BACKGROUND:The diagnosis of equine sinonasal disorders has been greatly enhanced by using computed tomographic (CT) imaging. OBJECTIVES:To explore associations between specific diagnoses and clinical and CT findings and between specific diagnoses and case outcome in equine sinonasal disease. STUDY DESIGN:Retrospective case series. METHODS:Data were collected from medical records from 19 equine hospitals on cases of sinonasal disease, all of which underwent CT imaging. Case outcome was obtained from clinical records, and/or by contacting clients and referring veterinarians. Logistic regression analysis was used to examine associations between specific diagnoses and clinical and CT variables and examine associations between specific diagnoses and case outcome. RESULTS:Dental sinusitis due to apical infection was the most common cause of sinusitis (n = 693; 43.3% of cases). Other causes were primary sinusitis (n = 329; 20.6%), sinus cyst (n = 178; 11.1%), progressive ethmoid haematoma (PEH) (n = 100; 6.3%), traumatic sinonasal disease (n = 90; 5.6%), sinonasal neoplasia or suspect neoplasia (n = 86; 5.4%), other non-neoplastic sinonasal growths (n = 11; 0.6%), mycotic infection (n = 65; 4.1%), sinus pneumocele (n = 5; 0.3%), oro-nasal fistulae-related sinusitis (n = 4; 0.25%), sinus mucocele (n = 2; 0.13%) and facial suture infection (n = 1; 0.06%) cases. Facial swelling was more common with sinonasal cysts, tumours, trauma and mycosis than other diagnoses. Nasal malodour was most common with dental sinusitis. Nasal airflow obstruction was most common with sinonasal cysts, PEH and tumours. Empyema of the nasal conchal bullae was least common with sinus cysts, PEH, trauma and tumours (less purulent types of sinusitis). More severe grades of hyperostosis were associated with sinus cysts and tumours. Sinonasal tumours (odds ratio [OR] 0.03, 95% confidence interval [CI] 0.01-0.07) and PEH (OR 0.23, 95% CI 0.12-0.43) had a significantly lower likelihood of cure than primary sinusitis. MAIN LIMITATIONS:This was a retrospective study, and histology was not performed in some cases. CONCLUSIONS:Equine sinonasal disease has a range of underlying causes which impacts the clinical presentation and outcome.
BACKGROUND:Early and accurate recognition of a strangulating lesion is essential to expedite surgical intervention in horses presenting with colic. OBJECTIVE:To evaluate the use of a colour grading scale in the visual assessment of peritoneal fluid, before and after centrifugation, and assess its ability to predict the presence of a strangulating lesion. STUDY DESIGN:Prospective clinical study. METHODS:Peritoneal fluid samples from 231 equids presenting with colic were visually analysed immediately after collection and assigned a numerical value based on a developed colour scale. Peritoneal fluid was centrifuged (4440g for 3 min), and the visual assessment repeated. Clinicopathological data, lesion location/type, need for surgery and outcome were recorded. Logistic regression was used to outline associations between variables and the presence of a strangulating lesion. A receiver operating characteristic (ROC) curve was constructed to identify cut-off values that correctly classified the highest percentage of strangulating and non-strangulating lesions. RESULTS:Of the 231 equids included in the study 58 (25.1%) were diagnosed with a strangulating lesion. Using ROC analysis, the area under the curve (AUC) of the peritoneal fluid colour scale (i.e., 1-10), colour grade (i.e., yellow, orange or red) and transparency before centrifugation for the detection of strangulating lesion was 0.85, 0.82 and 0.74. After centrifugation the AUC of the peritoneal fluid colour scale, colour grade and transparency for the detection of strangulating lesion was 0.87, 0.84 and 0.55 (95% confidence interval [CI], 0.81-0.93, 0.78-0.89 and 0.5-0.6), respectively. MAIN LIMITATIONS:Multiple observers analysed samples, which may have resulted in inaccurate reporting due to variances in colour perception. Confirmation bias may have influenced colour judgement as observers were not blinded to case details. A limited number of strangulating lesions were included. CONCLUSIONS:Visual examination of peritoneal fluid colour following centrifugation is easy to perform and may be a distinguishing marker of ischaemia in equids presenting with strangulating lesions of the intestines.
