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Objective: To determine if in vivo cryoneurolysis inhibits ex vivo compound action potential (CAP) conduction in the porcine saphenous nerve and if this occurs rapidly enough to justify performing the technique before stifle surgery., Study Design: Blinded, controlled, randomized, preclinical study., Animals: A group of eight healthy, 8 weeks old, intact, female pigs anesthetized for an unrelated terminal study., Methods: Both saphenous nerves of each pig were exposed surgically, and 15 mm of a 20 gauge, closed-tip, commercial cryoneurolysis cannula were inserted cranial to each nerve within the neurovascular fascial sheath along its long axis. The cannula was only actuated on one limb, according to random allocation. Nerves were excised within 15 minutes of actuation and underwent testing in a nerve conduction chamber, where stimulus voltage was increased sequentially (from 0.1 to ≤ 1.9 V). An anesthesiologist blinded to treatment viewed recordings of time versus voltage for each nerve and answered 'yes' or 'no' when asked if an evoked CAP was observed. Fisher's exact test evaluated the incidence of CAP conduction between groups (p < 0.05 considered significant). Nerves were submitted for hematoxylin and eosin staining for blinded histopathological examination., Results: A CAP was conducted in 8/8 and 1/8 of the control and treated nerves, respectively (p = 0.001). Maximal responses in control nerves were 1.92 ± 0.19 mV (mean ± standard error). In the single treated nerve that conducted a CAP, the maximal CAP amplitude was 0.4 mV, lower than the lowest maximal CAP (1.19 mV) in the control nerves. All control nerves were histologically normal, and all treated nerves displayed mild perivascular and perineural inflammation (cuffs of lymphocytes, plasma cells and eosinophils, and edema)., Conclusions and Clinical Relevance: The rapid inhibition of CAP conduction warrants clinical investigation of saphenous cryoneurolysis for both intraoperative antinociception and postoperative analgesia in pigs undergoing experimental stifle surgery., (Copyright © 2024 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

In addition to its role as cellular energy currency, adenosine triphosphate (ATP) serves as an extracellular messenger that mediates diverse cell-to-cell communication. Compelling evidence supports that ATP is released from cells through pannexins, a family of membrane proteins that form heptameric large-pore channels. However, the activation mechanisms that trigger ATP release by pannexins remain poorly understood. Here, we discover lysophospholipids as endogenous pannexin activators, using activity-guided fractionation of mouse tissue extracts combined with untargeted metabolomics and electrophysiology. We show that lysophospholipids directly and reversibly activate pannexins in the absence of other proteins. Secretomics experiments reveal that lysophospholipid-activated pannexin 1 leads to the release of not only ATP but also other signaling metabolites, such as 5'-methylthioadenosine, which is important for immunomodulation. We also demonstrate that lysophospholipids activate endogenous pannexin 1 in human monocytes, leading to the release of IL-1β through inflammasome activation. Our results provide a connection between lipid metabolism and purinergic signaling, both of which play major roles in immune responses.

Objective: To evaluate the effect of training with a high-fidelity surgical simulator on outcomes of live animals and students participating in a feline ovariohysterectomy teaching laboratory., Study Design: Nonrandomized controlled trial., Sample Population: Cats (n = 186) and students (n = 146)., Methods: Live animals were paired with student surgeons. Outcomes for animals and students were evaluated over two consecutive years before (year 1: NO SIM) and after (year 2: SIM) the introduction of a graded student teaching laboratory conducted on a high fidelity surgical simulator. Live animal surgical times and postoperative pain scores using the Glasgow Composite Measure Pain Scale - Feline acute pain scale as well as self-declared student confidence were assessed and the scores of the two groups were compared., Results: The duration of the live animal surgical procedure was on average 6 min shorter in the SIM group (p = .04). A pain score triggering intervention (> = 5/20) occurred less frequently in the SIM group (n = 1/82) than in the NO-SIM (n = 16/104) group (p < .01). Similarly, rescue analgesia was administered less frequently (4/82 vs 16/104, p = .03) in the SIM group. Student confidence prior to the live animal procedure was higher (median = 7/10 [IQR = 6-8]) in the SIM group than in the NO-SIM group (median = 6/10 [IQR = 4-7]) (p < .01)., Conclusion: Surgical simulator training prior to live animal procedures improves live animal outcomes and student confidence., Clinical Significance: Surgical simulator competency should be considered a prerequisite to participation in live animal teaching laboratories. This would improve both animal welfare and the student experience., (© 2023 American College of Veterinary Surgeons.)

