Risk of burnout and depression: A survey of veterinary anaesthesia specialists in-training during COVID-19.

OBJECTIVE: To investigate risk, risk factors and effects on adherence to adequate clinical standards, of burnout and depression in veterinary anaesthesia residents. STUDY DESIGN: Closed online cross-sectional survey study. STUDY POPULATION: A sample of 89 residents registered to the European and/or the American Colleges of Veterinary An (ae)sthesia and Analgesia out of a total of 185. METHODS: A link to access an online questionnaire, which included the Maslach Burnout Inventory-Human Services Survey (MBI-HSS), the Harvard National Depression Screening Day Scale (HANDS) and 28 questions developed to assess adherence to adequate clinical standards, was sent by email to 185 residents. The three components of the MBI-HSS namely emotional exhaustion (EE), depersonalization and reduced personal accomplishment were analysed separately. Analysis of proportions and two-step regression statistical modelling were used for data analysis, and p values < 0.05 were considered statistically significant. RESULTS: The response rate was 48%. Based on HANDS and MBI-HSS scores, 49% of the residents were at high risk of both depression and burnout. These residents expressed greater concern of delivering inadequate animal care (p < 0.001), of decreased quality of supervision during COVID-19 (p = 0.038) and of negative impact of the pandemic on their training programme (p = 0.002) than residents at low-to-moderate risk. Working in a clinical environment for ≥ 60 hours/week was a risk factor for both depression (p = 0.016) and EE (p = 0.022), while female sex was a risk factor for EE only (p = 0.018). CONCLUSIONS AND CLINICAL RELEVANCE: A large proportion of residents is at high risk of depression and burnout, a scenario likely worsened by the pandemic. The findings of this study suggest that reducing the clinical workload and increasing the level of support and supervision may help to improve residents' mental health.

ISOFLURANE ANESTHESIA IN BUDWING PRAYING MANTISES (PARASPHENDALE AGRIONINA).

Praying mantises have gained increasing popularity as pets and may be anesthetized to allow morphological identification and clinical procedures. The aim of this study was to evaluate the effects and anesthetic-related complications of isoflurane in oxygen in 15 client-owned budwing mantises (Parasphendale agrionina) undergoing photographic identification. Each mantis was placed in a self-constructed anesthetic chamber and exposed to a mixture of approximately 5% isoflurane in oxygen until anesthetic induction was achieved. Time to anesthetic induction, time to recovery from anesthesia, and quality of anesthesia based on scoring of righting reflex, front legs withdrawal, and muscular tone, were evaluated and recorded, as well as the occurrence of undesired effects. In most mantises, immobility, loss of righting reflex, and myorelaxation were achieved within minutes after the beginning of isoflurane exposure and lasted a time sufficient to allow completion of the procedure. However, mantises aged ≥12 mo had longer time to anesthetic induction (4.3 ± 0.6 m), as well as shorter time to recovery (19.0 ± 8.0 m), than mantises aged <12 mo (0.8 ± 0.4 and 30.0 ± 15.0; P < 0.05). Complications were not observed, and all mantises were returned to their owner on the same evening.

Use of nociceptive threshold testing in cats in experimental and clinical settings: a qualitative review.

OBJECTIVE: The objective of this study was to review the scientific articles on the use of nociceptive threshold testing (NTT) in cats and to summarize the clinical and experimental applications in this species. DATABASES USED: Pertinent literature was searched with PubMed, Scopus, Web of Science, Universitätsbibliothek Basel (swissbib Basel Bern) and Google Scholar. The search was then refined manually based first on article titles and abstracts, and subsequently on full texts. CONCLUSIONS: Of the four classical acute nociceptive models used for NTT, thermal and mechanical are most commonly used in cats. Thermal stimulation is applicable in experimental settings and has been used in pharmacodynamics studies assessing feline antinociception. Although mechanical stimulation is currently less used in cats, in the future it might play a role in the evaluation of clinical feline pain. However, the low response reliability after stimulus repetition within a narrow time interval represents a major limitation for the clinical use of mechanical thresholds in this species. Challenges remain when thermal thresholds are used to investigate analgesics that have the potential to affect skin temperature, such as opioids and α2-adrenergic agonists, and when a model of inflammatory pain is reproduced in experimental cats with the purpose of evaluating non-steroidal anti-inflammatory drugs as analgesics.

