Spontaneous poisoning by larvae of Perreyia flavipes (Pergidae) in sheep

Abstract

RESUMO.-[Intoxicação espontânea por larvas deAlthough there were 11 cattle in the same paddock, none of them was affected. High numbers of compact masses containing up to 150 larvae were scattered in the paddock where the animals were grazing. Most affected sheep showed severe apathy during 24-36 h before death, but weakness, muscular tremors and depression were also observed. Necropsy was performed on six sheep and the main macroscopic lesions were hemorrhages in the subcutaneous tissues, endocardium, gallbladder wall, and abomasal mucosa. In all animals was found hydrothorax, hydropericardium, ascites, and mild jaundice. Edema in the abomasal folds, mesentery, perirenal tissues, and gallbladder wall were also seen. The livers were yellowish with disseminated pinpoint hemorrhages in the parenchyma and had an enhanced lobular pattern. Perreyia flavipes larval body fragments and heads were found in the forestomach contents of the six sheep. Feces were scant, dry and formed balls coated by mucus and streaks of blood. Similar contents were also present at the end of the cecum. Prominent microscopic lesions included severe and diffuse periacinar or massive necrosis of hepatocytes associated with multifocal random hemorrhages. Diffuse necrosis of lymphoid follicles in lymph nodes and Peyer´s patches, lymphoid depletion and necrosis in germinative centers of the spleen, and diffuse vacuolization in the renal tubular epithelia were also seen. Edema nas pregas do abomaso, mesentério, tecidos perirenais e parede da vesícula biliar também foram observados. Os fígados estavam amarelados, com petéquias disseminadas no parênquima e padrão lobular aumentado. Fragmentos de corpos e cabeças de larvas de Perreyia flavipes foram encontrados nos conteúdos ruminais dos seis animais. O conteúdo da porção final do cólon, ceco e reto estava seco, com muco aderido e estrias de sangue. Necrose de hepatócitos periacinar ou massiva associada com hemorragias multifocais aleatórias foi o principal achado histológico, mas também havia necrose difusa em folículos linfóides nas placas de Peyer e linfonodos, depleção linfóide e necrose em centros germinativos no baço e vacuolização no epitélio tubular renal.

Perreyia flavipes larvae toxicity

“…Similar results were reported for toxicity of Lophyrotoma interrupta and Arge pullata larvae to ruminants , Thamsborg et al 1987. As previously suggested (Raymundo et al, 2008), sheep were more susceptible to P. ϔlavipes larvae toxicity than were cattle, in which the STD was reported to be 40g/kg . Neuromuscular disorders are common to many diseases and may be linked to hypoglycemia in association with hepatic detoxicant agents (Radostits et al 2002).…”

“…Clinicopathological ϐindings were comparable to those observed in spontaneous P. ϔlavipes poisoning in sheep (Raymundo et al 2008. The smallest toxic dose (STD) of Perreyia ϔlavipes larvae to sheep was 7.5 g/kg.…”

“…Larvae have been linked to spontaneous poisoning and deaths in different species and countries including the following: larvae of Lophyrotoma interrupta (Pergidae) poisoning cattle and sheep in Australia (Da-dswell et al 1985, larvae of Arge pullata (Argidae) poisoning sheep and goats in Denmark (Thamsborg et al 1987), larvae of Perreyia lepida (Pergidae) suspected of poisoning pigs in Brazil (Camargo, 1955 ), and larvae of Perreyia ϔlavipes (Pergidae) poisoning cattle and sheep in Uruguay (Dutra 1997 as well as cattle (Raymundo et al . 2009, Soares et al 2008, sheep (Raymundo et al 2008) and pigs (Jonck et al 2010) in Brazil. Experimental intoxication by Perreyia ϔlavipes larva e has been conducted in pigs (Soares et al 2001), cattle and sheep (Dutra 1997).…”

Intoxicação espontânea pelas larvas de Perreyia flavipes em bovinos no Estado de Santa Catarina, Brasil

“…Ocorreram outros surtos de intoxicação pelas larvas de P. flavipes em bovinos (SOARES et al, 2008) e ovinos (RAYMUNDO et al, 2008) no mesmo período no Rio Grande do Sul. SOARES et al (2008) relacionaram o aumento do número de larvas de P. flavipes no ambiente e, conseqüentemente, os surtos de intoxicação, à baixa precipitação pluviométrica no final do ano de 2005 e à alta precipitação no início de 2006.…”

“…A intoxicação natural pelas larvas da P. flavipes foi descrita em bovinos no Uruguai (DUTRA, 1997) e no Rio Grande do Sul (SOARES et al, 2008). Experimentalmente, as larvas se mostraram tóxicas para suínos na dose de 10g kg -1 (SOARES et al 2001), bovinos na dose de 40g kg -1 (DUTRA,1997) e ovinos na dose de 7,5g kg -1 (RAYMUNDO, 2008).…”