Experimental maxillofacial surgery is commonly performed in pigs; however, locoregional anesthesia of this area has not been described. This study evaluated the feasibility of a novel maxillary nerve block approach. In part I, cadavers were used to determine anatomic landmarks and assess maxillary nerve dye staining by using 0.03 mL kg -1 of a 1:10 mixture of commercial food dye and 0.5% bupivacaine. In part II, 10 additional pig cadavers underwent bilateral ultrasound-guided maxillary nerve blocks by using trans-infraorbital canal needle placement. The maxillary nerve was harvested and scored based on degree of staining (0 and 1, absent or incomplete staining; 2, staining; >1 cm circumferentially). Intracranial and intraconal spread of dye was evaluated. A Kruskal-Wallis test was used to compare infraorbital canal length estimated either externally via landmarks, internally via ultrasound, or actually measured after dissection. In 18 of 20 (90%) injections, successful staining (score = 2) of maxillary nerves was obtained for a nerve length of 2.4 ± 0.3 cm. Two of 20 cases (10%) had inadequate staining (score <2). At dissection of these 2 cases, the needle tip was observed to have collided with an unerupted tooth (third molar). No intracranial or intraconal spread of dye was observed. We detected no statistical differences between the estimated external, estimated internal, or actual dissection methods for measurement of infraorbital canal length ( P = 0.3). Ultrasound-guided trans-infraorbital maxillary nerve block in pigs is a feasible technique, warranting further work to evaluate its in vivo efficacy and safety.

Objective: Novel locoregional techniques use dye studies to confirm successful nerve targeting. The goal was to objectively quantify and compare nerve staining characteristics of dye mixtures commonly reported in the literature using image analysis software., Study Design: Prospective, randomized cadaveric study., Methods: Thirty-six brachial plexus nerves from unpreserved pig cadavers were randomized into three groups of 12: FD (1:10 mixture of blue food dye and bupivacaine 0.5%), MB (methylene blue 1%) and TM (0.1:10 mixture of blue tissue marker and lidocaine 2%). Nerves were immersed in dye for 1, 15, 30 or 60 minutes (n = 3 each). Images of nerves before immersion (baseline) and at each time point with epineurium intact (superficial staining) and after longitudinal bisection (deep staining) were processed using image analysis software. Color saturation values were divided into quartiles (dark, medium-dark, medium-light or light). Percentage of stained nerve area in each quartile was calculated and compared using two-way anova., Results: Superficially, at minute 1, dark saturation covered 40% of nerve area in FD versus 19% in MB (p = 0.04) and 0% in TM (p < 0.0001). In bisected nerves, dark and medium-dark saturations occurred only in FD; medium-light saturation comprised anywhere from 4% to 22.5% over time in FD versus <1% at any time in MB (p = 1.000; p = 0.343; p = 0.383; p = 0.262). Deep staining was not found in TM at any point., Conclusion and Clinical Relevance: Food dye rapidly stains superficial and deep nerve layers. Based on these characteristics, investigators can choose the appropriate dye for their study., (Copyright © 2023 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

Objective: To test whether the use of low-dose epidural anesthesia (EA) in goats undergoing lower urinary tract surgery reduces the requirements of perioperative analgesics, contributes to intraoperative hypotension, and improves postoperative comfort during the first 24 hours after surgery., Animals: Retrospective analysis of 38 goats between January 2019 and July 2022., Procedures: Goats were divided into 2 groups (EA or no EA). Demographic characteristics, surgical procedure, time of anesthesia, and anesthetic agents used were compared between treatment groups. Outcome variables potentially related to the use of EA included dose of inhalational anesthetics, incidence of hypotension (mean arterial pressure < 60 mm Hg), intraoperative and postoperative administration of morphine, and time to first meal after surgery., Results: EA (n = 21) consisted of bupivacaine or ropivacaine 0.1% to 0.2% with an opioid. There were no differences between groups except for age (EA group was younger). Less inhalational anesthetic (P = .03) and less intraoperative morphine (P = .008) were used in the EA group. The incidence of hypotension was 52% for EA and 58% for no EA (P = .691). Administration of postoperative morphine was not different between groups (EA, 67%, and no EA, 53%; P = .686). Time to first meal was 7.5 hours (3 to 18 hours) for EA and 11 hours (2 to 24 hours) for no EA (P = .057)., Clinical Relevance: Low-dose EA reduced the use of intraoperative anesthetics/analgesics in goats undergoing lower urinary tract surgery without an increased incidence of hypotension. Postoperative morphine administration was not reduced.