Mandibular nerve block in juvenile Nile crocodile: a cadaveric study.

OBJECTIVE: To develop a technique for performing the mandibular nerve block in Nile crocodiles. STUDY DESIGN: Experimental cadaveric study. ANIMALS: A total of 16 juvenile Nile crocodile heads. METHODS: To study the course of the mandibular nerve, one head was dissected. Computed tomography (CT) examination was performed in two heads to identify useful landmarks. Thereafter, a hypodermic needle was inserted through the external mandibular fenestra of 17 hemimandibles (13 heads), and a mixture of methylene blue and iohexol was injected. Injection volumes were 0.5 (n = 7) and 1.0 mL (n = 10) for hemimandibles < 15 and ≥ 15 cm long, respectively. Iohexol spread and nerve staining with methylene blue were assessed with CT and anatomical dissection, respectively. Data were analysed with one-sample t test or Mann-Whitney U test. Significance was set at p < 0.05. RESULTS: Both anatomical dissection and imaging confirmed the external mandibular fenestra as a useful anatomical landmark for needle insertion. The CT images acquired after needle positioning confirmed that its tip was located on the medial bony mandibular surface formed by the fusion of the angular and coronoid bones in 100% cases. In all the hemimandibles, the rostrocaudal spread of contrast was > 23 mm. The length of the stained mandibular nerve in the temporal region and of the stained medial branch of the mandibular nerve, as well as the dorsoventral and mediolateral spread of iohexol, was greater in group 1.0 than in group 0.5 (p < 0.001). The caudal spread of iohexol was greater in group 1.0 than in group 0.5 (p = 0.01). CONCLUSIONS AND CLINICAL RELEVANCE: The technique developed in this study is feasible. Both injection volumes resulted in staining of the mandibular nerve. The spread of contrast in the anatomical region of interest may result in successful sensory block.

Effect of Insulin and Fasting Regimen on Blood Glucose Concentrations of Diabetic Dogs During Phacoemulsification.

This study aimed to compare four protocols for preanesthetic insulin administration and fasting time with respect to the variation of intraoperative blood glucose (BG) concentrations versus preanesthetic values (baseline). The patient records of dogs undergoing cataract surgery were included. Data on anesthetic protocols, comorbidities, and intraoperative complications (hyper- and hypoglycemia, hypotension, hypothermia, and bradycardia) were analyzed. The insulin/fasting protocols included (A) 12 hr fasting and half insulin dose, (B) 6 hr fasting and half insulin dose, (C) 12 hr fasting and full insulin dose, and (D) 12 hr fasting and no insulin. Forty-eight dogs were included (14 in A, 10 in B, 13 in C, and 11 in D). Protocol D resulted in a significant increase of intraoperative BG concentrations compared with baseline (P = .001), whereas in the remaining groups, the baseline BG did not differ from intraoperative values. There were no statistically significant associations between the treatment group and the occurrence of intraoperative complications or the presence of diagnosed comorbidities. In conclusion, different insulin and fasting regimen protocols may be used for diabetic patients with no apparent benefit or risk from one protocol versus another. The use of insulin before surgery results in lesser increase of BG intraoperatively as compared with preanesthetic values. However, whether this should be interpreted as better perioperative control of glycemia remains debatable.

Anesthesia and Anesthetic-Related Complications of 8 Elegant-Crested Tinamous (Eudromia elegans) Undergoing Experimental Surgery.

