Anaesthesia, sedation and transportation of juvenile Menidia estor (Jordan) using benzocaine and hypothermia

Anaesthesia, sedation and transportation of the Atherinopsid, Menidia estor, were investigated using benzocaine, hypothermia and combinations of the two. The optimum dose rates of benzocaine for sedation of juvenile Chirostoma estor were 15 and 18 mg L⁻¹. When hypothermia was used alone, stable sedation of C. estor was induced at 15 and 12°C, with no mortalities and full recovery after about 8 min. There was synergism when benzocaine and hypothermia were combined, with the optimal combination being at 15°C and 12 mg L⁻¹ benzocaine. Successful transportation was conducted over 3.5 and 8.5 h using combined benzocaine and hypothermia. Aloe vera extract used in the transportation medium reduced scale loss. This work has, for the first time, defined a systematically derived system of safe, long distance, live transportation of this species and others of the genus Menidia.     

A review of the general pharmacology of ketamine and its clinical use for injectable anaesthesia in horses

Ketamine is the most commonly used injectable anaesthetic in horses. Combinations of ketamine have been used to produce short durations of anaesthesia or as total intravenous anaesthesia (TIVA) for longer diagnostic or surgical procedures. In recent years, ketamine has been used for pain management due to its effectiveness in producing analgesia at subanaesthetic doses. This paper provides a review of the pharmacological effects of ketamine in general and its clinical use for injectable anaesthesia and pain management in horses.     

Sedative effects of an intramuscular or intranasal combination of sufentanil and midazolam in New Zealand White rabbits

ObjectiveTo evaluate the sedative effects of a combination of sufentanil and midazolam administered intramuscularly (IM) or intranasally (IN) prior to induction of anesthesia with propofol in New Zealand White rabbits.Study designProspective, randomized, crossover, experimental study.AnimalsA total of 11 adult New Zealand White rabbits.MethodsSufentanil (0.5 μg kg^–1) and midazolam (2 mg kg^–1) were administered to rabbits via IM or IN route. The righting reflex was assessed, and sedation was scored. Heart rate, respiratory rate (f_R) and temperature were recorded prior to treatment administration and after loss of the righting reflex.ResultsMeasured variables remained within normal physiologic ranges for all rabbits. The only statistically significant change was for f_R, which was significantly lower after sedation for both routes. The time to loss of righting reflex was 14.8 ± 6.5 and 12.5 ± 7.4 minutes and sedation scores were 6 (4–8) and 7 (6–8) for IM and IN routes, respectively, with no difference between treatments. No adverse effects were observed during the experimental period.Conclusions and clinical relevanceSufentanil combined with midazolam administered either IM or IN resulted in moderate to deep sedation in New Zealand White rabbits at the dose rates studied.     

Serum concentrations and effects of detomidine delivered orally to horses in three different mediums

Objective To compare the effect of orally delivered detomidine on head posture when administered alone or in combination with two different food items, and to determine the serum concentrations of detomidine after oral delivery. Study Design Prospective randomized experimental study. Animals Fifteen adult grade mares weighing 328–537 kg. Methods The horses were randomly assigned to one of the three treatment groups (five horses each). The groups were given detomidine (0.06 mg kg^?1): alone; mixed with 3 mL of an apple sauce and gum mixture; or mixed with 3 mL molasses. Head droop, measured before treatment and at 15, 30, 45, 60, 75, 90, and 105 minutes after treatment, was used to evaluate sedation. Yohimbine (0.1 mg kg^?1 IV) was administered after the 90‐minute evaluation. Blood samples were collected from the detomidine‐alone group before treatment and at 15, 30, 45, 60, 75, and 90 minutes after treatment. Sera were analyzed for detomidine equivalent concentrations by an ELISA. Head droop percentages were compared using a repeated measures analysis of variance. Results Significant mean head droop developed in each treatment group by 30 minutes and persisted until reversal with yohimbine. After yohimbine administration, head positions returned to 87–91% of pre‐treatment levels. There were no significant differences among the oral treatment groups at any time. Mean serum detomidine equivalents increased slowly until 45‐minute post‐administration, but never exceeded 30 ng mL^?1. Conclusions Orally administered detomidine results in measurable serum drug concentrations using any of the delivery mediums investigated, and can be expected to produce profound head droop in horses approximately 45 minutes after administration.     

