile or ribotype, isolates underwent genomic sequencing. Faecal samples were obtained from a total of 59 humans, 72 dogs and 9 cats, representing 47 complete households (i.e. where a sample was available from the owner and at least one pet). Of these, C. difficile was detected in 30 humans, 10 dogs and 0 cats. There were only two households where C. difficile was detected in both the owner and pet. In one of these households, the C. difficile isolates were of different toxin profiles/ribotypes (A+/B+ / RT 499 from the owner, A-/B- / RT PR22386 from the dog). In the other household, the isolates were genetically identical (one SNP difference). Interestingly, the dog from this household had recently received a course of antibiotics (cefpodoxime and metronidazole). Our findings suggest that inter-species transmission of C. difficile occurs infrequently in households with human C. difficile infections.

Objectives Carbapenems are a critically important class of antimicrobials used to treat infections caused by multi-drug-resistant bacteria. Following an outbreak of a carbapenemase (NDM-5)-producing strain of Escherichia coli at our veterinary institution, we opted to describe the use of carbapenems in our institution and the role that drug contraindications in patients may have played when culture and susceptibility testing identified alternative drug options. Materials and Methods Medical record reviews of all cases where a carbapenem was prescribed were performed, and indications for use, timing of prescribing relative to culture and susceptibility reports, and alternative possible antimicrobial treatments were extracted. Contraindications to alternative antimicrobials were also documented. Results Carbapenems were prescribed infrequently: from 2013 to 2018, they accounted for 0.47% of all antimicrobial prescriptions and were administered to 108 of 56,776 (0.2%) patients seen at our institution. They were prescribed empirically in slightly more than half of the patients (57.6%). Among cases where a carbapenem was prescribed after culture and susceptibility results were available, alternative antimicrobials could have been used in 68.3% of cases. Clinical Significance Variability in use of these drugs within an institution highlights the need to develop well-defined use guidelines, including when to use these drugs empirically and how to safely de-escalate or choose alternative drugs guided by culture and susceptibility results.

OBJECTIVE To assess the potential contamination of commercial raw dog food products with bacteria of the Enterobacterales order that produce extended spectrum beta-lactamase (ESBL) and carbapenemase enzymes, determine risk factors for contamination, and understand isolate genetic diversity. SAMPLES A total of 200 canine raw food products. METHODS Products were cultured on selective chromogenic agar following enrichment steps. Whole-genome sequencing was performed for isolates that were confirmed to produce an ESBL. Isolates were characterized by antimicrobial resistance genes, and multilocus sequences typing, and compared to other isolates in the NCBI database for clonality. Preservation method and protein sources were assessed as potential risk factors for contamination with ESBL and carbapenemase-producing bacteria of the Enterobacterales order. RESULTS No carbapenemase-producing Enterobacterales (CPE) were identified, but ESBL-producing Enterobacterales bacteria were isolated from 20/200 products (10.0%; 95% CI, 7.3 to 16.5%), all of which were frozen. Pork-derived protein source products were 8.1 times ( P = .001; 95% CI, 2.53 to 26.2) more likely to carry ESBL-producing Enterobacterales bacteria than other protein sources. WGS analysis confirmed the presence of ESBL genes in a total of 25 distinct isolates (19 Escherichia coli , 5 Klebsiella pneumoniae , and 1 Citrobacter braakii ). Genes encoding CTX-M type ESBL enzymes were the most common (24/25 isolates, 96.0%) with bla CTX-M-27 being the most common allele (8/25, 32.0%). CLINICAL RELEVANCE Frozen, raw food products may serve as a route of transmission of ESBL-producing Enterobacterales bacteria to companion animals. Veterinarians should advise owners about the risks of raw food diets, including potential exposure to antimicrobial-resistant bacteria.

