RESUMO
Astylus atromaculatus is a pollen beetle native to South America, commonly found in crop flowers. Experimental intoxication of sheep and guinea pigs by this beetle resulting in fibrinonecrotizing enteritis has been reported. We describe here 6 natural outbreaks of intoxication in cattle associated with consumption of alfalfa (5 of 6) and mixed native (1 of 6) pastures heavily contaminated with A. atromaculatus. The outbreaks occurred during the summer (January-February) of 2023 in Argentina (n = 4) and Uruguay (n = 2), in beef cattle under extensive or semi-extensive rearing systems, with overall cumulative incidence and mortality of 22.3% and 17.8%, respectively. The main clinical signs included acute onset of anorexia, lethargy, hyperthermia, hindlimb weakness, reluctance to move, and diarrhea, for up to 15 d. In 2 outbreaks, sudden death was observed. Eight Hereford, Angus, and/or crossbreed heifers, cows, steers, and/or calves were autopsied. Gross and microscopic findings included multifocal necrosis with fibrinous pseudomembranes in the forestomachs and/or small and large intestines. Fragments or whole specimens of A. atromaculatus were identified in the ruminal content of all animals. Testing for multiple gastroenteric pathogens was negative as was testing of A. atromaculatus for cantharidin and batrachotoxin. GC-MS and LC-MS/MS performed on the beetles did not identify any known toxic compounds. Based on the exposure to A. atromaculatus-contaminated pasture, gross and microscopic lesions, and negative results of all testing for multiple gastroenteric pathogens, a diagnosis of intoxication by A. atromaculatus is proposed. Disease caused by A. atromaculatus consumption has not been reported previously in cattle, to our knowledge.
Assuntos
Doenças dos Bovinos , Besouros , Doenças dos Ovinos , Animais , Bovinos , Feminino , Ovinos , Cobaias , Cromatografia Líquida/veterinária , Espectrometria de Massas em Tandem/veterinária , Pólen , Surtos de Doenças/veterinária , Doenças dos Bovinos/patologia , Doenças dos Ovinos/patologiaRESUMO
Clinical History: Two 18-month-old female bison and a heifer died suddenly in the same ranch. The three animals were submitted for postmortem examination and diagnostic workup. The changes of one of the bison are presented here. Necropsy Findings: The carcass was in fair nutritional condition, with small amount of fat reserves, but still well fleshed, and in mild state of post-mortem decomposition. There was a small amount of clotted dark-red blood in the nostrils and anus. The heart presented extensive sub-endocardial hemorrhages in all four chambers. These lesions were most pronounced in both ventricles where they extended deep into the underlying myocardium (Fig. 1 and Fig. 2). The mucosa of the abomasum was diffusely and mildly congested, and the mucosa of the small and large intestine was diffusely and severely congested (Fig. 3). There was a moderate amount of red fluid in the lumen of the small intestine, cecum, and colon. Both lungs had a few, small, well delineated, deep, firm, multifocal dark-red areas in all pulmonary lobes, but lung tissue samples floated when placed into formalin. Follow-up questions: Microscopic description Morphologic diagnosis Most likely etiology(AU)
Assuntos
Animais , Autopsia , Bison , NeriumRESUMO
We describe and illustrate lesions in an outbreak of lead arsenate poisoning in beef cattle that ingested pesticide residues stored in an abandoned building of a former orange orchard. Of 70 exposed cattle, 14 had diarrhea, paresis, ataxia, recumbency, and/or seizures. Ten of the affected animals died after a clinical course of 12-18 h. Pathologic findings in 3 steers included extensive necrohemorrhagic, ulcerative rumenitis, omasitis, and abomasitis; lymphocytolysis in lymphoid organs; and nephrosis. Hepatic arsenic and lead levels in cases 1-3 were 20, 24, and 31 ppm, and 8.3, 25, and 9.4 ppm, respectively. Lesions in the forestomachs and lymphoid tissues have been rarely reported in cases of lead arsenate poisoning. In southern South America, these lesions are indistinguishable from those produced by Baccharis coridifolia, a toxic plant that contains macrocyclic trichothecenes, thus these conditions should be considered in the differential diagnosis of necrotizing lesions in alimentary and lymphoid organs.