BACKGROUND:Defining the reliability of oscillometry (NIBP) for measuring mean arterial pressure (MAP) during normotension and hypovolaemic hypotension could help with cardiovascular monitoring and management in horses anaesthetised in dorsal recumbency. OBJECTIVES:To assess agreement between NIBP and invasive MAP during normotension and hypovolaemic hypotension in dorsally-recumbent, anaesthetised horses. STUDY DESIGN:Prospective experimental study using 11 horses. METHODS:Under isoflurane anaesthesia, blood was removed at 5 mL/kg bwt increments up to 25 mL/kg bwt and returned in a similar fashion. Paired NIBP (from the tail base with a cuff width-to-tail circumference ratio of 0.25) and invasive MAP measurements (metatarsal, facial, and transverse facial arteries; MT, FA, TFA) were obtained before and during blood removal/return and analysed using a Bland-Altman analysis for repeated measurements. Sensitivity and specificity of NIBP to detect hypotension (MAP <70 mmHg) were calculated, and an optimum NIBP MAP cut-off for hypotension was estimated. RESULTS:A total of 280 paired NIBP and invasive MAP were compared. The ACVIM validation criteria were met for bias, precision, and limits of agreement (LoA) for all peripheral arterial locations. Correlations between paired measurements, which just fell short of the 0.9 required, were 0.888, 0.887, and 0.856 for the MT, FA, and TFA, respectively. Oscillometric technique underestimated invasive mean arterial pressure by an average of -2.5 mmHg (LoA -23 to 19), -1.3 mmHg (LoA -22 to 19), and -4.7 mmHg (LoA -27 to 18) when compared to the MT, FA, and TFA, respectively. MAIN LIMITATIONS:Only adult horses in dorsal recumbency were studied. CONCLUSIONS:NIBP, as studied here, was deemed acceptable compared to invasive MAP in the MT, FA, and TFA under normotension and hypovolaemic hypotension but not a replacement for invasive blood pressure monitoring in horses.
BACKGROUND:There is an ethical debate about the application of ovum pick-up (OPU) and intracytoplasmic sperm injection (ICSI) in mares. OBJECTIVES:To survey the opinions of equine veterinarians and breeders of sport horses on the ethics of using OPU-ICSI in mares. STUDY DESIGN:Cross-sectional descriptive study. METHODS:Three surveys were distributed. The first targeted breeders ('Breeder Survey') who were actively involved in sport horse breeding. The second targeted veterinarians performing OPU ('OPU-Reprovets Survey'). The third targeted general equine practitioners ('Practitioner Survey'). There were six questions common to all surveys, and, for analyses, respondents were categorised into four groups: equine veterinarians not performing OPU (VET), equine veterinarians performing OPU (OPUVET), breeders not using OPU in their breeding programme (BREEDER), and those using OPU in their breeding programme (OPUBREEDER). RESULTS:A total of 225, 92 and 112 responses were returned from the Breeders, OPU-Reprovets and Practitioner surveys, respectively. Differences emerged between groups in how ethically challenging the procedure was perceived to be. A greater proportion of veterinarians not performing OPU (VET; 58.8%) and breeders not using the technology (BREEDER; 55.2%) rated OPU-ICSI as ethically challenging (scores 4-5 on a 5-point scale), compared with veterinarians performing OPU (OPUVET; 35.2%) and breeders using the technology (OPUBREEDER; 19.6%). Across all groups, mare welfare was the main theme when considering the use of OPU-ICSI, and for BREEDER and OPUBREEDER this was closely followed by Genetic diversity and overuse. MAIN LIMITATIONS:Potential for motivational and response bias. CONCLUSIONS:These results demonstrate differences in perception of ethical acceptability of OPU-ICSI between veterinarians and breeders with and without direct experience of OPU-ICSI. Despite these differences, mare welfare was consistently prioritised across all respondent groups, highlighting the importance of further research to better characterise the mare experience during OPU and to support evidence-based guidance for clinical and breeding practice.
