Experimental poisoning by Niedenzuella stannea in cattle and corresponding detection of monofluoroacetate

Abstract

In Brazil sodium monofluoroacetate (MFA) containing plants are represented by 16 species that belong to three principle genera: Palicourea ( Rubiaceae ), Amorimia ( Malpighiaceae ), and Tanaecium ( Bignoniaceae ). These plants can cause acute cardiac failure often referred to as sudden death syndrome. The objective of this paper was to determine if N. stannea contains MFA and to report the clinical signs and pathology of cattle experimentally poisoned by this plant. MFA was detected in all N. stannea plant parts except mature leaves. Niedenzuella stannea was dosed to cattle at single doses of 15-30g kg-1 bw. Clinical signs and pathology observed were similar to those reported by other MFA-containing plants. Animals showed marked tachycardia, labored breathing, muscle tremors, loss of balance, ataxia, falling, recumbence, pedaling movements, and opisthotonous leading to death in few minutes. Gross lesions included engorgement of the large veins, severe lung edema, and petechiae , ecchymosis and suffusions in the pericardium, epicardium and pleura. Histologically, hydropic vacuolar degeneration and necrosis of epithelial cells of the kidney were observed. Cattle that received daily doses of 4g kg-1 body weight for 24 days showed no clinical signs. In summary, this is the first report that N. stannea contains monofluoroacetate and causes sudden death in cattle.

Hypomagnesemia in beef cattle

“…In Uruguay, the most frequent causes of sudden death in cattle, which must be differentiated from hypomagnesemia in beef cattle, include ruminal bloat (Moraes et al 1993, Rivero et al 2000, poisonings by plants containing hydrocyanic acid or nitrites and nitrates (Riet-Correa et al 2009, García y Santos & Capelli 2016), organophosphorus compounds or chlorinated insecticides, urea, ionophore antibiotics, electrocution by lightning or electric shock (Constable et al 2017), vitamin E and selenium deficiency (Rivero et al 1989, Rodríguez et al 2018 and some infectious diseases such as anthrax (Bacillus anthracis), blackleg (Clostridium chauvoei) (Matto et al 2009) and bacillary hemoglobinuria (Clostridium haemolyticum) (Navarro et al 2017). Plants containing fluoroacetic acid, which in other countries are the main cause of sudden death associated with exercise (Vasconcelos et al 2008, Riet-Correa et al 2009, Lee et al 2012, Lima et al 2016, Arruda et al 2017 have not been described in Uruguay.…”

Plantas cardiotóxicas para ruminantes no Brasil

“…Os surtos ocorrem principalmente durante a estação seca, entre junho e agosto, quando a planta está em brotação. A toxicidade da planta foi demonstrada em bovinos e ovinos pela administração de folhas jovens (Caldeira et al 2016, Arruda et al 2017. A evolução da intoxicação é aguda ou hiperaguda, dependendo da quantidade de planta ingerida.…”

“…Experimentalmente em bovinos, doses de 15g/kg produziram sinais clínicos seguidos de recuperação. A menor dose que provocou a morte de bovinos foi 20g/kg (Arruda et al 2017).…”

“…Experimentalmente em bovinos, doses de 15g/kg provocaram apenas sinais clínicos com consequente recuperação dos animais. Doses entre 20-30g/kg provocaram sinais clínicos e morte (Arruda et al 2017).…”

“…Na intoxicação por P. aeneofusca descreveramse lesões inespecíficas no coração, tais como áreas difusas de hemorragia, edema das células de fibras de Purkinje e necrose coagulativa de fibras miocárdicas, com fibras em cariólise ou picnose, aumento da eosinofilia citoplasmática e perda das estriações transversais. Nos miocardiócitos podem ser observados vacúolos intranucleares discretos com marginalização da cromatina e nos espaços intersticiais pode haver edema discreto, depósitos de fibrina e infiltração de células mononucleares (Brito et al 2016, Arruda et al 2017. Possivelmente essas lesões também podem ser encontradas em outras intoxicações por plantas que contêm MFA.…”