Although equine strangles is reportable in all states, synchronous reporting of this disease does not occur across the country. States have variable regulations on reporting (actionable, notifiable, and monitored) and no mandatory comprehensive databases exist for tracking prevalence. In this study, we solicited veterinarians’ opinions on reporting of strangles and factors influencing their opinion. Two hundred and fifty veterinarians practicing within the United States A structured survey was administered online. A total of 250 veterinarians participated: 84 participants (34%) believed that strangles should continue to be nationally monitored and that individual states should have jurisdiction over laboratory-confirmed positive cases; 58 (23.2%) believed strangles should become nationally monitored with mandatory notification of positive cases to a central forum; 24 participants (9.6%) thought strangles should become notifiable nationally; and 44 (17.6%) thought strangles should become notifiable and actionable. Veterinarians who were currently in the habit of reporting strangles were also more likely to want increased reporting (Or=1.87), though this association was not quite statistically significant  (P = 0.054), as did veterinarians who ranked strangles as “very important” or “important” relative to other infectious disease (OR 3.77, P = .037). Veterinarians practicing in the Southwest (P = .01) and West (P = .04) were significantly less likely than northeast practitioners to rank strangles of higher importance. Opinions on equine strangles and desire for increased reporting were varied in the sampled veterinary community. Information obtained in this study regarding veterinarians’ current views on strangles reporting could inform future policy regarding the disease.

Intravenous regional limb perfusions (RLP) are widely used in equine medicine to treat distal limb infections, including synovial sepsis. RLPs are generally deemed successful if the peak antibiotic concentration (Cmax) in the sampled synovial structure is at least 8-10 times the minimum inhibitory concentration (MIC) for the bacteria of interest. Despite extensive experimentation and widespread clinical use, the optimal technique for performing a successful perfusion remains unclear. The objective of this meta-analysis was to examine the effect of technique on synovial concentrations of antibiotic and to assess under which conditions Cmax:MIC ≥ 10. A literature search including the terms "horse", "equine", and "regional limb perfusion" between 1990 and 2021 was performed. Cmax (μg/ml) and measures of dispersion were extracted from studies and Cmax:MIC was calculated for sensitive and resistant bacteria. Variables included in the analysis included synovial structure sampled, antibiotic dose, tourniquet location, tourniquet duration, general anesthesia versus standing sedation, perfusate volume, tourniquet type, and the concurrent use of local analgesia. Mixed effects meta-regression was performed, and variables significantly associated with the outcome on univariable analysis were added to a multivariable meta-regression model in a step-wise manner. Sensitivity analyses were performed to assess the robustness of our findings. Thirty-six studies with 123 arms (permutations of dose, route, location and timing) were included. Cmax:MIC ranged from 1 to 348 for sensitive bacteria and 0.25 to 87 for resistant bacteria, with mean (SD) time to peak concentration (Tmax) of 29.0 (8.8) minutes. Meta-analyses generated summary values (θ) of 42.8 x MIC and 10.7 x MIC for susceptible and resistant bacteria, respectively, though because of high heterogeneity among studies (I2 = 98.8), these summary variables were not considered reliable. Meta-regression showed that the only variables for which there were statistically significant differences in outcome were the type of tourniquet and the concurrent use of local analgesia: perfusions performed with a wide rubber tourniquet and perfusions performed with the addition of local analgesia achieved significantly greater concentrations of antibiotic. The majority of arms achieved Cmax:MIC ≥ 10 for sensitive bacteria but not resistant bacteria. Our results suggest that wide rubber tourniquets and concurrent local analgesia should be strongly considered for use in RLP and that adequate therapeutic concentrations (Cmax:MIC ≥ 10) are often achieved across a variety of techniques for susceptible but not resistant pathogens.