BACKGROUND:Pulmonary vein (PV) myocardial sleeves (MSs) harbour an arrhythmogenic substrate for atrial fibrillation. However, equine-specific data on MS distribution and wall thickness are limited yet essential for developing ablation strategies. In humans, posterior interatrial connections can compromise right-sided PV isolation. OBJECTIVES:To study equine PV MS distribution, quantify ostial/branch diameters, antral lengths, characterise MS distal edge morphology, measure wall thickness and explore an interatrial myocardial continuity between the MSs of caudal branches draining through ostium III (PV III) and caudal vena cava (CaVC). STUDY DESIGN:Post-mortem, cross-sectional. METHODS:Twenty-three Warmblood hearts underwent left atrial and PV dissection. All four ostia (I-IV) were opened. From calibrated photographs, ostial and branch diameters, antral length, MS length and coverage, distal edge morphology (sharp/blurred), and myocardial thickness were assessed at standardised locations. In 6/23 hearts, a 3 × 1 cm dorsal interatrial septum (IAS) sample including PV III, and CaVC MSs was stained with Masson's trichrome and examined for myocardial continuity. RESULTS:Four principal ostia were present in 20/23 hearts and 5 in 3/23, with variable accessory vein openings. Ostia II and III were largest, I smallest. PV III showed full antral MS coverage with branch extensions, whereas MSs in other PVs were often confined to the antrum. Distal MS edges were often blurred at PV III. The MS thickness was largest at ostia II and III and smallest at ostium I. Histology showed that the dorsal interatrial myocardium was continuous with the PV III and CaVC MSs. MAIN LIMITATIONS:Postmortem study, Warmblood cohort, few samples, no electrophysiology. CONCLUSIONS:Equine PV MS anatomy is ostium-specific in extent, distal edge, and thickness. These data provide anatomical information relevant to ablation planning and to future catheter design. Morphological evidence suggests a dorsal interatrial myocardial continuity through the IAS that warrants electro-anatomical confirmation.
Rhodococcus equi is a facultative intracellular pathogen and a major cause of pneumonia in foals worldwide. The standard treatment for affected foals is a combination of a macrolide with rifampicin. The widespread use of this combination has led to the emergence of multidrug-resistant (MDR) strains of R. equi. Consequently, antimicrobial susceptibility testing is essential for guiding treatment of rhodococcal pneumonia. Unfortunately, clinical breakpoints for macrolides and other antimicrobials against R. equi for foals are lacking, thereby complicating clinical interpretation of in vitro results. This review summarises current knowledge of antimicrobial resistance in R. equi, the methods used for susceptibility testing and the challenges of interpreting susceptibility testing for guiding treatment of this intracellular infection. We discuss the limitations of extrapolating breakpoints from other species of bacteria and animals and emphasise the importance of integrating minimum inhibitory concentration data, knowledge of intracellular antimicrobial activity and principles of pharmacokinetics and pharmacodynamics to inform therapeutic decisions. In the absence of standardised interpretive criteria of results of susceptibility testing, we propose evidence-based guidelines to support veterinarians and diagnostic laboratories in managing R. equi infections of foals.
BACKGROUND:Visual assessment of mild to moderate hindlimb lameness has low sensitivity and specificity, potentially leading to flawed diagnostic procedures. Pelvic axial rotation (roll) makes the assessment more complex but is also a potential source of information. OBJECTIVES:To describe pelvic roll patterns in horses with unilateral hindlimb lameness before and after diagnostic analgesia. STUDY DESIGN:Retrospective study. METHODS:Optical motion capture data from 20 horses with unilateral hindlimb lameness before and after successful local analgesia (assessed visually and objectively) were retrospectively retrieved. Pelvic rotation discrete variables (e.g., range of motion, angular velocities) were calculated. Measurements before and after diagnostic analgesia were compared using mixed models with horse as random effect or Wilcoxon signed rank test for non-normally distributed variables. RESULTS:Pelvic roll range of motion from time of pelvic vertical minimum to time of vertical maximum differed between lame and sound diagonals at baseline by 0.8° ± 0.17° (least square mean ± SE). This was reduced to 0.3° ± 0.17° after diagnostic analgesia (p = 0.004). Additionally, maximum roll angular velocity during push-off of the lame limb increased from 51° ± 12°/s (median ± median absolute deviation) to 61° ± 12°/s (+13%, p < 0.001). The pelvic rotation parameters showing the clearest difference before and after diagnostic analgesia varied between horses. MAIN LIMITATIONS:A small sample of clinical cases with varying diagnoses and of diverse breeds. CONCLUSIONS:Pelvic roll may change due to hindlimb lameness and return towards symmetry in response to diagnostic analgesia. Roll differences can contribute to changes in hip hike symmetry. The findings suggest that future studies should investigate if pelvic roll may provide additional information useful for lameness assessment.
