Lesões perinatais em cordeiros induzidas pela administração de Tetrapterys multiglandulosa (Malpighiaceae) a ovelhas em diferentes estágios de gestação

Abstract

ABSTRACT.-Cardinal S.G., Aniz A.C., Santos B.S., Carvalho N. In order to verify the effects of non-lethal doses of Tetrapterys multiglandulosa on ovine fetuses, experimental poisoning in sheep at different days of pregnancy was performed. Green leaves of shooting plants were administered to 9 pregnant ewes divided into three experimental groups. Sheep from Group 1 received four doses of 5g/kg of fresh leaves for 4 days; those from Group 2 received 10g/kg for 2 days; Group 3 sheep received a dose of 20g/kg for one day, and sheep from Group 4 did not receive the plant and served as negative controls. To check the plant toxicity, a male sheep (positive control) received 5g/ kg until the onset of clinical signs. No signs of poisoning were observed in pregnant ewes; three lambs died 1-5 days after birth, and a fourth lamb died within 3 months after have been born. The positive control died after 38 days of daily consumption of the plant, presenting tachypnea, tachycardia, drowsiness, incoordination, weakness and sudden death. All four dead lambs and the positive control sheep were necropsied. The gross lesions were whitish areas in the myocardium, increased lobular pattern of the liver, dark red lungs, metabolization of pericardial fat, and ruminal distention with free gas. Histological findings were cardiac fibrosis, cardiomyocyte necrosis, pulmonary congestion and edema, and spongy degeneration in subcortical cerebral white matter. Tetrapterys multiglandulosa resulted toxic for ovine fetuses at doses that were not suffient to induce clinical signs in the pregnant ewes, demonstrating that the poisoning may be a cause of death of lambs soon after birth, even several months after the ingestion of the plant has been discontinued.

Spontaneous poisoning by Ateleia glazioviana (leg. Papilionoideae) in sheep and goats in the West region of Santa Catarina

“…In the group of plants that cause cardiac lesions from subacute to chronic evolution, it could be described experimental reproduction by Tetrapterys spp. in sheep and goats (Melo et al 2001, Carvalho et al 2006, Almeida 2006, Almeida et al 2008, Cardinal et al 2010. The differential diagnosis between poisoning by these plants is based mainly on the plant disease epidemiology and their presence in the region.…”

Plantas cardiotóxicas para ruminantes no Brasil

“…Constataram-se apenas sinais clínicos discretos (Tokarnia et al 1989). Experimentalmente a intoxicação também foi reproduzida em ovinos (Riet-Correa et al 2005, Cardinal et al 2010.…”

Aborto em bovinos devido à intoxicação por Tetrapterys acutifolia (Malpighiaceae)

“…Evidências macroscópicas e histopatológicas de insuficiência cardíaca no feto e ausência de lesões placentárias observadas nos animais deste estudo, bem como em ovinos intoxicados por Ateleia glazioviana (Raffi et al 2004) e caprinos intoxicados por Tetrapterys multiglandulosa (Cardinal et al 2010) reforçam essa hipótese. Por outro lado, é difícil precisar até que ponto as lesões no SNC dos fetos contribuem para o óbito.…”

“…Tal lesão foi semelhante à descrita, inicialmente, por Tokarnia et al (1989) em bovinos intoxicados por Tetrapterys spp. que exibiam sinais clínicos de insuficiência cardíaca, e mais tarde também em ovinos intoxicados por T. multiglandulosa (Riet-Correa et al 2005, Carvalho et al 2006, Cardinal et al 2010, bem como aquela demonstrada em bovinos e ovinos, que manifestam uma síndrome letárgica, após a ingestão de altas doses de Ateleia glazioviana , Stigger et al 2001, Raffi et al 2004. Estudos recentes por microscopia eletrônica compro-varam que a espongiose do sistema nervoso é causada por edema intramielínico (Riet-Correa et al 2005), semelhante ao que ocorre na intoxicação por A. glazioviana (Raffi et al 2006).…”