Reliable protocols for short-term anesthetics are essential to safeguard animal welfare during medical investigations. The aim of the study was to assess the adequacy and reliability of an anesthetic protocol and to evaluate physiological and clinical responses, in relation to the drug plasma concentrations, for pigs undergoing short-term anesthesia. A second aim was to see whether an intravenous dosage could prolong the anesthesia. The anesthesia was induced by an intramuscular injection of dexmedetomidine, tiletamine zolazepam, and butorphanol in 12 pigs. In six of the pigs, a repeated injection intravenously of one-third of the initial dose was given after one hour. The physiological and clinical effects from induction to recovery were examined. Plasma concentrations of the drugs were analyzed and pharmacokinetic parameters were calculated. Each drug's absorption and time to maximal concentration were rapid. All pigs were able to maintain spontaneous respiration. The route of administration did not alter the half-life of the drug. The results suggest that intramuscular administration of the four-drug combination provides up to two hours of anesthesia with stable physiological parameters and an acceptable level of analgesia while maintaining spontaneous respiration. A repeated intravenous injection may be used to extend the time of anesthesia by 30 min.

Physiological and Clinical Responses in Pigs in Relation to Plasma Concentrations during Anesthesia with Dexmedetomidine, Tiletamine, Zolazepam, and Butorphanol.

Pinniped populations around the world increased rapidly after hunting and culling during the nineteenth and twentieth centuries ended. Some believe that pinnipeds are now preventing the recovery of certain fish populations, and that controlling pinniped population abundance using lethal measures such as harvesting or by non-lethal means like contraception could recover fish populations. It is unclear, however, how effective and how long it would take for such methods of population control to bring numbers of pinnipeds down to target levels. We used sex- and age-structured population models to estimate how quickly harbor seal (Phoca vitulina) abundance in British Columbia, Canada, could be reduced by 50%, through combinations of lethal removals and sterilization of adult females. Models were fit to seal abundance, demographic, and harvest data collected between 1879 and 2014. Simulation modeling suggests reliance on contraception exclusively is unlikely to reduce the current harbor seal population (numbering ~100,000) by 50% within 25 years, and would result in more variable outcomes, compared to lethal removals. Contraception could be combined with harvesting to maintain a target abundance of harbor seals (although captive studies with harbor seals are needed to confirm the efficacy of contraception). Our simulation modeling approach provides a useful framework to assess how non-lethal measures could be integrated into policies that promote active population control of harbor seal numbers. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/jwmg.22400

Comparing lethal and non‐lethal methods of active population control for harbor seals in British Columbia

The overall aim of the present thesis was to improve the welfare of animals in research by refining the perioperative nursing and anaesthesia care of growing pigs in accordance with the 3Rs, replace, reduce and refine.
Forty-six pigs were trained during a 14-day acclimatisation period to accept blood and urine sampling and ultrasound examination. A polymer coated catheter for repeated blood sampling from the jugular vein was assessed. The effects of zolazepam-tiletamine and medetomidine (ZTMe) was compared with midazolam, ketamine and fentanyl (MiKF) regarding the quality of induction and physiological variables in a subsequent total intravenous anaesthesia (TIVA) with MiKF. A combination of zolazepam-tiletamine, dexmedetomidine and butorphanol (ZTDeB) intended for short-term anaesthesia was evaluated and physiological responses and drug plasma concentrations were examined. An artificial intelligence (AI) technology based on image vision was adapted for monitoring of the activity prior to anaesthesia and post-anaesthesia during treatment with transdermal fentanyl or buprenorphine injections. Facial expression was scored and plasma concentrations of the drugs were analysed.
The training enabled blood and urine sampling and ultrasound examination without restraints. It was possible to collect blood from the catheters for up to ten days. ZTMe had better results than MiKF in areas such as shorter induction time, better intubation scoring results and less adjustment and amount of TIVA required for up to six hours of TIVA. ZTDeB provided two hours of anaesthesia with stable physiological variables and spontaneous breathing. The plasma concentration profile of the drugs was in line with the duration of the effect. Measurement of activity in pigs with the AI technique was encouraging. Both opioids, at the doses used, resulted in plasma concentrations above the suggested therapeutic levels. Assessment of facial expressions was time consuming and several factors influenced the result.
In summary, the results showed that nursing interventions, adjustment of anaesthesia techniques and the use of AI technology for the measurement of activity can contribute to stress-free handling and improved animal welfare in growing pigs according to the 3Rs.

Nursing and anaesthesia care of growing pigs

Increasing attention is currently being given to fetal and neonatal anesthesia and analgesia by members of the medical and veterinary professions and animal research community. While interventions are rarely carried out on the fetus prior to labor in veterinary clinical practice, the use of invasive surgical procedures in animal models has been an integral part of fetal and neonatal research for many decades. Due to a similar degree of neurologic maturation at birth, sheep and nonhuman primates are commonly used to advance the clinical management of human infants before, during and after birth and to refine surgical techniques and therapies for in utero procedures in human fetuses. While large animal species represent the majority of the published maternal:fetal surgical models, intracranial injection and electroporation of fetuses is increasingly used for gene transfer during surgical exposure of the gravid uterus and has been described in rodents and ferrets. This chapter is intended for use by investigative groups, veterinarians, and animal care professionals utilizing these animal models in the research setting. It reviews current literature and highlights key concepts related to the use of anesthetics and analgesics in the pregnant dam, the fetus and the newborn, including considerations and rationale for drug selection and supportive care. 

Anesthesia and analgesia in the fetus and neonate

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.

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

The overabundant populations of wildlife have caused many negative impacts, such as human‐wildlife conflicts and ecological degradation. The existing approaches like injectable immunocontraceptive vaccines and lethal methods have limitations in many aspects, which has prompted the advancement of oral immunocontraceptive vaccine. There is growing interest in oral immunocontraceptive vaccines for reasons including high immunization coverage, easier administration, frequent boosting, the ability to induce systemic and mucosal immune responses, and cost‐effectiveness. Delivery systems have been developed to protect oral antigens and enhance the immunogenicity, including live vectors, microparticles and nanoparticles, bacterial ghosts, and mucosal adjuvants. However, currently, no effective oral immunocontraceptive vaccine is available for field trials because of the enormous development challenges, including biological and physicochemical barriers of the gastrointestinal tract, mucosal tolerance, pre‐existing immunity, antigen residence time in the small intestine, species specificity and other safety issues. To overcome these challenges, this article summarizes achievements in delivery systems and contraceptive antigens in oral immunocontraceptive vaccines and explores the potential barriers for future vaccine design and application.

Gangshi Li

Papers

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

Oral immunocontraceptive vaccines: A novel approach for fertility control in wildlife