BACKGROUND:Tissue Doppler imaging (TDI) may improve the assessment of myocardial function in neonatal foals. OBJECTIVES:To document the feasibility of left ventricular pulsed wave (PW) TDI, inter- and intra-observer variability and wave pattern over the first 5 days of life. STUDY DESIGN:Prospective observational study. METHODS:Transthoracic echocardiography was performed in 25 healthy Standardbred foals within the first 24 h after birth (T1), between 60-84 h (T2), and 108-132 h (T3) after birth using right parasternal short-axis (R-LV SAX) and subcostal long-axis views at the mitral annulus, both at the interventricular septum (SC-MV IVS) and free wall (SC-MV FW). Systolic (S1, Sm) and diastolic (E1, Em, Am) peak velocities were measured at each site. Intra- and inter-observer variability was assessed using intraclass correlation coefficients (ICC). Longitudinal changes were analysed using Friedman's test with Sidak-adjusted pairwise comparisons. Em and Am were compared using the paired Wilcoxon test. RESULTS:Pulsed wave tissue Doppler imaging was feasible in all foals. S1 and E1 were frequently indistinguishable. ICCs showed excellent agreement for most variables; measurement variability was low. Sm (R-LV SAX: T1 = 9.3 [8.2-11.0] cm/s; T3 = 12 [11.1-12.7] cm/s; p < 0.01), Em (R-LV SAX: T1 = 15.8 [14.1-20.1] cm/s; T3 = 22.1 [20.2-25.5] cm/s; p = 0.003; SC-MV FW: T1 = 16.9 [15.2-20.6] cm/s; T3 = 21.0 [18.1-22.3] cm/s; p = 0.019) and R-LV SAX Em/Am (T1 = 1.5 [1.3-1.9] cm/s; T3 = 1.9 [1.7-2.6] cm/s; p = 0.003) increased over time. Em was higher than Am in the R-LV SAX view at all time points. MAIN LIMITATION:Effective sample size varied across analyses. CONCLUSIONS:Pulsed wave tissue Doppler imaging was feasible. Sm and Em increased over time, while Am remained stable, indicating early ventricular adaptation to extra-uterine life. PW TDI may be a useful tool in myocardial function monitoring of neonatal foals.
BACKGROUND:Chronic jugular vein thrombosis may result in persistent venous obstruction and impaired head drainage. Although surgical thrombectomy is performed in selected cases, experimental comparisons between mechanical techniques for chronic thrombus removal in horses are lacking. OBJECTIVES:To compare Fogarty catheter thrombectomy alone with a combined Vollmar ring-Fogarty technique for restoration and maintenance of luminal patency in experimentally induced chronic jugular thrombosis. STUDY DESIGN:Randomised in vivo study. METHODS:Chronic right jugular thrombosis was induced in 10 healthy adult horses. After confirmation of thrombus chronicity (D13), horses underwent thrombectomy using the Fogarty catheter (FG; n = 5) or a combined Vollmar ring-Fogarty technique (VFG; n = 5). Clinical, ultrasonographic, and venographic evaluations were performed until D27 and analysed in two phases: thrombus induction/chronicity (D0-D13; n = 10) and post-thrombectomy follow-up (D13-D27; n = 5 per group). Quantitative data are presented as mean ± SD. RESULTS:Both techniques restored luminal patency intraoperatively. The Vollmar-Fogarty approach removed a greater thrombus mass (32 ± 6 g vs. 8 ± 2 g), yet VFG horses developed variable early postoperative re-occlusion with persistent partial obstruction at 6 h. In contrast, 3/5 FG horses demonstrated partial luminal patency at D14. At D27, sustained functional patency was observed in 3/5 FG and 1/5 VFG horses; remaining cases showed partial recanalisation with serpiginous channels. Thrombus length progressively decreased in both groups, and no major intraoperative complications occurred. MAIN LIMITATIONS:Small sample size and use of an experimental model in healthy horses may limit generalisability. Imaging assessments were performed by a single investigator, although blinded analysis was undertaken. CONCLUSIONS:Both techniques re-established venous flow in chronic jugular thrombosis; however, Fogarty thrombectomy achieved more sustained patency at 27 days despite removing smaller thrombus fragments. Further clinical studies are warranted.