The aim of this study was to describe the anesthetic effects of an injectable anesthetic protocol, based on ketamine, midazolam, and medetomidine, followed by inhalational sevoflurane, in 8 elegant-crested tinamous (Eudromia elegans) undergoing experimental surgery. Initial doses for both injectable agents were tested in 1 bird and then refined with an algorithm based on the effects observed in the pilot procedure. Heart and respiratory rates, as well as nociceptive reflexes, were evaluated before anesthesia (baseline) and intraoperatively, at 10 minute intervals. The time from injection to anesthetic induction and surgical anesthesia, as well as the time from atipamezole injection to recovery, was recorded for each bird. The median doses of medetomidine and ketamine were 0.075 mg/kg and 33 mg/kg, respectively. Anesthetic induction was achieved within 10 (range, 4-45) minutes from intramuscular injection, whereas time to surgical anesthesia was 22 ±16 minutes. The baseline heart rate values were significantly higher than those measured intraoperatively at any time point (P = .001). Intraoperatively, 5 of 8 tinamous (63%) developed cardiac arrhythmias. Other encountered complications were regurgitation in 2 birds (25%), cardiac arrest in 1 bird (13%) soon after injection of the anesthetic agents, and prolonged recovery in another bird (13%), which was euthanized. Necropsy of the 2 fatal outcomes (25%) showed evidence of hepatic lipidosis in both (100%) and intramyocardial fat accumulation in 1 bird (50%). This report highlights the challenges of tinamou anesthesia. Cardiac complications are common in this species, and close monitoring of intraoperative cardiovascular variables is recommended for prompt recognition and treatment.

Quantitative sensory testing with Electronic von Frey Anesthesiometer and von Frey filaments in nonpainful cats: a pilot study.

OBJECTIVE: Measurement of sensory thresholds could represent a complementary tool to behavioural pain scores in cats. The aim of this study was to investigate the feasibility of quantitative sensory testing (QST) with the Electronic von Frey Anesthesiometer (EVF) and von Frey filaments (VFF) in healthy cats, and to assess the limits of agreement (LOA) between the two devices. STUDY DESIGN: Prospective clinical study. ANIMALS: A total of 15 client-owned healthy cats. METHODS: Two investigators (A and B) carried out the measurements independently. The EVF and the VFF were applied on the upper lip and at the level of the medial aspect of the stifle. A 1-hour interval was allowed between the sets of measurements taken by investigators A and B; each investigator repeated the entire session of measurements after 24 hours. The LOA between the EVF and the VFF were analysed with the intraclass correlation coefficient (ICC), and with the Bland Altman method. RESULTS: QST with both the EVF and the VFF was feasible in healthy cats; however, the willingness of the cats to cooperate was negatively affected by the repetition of the measurements on the second day. The presence of the cat owners seemed to facilitate the trial. There was a fair agreement between the EVF and the VFF (ICC = 0.49; 95% confidence interval: 0.13-0.70). CONCLUSIONS: and clinical relevance Our findings indicate that both EVF and VFF may be used for QST in cats. Further trials will be needed to verify the usefulness of QST with EVF and VFF in feline patients suffering from actual chronic pain.

Medetomidine-ketamine-sevoflurane anaesthesia in juvenile Nile crocodiles (Crocodylus niloticus) undergoing experimental surgery.

OBJECTIVE: To describe the anaesthetic, physiological and side effects of intramuscular (IM) medetomidine and ketamine, followed by inhalational anaesthesia with sevoflurane, in Nile crocodiles (Crocodylus niloticus). STUDY DESIGN: Observational trial. ANIMALS: Ten juvenile captive-bred Nile crocodiles undergoing surgical implantation of skeletal beads and muscular electrodes. METHODS: During preanaesthetic examination, the following variables were assessed: heart (HR) and respiratory (fR) rates, and response to palpebral, corneal and toe- and tail-pinch withdrawal reflexes. The crocodiles were injected IM with an initial combination of medetomidine and ketamine and re-evaluated at 5 minute intervals for 20 minutes, or until they appeared unresponsive. If that did not occur, the drugs were redosed according to a decision tree based on the observed effects. The righting, biting and palatal valve reflexes were assessed in the unresponsive crocodiles, and used to confirm anaesthetic induction. Anaesthesia was maintained with sevoflurane in oxygen. At the end of surgery, medetomidine was antagonized with IM atipamezole. RESULTS: The decision tree identified 0.3 mg kg-1 medetomidine and 15 mg kg-1 ketamine as a useful drug combination, which resulted in anaesthetic induction and surgical anaesthesia 16 ± 8 and 16 (25-20) minutes after injection, respectively. Compared to baseline, HR and fR significantly decreased after anaesthetic induction (p < 0.001), but then remained stable throughout surgery. Intraoperatively, cloacal temperature [27 (26-30) °C] did not change over time (p = 0.48). The total dose of atipamezole was 2 (1-3) mg kg-1 and time to recovery was 36 (20-60) minutes. Perioperative complications were not observed. CONCLUSIONS: and clinical relevance Medetomidine and ketamine, injected IM and followed by sevoflurane anaesthesia, may be regarded as a useful anaesthetic technique for juvenile Nile crocodiles undergoing minimally invasive experimental surgery.

