Comparison of tiletamine and zolazepam pharmacokinetics in tigers (Panthera tigris) and leopards (Panthera pardus): Do species differences account for adverse effects in tigers?

Current practice for the chemical immobilisation of non-domestic feline species: An online survey study

BACKGROUND

Safe chemical immobilisation of wild felids is essential for both conservational management and clinical purposes. However, little is known about drug protocols and current practice.

METHODS

This study was designed as an online survey based on a questionnaire. Descriptive/correlation statistics and analysis of proportions were used for data analysis.

RESULTS

The preferred immobilisation technique was the use of darts (37% of the respondents), while the most popular drug combination was a mixture of benzodiazepines, alpha-2 adrenoreceptor agonists and dissociative anaesthetics (27%). The inclusion of ketamine in the drug mixture was associated with a quicker anaesthetic onset, as estimated by the participants (p < 0.001). Common complications were prolonged recovery (46%), bradycardia (35%), hypoventilation (32%), hypothermia (26%) and arousal (26%). Commonly encountered problems were inappropriate equipment (39%), lack of suitable drugs (27%) and inadequate knowledge of species-specific pharmacology (29%) and physiology (24%).

LIMITATIONS

Incomplete adherence to the Checklist for Reporting Results of Internet E-Surveys is acknowledged.

CONCLUSIONS

Drug protocols including both alpha-2 adrenoreceptor agonists and dissociative anaesthetics are preferred in wild felids, and the inclusion of ketamine may be useful to achieve a quick onset. Equipment/drug availability and species-specific knowledge are potential areas of improvement to improve wild felid anaesthesia.

Dexmedetomidine and ketamine simultaneous administration in tigers (Panthera tigris): pharmacokinetics and clinical effects

Background

The study determines the pharmacokinetic profiles of dexmedetomidine (DEX), ketamine (KET) and its active metabolite, norketamine (NORKET), after simultaneous administration. Moreover, the study evaluates the sedative effects of this protocol, its influence on the main physiological variables and the occurrence of adverse effects.

Methods

Eighteen captive tigers were initially administered with a mixture of DEX (10 µg/kg) and KET (2 mg/kg) by remote intramuscular injection. In case of individual and specific needs, the protocol was modified and tigers could receive general anaesthesia, propofol or additional doses of DEX and KET.

Results

Based on the immobilisation protocol, nine animals were assigned to the standard protocol group and the other nine to the non-standard protocol group. Higher area under the first moment curve (AUMC_0-last) and longer mean residence time (MRT_0-last) (P<0.05) were observed in the non-standard protocol group for DEX, KET and NORKET, and higher area under the concentration-time curve from administration to the last measurable concentration (AUC_0-last) only for KET. The KET metabolisation rate was similar (P=0.296) between groups. No differences between groups were detected in terms of stages of sedation and recoveries. All physiological variables remained within normality ranges during the whole observation period. During the hospitalisation period, no severe adverse reactions and signs of resedation were observed.

Conclusion

The simultaneous administration of 10 µg/kg of DEX and 2 mg/kg of KET can be considered an effective protocol for chemical immobilisation of captive tigers, along with dosage adjusments or when other drugs are needed.

Validation of an HPLC assay for determination of Telazol in pregnant pigs: application to placental transfer study

Anesthetics utilized for the immobilization of pregnant mammals are prone to crossing the placental barrier and cause adverse effects to the fetuses. In this study, we develop a facile method employing high performance liquid chromatography (HPLC) for the study of Telazol crossing the placental barrier of pregnant pigs. The method mainly relies on the efficient extraction strategy that includes the mobile phase composed of 10 mM ammonium acetate aqueous solution-acetonitrile (1:4, v/v). When the injected dose of Telazol is 10 mg/kg (5 mg/kg of each constituent drug, zolazepem and tiletamine), zolazepam can cross the placental barrier as it is detected in both uterus and umbilical cord with approximately the same content. Conversely, tiletamine is detected in neither uterus nor umbilical cord, indicating the absence of placental transfer of tiletamine. The different absorption rates of the two dosage-equal compounds by pigs are found to be the main cause of their different abilities to cross the placental barrier.

A comprehensive and sensitive method for hair analysis in drug-facilitated crimes and incorporation of zolazepam and tiletamine into hair after a single exposure

Hair is a highly relevant specimen that is used to verify drug exposure in victims of drug-facilitated crime (DFC) cases. In the present study, a new analytical method involving ultrahigh-performance liquid chromatography-tandem mass spectrometry was developed for determining the presence of model drugs, including zolazepam and tiletamine and their metabolites in hair specimens from DFCs. The incorporation of zolazepam and tiletamine into hair after a single exposure was investigated in Long-Evans rats with the ratio of the hair concentration to the area under the curve. For rapid and simple sample preparation, methanol extraction and protein precipitation were performed for hair and plasma, respectively. No interference was observed in drug-free hair or plasma, except for hair-derived diphenhydramine in blank hair. The coefficients of variance of the matrix effects were below 12%, and the recoveries of the analytes exceeded 70% in all of the matrices. The precision and accuracy results were satisfactory. The limits of quantification ranged from 20 to 50 pg in 10 mg of hair. The drug incorporation rates were 0.03 ± 0.01% for zolazepam and 2.09 ± 0.51% for tiletamine in pigmented hair. We applied the present method to real hair samples in order to determine the drug that was used in seven cases. These results suggest that this comprehensive and sensitive hair analysis method can successfully verify a drug after a single exposure in crimes and can be applied in forensic and clinical toxicology laboratories.