Wild animals are commonly captured for conservation, research, and wildlife management purposes. However, capture is associated with a high risk of morbidity or mortality. Capture-induced hyperthermia is a commonly encountered complication believed to contribute significantly to morbidity and mortality. Active cooling of hyperthermic animals by dousing with water is believed to treat capture-induced pathophysiological effects, but remains untested. This study aimed to determine the pathophysiological effects of capture, and whether cooling by dousing with cold water effectively reduces these effects in blesbok (Damaliscus pygargus phillipsi). Thirty-eight blesbok were randomly allocated into three groups: a control group that was not chased (Ct, n=12), chased not cooled (CNC, n=14), and chased plus cooled group (C+C, n=12). The CNC and C+C groups were chased for 15 min prior to chemical immobilization on day 0. Animals in the C+C group were cooled with 10 L of cold water (4 C) for 10 min during immobilization. All animals were immobilized on days 0, 3, 16, and 30. During each immobilization, rectal and muscle temperatures were recorded, and arterial and venous blood samples collected. Blesbok in the CNC and C+C groups presented with capture-induced pathophysiological changes characterized by hyperthermia, hyperlactatemia, increased markers of liver, skeletal, and cardiac muscle damage, hypoxemia, and hypocapnia. Cooling effectively returned body temperatures to normothermic levels, but neither the magnitude nor the duration of the pathophysiological changes differed between the CNC and C+C groups. Therefore, at least in blesbok, capture-induced hyperthermia appears not to be the primary cause of the pathophysiological changes, but is more likely a clinical sign of the hypermetabolism resulting from capture-induced physical and psychological stress. Although cooling is still recommended to prevent the compounding cytotoxic effects of persistent hyperthermia, it is unlikely to prevent stress- and hypoxia-induced damage caused by the capture procedure., (© Wildlife Disease Association 2023.)

Objective: To evaluate the duration and analgesic quality of bupivacaine mixed with dexmedetomidine (BUP-DEX) or bupivacaine liposome suspension (BLS) administered as a transverse abdominis plane (TAP) block, compared with a negative control (no TAP block; CTRL) in dogs., Animals: 26 mixed-breed shelter dogs undergoing elective ovariohysterectomy between January 28 and December 8, 2020., Procedures: Each dog was randomly assigned to receive either an ultrasound-guided TAP block with either BUP-DEX or BLS or to receive no TAP block at time 0 after induction of general anesthesia. Superficial and abdominal wall pain scores were evaluated before time 0 and at 4, 6, 12, 24, 48, 72, and 96 hours later. Additionally, sedation scores and time to return of various behaviors, such as eating or drinking, were compared., Results: The CTRL group had significantly greater pain scores than the BUP-DEX and BLS groups, but no differences were found between the BUP-DEX and BLS groups. Postoperatively, significantly more dogs needed rescue analgesia and the time to need it was shorter for the CTRL group, compared with the BUP-DEX or BLS groups. Additionally, the CTRL group had greater sedation scores than the other 2 groups. No significant differences were observed in any of the evaluated outcome variables such as eating or drinking., Clinical Relevance: A TAP block appeared to provide adequate postoperative analgesia for abdominal surgery in the dogs of the present study undergoing elective ovariohysterectomy. The BLS TAP block did not appear to provide any extra benefit beyond what BUP-DEX TAP block added under these specific conditions.

Objective: To compare the thermoregulatory and analgesic effects of high-dose buprenorphine versus morphine in cats undergoing ovariohysterectomy., Animals: 94 client-owned cats., Procedures: Cats were randomized to receive either buprenorphine 0.24 mg/kg or morphine 0.1 mg/kg subcutaneously (SC) during recovery from ovariohysterectomy. Body temperature measurements were obtained before anesthesia, during anesthesia (averaged), at extubation, and 2, 4, and 16 to 20 hours postoperatively. Signs of pain were assessed, and demographic characteristics were compared between groups. The effects of treatment and time on body temperature, point prevalence of hyperthermia (> 39.2 °C), and pain scores were compared with linear or generalized mixed-effect models., Results: Cats receiving morphine (vs. buprenorphine) were older and heavier (both, P ≤ 0.005). Other group characteristics did not differ between treatments. Cats receiving buprenorphine (vs. morphine) had higher postoperative temperatures (P = 0.03). At 2, 4, and 16 to 20 hours after extubation, the point prevalence of hyperthermia was greater (P = 0.001) for cats receiving buprenorphine (55% [26/47], 44% [21/47], and 62% [27/43], respectively) versus morphine (28% [13/46], 13% [6/46], and 47% [21/44], respectively). There were no differences in pain scores between groups or over time. Five cats receiving buprenorphine and 6 receiving morphine required rescue analgesia within the 24-hour period., Clinical Relevance: Administration of buprenorphine (0.24 mg/kg SC), compared with morphine (0.1 mg/kg SC), resulted in higher body temperatures without an apparent advantage with regard to analgesia during the first 20 postoperative hours than morphine. Opioid-induced postoperative hyperthermia could confound the diagnosis of fever from different sources.