Peri-anaesthetic mortality and nonfatal gastrointestinal complications in pet rabbits: a retrospective study on 210 cases.

OBJECTIVE: The aim of this study was to determine the incidence and the associated risk factors of peri-anaesthetic mortality and gastrointestinal complications in pet rabbits. STUDY DESIGN: Retrospective cohort study. ANIMALS: A total of 185 pet rabbits admitted to the Exotic Referal Service of Beaumont Sainsbury's Animal Hospital over the period 2009-2016. METHODS: The clinical records of the rabbits were obtained from the database. To evaluate the incidence of peri-anaesthetic mortality, three possible outcomes were considered: alive, dead or euthanized within the 72 hours following the anaesthetic event. Food intake and stool production during the first 72 hours following the anaesthetic event were evaluated to investigate the occurrence of gastrointestinal complications. Thereafter, various hypothesized risk factors, including administration of alpha-2 agonists, body weight, American Society of Anaesthesiologists classification and endotracheal intubation were tested against peri-anaesthetic mortality and gastrointestinal complications, with both univariate and multivariate binary logistic regression. RESULTS: Twenty-five out of 185 rabbits underwent two anaesthetic events; therefore, data from 210 cases were used. Of these 210 cases, six died during sedation or general anaesthesia and four (one of which euthanized) died during the first 72 postoperative hours, accounting for an actual mortality rate equal to 4.8% (95% confidence interval, 0.025-0.086). Peri-anaesthetic gastrointestinal complications developed in 77 (38%) out of the 204 anaesthetic events whose outcome was not intraoperative death (95% confidence interval, 0.314-0.446). Species-specific risk factors could not be identified for peri-anaesthetic mortality; however, the odds for post-anaesthetic gastrointestinal complications increased significantly with body weight (p = 0.01). CONCLUSIONS AND CLINICAL RELEVANCE: Our findings confirm that rabbits continue to have a higher incidence of peri-anaesthetic mortality than dogs and cats, and highlight a high risk for nonfatal peri-anaesthetic gastrointestinal complications in this species.

Sedative effects of intramuscular alfaxalone in pet guinea pigs (Cavia porcellus).

OBJECTIVE: To evaluate the efficacy and side effects of alfaxalone administered intramuscularly (IM) as a sedative agent in guinea pigs undergoing survey radiographs. STUDY DESIGN: Prospective clinical trial. ANIMALS: A total of 30 client-owned guinea pigs. METHODS: Following baseline assessments, 5 mg kg-1 alfaxalone was administered IM. Heart rate, arterial haemoglobin oxygen saturation, respiratory rate, rectal body temperature, palpebral reflex, response to toe and ear pinch, righting reflex, posture, jaw tone and reaction to manipulation were assessed before and after sedation at 5-minute intervals. The time elapsed from onset of sedation to return of locomotion and coordinated limb movements, the quality of recovery and the occurrence of undesired effects were observed and recorded. RESULTS: The mean ± standard deviation onset of sedation was 2.7 ± 0.6 minutes. The physiological variables remained within normal ranges until completion of the procedure. Palpebral reflex and responsiveness to both ear and toe pinch were maintained during sedation. Neither hypoxaemia nor hypothermia was observed. The duration of sedation was 29.3 ± 3.2 minutes. Sedation and recovery were uneventful, and adverse effects were not observed. CONCLUSIONS AND CLINICAL RELEVANCE: In conclusion, 5 mg kg-1 of IM alfaxalone represents a valuable sedation protocol for healthy guinea pigs undergoing minor noninvasive procedures. Further trials are required to investigate its cardiovascular effects, clinical usefulness in unhealthy patients and its combined use with analgesics for procedures associated with nociception.

