03039naa a2200385 a 450000100080000000500110000800800410001902200140006002400510007410000160012524501280014126000090026950004610027852013300073965300400206965300190210965300230212865300210215165300260217265300140219865300560221265300180226865300410228665300320232765300120235970000150237170000180238670000190240470000160242370000300243970000190246970000210248870000170250977301270252610652382025-06-26       2025    bl uuuu     u00u1 u    #d  a1040-63877 ahttps://doi.org/10.1177/104063872513412342DOI1 aMACHADO, M.  aAcute fatal Leptospira kirschneri infection in suckling lambs and calves in Uruguay. (Brief report).h[electronic resource]  c2025  aArticle history: First published online May 12, 2025. -- Corresponding author:   Machado, M.; Plataforma de Salud Animal, Instituto Nacional de Investigación Agropecuaria, Ruta 5, km 386, Tacuarembó, Uruguay; email:mmachado@inia.org.uy -- Funding: The research was funded by grants from the Unidad Mixta Pasteur + INIA, INIA (PL_27), and from FOCEM (Fondo para la Convergencia Estructural del Mercosur; COF 03/11). -- Publisher: SAGE Publications Inc. --  aABSTRACT.- Leptospira kirschneri is an emerging human and animal pathogen. Here we describe 2 unrelated outbreaks of acute fatal leptospirosis caused by L. kirschneri in suckling lambs and calves diagnosed following a flooding event in the spring of 2023 in northern Uruguay. In outbreak 1, the sheep flock was raised in a low-lying area previously used for rice cultivation; 20 lambs died after developing apathy, jaundice, and hemoglobinuria. In outbreak 2, 2 calves were found dead. At autopsy, 4 lambs and 2 calves had marked jaundice, hemoglobinuria, dark-red kidneys, and hepatomegaly. Microscopically, we found marked hemoglobinuric nephrosis, lymphohistiocytic tubulointerstitial nephritis, hepatocellular dissociation, and random hepatocellular necrosis with periportal lymphohistiocytic hepatitis and canalicular cholestasis. Positive immunostaining for Leptospira sp. was found in the liver (lamb C), both the liver and kidney (calf B), and the liver (calf A). Leptospira kirschneri was PCR-confirmed using kidney and liver samples from the autopsied animals. Acute leptospirosis caused by L. kirschneri has not been reported previously in sheep and cattle, to our knowledge. Our findings highlight that L. kirschneri infection can cause acute leptospirosis in unvaccinated lambs and calves. © 2025 The Author(s).  aGood health and well-being - Goal 3  aHemoglobinuria  aINIA LA ESTANZUELA  aINIA TACUAREMBÓ  aLeptospira kirschneri  aLivestock  aPLATAFORMA DE INVESTIGACIÓN EN SALUD ANIMAL - INIA  aSouth America  aSustainable Development Goals (SDGs)  aUNIDAD MIXTA PASTEUR + INIA  aUruguay1 aCIUFFO, C.1 aGIANNITTI, F.1 aSILVEIRA, C.S.1 aPERDOMO, T.1 aQUEIROZ-MACHADO, C. R. R.1 aCARRIQUIRY, R.1 aZARANTONELLI, L.1 aMENCHACA, A.  tJournal of Veterinary Diagnostic Investigation, 2025, Vol. 37(4), pages 679-683. https://doi.org/10.1177/10406387251341234