Introduction: Bovine neosporosis represents a significant threat to reproduction and production in livestock systems worldwide. This disease is caused by the protozoan Neospora caninum, resulting in abortions of cows and neurological signs in newborn calves. This leads to significant economic losses, decreasing meat and milk production, especially in tropical regions. The infection has an endogenous and exogenous cycle of transmission involving dogs that shed the oocysts, with the highest transmission successes in humid areas. Similarly, there is a lack of knowledge about the epidemiological risk factors and management practices involved in the transmission success in tropical humid regions. Methods: In this sense, a cross-sectional epidemiological survey was conducted on 150 farms from 24 municipalities of the Huila area. A total of 360 cattle were sampled, and information about the production system was collected using a structured poll with 128 questions. Results: In these cattle, 53% (191/360) were positive for antibodies against Neospora caninum using ELISA. The logistic regression analysis using the information collected from the poll identified the presence of flooring type, water access, production systems, and feed management as risk factors. Among the protective factors were identified the geographical area, molasses supplementation, and biosecurity practices such as animal separation and access control. Discussion: This study identified for the first time the epidemiological risk factors associated mainly with the exogenous cycle of neosporosis. The present study contributes to the design of intervention strategies oriented to minimize the impact of parasitism in Colombian herds.

Enzootic bovine leukosis (EBL), paratuberculosis (PTB), and bovine tuberculosis (bTB) are chronic infectious diseases affecting dairy systems with important implications for productivity and animal health. An analytical observational study evaluated 733 cattle from 37 specialized dairy herds in a highland dairy region of Colombia using serological (ELISA) and molecular methods (qPCR, ddPCR) to detect bovine leukemia virus (BLV), Mycobacterium avium subsp. paratuberculosis (MAP), and Mycobacterium bovis. Descriptive analyses, bivariate associations, and multivariable logistic regression evaluated factors associated with BLV infection and its relationship with MAP detection.At herd level, BLV was detected in 70.3% by ddPCR and 67.6% by ELISA, MAP in 24.3% by ELISA and 18.9% by qPCR, and no M. bovis was detected. At animal level, BLV prevalence was 34.8% by ddPCR and 31.9% by ELISA, MAP detection was low (1.2% in fecal samples), and no M. bovis was detected using any diagnostic method. No statistically significant association between BLV and MAP was found (OR = 0.23; 95% CI: 0.03–1.78; p = 0.18), consistent across alternative diagnostic definitions. Age was the only variable independently associated with BLV infection, with increasing odds at older ages.BLV infection was highly prevalent in the study population, whereas MAP detection was limited and M. bovis absent. The lack of BLV-MAP association, combined with age-related patterns, underscores the importance of considering infection dynamics and appropriate diagnostic methods when interpreting epidemiological relationships in dairy systems. These findings support differentiated, pathogen-specific surveillance and control strategies.

Mycobacterium avium subsp. paratuberculosis (MAP) prevalence estimates vary widely across Colombian regions, with no prior longitudinal assessment of Colombian dairy systems across ecologic life zones. We assessed the temporal dynamics of MAP infection in Colombian cattle across 6 distinct ecologic life zones and explored age-related differences in MAP detection using combined serologic and molecular approaches. We longitudinally sampled 129 cattle from 6 municipalities in distinct Holdridge life zones. The animals were stratified by age group and sampled 3 times at 2-mo intervals during 2023 (Aug–Dec). Serum and fecal samples were tested by indirect ELISA and IS 900 real-time PCR (rtPCR), respectively. The apparent ELISA prevalence remained stable between 37.2% and 38% across sampling rounds (adjusted true prevalence = 29.9%). Seropositivity increased consistently with age, from 11.9% in animals <1-mo-old to 49% in animals ≥3-y-old. All of the fecal samples tested negative by rtPCR. No consistent seroprevalence clustering was observed across ecologic life zones on descriptive assessment, although management and host factors were not evaluated. We found longitudinal evidence of stable, age-related MAP seroprevalence across ecologic zones in Colombia, highlighting subclinical persistence and diagnostic limitations.