What is the evidence? The issue of verifying correct needle position during epidural anaesthesia in dogs.

OBJECTIVES: To review the methods for verifying the needle position while performing epidural anaesthesia in dogs, and to discuss the advantages, disadvantages, usefulness and reliability of each technique in the experimental and clinical research setting. DATABASES USED: PubMed, Scopus, Google Scholar and the Basel University Library online catalogues; the latter, which was provided by the University of Berne, were used as databases. The results were filtered manually based on the titles and abstracts in order to narrow the field. CONCLUSIONS: Besides some drawbacks, including the potential side effects of contrast medium injection, which may limit its routine use in clinical patients, epidurography should still be regarded as one of the most reliable techniques to verify needle position in dogs. Ultrasonography, electrical nerve stimulation, loss of resistance and the hanging drop technique are regarded as less invasive than epidurography and, for this reason, their use may be more applicable to clinical patients. However, these methods have been described in only a few published reports, all of which involved a limited number of dogs. Finally, the detection of epidural pressure waves has been investigated more extensively in dogs, and the findings of these studies suggest that this technique may be used to verify epidural needle placement for experimental and clinical research, on condition that all the negative subjects are excluded from the study.

Combination of magnesium sulphate and ropivacaine epidural analgesia for hip arthroplasty in dogs.

OBJECTIVE: The aim of this study was to determine whether lumbosacral epidural administration of magnesium sulphate added to ropivacaine prolongs and improves perioperative analgesia, without adverse effects on motor block duration or hind limb neurological function, in dogs undergoing hip arthroplasty. STUDY DESIGN: Investigator-blind, controlled, randomized, prospective clinical trial. ANIMALS: A group of 20 client-owned dogs undergoing hip arthroplasty were allocated randomly to either group C (control, 1 mg kg-1epidural ropivacaine) or group M (magnesium, epidural injection of 1 mg kg-1 ropivacaine and 2 mg kg-1magnesium sulphate). METHODS: All dogs were premedicated with intramuscular acepromazine. General anaesthesia was induced with propofol and maintained with isoflurane in oxygen. Intraoperatively, nociception was assessed based on changes in heart rate, respiratory rate and mean arterial pressure above baseline values. Postoperatively, pain was evaluated with a Sammarco pain score, a Glasgow pain scale and a visual analogue scale (VAS). Tarlov's scale was used to quantify motor block. All dogs were evaluated at recovery and then 1, 2, 3, 4, 5 and 24 hours after that. Rescue analgesia was provided during surgery with fentanyl and, postoperatively, with buprenorphine. Groups were compared using one-way repeated-measure analysis of variance followed by the Holm-Sidak method for multiple comparison or nonparametric tests when appropriate. RESULTS: The two treatment groups did not differ (p > 0.05) with respect to intraoperative physiological variables, rescue analgesia, postoperative pain scores (Sammarco q = 1.00; Glasgow q = 3.10; VAS q = 0.50) and duration of the motor block (Tarlov's q = 2.40). CONCLUSIONS AND CLINICAL RELEVANCE: The addition of epidural magnesium to ropivacaine did not improve or prolong the analgesia provided by ropivacaine alone. Further studies are needed to determine whether an epidural magnesium dose of >2 mg kg-1 would exert better analgesia, without causing adverse effects, in dogs undergoing orthopaedic surgery.

