Miriam Alva-Trujillo

Information on Leptospira spp. exposure in Mexican equids remains limited. This cross-sectional study evaluated seropositivity and antigen-specific seroreactivity in 313 apparently healthy equids enrolled by convenience sampling in Los Tuxtlas (n = 119), Sotavento (n = 108), and Capital (n = 86), Veracruz, Mexico, from 2 October 2023 to 6 March 2024. Sera were examined by the microscopic agglutination test (MAT) against 13 antigens; titers ≥ 1:100 defined seropositivity. Overall seropositivity was 57.5% (180/313; 95% confidence interval [CI]: 52.0–62.9), with regional proportions of 49.6%, 65.7%, and 58.1%, respectively (unadjusted p = 0.048). Modified Poisson models with robust variance were fitted separately for region with species and region with sex. For Sotavento versus Los Tuxtlas, the adjusted prevalence ratio was 1.33 after adjustment for species (95% CI: 1.06–1.67) and 1.33 after adjustment for sex (95% CI: 1.06–1.66). Antigen-specific seroreactivity was most frequent for Australis (63/313; 20.1%), Bratislava (62/313; 19.8%), and Pyrogenes (57/313; 18.2%); these are overlapping antigen responses, not mutually exclusive serogroup estimates. Environmental and management exposures were not measured at the animal level. The findings support surveillance at the animal–human–environment interface but do not demonstrate active shedding or zoonotic transmission.

Hybrid equids such as mules and hinnies play a critical role in supporting livelihoods in low- and middle-income countries but remain underrepresented in veterinary research. One key challenge is the absence of a practical and internally validated method for estimating body weight in mules and hinnies, which is essential for accurate dosing and management, particularly in the absence of a weighbridge. This study aimed to evaluate the performance of existing equid weight estimation models on mules and hinnies and to develop a new mules and hinnies -specific model to improve predictive accuracy and field usability. Three hundred and sixteen healthy mules and hinnies were assessed across nine countries. Sixteen morphological measurements were collected, and body weight was recorded using a digital weighbridge. Existing models were tested for their feasibility, and linear regression model was developed to predict mules and hinnies’ weighbridge body weight from morphological measurements. Model performance was assessed using repeated cross-validation and standard error metrics. Machine learning methods were used as a secondary analysis to explore feature importance. Morphological predictors showed strong associations with weighbridge weight. Linear models demonstrated reliable predictive performance, with low prediction error across weight ranges. The new mules and hinnies-specific model based on heart girth, chest width, and forearm girth, achieved an adjusted r² of 0.94 (p < 0.001), providing estimates of live-weight without requiring classification by sex, conformation, or type. These findings demonstrate that simple morphological measurements can provide good estimates of body weight of mules and hinnies in field settings, greatly supporting the daily management of mules and hinnies in different contexts, and contribute to improve their health and welfare globally.

There is great need for veterinary care for working equids worldwide. Addressing this need provides an opportunity for veterinary students to gain primary care experience. An annual two week collaborative outreach and educational program with Michigan State University (MSU), the Universidad Nacional Autónoma de México (UNAM) and the Universidad Veracruzana (UV) was developed to provide care for working equids in rural Mexican communities. From 2017 to 2019 24 US veterinary students and 25 Mexican veterinary students, interns and residents examined, vaccinated and dewormed more than 2200 equids and performed more than 80 castrations, 100 rectal palpations for pregnancy diagnosis, 220 dental floats and 320 hoof trims. They also treated many wounds, sarcoids, vampire bat bites and tick infestations and also saw unusual cases including tetanus, eye injuries, nuchal bursitis, cervical vertebral malformation and suspected vesicular stomatitis. Development of the collaborative MSU-UNAM-UV Equine Welfare in Practice Clerkship required vision, learning, relationship building, creativity, fund-raising and perseverance to develop and agree on mutually beneficial objectives for all participants. The project is largely financed through private donations and supplies provided by pharmaceutical companies. The outcome has been a highly successful program that could be used as a model by other Colleges of Veterinary Medicine world-wide.