Objective: To develop a scale to diagnose and assess the severity of postamputation pain (PAP) in dogs., Study Design: Single-center retrospective study., Animals: A total of 66 dogs that underwent thoracic or pelvic limb amputation and 139 dogs that underwent tibial plateau leveling osteotomy (TPLO) at a veterinary teaching hospital., Methods: An online survey regarding postoperative behavioral changes was sent to owners. Categorical, multiple-choice responses were entered into a univariable logistic regression model and tested for association with amputation using the Wald test. If p < 0.2, variables were forwarded to a multivariable logistic regression model for manual build. Model simplicity and predictive ability were optimized using the area under the receiver operating curve (AUROC) characteristic, and model calibration was assessed using the Hosmer-Lemeshow test. The selected model was converted to an integer scale (0-10), the Canine Postamputation Pain (CAMPPAIN) scale. Univariable logistic regression related each dog's calculated score to the probability of PAP., Results: Multivariable logistic regression identified four independent predictors of PAP (p < 0.05): 1) restlessness or difficulty sleeping, 2) episodes of panic or anxiety, 3) sudden vocalization, and 4) compulsive grooming of the residual limb. Score AUROC was 0.70 (95% confidence interval = 0.63-0.78) with good calibration (Hosmer-Lemeshow statistic p = 0.82). A score of 2 corresponded to a risk probability of 0.5. Taking a score ≥ 2 to indicate PAP, score specificity and sensitivity were 92.1% and 36.4%, respectively. When this score was used to diagnose PAP, prevalence was 36.4% (24/66) and 7.9% (11/139) in the amputation and TPLO groups, respectively., Conclusions and Clinical Relevance: Postamputation pain is characterized by specific postoperative behaviors and appears to affect approximately one-third of canine amputees. The CAMPPAIN scale generated from these data could facilitate diagnosis, treatment and further study of PAP but requires external validation., (Copyright © 2021 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

Etorphine-azaperone is the most commonly used drug combination for chemical immobilisation of free-ranging white rhinoceroses, but causes several profound physiological disturbances, including muscle tremors. The addition of benzodiazepine sedatives, such as midazolam, has been proposed to reduce the muscular rigidity and tremors in immobilised rhinoceroses. Twenty-three free-ranging, sub-adult white rhinoceros bulls were darted and captured using a combination of etorphine plus either azaperone or midazolam. Skeletal muscle tremors were visually evaluated and scored by an experienced veterinarian, and tremor scores and distance run were compared between groups using the Wilcoxon rank sum test. No statistical differences were observed in tremor scores (p = 0.435) or distance run (p = 0.711) between the two groups, and no correlation between these variables was detected (r = -0.628; p = 0.807). Etorphine-midazolam was as effective as etorphine-azaperone at immobilising rhinoceroses, with animals running similar distances. Although the addition of midazolam to the etorphine did not reduce tremor scores compared to azaperone, it might have other beneficial immobilising effects in rhinoceroses, and further investigation is necessary to elucidate possible methods of reducing muscle tremoring during chemical immobilisation of rhinoceroses.

This study used electrical impedance tomography (EIT) measurements of regional ventilation and perfusion to elucidate the reasons for severe gas exchange impairment reported in rhinoceroses during opioid-induced immobilization. EIT values were compared with standard monitoring parameters to establish a new monitoring tool for conservational immobilization and future treatment options. Six male white rhinoceroses were immobilized using etorphine, and EIT ventilation variables, venous admixture, and dead space were measured 30, 40, and 50 min after becoming recumbent in lateral position. Pulmonary perfusion mapping using impedance-enhanced EIT was performed at the end of the study period. The measured impedance (∆Z) by EIT was compared between pulmonary regions using mixed linear models. Measurements of regional ventilation and perfusion revealed a pronounced disproportional shift of ventilation and perfusion toward the nondependent lung. Overall, the dependent lung was minimally ventilated and perfused, but remained aerated with minimal detectable lung collapse. Perfusion was found primarily around the hilum of the nondependent lung and was minimal in the periphery of the nondependent and the entire dependent lung. These shifts can explain the high amount of venous admixture and physiological dead space found in this study. Breath holding redistributed ventilation toward dependent and ventral lung areas. The findings of this study reveal important pathophysiological insights into the changes in lung ventilation and perfusion during immobilization of white rhinoceroses. These novel insights might induce a search for better therapeutic options and is establishing EIT as a promising monitoring tool for large animals in the field. NEW & NOTEWORTHY Electrical impedance tomography measurements of regional ventilation and perfusion applied to etorphine-immobilized white rhinoceroses in lateral recumbency revealed a pronounced disproportional shift of the measured ventilation and perfusion toward the nondependent lung. The dependent lung was minimally ventilated and perfused, but still aerated. Perfusion was found primarily around the hilum of the nondependent lung. These shifts can explain the gas exchange impairments found in this study. Breath holding can redistribute ventilation.