Comparison of intratesticular lidocaine, sacrococcygeal epidural lidocaine and intravenous methadone in cats undergoing castration: a prospective, randomized, investigator-blind clinical trial.

OBJECTIVE: The objective of this study was to compare three analgesic protocols for feline castration. STUDY DESIGN: Prospective, randomized clinical study. ANIMALS: Forty-nine client-owned cats. METHODS: Cats were injected with intramuscular (IM) dexmedetomidine (15 µg kg-1) and alfaxalone (3 mg kg-1) and assigned randomly to one of three treatment groups. Group ITL (n = 15) were administered intratesticular 2% lidocaine (0.05 mL each testicle), group SCL (n = 15) a sacrococcygeal epidural injection of 2% lidocaine (0.1 mL kg-1) and group IVM (n = 19) intravenous (IV) methadone (0.3 mg kg-1), before surgery. Cardiorespiratory variables were recorded. In case of autonomic nociceptive response, IV fentanyl (2 µg kg-1) was administered. During recovery, time from IM atipamezole (75 µg kg-1, administered at the end of surgery) to sternal recumbency and to active interaction was recorded. Quality of recovery was assessed using a simple descriptive scale. Postoperative analgesia was evaluated using a visual analogue scale and the UNESP-Botucatu multidimensional composite pain scale (MCPS) at return of active interaction and then 1, 2 and 3 hours later. RESULTS: The three analgesic protocols were comparable in terms of intraoperative fentanyl and propofol requirement. Cardiorespiratory variables stayed within normal ranges in the majority of the cases, although group IVM had the lowest intraoperative respiratory rate (p = 0.0009). No differences were detected between groups in UNESP-Botucatu MCPS scores (p = 0.21). However, group ITL showed higher visual analogue scale score than group IVM (p = 0.001). Four cats enrolled in group ITL, as well as three of group SCL and one of group IVM, required rescue analgesics before the completion of pain assessment. CONCLUSIONS AND CLINICAL RELEVANCE: Intratesticular and sacrococcygeal epidural lidocaine injections could be regarded as good alternatives to systemic opioids in cats undergoing castration, although the benefits of these techniques seem to be of shorter duration than IV methadone.

Dexmedetomidine-methadone-ketamine versus dexmedetomidine-methadone-alfaxalone for cats undergoing ovariectomy.

OBJECTIVE: To compare the duration, quality of anaesthesia and analgesia, and quality of recovery of dexmedetomidine and methadone combined with either ketamine or alfaxalone. STUDY DESIGN: Randomized, prospective clinical trial. ANIMALS: A group of 44 healthy client-owned cats presenting for ovariectomy. METHODS: Cats were randomly assigned to one of the two treatment groups: DAM (n=22), which was administered intramuscularly (IM) dexmedetomidine (15 µg kg-1), methadone (0.3 mg kg-1) and alfaxalone (3 mg kg-1), and DKM (n=22), which was administered IM dexmedetomidine (15 µg kg-1), methadone (0.3 mg kg-1) and ketamine (3 mg kg-1). During anaesthesia, heart rate, respiratory rate and systolic arterial pressure were measured every 5 minutes. Cats that moved or had poor muscle relaxation were administered an additional 1 mg kg-1 of either alfaxalone (DAM) or ketamine (DKM) intravenously (IV). In cases of increased autonomic responses to surgical stimulation, fentanyl (2 µg kg-1) was administered IV. At the end of the surgery, atipamezole (75 µg kg-1) was administered IM, and the times to both sternal recumbency and active interaction were recorded. Quality of recovery was evaluated with a simple descriptive scale. The UNESP-Botucatu multidimensional composite pain scale and a visual analogue scale were used to evaluate postoperative analgesia at the return of active interaction and 1, 2 and 3 hours later. RESULTS: The additional anaesthesia and rescue fentanyl requirements were similar between groups. The quality of recovery was better in the DAM group than in the DKM group [simple descriptive scale scores: 0 (0-1) and 1 (0-3), respectively; p=0.002]. Postoperative pain scores decreased progressively over time in both groups, with no significant differences (p=0.08) between them. CONCLUSIONS AND CLINICAL RELEVANCE: Both protocols provided comparable quality of anaesthesia and analgesia and were suitable for cats undergoing ovariectomy. In combination with methadone and dexmedetomidine, alfaxalone and ketamine showed comfortable and reliable recoveries.