Comparison of Computed Tomographic Images of Birds Obtained With Sedation vs General Anesthesia

Computed tomography (CT) is an increasingly available and valuable imaging modality for the diagnosis of companion avian pets. Previously, CT studies of birds required general anesthesia with inhalant anesthetics. Owing to the risks associated with general anesthesia, the authors of this article investigated the effect of sedation on birds during a CT examination. In this study, 10 psittacine birds were imaged using a 40-slice helical CT scanner. Birds were sedated with midazolam and butorphanol and placed in a positioning device. Following the initial study, birds were removed from the device and placed under general anesthesia with isoflurane. A second study was then performed. Two radiologists, blinded to the identity of the birds and partially blinded to the conditions of the study, reviewed the images. Studies were evaluated using a questionnaire consisting of 18 questions. Each question was scored on a Likert scale. A Wilcoxon signed rank test compared scores of sedated and anesthetized birds. A significant difference (P = 0.05) between sedated and anesthetized studies was found for 2 of 18 (11.1%) questions for radiologist 1 and 1 of 18 (5.5%) questions for radiologist 2, with differences identified in the scleral ossicles and the femoral heads. Interrater agreement for all questions using a linearly weighted κ was 0.334 and 0.311 for sedated and anesthetized birds, respectively, indicating fair agreement. The interrater agreement, excluding the head and musculoskeletal system, was 0.381 for sedated animals, indicating fair agreement, and 0.404 for anesthetized birds, indicating moderate agreement. Based on our results, performing CT studies in birds with sedation is a viable alternative to studies performed under general anesthesia.     

Comparison between the effects of postanesthetic xylazine and dexmedetomidine on characteristics of recovery from sevoflurane anesthesia in horses

Objective

To compare postanesthetic xylazine and dexmedetomidine on recovery characteristics from sevoflurane anesthesia in horses.

Comparison of sedation and mechanical antinociception induced by intravenous administration of acepromazine and four dose rates of dexmedetomidine in donkeys

Objective

To assess and compare the sedative and antinociceptive effects of four dosages of dexmedetomidine in donkeys.

Preliminary Results of Behavioral and Cardiopulmonary Effects of a Constant Rate Infusion of Remifentanil–Xylazine for Sedation in Horses

Standing surgical procedures are performed commonly in horses under sedation. The use of a xylazine and remifentanil combination has not been investigated in horses. We proposed to evaluate behavioral and cardiopulmonary effects of an intravenous (IV) infusion of xylazine with remifentanil for sedation in horses. Xylazine (0.8 mg/kg IV) followed in 3 minutes by remifentanil (0.0005 mg/kg IV), and a constant rate infusion of xylazine and remifentanil (0.65 mg/kg/h; 0.0225 mg/kg/h, respectively) was administered in three horses. Heart rate, respiratory rate (RR), arterial blood pressures, quality of sedation, pH, partial pressure of arterial CO₂ (PaCO₂), partial pressure of arterial O₂ (PaO₂), ataxia, sedation, and sedation overall outcome were assessed. Heart rate and RR remained within normal values during sedation without significant changes from baseline. Systolic, mean, and diastolic arterial blood pressures were increased during sedation. There were no significant changes in pH, PaCO₂, and PaO₂. Sedation developed immediately after injection of xylazine in the three horses but did not increase after remifentanil bolus or IV infusion of both drugs. None of the mares had ataxia. Adverse effects during and after sedation were present: excitement, increase in locomotor activity, and decrease in the gastrointestinal motility. The combination of xylazine and remifentanil sedation protocol produces adverse effects. This protocol cannot be recommended for clinical conditions, at the described doses.