PubMed1997
The objective of this work was to determine optimal treatment regimens for organophosphate (OP) or carbamate insecticide toxicoses in fowl using the antidotes atropine sulfate and pralidoxime chloride (2-PAM). Broiler chicks in treatment groups, each comprising 3 replicates of 6-7 birds/replicate, were gavaged on a body weight (BW) basis with the OP and carbamate insecticides, diazinon and methomyl, respectively, at lethal dosages. Treatment groups were injected with either or both of the antidotes at various dosages as soon as clinical signs appeared. Birds appearing healthy 24 h thereafter were regarded as having been treated successfully. At a dosage of 100 mg/kg BW, atropine was mildly toxic and at 200 mg/kg 2-PAM was severely toxic (but not lethal), whereas at dosages of 50 and 100 mg/kg BW, respectively, the antidotes were at their most effective. With diazinon, atropine alone was only partially effective (12/20 survivors), whereas 2-PAM was extremely efficacious. (20/20 survivors); the combination of the 2 antidotes at 2 dosages was slightly less effective (19/20 survivors) than 2-PAM alone. For methomyl toxicity, atropine was largely successful (18/20 survivors), whereas 2-PAM was mostly unsuccessful (10/20 survivors); the combination at high dosage was less effective (15/20 survivors) than atropine alone, but at a low dosage the combination was the most successful (20/20 survivors). The results indicate that anticholinesterase insecticide toxicoses in fowl should not be treated according to textbook recommendations, and antidotal dosage with atropine should be up to 100 times greater than is commonly recommended. The specific cause of the toxicoses should ideally be determined before treatment is given, but as this is often unknown, a combination of antidotes may be the optimal treatment protocol.