Alfaxalone versus alfaxalone-dexmedetomidine anaesthesia by immersion in oriental fire-bellied toads (Bombina orientalis).

OBJECTIVE: To determine a dexmedetomidine concentration, to be added to an alfaxalone-based bath solution, that will enhance the anaesthetic and analgesic effects of alfaxalone; and to compare the quality of anaesthesia and analgesia provided by immersion with either alfaxalone alone or alfaxalone with dexmedetomidine in oriental fire-bellied toads (Bombina orientalis). STUDY DESIGN: Pilot study followed by a prospective, randomized, experimental trial. ANIMALS: Fourteen oriental fire-bellied toads. METHODS: The pilot study aimed to identify a useful dexmedetomidine concentration to be added to an anaesthetic bath containing 20 mg 100 mL(-1) alfaxalone. Thereafter, the toads were assigned to one of two groups, each comprising eight animals, to be administered either alfaxalone (group A) or alfaxalone-dexmedetomidine (group AD). After immersion for 20 minutes, the toads were removed from the anaesthetic bath and the righting, myotactic and nociceptive reflexes, cardiopulmonary variables and von Frey filaments threshold were measured at 5 minute intervals and compared statistically between groups. Side effects and complications were noted and recorded. RESULTS: In the pilot study, a dexmedetomidine concentration of 0.3 mg 100 mL(-1) added to the alfaxalone-based solution resulted in surgical anaesthesia. The toads in group AD showed higher von Frey thresholds and lower nociceptive withdrawal reflex scores than those in group A. However, in group AD, surgical anaesthesia was observed in two out of eight toads only, and induction of anaesthesia was achieved in only 50% of the animals, as compared with 100% of the toads in group A. CONCLUSIONS AND CLINICAL RELEVANCE: The addition of dexmedetomidine to an alfaxalone-based solution for immersion anaesthesia provided some analgesia in oriental fire-bellied toads, but failed to potentiate the level of unconsciousness and appeared to lighten the depth of anaesthesia. This limitation renders the combination unsuitable for anaesthetizing oriental fire-bellied toads for invasive procedures.

S-ketamine versus racemic ketamine in dogs: their relative potency as induction agents.

OBJECTIVE: To determine the potency ratio between S-ketamine and racemic ketamine as inductive agents for achieving tracheal intubation in dogs. STUDY DESIGN: Prospective, randomized, 'blinded', clinical trial conducted in two consecutive phases. ANIMALS: 112 client-owned dogs (ASA I or II). METHODS: All animals were premedicated with intramuscular acepromazine (0.02 mg kg(-1)) and methadone (0.2 mg kg(-1)). In phase 1, midazolam (0.2 mg kg(-1)) with either 3 mg kg(-1) of racemic ketamine (group K) or 1.5 mg kg(-1) of S-ketamine (group S) was administered IV, for induction of anaesthesia and intubation. Up to two additional doses of racemic (1.5 mg kg(-1)) or S-ketamine (0.75 mg kg(-1)) were administered if required. In phase 2, midazolam (0.2 mg kg(-1)) with 1 mg kg(-1) of either racemic ketamine (group K) or S-ketamine (group S) was injected and followed by a continuous infusion (1 mg kg minute(-1)) of each respective drug. Differences between groups were statistically analyzed via t-test, Fisher exact test and ANOVA for repeated measures. RESULTS: Demographics and quality and duration of premedication, induction and intubation were comparable among groups. During phase 1 it was possible to achieve tracheal intubation after a single dose in more dogs in group K (n = 25) than in group S (n = 16) (p = 0.046). A dose of 3 mg kg(-1) S-ketamine allowed tracheal intubation in the same number of dogs as 4.5 mg kg(-1) of racemic ketamine. The estimated potency ratio was 1.5:1. During phase 2, the total dose (mean ± SD) of S-ketamine (4.02 ±1.56 mg kg(-1)) and racemic ketamine (4.01 ± 1.42) required for tracheal intubation was similar. CONCLUSION AND CLINICAL RELEVANCE: Racemic and S-ketamine provide a similar quality of anaesthetic induction and intubation. S-ketamine is not twice as potent as racemic ketamine and, if infused, the potency ratio is 1:1.