BACKGROUND:Vaccination recommendations for foals against Clostridium tetani vary. Available studies assessing foal immune responses, maternal antibody interference, or individual variation often used small foal numbers. OBJECTIVES:To quantify antibody responses after tetanus vaccination in foals and explore associations with passively transferred tetanus antibodies. STUDY DESIGN:Longitudinal cohort study. METHODS:Sixty-two Warmblood foals from a single stud farm were followed from birth to 360 days of age. Foals received tetanus vaccinations at day 180 (d180) and d220 of life. Serum samples were collected at 19 time points during the study period and analysed using a fluorescent bead-based Tetanus Multiplex assay to quantify total and isotype-specific anti-tetanus antibodies. RESULTS:Passively transferred anti-tetanus antibodies in foal serum started to decline on d15 until d180. The first tetanus vaccination on d180 did not induce detectable antibodies. Following the second vaccination on d220, antibodies peaked on d230, before declining again to concentrations below pre-vaccination by d360. A weak correlation was observed between maternally derived antibodies on d5 and the vaccine-induced response on d230 (rsp = -0.36). Antibodies between pre- (d180) and post-vaccination (d230) did not correlate (rsp = -0.16). IgG1 contributed majorly to the initial vaccine-induced response, whereas IgM remained unaffected. The individual variability in antibody responses was high, with 38.7% of the foals showing low responsiveness to vaccination. MAIN LIMITATIONS:Only foals from a single farm were included; only one vaccine and tetanus vaccination schedule were evaluated, and a nonvaccinated control group or foals without maternal antibodies were not available. CONCLUSIONS:The variability in foal responses and the rapid post-vaccination antibody decline suggest that tetanus vaccination schedules for foals, including booster timing, may benefit from optimisation. Low vaccine responses at a time when passively transferred antibody concentrations had waned challenges the hypothesis of maternal antibodies as the sole reason for reduced antibody induction in foals.
BACKGROUND:Carpal lameness is a common cause of wastage in Thoroughbred racehorses, with the middle carpal joint most frequently affected. Evaluation of the dorsoproximal-dorsodistal oblique (DPr-DDiO) radiographic projection of the third carpal bone (C3) is fundamental in clinical and pre-purchase assessment of Thoroughbred racehorses. A standardised grading system is needed to improve consistency of diagnosis and reporting between clinicians. OBJECTIVES:To develop and assess inter-rater reliability of a novel grading system for evaluating radiological features of the third carpal bone on the C3 skyline projection. STUDY DESIGN:Retrospective multi-rater agreement study. METHODS:The novel grading system assessed bone radiopacity changes (Grades 0-4) and lucency characteristics (Grades A-C). Bone density ranged from Grade 0 (even trabecular distribution) to Grade 3 (severe radiopacity), with Grade 4 indicating overt evidence of fracture. Lucencies were classified as A (small, dorsal), B (linear or curvilinear, central), or C (extensive). Six observers independently graded 250 radiographs from a first-opinion Thoroughbred racehorse caseload. Inter-rater agreement was determined using Kappa statistics. RESULTS:Category-specific bone density grading revealed moderate agreement for Grades 0, 1, and 3 (κ = 0.45, 0.41, and 0.53), fair agreement for Grade 2 (κ = 0.36), and moderate to substantial agreement for Grade 4 (κ = 0.68). Inter-rater agreement on lucency classification ranged from fair (Grade B, κ = 0.28; Grade A, κ = 0.39) to moderate (Grade C, κ = 0.52). Unweighted kappa for bone density grading was 0.44 and 0.47 for presence of lucency grading. Weighted kappa for bone density grading was 0.59, indicating moderate agreement. MAIN LIMITATIONS:All observers were highly experienced clinicians and intra-observer reliability was not assessed. CONCLUSIONS:Inter-rater agreement using a novel grading system for the evaluation of the C3 'skyline' radiographic projection was generally moderate, and substantial for fracture. Adoption of this grading system in clinical practice will assist standardisation of diagnostic and prognostic evaluation of this important injury site.
BACKGROUND:Orthograde endodontic treatment of equine cheek teeth is performed infrequently with variable success rates of obturation with calcium hydroxide paste (CHP). A novel flowable calcium silicate cement (eCSC) formulated for use as an obturation material in equine teeth has demonstrated acceptable canal filling volumes and evidence of dentinal tubule penetration. However, clinical outcomes of eCSC-obturated equine teeth have not been reported. OBJECTIVES:To report the clinical outcomes of orthograde endodontic treatment using eCSC. STUDY DESIGN:Retrospective case series. METHODS:Horses that underwent orthograde endodontic treatment using eCSC at a single referral centre between October 2020 and March 2026 and had ≥12 months follow-up were included in the study. RESULTS:Seven horses, with endodontic treatments on six cheek teeth and one incisor were included. The success rate of eCSC was 6 of 7 cases, with up to 5.5 years of follow-up. One eCSC case demonstrated healing of a draining tract to the paranasal sinus on CT and histologically showed no evidence of periapical infection or inflammation 16 months after treatment. The singular failed eCSC-treated tooth demonstrated incomplete cleaning and obturation of one pulp canal on histological examination. MAIN LIMITATIONS:Small case numbers, heterogeneous follow-up, and a single operator limit the generalisability of these findings. CONCLUSIONS:Orthograde endodontic treatment of equine teeth using eCSC can result in long-term clinical success. CT and histopathological findings available for one case support biological healing in successfully treated eCSC cases. A prospective, multi-centre study with standardised follow-up is warranted to establish the predictability and indications of eCSC as an obturation material for equine endodontics.
