Aldicarb Toxicosis in a Flock of Sheep

Abstract

Abstract. Abstract. Aldicarb toxicosis was diagnosed in 200 sheep that died suddenly. Carbamate insecticide toxicosis Aldicarb toxicosis was diagnosed in 200 sheep that died suddenly. Carbamate insecticide toxicosis was suspected based on observed clinical signs (hypersalivation, diarrhea, urination, paddling, seizures, miosis, was suspected based on observed clinical signs (hypersalivation, diarrhea, urination, paddling, seizures, miosis, and deaths occurring within 1 hour). Tissue samples were submitted from 4 Columbian ewes for pathologic and deaths occurring within 1 hour). Tissue samples were submitted from 4 Columbian ewes for pathologic and analytical evaluation. Severe diffuse pulmonary edema was observed on gross and histologic examination. and analytical evaluation. Severe diffuse pulmonary edema was observed on gross and histologic examination. Inhibition of cholinesterase activity in retina (21.2-68.1% of normal activity, n = 3), brain (40.6-45.6% of normal activity, n = 3), and whole blood (27% of normal activity, n = 3), and whole blood (27% of normal activity, n = 1) supported a diagnosis of carbamate 1) supported a diagnosis of carbamate toxicosis. Reversal of brain and whole blood cholinesterase activities (reactivation factor > 1.4) following an toxicosis. Reversal of brain and whole blood cholinesterase activities (reactivation factor > 1.4) following an in vitro 1 hour incubation at 37 C was also consistent with carbamate poisoning. Aldicarb toxicosis was confirmed following its detection in rumen contents at 1.5, 5.5, and 334 ppm using both high-pressure liquid chromatography with UV detection and gas chromatography with nitrogen/phosphorus detection. raphy with UV detection and gas chromatography with nitrogen/phosphorus detection.Aldicarb (2-methyl-2[methylthio]propionaldehyde O-[methylcarbamoyl]-oxime) (Temik®) is a highly toxic carbamate insecticide. Carbamate insecticides are potent reversible inhibitors of acetylcholinesterase activity. A toxic dose of aldicarb produces severe cholinergic signs including salivation, urination, defecation, ataxia, dyspnea, seizures, and death. The onset of clinical signs is rapid, and the severity is dependent on the dose, route of exposure, and species involved.

Novel effects of memantine in antagonizing acute aldicarb toxicity: Mechanistic and applied considerations

“…Carbamate insecticides are considered safer than organophosphate (OP) insecticides because they produce poisoning by virtue of reversible inhibition of acetylcholinesterase (AChE). Aldicarb, which is not only one of the most toxic carbamates, but also more toxic than several OP insecticides, has recently been encountered in several accidental poisonings in animals [Spierenburg et al, 1985;Dorman et al, 1990;Kerr et al, 19911 as well as in humans [Goes et al, 1980;Lee and Ransdell, 1984;Parks et al, 1987;Goldman et al, 19901. Although the mechanism of toxic action of aldicarb is reported to be similar to other carbamate insecticides, i.e., reversible AChE inhibition at the synapses and neuromuscular junctions [Casida, 1963;O'Brien, 1967;Cambon et al, 19791 leading into accumulation of acetylcholine, the toxic manifestations differ very widely. For example, carbofuran, propoxur, and carbaryl produced toxic signs involving central as well as peripheral nervous systems [Gupta andKadel, 1989a,b, 1990b1, whereas, aldicarb in preliminary studies exhibited signs predominantly of the peripheral nervous system.…”

Intoxicação por aldicarb ("chumbinho"): I. Estudo das alterações post mortem microscópicas em cães e gatos - II. Avaliação dos efeitos tóxicos agudos em camundongos

“…Em todos estes casos, as intoxicações tiveram caráter intencional e os animais apresentavam indícios do agente tóxico no conteúdo gástrico ou em alimentos utilizados supostamente como iscas para este propósito criminoso. Em seres humanos que vieram a óbito após exposição oral ao aldicarb, o achado das granulações em conteúdo gástrico durante o procedimento necroscópico também foi relatado (PROENÇA et al, 2004), bem como no conteúdo ruminal de ovelhas (DORMAN et al, 1992), auxiliando na condução da investigação diagnóstica.…”

“…O quadro de intoxicação por aldicarb é semelhante ao promovido pelos demais praguicidas anticolinesterásicos, mas, por se tratar de um agente extremamente tóxico, tende a iniciar seus efeitos rapidamente, podendo levar o paciente ao óbito em poucos minutos após a exposição oral. A morte pode ocorrer dentro de minutos a horas após a exposição e é atribuída principalmente à excessiva secreção pulmonar, constrição bronquiolar e paralisia respiratória (DORMAN et al, 1992).…”

“…Grendom, Frost e Baum (1997) citaram a ocorrência de alterações post mortem compatíveis com quadro de hipóxia aguda em ovelhas, com presença de espuma em vias aérea superiores (alterações observadas em 8 das 9 ovelhas necropsiadas). Ainda em ovelhas que vieram a óbito após intoxicação pelo aldicarb, os achados foram semelhantes, incluindo o edema pulmonar e grande quantidade de espuma em traquéia em todos animais necropsiados (4 animais) e, microscopicamente, a presença de severo edema alveolar agudo difuso em todos os animais avaliados (3 animais) (DORMAN et al, 1992).…”

“…Remetendo também às alterações pulmonares, Lobo Jr. (2003) destaca a ocorrência de hemorragia à necropsia de cães, além do achado do agente tóxico em meio ao conteúdo gástrico dos animais. Dorman et al (1992) atentam para a ocorrência comum de edema pulmonar nas intoxicações pelo aldicarb.…”