Nerve stimulator-guided sciatic-femoral nerve block in raptors undergoing surgical treatment of pododermatitis.

OBJECTIVE: To describe the nerve stimulator-guided sciatic-femoral nerve block in raptors undergoing surgical treatment of pododermatitis. STUDY DESIGN: Prospective clinical trial. ANIMALS: Five captive raptors (Falco peregrinus) aged 6.7 ± 1.3 years. METHODS: Anaesthesia was induced and maintained with isoflurane in oxygen. The sciatic-femoral nerve block was performed with 2% lidocaine (0.05 mL kg(-1) per nerve) as the sole intra-operative analgesic treatment. Intraoperative physiological variables were recorded every 10 minutes from endotracheal intubation until the end of anaesthesia. Assessment of intraoperative nociception was based on changes in physiological variables above baseline values, while evaluation of postoperative pain relied on species-specific behavioural indicators. RESULTS: The sciatic-femoral nerve block was feasible in raptors and the motor responses following electrical stimulation of both nerves were consistent with those reported in mammalian species. During surgery no rescue analgesia was required. The anaesthesia plane was stable and cardiorespiratory variables did not increase significantly in response to surgical stimulation. Iatrogenic complications, namely nerve damage and local anaesthetic toxicity, did not occur. Recovery was smooth and uneventful. The duration (mean ± SD) of the analgesic effect provided by the nerve block was 130 ± 20 minutes. CONCLUSION AND CLINICAL RELEVANCE: The sciatic-femoral nerve block as described in dogs and rabbits can be performed in raptors as well. Further clinical trials with a control groups are required to better investigate the analgesic efficacy and the safety of this technique in raptors.

Alfaxalone anesthesia by immersion in oriental fire-bellied toads (Bombina orientalis).

OBJECTIVES: To establish an effective alfaxalone concentration to be used for bath immersion of fire-bellied toads (Bombina orientalis) and to describe its effects. STUDY DESIGN: Prospective experimental study. ANIMALS: Thirteen oriental fire-bellied toads. METHODS: The study was carried out in two phases. The pilot phase involved five animals and aimed to identify an alfaxalone concentration capable of producing induction of anesthesia, defined as immobility with a head down position and loss of responsiveness to stimulation with a stick. The following trial in an additional eight toads used the effective alfaxalone concentration established during the pilot phase. Data from 11 animals (three toads in the pilot study and the eight additional toads) were analyzed. Twenty minutes after immersion in the anesthetic solution, the toads were removed from the bath, and heart rate, respiratory rate, the righting, myotactic and the nociceptive withdrawal reflexes were evaluated every 5 minutes. The loss of both righting and nociceptive withdrawal reflexes was considered indicative of a surgical depth of anesthesia. The time elapsed from anesthetic induction to return of righting reflex, the quality of recovery and the occurrence of undesired effects were observed and recorded. RESULTS: Immersion was found to be a suitable anesthetic technique for oriental fire-bellied toads and 200 mg L(-1) alfaxalone concentration produced anesthetic induction in 10 out of 11 toads. Side effects, such as skin irritation, erythema and changes in cutaneous pigmentation, were not observed in any animal. The duration of anesthesia ranged from 10 to 30 minutes after removal of the toads from the alfaxalone bath, and surgical depth of anesthesia was never achieved. CONCLUSIONS AND CLINICAL RELEVANCE: It was concluded that alfaxalone anesthesia induced by immersion in a concentration of 200 mg L(-1) is only suitable for toads undergoing non-invasive short procedures.