BACKGROUND:Equine regenerative medicine products involving platelet-rich plasma (PRP), mesenchymal stromal cells (MSCs), and their derivatives are increasingly explored for antimicrobial and therapeutic roles, but their efficacy and between-study variability remain unclear. OBJECTIVES:To systematically review and meta-analyse in vitro and in vivo evidence on antimicrobial effects of equine regenerative medicine products and to evaluate their efficacy against key pathogens. STUDY DESIGN:Systematic review and meta-analysis: METHODS: We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses and searched studies (2010-2025) reporting PRP/MSC antimicrobial interventions in equine models. In vitro studies reporting colony-forming unit (CFU) outcomes were meta-analysed. Continuous outcomes were pooled as standardised mean differences (SMD; the mean difference divided by the pooled standard deviation with 95% confidence intervals [CI]), using a random-effects model. Heterogeneity was assessed by I2 and significance as p < 0.05. Predefined subgroup analyses by product class and pathogen were performed. Risk of bias was assessed with a predefined checklist. In vivo outcomes were synthesised narratively. RESULTS:Twenty-four studies met inclusion criteria; 13/17 in vitro studies contributed CFU data for meta-analysis. Platelet-derived products showed a pooled SMD of 0.94 (95% CI 0.33-1.54; p = 0.003; I2 = 27%) against Staphylococcus aureus. Against Escherichia coli, regenerative products showed a non-significant effect (SMD 1.07; 95% CI 0.01-2.13; p = 0.05; I2 = 65%). MSC-based products produced a non-significant SMD of 0.55 (95% CI -0.46-1.55; p = 0.29; I2 = 38%) versus S. aureus. Seven in vivo studies reported clinical improvements, and combination therapies with antibiotics often enhanced bacterial clearance. MAIN LIMITATIONS:Interpretation is limited by substantial methodological heterogeneity across studies and by potential risk of bias. CONCLUSION:Platelet-derived regenerative products demonstrate in vitro antimicrobial activity against a representative Gram-positive bacterium, S. aureus; however, current heterogeneous and limited in vivo evidence provides only tentative support for their use as adjuncts, rather than standalone antimicrobial therapies. Well-designed, standardised in vitro and in vivo studies are needed.
BACKGROUND:Assessing mammary gland health in donkeys is challenging due to the lack of species-specific diagnostic criteria for subclinical mastitis. Although somatic cell count (SCC) is widely used in dairy ruminants, its diagnostic value in jennies remains unclear. Each donkey teat contains two anatomically independent duct systems, potentially influencing microbial distribution. OBJECTIVES:To evaluate mammary gland health at the individual duct level in lactating jennies by assessing SCC, bacteriological findings, and total bacterial count (TBC), and to investigate associations with host-related factors. STUDY DESIGN:Non-randomised cross-sectional observational study. METHODS:Milk samples were collected separately from the medial and lateral ducts of both teats (four ducts per animal) in 29 clinically healthy lactating jennies (116 samples). SCC was determined by direct microscopic count; bacteriology was performed with MALDI-TOF identification. TBC was expressed as CFU/mL. SCC and TBC were log10-transformed prior to mixed-effects linear regression, with animal as a random effect. RESULTS:Using an exploratory threshold of ≥200,000 cells/mL, increased SCC was detected in few ducts and was not consistently associated with bacteriological positivity. Median SCC and TBC were low but highly skewed. Bacteriological positivity occurred in 62.1% of jennies, mainly involving environmental and opportunistic microorganisms. Marked microbiological heterogeneity was observed between ducts within the same gland. Lactation stage (4-6 months) was associated with increased SCC (p < 0.05), whereas age, parity, and use were not consistently associated. An apparent association between younger age and higher TBC was not maintained after excluding one outlier. No significant correlation was found between SCC and TBC. MAIN LIMITATIONS:Small sample size, uneven age distribution, cross-sectional design, and absence of differential cell counting. CONCLUSIONS:Clinically healthy lactating jennies showed generally low SCC and bacterial loads, but duct-level sampling revealed substantial intra-gland heterogeneity. SCC showed limited concordance with bacteriology, supporting the need for donkey-specific mastitis criteria.