Objective: Thermal radiofrequency (TRF) of the saphenous nerve (a sensory nerve) combined with pulsed radiofrequency (PRF) of the sciatic nerve (a sensory and motor nerve) might relieve intractable stifle osteoarthritis (OA) pain in dogs. The objective was to determine if saphenous nerve TRF induces Wallerian degeneration and if sciatic nerve PRF induces degeneration or dysfunction., Study Design: Blinded, controlled, randomized, preclinical study., Animals: A group of six intact, female Beagle dogs aged 14-16 months., Methods: In each dog, one pelvic limb was assigned randomly to the control group and the other to the treatment group. Dogs were anesthetized and, using ultrasonography, radiofrequency electrodes were positioned adjacent to saphenous and sciatic nerves bilaterally; TRF and PRF were performed only in the treatment limb. Motor nerve conduction velocity (MNCV) was measured in both sciatic nerves 2 weeks later, and the dogs were euthanized. Hematoxylin and eosin-stained sections of saphenous and sciatic nerves were examined using light microscopy. Degeneration and inflammation were scored 0 (none) to 3 (severe). A one-tailed, paired Wilcoxon signed-rank test was used to test for differences in scores and MNCV between control and treatment nerves., Results: Degeneration and inflammation scores were higher in treatment saphenous nerves in 5/6 dogs [83%; 95% confidence interval (CI), 36%, 99%]; however, after Bonferroni correction only degeneration score was higher (p = 0.0313). Degeneration, inflammation or decreased MNCV were not observed in sciatic nerves (each outcome: 0/6 nerves, 0%; 95% CI, 0%, 48%). No dogs experienced postprocedural pain or neurological deficits., Conclusions and Clinical Relevance: The degeneration in TRF-treated saphenous nerves appears sufficient to impair transmission. Sciatic nerve PRF did not cause degeneration with attendant motor deficits, consistent with a proposed neuromodulatory mechanism. A clinical trial is needed to confirm the combined techniques produce analgesia without motor deficits in dogs with stifle OA., (Copyright © 2019 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

One of the most important goals of palliative medicine and hospice care is pain relief. Although great strides have been made in veterinary analgesia, severe pain, especially at home, is still difficult to control. Pain control in the context of palliative medicine and hospice care is far more advanced in human medicine. Many modalities used in chronically or terminally ill humans might be adapted to animals to better manage severe pain. This article discusses drugs and procedures used to control pain in humans that are relatively nascent or unavailable in veterinary medicine and deserve further attention., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The effects of etorphine on the pulmonary vascular system of white rhinoceros ( Ceratotherium simum) have not been described and could play a role in the severe hypoxemia that develops after immobilization with etorphine-based drug combinations. Characterization of these effects requires measurement of pulmonary vascular pressures and cardiac output (CO). To refine a technique for pulmonary arterial catheterization, five boma-habituated white rhinoceros (three females and two males weighing 1,012-1,572 kg) were immobilized by remote injection with etorphine plus azaperone followed by butorphanol. This afforded the opportunity to perform a pilot study and acquire preliminary measurements of pulmonary arterial pressure (PAP) and CO before and after supplemental etorphine given intravenously. Ultrasonographic guidance was used to insert a sheath introducer into a linguofacial branch of a jugular vein. A 160-cm-long pulmonary artery catheter with a balloon and thermistor was then passed through the introducer and positioned with its tip in the pulmonary artery. It was not long enough to permit wedging for measurement of pulmonary artery occlusion pressure. Mean PAP was 35 mm Hg (minimum, maximum 32, 47 mm Hg) and increased ( P = 0.031) by 83% (28, 106%) after supplemental etorphine. Thermodilution CO was 120 L/min (92, 145 L/min) and increased 27% (3, 43%) ( P = 0.031). Heart rate was 100 (88, 112) beats/min and increased 20% (4, 45%) ( P = 0.031), whereas arterial partial pressure of oxygen was 35 mm Hg (30, 94 mm Hg) and decreased 47% (20, 72%) ( P = 0.031). The cardiovascular observations could result from etorphine-induced generalized sympathetic outflow, as has been reported in horses. Further studies of etorphine in isolation are needed to test this suggestion and to discern how the changes in pulmonary vascular pressures and blood flow might relate to hypoxemia in etorphine-immobilized white rhinoceros.

Structural and functional elements of biological systems are highly conserved across vertebrates. Many neurological and psychiatric conditions affect both humans and animals. A cross-species approach to the study of brain and behaviour can advance our understanding of human disorders via the identification of unrecognized natural models of spontaneous disorders, thus revealing novel factors that increase vulnerability or resilience, and via the assessment of potential therapies. Moreover, diagnostic and therapeutic advances in human neurology and psychiatry can often be adapted for veterinary patients. However, clinical and research collaborations between physicians and veterinarians remain limited, leaving this wealth of comparative information largely untapped. Here, we review pain, cognitive decline syndromes, epilepsy, anxiety and compulsions, autoimmune and infectious encephalitides and mismatch disorders across a range of animal species, looking for novel insights with translational potential. This comparative perspective can help generate novel hypotheses, expand and improve clinical trials and identify natural animal models of disease resistance and vulnerability.

