David Alexander Martínez Rodríguez

Los potros neonatos son susceptibles a enfermedades potencialmente mortales. Por tanto, es importante identificar marcadores que permitan predecir la supervivencia de estos pacientes, e iniciar el tratamiento adecuado para cada caso. Este estudio fue realizado en el Centro de Perinatología Equina Foal Care ubicado en Cajicá, Cundinamarca. Se revisaron y analizaron las historias clínicas de 106 potros que ingresaron a hospitalización entre septiembre de 2019 y diciembre de 2020 para evaluar el valor predictivo de los parámetros de gases sanguíneos y electrolitos frente a la supervivencia de potros neonatos hospitalizados. Se utilizaron diferentes pruebas estadísticas como la prueba de Kolmogorov Smirnov, U de Mann-Whitney, regresión logística binaria, pruebas de chi cuadrado, odds ratio y análisis de la curva de características del operador del receptor (ROC). Se observó que el desorden ácido-básico más común al ingreso a hospitalización fue la acidosis metabólica (37/106), y el desequilibrio electrolítico más frecuente fue la hipocalcemia (89/106). La variable más significativamente relacionada con la supervivencia fue el pH > 7,35 (p = ,007; OR = 0,288; IC = 95 %, 0,117-0,706). Los factores de riesgo asociados con la no supervivencia de los potros fueron pH < 7,35, lactato > 4,5 y glucosa < 119,5 mg/dl.

Maternal antibodies interfere with BRSV vaccine responses and efficacy in young calves. The objective of this study was to determine if vaccination before the complete absorption of colostral antibodies results in adequate immune priming and clinical protection of beef calves. Within 6 h of life, calves were randomly assigned to 2 different treatment groups. Group Vacc (n = 25) received a single dose of a modified-live virus (MLV) BRSV vaccine intranasally (IN) and group Control (n = 25) received 2 mL of 0.9% saline IN. At approximately 3 months of age, all calves were experimentally challenged with BRSV. Serum and nasal secretion samples were collected before and after challenge for BRSV real-time RT-PCR and antibody testing. Respiratory signs were not observed before challenge. After challenge, respiratory scores were similar between groups. On the challenge day, >40% of calves in each group were febrile. The mean serum and nasal BRSV-specific antibody titers indicated natural BRSV exposure before the experimental challenge in both groups. All calves tested positive for BRSV and had a similar duration of shedding after challenge. Based on these results, vaccination at birth does not offer advantages for immune priming or clinical protection for beef calves in BRSV-endemic cow-calf herds.

Ingestion of certain plants belonging to the genus Senna in animals can cause a rapidly progressive disease with myonecrosis. Natural senna intoxication was suspected in cattle that were grazing on contaminated pasture. Three calves presented with clinical signs of acute illness, characterised by sternal recumbency and absent patellar and withdrawal reflexes. Senna obtusifolia and Senna occidentalis plants were found in the grazing pastures. Serum biochemistry levels of creatine kinase and aspartate aminotransferase were higher than the reference ranges. Major pathologic findings included multifocal pale tan and dry skeletal muscle with severe segmental monophasic myonecrosis. Senna seeds were identified in the ruminal contents. A diagnosis of Senna intoxication was made given the clinical history and the compatible clinicopathological and pathologic findings. In addition, Senna plants in the pasture along with the Senna seeds were found in the ruminal contents in the affected heifer.