BACKGROUND:Campylorrhinus lateralis ('wry nose') is a rare congenital maxillofacial deformity of foals resulting in compromise of the airway and severe class 4 malocclusion. Various surgical techniques to correct the deformity have been described, but contemporary data on single-stage transection and fixation, including use of a rib graft, and long-term functional and cosmetic outcomes remain underreported. OBJECTIVES:To describe the transection-and-fixation technique and perioperative management used to correct wry nose in horses, and to report postoperative complications and long-term outcomes of horses undergoing this treatment. STUDY DESIGN:Retrospective case series. METHODS:Wry nose of four horses was corrected by using a single-stage transection-and-fixation technique. Pre-operative assessment included physical, oral, and radiographic examinations, and when available, CT imaging. The surgical procedure involved temporary tracheostomy and laryngotomy, resection of the nasal septum, osteotomy and fixation of the nasal bones, and orthognathic transection and fixation of the premaxillae and maxillae, with bone grafting and alar fold resection performed when indicated. The outcome of horses with complete records and ≥12 months follow-up is reported using descriptive statistics. RESULTS:All four horses were presented with respiratory difficulty. The transected premaxillae were stabilised with pins and wires, and the transected nasal bones were stabilised with plates/screws; only one horse received a rib graft. All horses developed a plate-associated infection, and one horse developed an oronasal fistula. At the time of follow-up, all grazed and masticated normally, maintained good body condition, and owners were satisfied with the functional and cosmetic outcome. MAIN LIMITATIONS:Small sample size, retrospective design. CONCLUSIONS:Correcting wry nose of four foals using a single-stage transection-and-fixation procedure achieved satisfactory long-term outcomes. Respiratory function of all horses improved, and all horses grazed and masticated normally. Three horses were able to perform their intended athletic endeavour. All owners reported satisfaction with the functional and cosmetic outcome.
BACKGROUND:Equine neuroaxonal dystrophy/degenerative myeloencephalopathy (eNAD/EDM) is the second most common diagnosis of spinal ataxia in horses in the United States. The disease develops due to a combination of vitamin E deficiency and an unknown genetic risk factor(s), and there currently is no effective treatment. OBJECTIVES:We performed transcriptomic profiling of the liver and small intestine of horses with and without eNAD/EDM, as both tissues are the main locations for absorption, metabolism, and delivery of vitamin E to the nervous system. STUDY DESIGN:Case-control exploratory study. METHODS:Postmortem-confirmed cases of eNAD/EDM were compared to horses that had eNAD/EDM excluded at necropsy and were euthanised for either non-neurologic disease or for cervical vertebral compressive myelopathy (CVCM), which were included due to the logistical challenge of obtaining control horses that have undergone a full neuropathologic review. RNA was isolated from frozen liver (eNAD/EDM n = 34, non-eNAD/EDM n = 27) and small intestinal (eNAD/EDM n = 18, non-eNAD/EDM n = 18) samples. Gene expression was compared between groups using a linear model, adjusting for age, breed, and RNA integrity score. RESULTS:No genes were differentially expressed at pFDR <0.05 in either tissue between eNAD/EDM and non-eNAD/EDM horses. However, one of the top genes, NPC1L1, was upregulated in the liver of horses with eNAD/EDM (log2FC = 0.93, punadjusted < 0.05). In the small intestine, 747 genes were differentially expressed (punadjusted <0.05), including two genes that were markedly downregulated in both tissues. These genes have high sequence homology to LGALS9. MAIN LIMITATIONS:Non-neurologic control numbers were limited. Tissues were collected at the time of euthanasia and therefore may not capture biological processes that were occurring at the time the neurological damage developed. CONCLUSIONS:Processes related to both cholesterol transport and autophagy may be altered in horses with eNAD/EDM. Two new candidate genes for eNAD/EDM, NPC1L1 and LGALS9, were identified for further investigation.
