Jordyn M. Boesch

Biochemical Variables in Free-ranging White-tailed Deer (Odocoileus virginianus) after Chemical Immobilization in Clover Traps or Via Ground-darting

Abstract 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 µg/kg butorphanol (401, 1070 µg/kg), plus 235 µg/kg medetomidine (160, 429 µg/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°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.

Evaluation of righting reflex in cane toads (Bufo marinus) after topical application of sevoflurane jelly

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.

Evaluation of oral maropitant as an antiemetic in cats receiving morphine and dexmedetomidine

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.

Anesthesia for the horse with colic.

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.

Failure to reverse prolonged vecuronium-induced neuromuscular blockade with edrophonium in an anesthetized dog.

A case of prolonged muscle relaxation after vecuronium in an anesthetized dog is presented. After using peripheral nerve stimulation to confirm partial recovery of neuromuscular transmission, administration of 0.5 mg/kg IV of intravenous edrophonium failed to complete the reversal process. Subsequent administration of neostigmine resulted in complete recovery from blockade. Without monitoring neuromuscular function with a peripheral nerve stimulator until reversal was complete, it was very likely this patient would have been extubated with incomplete neuromuscular transmission. Several factors affecting the duration of neuromuscular blockade and its reversal are addressed.

LABORATORY VALIDATION OF A POINT-OF-CARE CARDIAC TROPONIN I ASSAY FOR USE IN WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS)

Abstract:  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.

Epidural anaesthesia for treatment of neuropathic pain associated with pelvic limb amputation in a domestic shorthair cat

An approximately 3-year-old, intact female, domestic shorthair cat presented to a shelter with a chronic fracture of the right femur. She underwent amputation of her right pelvic limb at the coxofemoral joint. On adoption two weeks following amputation, her owner noted clinical signs of pain associated with the stump, including resentment of stump palpation, paroxysmal vocalization and excessive grooming of the stump. Physical examination, including orthopaedic and neurological evaluation, was unremarkable except for subtle resentment of stump palpation. The history and clinical signs were consistent with neuropathic pain associated with the stump. A multimodal analgesic protocol consisting of oral meloxicam, gabapentin and amitriptyline was initiated; however, only mild improvement was noted and these medications were discontinued. A lumbosacral epidural injection of bupivacaine, buprenorphine and triamcinolone was performed under fluoroscopic guidance. The epidural injection resulted in immediate, complete resolution of clinical signs of pain that had not returned nine months later.

Maropitant administered orally 2–2.5 h prior to morphine and dexmedetomidine reduces the incidence of emesis in cats

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.

A cross-species approach to disorders affecting brain and behaviour

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.Many disorders of brain and behaviour affect human and veterinary patients. In this Perspectives, Orrin Devinsky and colleagues outline a cross-species approach to understanding neurological and psychiatric conditions, including pain, cognitive decline, epilepsy, anxiety and CNS infections, and propose that collaborations between physicians and veterinarians will generate new insights for therapy development.

HYPERKALEMIA IN TWO JAGUARS (PANTHERA ONCA) ANESTHETIZED WITH DEXMEDETOMIDINE, KETAMINE, AND ISOFLURANE

Abstract:  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.