ObjectiveAlthough equine strangles is reportable in all states, synchronous reporting of this disease does not occur across the country. States have variable regulations on reporting (actionable, notifiable, and monitored) and no mandatory comprehensive databases exist for tracking prevalence. In this study, we solicited veterinarians’ opinions on reporting of strangles and factors influencing their opinion.Samples250 veterinarians practicing within the United States.ProceduresA structured survey was administered online.ResultsA total of 250 veterinarians participated: 84 participants (34%) believed that strangles should continue to be nationally monitored and that individual states should have jurisdiction over laboratory confirmed positive cases; 58 (23.2%) believed strangles should become nationally monitored with mandatory notification of positive cases to a central forum; 24 participants (10.5%) thought strangles should become notifiable nationally; and 44 (19.2%) thought strangles should become notifiable and actionable. Veterinarians who already reported strangles cases were 87% more likely (P = 0.054) to want increased reporting, as did veterinarians who ranked strangles as “very important” or “important” relative to other infectious disease (OR 3.77, P = 0.037). Veterinarians practicing in the southwest (P=0.01) and west (P = 0.04) were significantly less likely than northeast practitioners to rank strangles of higher importance.Clinical RelevanceOpinions on equine strangles and desire for increased reporting were varied in the sampled veterinary community. Information obtained in this study regarding veterinarians’ current views on strangles reporting could inform future policy regarding the disease.

OBJECTIVES:Carriage of Clostridioides difficile by different species of animals has led to speculation that animals could represent a reservoir of this pathogen for human infections. The objective of this study was to compare C. difficile isolates from humans, dogs, and cattle from a restricted geographic area. METHODS:C. difficile isolates from 36 dogs and 15 dairy calves underwent whole genome sequencing, and phenotypic assays assessing growth and virulence were performed. Genomes of animal-derived isolates were compared to 29 genomes of isolates from a pediatric population as well as 44 reference genomes. RESULTS:Growth rates and relative cytotoxicity of isolates were significantly higher and lower, respectively, in bovine-derived isolates compared to pediatric- and canine-derived isolates. Analysis of core genes showed clustering by host species, though in a few cases, human strains co-clustered with canine or bovine strains, suggesting possible interspecies transmission. Geographic differences (e.g., farm, litter) were small compared to differences between species. In an analysis of accessory genes, the total number of genes in each genome varied between host species, with 6.7% of functional orthologs differentially present/absent between host species and bovine-derived strains having the lowest number of genes. Canine-derived isolates were most likely to be non-toxigenic and more likely to carry phages. A targeted study of episomes identified in local pediatric strains showed sharing of a methicillin-resistance plasmid with dogs, and historic sharing of a wide range of episomes across hosts. Bovine-derived isolates harbored the widest variety of antibiotic-resistance genes, followed by canine CONCLUSIONS: While C. difficile isolates mostly clustered by host species, occasional co-clustering of canine and pediatric-derived isolates suggests the possibility of interspecies transmission. The presence of a pool of resistance genes in animal-derived isolates with the potential to appear in humans given sufficient pressure from antibiotic use warrants concern.

OBJECTIVE:To characterize antimicrobial use on four racetracks in the eastern US during the peak racing 2017-2018 seasons.PROCEDURES:Handwritten daily treatment sheets provided by attending veterinarians who listed treatments administered to horses stabled at the racetrack were obtained. Information contained in the treatment sheets included the date, name of the horse and its trainer, type of treatment, and a brief (usually 1-word) indication for treatment. The handwritten data listed on the racetrack treatment sheets were manually transcribed and analyzed.RESULTS:A total of 2,684 antimicrobial prescriptions were recorded, representing 6.8% of all drug treatments. The most frequently prescribed antimicrobials were enrofloxacin, with 854 prescriptions (31.8% of antimicrobial treatments), followed by gentamicin (570 [21.2%] prescriptions), ceftiofur (388 [14.5%] prescriptions,), and penicillin (220 [8.2%] prescriptions). The relative frequencies of antimicrobial class and indication for treatment varied significantly by racetrack and by prescribing veterinarian. Limitations associated with the data precluded ascertainment of the proportion of horses treated or exact indications for treatment.CLINICAL RELEVANCE:Antimicrobials appeared to be prescribed relatively infrequently at racetracks relative to other drugs, but highly or critically important antimicrobials were most often used. The appropriateness of use of these drugs remains unknown.