BACKGROUND:FLow-controlled EXpiration (FLEX) has been shown to significantly enhance oxygenation in horses under clinical and experimental conditions. OBJECTIVES:To compare pulmonary gas exchange during early recovery following general anaesthesia in horses ventilated with FLEX compared with conventional intermittent positive pressure ventilation (IPPV) and to assess recovery characteristics between ventilation modes. STUDY DESIGN:Randomised, crossover in vivo experiments. METHODS:Six adult horses underwent two 2-h anaesthetic episodes in a randomised crossover design (FLEX vs. IPPV), separated by a two-week washout. Arterial blood gases were analysed at 60- and 120-min post-induction. Arterial blood pressure, end-tidal inhalant concentrations, respiratory rate, and haemoglobin oxygen saturation were recorded in 5-min intervals during anaesthesia. The initial recovery period was defined as the first 20 min following return of spontaneous ventilation, during which arterial blood gases, end-tidal inhalant concentrations, and oxygen saturation were recorded in 5-min intervals. Horses were recovered using head and tail rope assistance. The time to sternal recumbency, standing, and the number of standing attempts were recorded. Data were analysed using linear mixed-effects models for repeated measures and paired tests for recovery outcomes. RESULTS:PaO2 was higher during general anaesthesia with FLEX (mean ± SD: 422 ± 24 vs. 202 ± 101 mmHg at 60 min; 433 ± 31 vs. 180 ± 59 mmHg at 120 min; p < 0.01). In recovery, PaO2 remained higher with FLEX (20 min: 114 ± 21 vs. 62 ± 11 mmHg; p < 0.01) and EtIso declined more rapidly (p < 0.01). Time to sternal and standing were shorter and attempts to stand fewer with FLEX (exploratory outcomes). MAIN LIMITATIONS:This study enrolled a small sample size, which may limit generalisability. Recovery was recorded from one camera angle, potentially restricting full assessment of recovery behaviour. No respiratory mechanics or regional ventilation distribution were quantified. CONCLUSIONS:FLEX improves oxygenation during early recovery and is associated with faster recovery times in healthy horses.
BACKGROUND:Arrhythmias can cause poor performance and sudden death in horses. Long-term (>24 h) electrocardiogram (ECG) monitoring has been used to identify arrhythmias in humans and is superior to short-term monitoring for transient arrhythmia detection. Televet is the current equine gold-standard ECG device. The Cardea SOLO™ (CS) is a single-use monitor with automated ECG analysis software allowing ECG monitoring for 7 days. OBJECTIVE:Our objective was to validate the performance of the CS compared to the Televet. STUDY DESIGN:Method validation. METHODS:ECGs were performed on 12 healthy horses simultaneously using both devices for 24 h on day 1 and day 7, with the CS left in place for all 7 days. Each ECG was manually reviewed to identify correctly and incorrectly classified complexes. Generalised linear models were used to identify differences in the arrhythmia classifications and the proportion of unusable minutes. For eight horses, Bland-Altman analysis and correlation were performed to test for agreement between the two devices for standard ECG measurements. RESULTS:The CS recorded and analysed ECGs for up to 7-days without adverse effects in all horses. The proportion of readable ECG decreased markedly after day 5 and CS identified more false positive premature complexes than Televet. The correlation between devices for ECG measurements ranged from good to excellent. MAIN LIMITATIONS:The major limitations of our study are the relatively small sample size (n = 12) and the challenge in starting both devices at the same time led to only eight horses being included in the device measurement comparisons. The CS is a single lead ECG which may have led to incorrectly classified premature depolarisation types on manual inspection. CONCLUSIONS:This study demonstrates the CS utility for 5-day ECG monitoring and screening for arrhythmias in healthy horses. CS utility for the detection of pathological arrhythmias requires further investigation.
BACKGROUND:Sepsis is an important cause of morbidity and mortality in foals. Early diagnosis can improve outcome but is complicated by non-specific clinical signs and delayed confirmation of infection via blood culture. Molecular assays represent a rapid and more sensitive alternative. OBJECTIVES:To evaluate and compare bacterial load and composition in blood and blood culture media (BCM) of sick and healthy foals using molecular assays and to compare results with traditional bacterial culture. STUDY DESIGN:Cross-sectional observational clinical study. METHODS:Thirteen septic foals, 10 sick non-septic and 8 healthy foals were included. Bacterial load and composition from whole blood (WB), pre-enriched BCM and contamination controls were analysed by quantitative PCR and sequencing of the universal bacterial 16S rRNA marker gene. RESULTS:WB sequencing yielded more positive samples (25/31) than BCM (6/62; p < 0.01). Positive blood culture and WB sequencing were comparable in only 3/12 foals. Sequencing samples were at high potential for contamination, with most samples having high relative abundances (RAs) of Paucibacter and Ralstonia. High RAs of Actinobacillus and Staphylococcus in septic foals may, however, suggest true pathogen detection. No significant differences in bacterial RAs, 16S rRNA gene load (qPCR), or other sequencing-based metrics were found between foal groups and between WB and contamination controls. MAIN LIMITATIONS:Inherent inaccuracies of classification schemes for septic and sick non-septic foals and the impact of contamination when sequencing low biomass samples. CONCLUSIONS:High-throughput sequencing represents a possible avenue for the diagnosis of bacteraemia in foals but has high potential for environmental and extraction-related contamination and cannot replace blood culture at this time. Further research to optimise detection yield and sensitivity on WB samples is warranted.