Objectives: The objectives of this study were to determine basic oral pharmacokinetics, and assess safety and analgesic efficacy of a cannabidiol (CBD) based oil in dogs with osteoarthritis (OA). Methods: Single-dose pharmacokinetics was performed using two different doses of CBD enriched (2 and 8 mg/kg) oil. Thereafter, a randomized placebo-controlled, veterinarian, and owner blinded, cross-over study was conducted. Dogs received each of two treatments: CBD oil (2 mg/kg) or placebo oil every 12 h. Each treatment lasted for 4 weeks with a 2-week washout period. Baseline veterinary assessment and owner questionnaires were completed before initiating each treatment and at weeks 2 and 4. Hematology, serum chemistry and physical examinations were performed at each visit. A mixed model analysis, analyzing the change from enrollment baseline for all other time points was utilized for all variables of interest, with a p ≤ 0.05 defined as significant. Results: Pharmacokinetics revealed an elimination half-life of 4.2 h at both doses and no observable side effects. Clinically, canine brief pain inventory and Hudson activity scores showed a significant decrease in pain and increase in activity ( p < 0.01) with CBD oil. Veterinary assessment showed decreased pain during CBD treatment ( p < 0.02). No side effects were reported by owners, however, serum chemistry showed an increase in alkaline phosphatase during CBD treatment ( p < 0.01). Clinical significance: This pharmacokinetic and clinical study suggests that 2 mg/kg of CBD twice daily can help increase comfort and activity in dogs with OA.

Two jaguars were anesthetized with dexmedetomidine, ketamine, and isoflurane. Arterial blood samples analyzed shortly after darting revealed no abnormalities. Samples analyzed 2 and 1.5 hr after darting revealed moderate hyperkalemia in both animals (6.8 and 6.2 mEq/L, respectively). Shortly after hyperkalemia was recognized, one jaguar developed electrocardiographic abnormalities (sinoventricular rhythm and widened QRS complexes), and a few minutes later, suffered cardiopulmonary arrest. Resuscitation with chest compressions, intermittent positive-pressure ventilation, and epinephrine was successful, and autonomous breathing and circulation resumed within a few minutes. Anesthesia-related hyperkalemia has been reported in a variety of large felids but has not been reported previously in jaguars. In all reports, α-2 adrenergic agonists were used as part of the immobilization protocol. Due to the presumptively high incidence and mortality caused by this complication, frequent monitoring of electrolyte concentrations and prompt treatment of hyperkalemia is recommended when anesthetizing large felids, including jaguars.

Objectives The main goal of this study was to test the antiemetic effects of maropitant administered orally 2-2.5 h prior to morphine and dexmedetomidine in cats. Methods Eighty-three healthy female cats were randomized to receive maropitant (8 mg orally; n = 39) or no treatment (control; n = 44), 2-2.5 h prior to morphine 0.1 mg/kg and dexmedetomidine 20 µg/kg intramuscularly. The incidence of sialorrhea, lip licking, retching and vomiting were recorded after morphine/dexmedetomidine injection. Results There were no differences between groups in terms of age or weight. The treated group received a mean ± SD dose of maropitant of 2.9 ± 0.6 mg/kg. The incidence of sialorrhea and lip licking was no different between groups. The incidence of retching (control 36% vs maropitant 13%; P = 0.012) and emesis (control 32% vs maropitant 13%; P = 0.03) was significantly reduced in cats treated with maropitant. Conclusions and relevance Maropitant 8 mg (total dose) administered orally 2-2.5 h prior to morphine and dexmedetomidine significantly reduced, but did not eliminate, the incidences of retching and vomiting. Maropitant did not decrease the occurrence of sialorrhea and lip licking, signs that may be indicative of nausea. Maropitant might be useful for morning administration to prevent emesis in outpatient cats requiring sedation or anesthesia; however, dose regimens or interval of administration might require improvement.

Objectives The aim of the study was to evaluate the antiemetic effects of maropitant, after oral administration, in cats receiving morphine and dexmedetomidine. Methods This prospective, blinded, randomized controlled trial involved 98 healthy female domestic shorthair cats. Cats were randomly assigned to receive maropitant PO 8 mg total (group M) administered 18 h prior to sedation with intramuscular dexmedetomidine 20 µg/kg and morphine 0.1 mg/kg, or no antiemetic treatment (group C). The occurrence of signs of nausea (sialorrhea and lip-licking), retching and emesis during the 30 mins following administration of dexmedetomidine and morphine was measured for each group. Results Two cats were excluded from the investigation. Cats in group M (n = 46) received an average of 2.5 mg/kg of maropitant PO. Compared with group C (n = 50), cats in group M had lower incidences of emesis (M: 4% vs C: 40%), retching (M: 8% vs C: 40%) and lip-licking (M: 30% vs C: 52%) (all P <0.05). The incidence of sialorrhea was not different between groups (M: 21% vs C: 22%). Conclusions and relevance Maropitant 8 mg total PO was effective in reducing morphine and dexmedetomidine-induced emesis by 10-fold, when administered as early as 18 h in advance to healthy cats. Maropitant PO could be useful for administration the evening prior to a scheduled procedure requiring sedation/anesthesia to decrease the incidence of emesis.

