Evaluation of Intravenous Lidocaine Overdose in Chickens (Gallus domesticus)

Objective- To evaluate the total toxic dose of lidocaine and serum lidocaine concentrations resulting in clinical signs of toxicity in chickens. Design- Experimental study Animals- Eight healthy, female, 55-week-old chickens (Lohman breed) weighing 1.45 ± 0.17 kg (mean ± SD) Procedure- A loading dose of 2% lidocaine (4 mg/kg) was administered IV, followed by a constant-rate infusion at a dose of 8 mg/kg/min using a syringe pump. Times to onset of convulsion and/or respiratory arrest were recorded and the total toxic dose of lidocaine was determined. Blood sample was withdrawn for lidocaine analysis at the onset of the major signs of intoxication (convulsion or respiratory arrest). Results- The total toxic dose of lidocaine required to produce systemic toxicity and corresponding serum lidocaine concentration were 28.96 ± 6.21 mg/kg and 38.5 ± 10.4 µg/mL, respectively. Conclusions and clinical relevance- Based on the results of this study, greater doses of lidocaine are needed to produce toxic manifestations in chickens as compared with mammals.