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ARS Home » Pacific West Area » Logan, Utah » Poisonous Plant Research » Research » Publications at this Location » Publication #421313
Research Project: Developing Mitigation Strategies for Poisonous Plants in Livestock Production Systems

Location: Poisonous Plant Research

Title: Oxalate nephropathy in cattle associated with the consumption of Megathyrsus maximus in Argentina

Author
item AVELLANEDA-CACERES, AGUSTIN - Consejo Nacional De Investigaciones Científicas Y Técnicas(CONICET)
item Lee, Stephen
item RUIZ, ALVARO - National Institute Of Agricultural Technology(INTA)
item SANDOVAL, GABRIELA - Consejo Nacional De Investigaciones Científicas Y Técnicas(CONICET)
item COLQUE-CARO, LUIS - Consejo Nacional De Investigaciones Científicas Y Técnicas(CONICET)
item Cook, Daniel
item AGUIRRE, LAURA - Consejo Nacional De Investigaciones Científicas Y Técnicas(CONICET)
item UZAL, FRANCISCO - University Of California, Davis
item MICHELOUD, JUAN - Consejo Nacional De Investigaciones Científicas Y Técnicas(CONICET)

Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Over a two-week period, 20 cows that were grazing a Megathyrsus maximus (Guinea grass) pasture died after exhibiting depression, respiratory difficulty and recumbency. Affected animals had increased serum urea, phosphorus and creatinine levels, and below normal calcium levels. Necropsy revealed moderate ascites, mildly enlarged, pale and mottled kidneys, and perirenal edema. Microscopically, there was hyperplasia of mesangial cells in the renal glomeruli, renal tubular epithelial necrosis, and hyaline casts and refractive crystals in cortical and medullary renal tubular lumens. Samples of M. maximus from the affected pasture contained soluble oxalate concentrations of 3.71%. These findings suggest that oxalate nephrosis was produced by M. maximus. The study highlights the critical need for monitoring oxalate levels in pastures and managing grazing practices, particularly under drought conditions, to prevent similar outbreaks in the future.

Technical Abstract: Over a two-week period, 20 cows that were grazing a Megathyrsus maximus (Guinea grass) pasture died after exhibiting depression, respiratory difficulty and recumbency. Affected animals had increased serum urea, phosphorus and creatinine levels, and below normal calcium levels. Necropsy revealed moderate ascites, mildly enlarged, pale and mottled kidneys, and perirenal edema. Microscopically, there was hyperplasia of mesangial cells in the renal glomeruli, renal tubular epithelial necrosis, and hyaline casts and refractive crystals in cortical and medullary renal tubular lumens. Samples of M. maximus from the affected pasture contained soluble oxalate concentrations of 3.71%. These findings suggest that oxalate nephrosis was produced by M. maximus. The study highlights the critical need for monitoring oxalate levels in pastures and managing grazing practices, particularly under drought conditions, to prevent similar outbreaks in the future.