OBJECTIVE To evaluate the effects of maropitant in cats receiving dexmedetomidine and morphine. DESIGN Randomized controlled trial. ANIMALS 66 healthy female domestic shorthair cats. PROCEDURES Cats were randomly assigned to receive maropitant (1 mg/kg [0.45 mg/lb], SC; maropitant group; n = 32) or saline (0.9% NaCl) solution (0.1 mL/kg [0.045 mL/lb], SC; control group; 34) 20 hours before IM administration of dexmedetomidine (20 μg/kg [9.1 μg/lb]) and morphine (0.1 mg/kg). Following administration of dexmedetomidine and morphine, the incidences of emesis, retching, and signs of nausea (sialorrhea and lip licking) were compared between the 2 groups. The aversive behavioral response of each cat to injection of maropitant or saline solution was scored on a visual analogue scale by each of 4 observers who were unaware of the treatment administered. RESULTS Only 1 of 32 cats in the maropitant group vomited, whereas 20 of 34 control cats vomited. The incidences of emesis and retching for the maropitant group were significantly lower than those for the control group. The incidence of signs of nausea did not differ between the 2 groups. Visual analogue scale scores for the maropitant group were significantly higher than those for the control group. CONCLUSIONS AND CLINICAL RELEVANCE Results of the present study indicated that administration of maropitant to healthy cats approximately 20 hours prior to administration of dexmedetomidine and morphine significantly decreased the incidence of emesis but did not decrease the incidence of signs of nausea. However, maropitant appeared to cause substantial discomfort when injected SC.

The VetScan® i-STAT® 1 Handheld Analyzer and cardiac troponin I (cTnI) cartridges (i-STAT cTnI assay) measured greater median cTnI concentration [cTnI] in free-ranging white-tailed deer (Odocoileus virginianus) hand-injected with anesthetic drugs after physical restraint in Clover traps than in those ground-darted with the same drugs. This suggested that Clover trapping induces myocardial damage, bringing the use of this capture method under scrutiny. The purpose of this study was to confirm the validity of the i-STAT cTnI assay in deer before recommending changes in capture methods. Median [cTnI] measured by the i-STAT cTnI assay ([cTnI]i) in heparinized whole blood collected from 52 healthy, reproductively mature, female deer physically restrained in a chute was 0.01 ng/ml (10-90% percentiles: 0.00-0.03 ng/ml; minimum, maximum: 0.00, 0.07 ng/ml); [cTnI]i was 0.00 ng/ml in 42% of the deer. There was no association between [cTnI]i and either clotting or hemolytic index. [cTnI]i was 0.00 ng/ml when deer skeletal muscle homogenate was added to deer blood with [cTnI]i of 0.00 ng/ml, confirming the i-STAT cTnI assay does not detect skeletal muscle troponins. When deer cardiac muscle homogenate was serially diluted with 1) deer blood, 2) deer plasma, and 3) cow blood, [cTnI]i was directly proportional (Y intercept=-0.09, 0.7, and -0.08 ng/ml, respectively; r2≥0.97) to the fraction of homogenate in each sample. Deer cardiac muscle homogenate was diluted with deer blood to produce three samples with low, intermediate, and high [cTnI]i; serial measurements (n=10) performed on each sample yielded coefficients of variation (CVs) of 8, 20, and 11%, respectively. Corresponding CVs when plasma was used as diluent were 13, 9, and 7%, respectively. [cTnI]i increased when plasma with a low [cTnI]i was stored at 20-24°C for 9 days. Three freeze-thaw cycles caused no systematic change in plasma [cTnI]i.

Objective: To evaluate the righting reflex after topical application of a sevoflurane jelly in cane toads (Bufo marinus)., Animals: 8 cane toads., Procedures: Toads were 6 to 8 months of age and weighed (mean ± SD) 142.0 ± 25.2 g. Sevoflurane jelly was applied to the dorsum of each toad at a dose of 25 μL/g in trial 1 and 37.5 μL/g in trial 2. Toads were placed in dorsal recumbency every 30 seconds until loss of the righting reflex. Jelly was then removed by rinsing the toads with tap water. Toads were then left undisturbed in dorsal recumbency until return of the righting reflex. Chamber sevoflurane concentration was measured to determine vaporization., Results: 6 of 8 toads in trial 1 and 8 of 8 toads in trial 2 lost the righting reflex. Mean ± SD time to loss of the reflex was 8.2 ± 1.3 minutes for trial 1 and 8.3 ± 0.9 minutes for trial 2; this difference was not significant. Mean ± SD time to return of the reflex was 25.6 ± 26.2 minutes for trial 1 and 84.4 ± 47.2 minutes for trial 2; this difference was significant. Chamber sevoflurane concentration did not change significantly, compared with baseline (time 0) concentration, at any time in trial 1; however, there was a significant change in chamber sevoflurane concentration from baseline (time 0) concentration in trial 2. Chamber sevoflurane concentrations were not significantly different between trial 1 and trial 2 at any time. Mean ± SD chamber sevoflurane concentration was 0.46 ± 0.2% for trial 1 and 0.57 ± 0.28% for trial 2., Conclusions and Clinical Relevance: Sevoflurane jelly applied topically at a dose of 37.5 μL/g induced a more reliable loss of righting reflex and longer recovery time than when applied at a dose of 25 μL/g in cane toads.

A 2-year-old castrated dog was presented for chronic coughing that was evaluated with bronchoscopy following intravenous boluses of propofol. During recovery the dog developed severe rigidity of muscles of the neck and thoracic limbs, which was unresponsive to treatment but subsided over 25 minutes. A presumptive diagnosis of propofol-associated dystonia was made. The clinical characteristics and theorized pathophysiology of propofol-associated dystonia are discussed.

This article discusses anesthesia for horses with colic from acute gastrointestinal disease. Emphasis is placed on new developments in pre-, intra-, and immediate postoperative management over the last decade, including early goal-directed therapy (EGDT) in the resuscitation of septic patients, the controversy over the optimal fluid type to administer, and the management of complications, such as cardiovascular depression, hypoventilation and hypoxemia, and decreased colloid oncotic pressure (COP). An update on analgesia is also provided; older drugs such as ketamine and lidocaine are increasingly being recognized both for their analgesic properties and other potentially beneficial effects in endotoxemic horses., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The objective of this prospective observational cohort study in free-ranging female white-tailed deer (Odocoileus virginianus) was to compare the physiologic effects of two methods of anesthetic drug administration: hand-injection in Clover traps and remote injection by dart after ground-stalking. Six trapped and 14 darted female deer were injected with a median (minimum, maximum) of 590 microg/kg butorphanol (401, 1070 microg/kg), plus 235 microg/kg medetomidine (160, 429 microg/kg) intramuscularly. In the trap, the deer struggled when approached and were restrained for injection. Darted deer sprinted away after injection. Once immobilized, deer were transported to a veterinary hospital where blood was collected and vital signs were measured on admission. Admission data from a subset of deer in which measurements were taken within 40 min of trapping (n = 6) or darting (n = 5) were analyzed. After salpingectomy under isoflurane and while still anesthetized, another blood sample was collected from all 20 deer. Body weight and immobilization drug doses were not different between groups. On admission, most deer from both groups were hypoxemic, although the darted deer were significantly more hypoxemic. The median rectal temperature in trapped deer was higher than in darted deer, and temperatures higher than 39 degrees C only occurred in trapped deer. The median heart rate in trapped deer was more than twice that in darted deer. Trapped deer had lower median pH and base excess; in trapped deer, the median plasma lactate concentration was more than fivefold higher than in darted deer. After surgery, the median serum creatine kinase concentration was nearly 10-fold higher in trapped deer, and the median cardiac troponin I concentration was higher in trapped deer but undetectable in 10 of 14 darted deer. The white-tailed deer immobilized by hand-injection in Clover traps experienced more severe physiologic perturbations than deer remotely injected by dart after ground-stalking. These perturbations might be sufficient to cause myocardial damage.

Observations: A 1-month-old Nubian goat presented for sialocyst resection. Physical examination and bloodwork were unremarkable. While pre-oxygenating, the goat was sedated with midazolam and morphine (0.1 mg kg(-1) each) intravenously (IV). General anesthesia was induced 5 minutes later with 1.7 mg kg(-1) propofol. Sevoflurane was administered in oxygen without assisted ventilation via a cuffed orotracheal tube. Throughout the first 85 minutes of anesthesia, the goat was well-oxygenated (SpO(2), > or =97%), ventilating adequately (Pe'CO(2), 36-48 mmHg), and had normal mean arterial blood pressure (MAP, 60-85 mmHg). Blood-gas values at 45 minutes were consistent with adequate ventilation on oxygen. At 75 minutes, the goat moved in response to surgical stimulation, requiring additional propofol (0.4 mg kg(-1)). After 10 minutes, MAP dropped precipitously to 40 mmHg and frequent multiform premature ventricular contractions (PVCs) were observed. Crystalloids, hetastarch, and dopamine (5 mug kg(-1) minute(-1)) were administered to correct the hypotension. Arterial blood-gas analysis revealed that the goat had become hypoxemic (PaO(2), 50 mmHg). Intermittent positive pressure ventilation (IPPV) was initiated. Subsequent blood-gas analysis did not show significant improvement in PaO(2) (53 and 56 mmHg, respectively). Occasional PVCs were observed thereafter. Surgery ended, and sevoflurane and IPPV were discontinued. The goat was extubated within 7 minutes and received 100% oxygen by mask. Diffuse crackles were ausculted over both hemithoraces. Suspecting pulmonary edema, furosemide (1 mg kg(-1)) was administered IV. Radiographs taken immediately post-operatively revealed a severe, caudodorsal airspace (alveolar) pattern, confirming the diagnosis. Respiration improved considerably within an hour with nasal oxygen and two additional doses of furosemide., Conclusions: The goat developed acute, drug-induced, noncardiogenic pulmonary edema in response to the second dose of propofol.