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To develop and begin establishing evidence for validity of an instrument to assess the quality of induction in dogs.Cross-sectional survey and video scoring.A total of 51 veterinary anesthesia personnel, four board-certified anesthesiologists and videos of induction of anesthesia in 18 dogs.In Part 1, an online survey was sent to veterinary anesthesia personnel to solicit expressions and words that they associate with induction of anesthesia. These expressions were evaluated by four anesthesiologists to create a composite scale (Auburn Induction Scale). In Part 2, 18 videos were reviewed by the same four anesthesiologists on two separate occasions. The videos were scored using the Auburn Induction Scale, a simple descriptive scale (SDS) and a visual analog scale (VAS). Intra-rater and inter-rater reliability was measured using an intraclass correlation coefficient (ICC). Significance was set at p0.05.The survey yielded 51 responses that were condensed into 133 expressions. The four anesthesiologists created 18 items incorporating the 133 expressions. The mean ± standard deviation intra-rater reliability ICC was 0.81 ± 0.08 for the Auburn Induction Scale, 0.71 ± 0.02 for the SDS and 0.71 ± 0.08 for the VAS for all raters. The mean ± standard deviation inter-rater reliability ICC was 0.69 ± 0.04 for the Auburn Induction Scale, 0.61 ± 0.05 for the SDS and 0.60 ± 0.06 for the VAS.In a research setting, widespread use of this scale may be helpful in increasing the accuracy of data and improving agreement between studies assessing induction of anesthesia in dogs. The results of this study have yielded a composite scale that is more reliable between and among raters than a unidimensional scale.

OBJECTIVE To determine factors associated with change in rectal temperature (RT) of dogs undergoing anesthesia. ANIMALS 507 dogs. PROCEDURES In a prospective observational study, the RT of dogs undergoing anesthesia at 5 veterinary hospitals was recorded at the time of induction of anesthesia and at the time of recovery from anesthesia (ie, at the time of extubation). Demographic data, body condition score, American Society of Anesthesiologists (ASA) physical status classification, types of procedure performed and medications administered, duration of anesthesia, and use of heat support were also recorded. Multiple regression analysis was performed to determine factors that were significantly associated with a decrease or an increase (or no change) in RT. Odds ratios were calculated for factors significantly associated with a decrease in RT. RESULTS Among the 507 dogs undergoing anesthesia, RT decreased in 89% (median decrease, −1.2°C [-2.2°F]; range, −0.1°C to −5.7°C [–0.2°F to −10.3°F]), increased in 9% (median increase, 0.65°C [1.2°F]; range, 0.1°C to 2.1°C [3.8°F]), and did not change in 2%. Factors that significantly predicted and increased the odds of a decrease in RT included lower weight, ASA classification > 2, surgery for orthopedic or neurologic disease, MRI procedures, use of an α2-adrenergic or μ-opioid receptor agonist, longer duration of anesthesia, and higher heat loss rate. Lack of μ-opioid receptor agonist use, shorter duration of anesthesia, and lower heat loss rate were significantly associated with an increase in RT. CONCLUSIONS AND CLINICAL RELEVANCE Multiple factors that were associated with a decrease in RT in dogs undergoing anesthesia were identified. Knowledge of these factors may help identify dogs at greater risk of developing inadvertent perianesthetic hypothermia.

OBJECTIVE To compare measurements of left ventricular volume and function derived from 2-D transthoracic echocardiography (2DE), transesophageal echocardiography (TEE), and the ultrasound velocity dilution cardiac output method (UDCO) with those derived from cardiac MRI (cMRI) in healthy neonatal foals. ANIMALS 6 healthy 1-week-old Standardbred foals. PROCEDURES Foals were anesthetized and underwent 2DE, TEE, and cMRI; UDCO was performed simultaneously with 2DE. Images acquired by 2DE included the right parasternal 4-chamber (R4CH), left apical 4- and 2-chamber (biplane), and right parasternal short-axis M-mode (M-mode) views. The longitudinal 4-chamber view was obtained by TEE. Measurements assessed included left ventricular end-diastolic volume (LVEDV), end-systolic volume (LVESV), ejection fraction, stroke volume (LVSV), cardiac output (CO), and cardiac index (CI). Bland-Altman analyses were used to compare measurements derived from biplane, R4CH, and M-mode images and UDCO with cMRI-derived measurements. Repeatability of measurements calculated by 3 independent reviewers was assessed by the intraclass correlation coefficient. RESULTS Compared with cMRI, all 2DE and TEE modalities underestimated LVEDV and LVESV and overestimated ejection fraction, CO, and CI. The LVSV was underestimated by the biplane, R4CH, and TEE modalities and overestimated by UDCO and M-mode methods. However, the R4CH-derived LVSV, CO, and CI were clinically comparable to cMRI-derived measures. Repeatability was good to excellent for measures derived from the biplane, R4CH, M-mode, UDCO, and cMRI methods and poor for TEE-derived measures. CONCLUSIONS AND CLINICAL RELEVANCE All assessed modalities yielded clinically acceptable measurements of LVEDV, LVESV, and function, but those measurements should not be used interchangeably when monitoring patient progress.

Objective To evaluate the effect of dexmedetomidine on alfaxalone immobilization in snakes. Study design Nonblinded, crossover study. Animals A total of eight mature common garter snakes (Thamnophis sirtalis). Methods Snakes were administered each of three treatments intracoelomically: alfaxalone (30 mg kg–1; treatment A), alfaxalone (30 mg kg–1) combined with dexmedetomidine (0.05 mg kg–1; treatment AD0.05); and alfaxalone (30 mg kg–1) combined with dexmedetomidine (0.10 mg kg–1; treatment AD0.10). A minimum of 10 days elapsed between experimental trials. Times to loss of righting reflex (LRR) and return of righting reflex (RRR) were recorded. Heart rate (HR) was recorded every 5 minutes throughout the period of LRR and averaged for each snake. Times to LRR and RRR, and mean HR in snakes that achieved LRR were reported. Results LRR occurred in eight (100%), five (63%) and three (38%) snakes in treatments A, AD0.05 and AD0.10, respectively. For all treatments, time to LRR ranged 3–20 minutes. Median (range) times to RRR were 39 (30–46), 89 (62–128) and 77 (30–185) minutes for treatments A, AD0.05 and AD0.10, respectively. In animals where righting reflex was lost, mean HR was lower in all dexmedetomidine treatments compared with treatment A. Conclusions and clinical relevance In this pilot study, alfaxalone resulted in reliable immobilization, whereas dexmedetomidine and alfaxalone combinations resulted in highly variable durations of immobilization with low HR in immobilized animals. For snakes that achieved LRR, the addition of dexmedetomidine (0.05 mg kg–1) to alfaxalone appeared to extend the period of immobilization compared with alfaxalone alone.

Impairment of oxygen uptake can occur during general anesthesia in horses resulting in hypoxemia. Multiple treatments have been investigated for correction of hypoxemia with varying levels of success. In clinical trials, albuterol, a short-acting β

OBJECTIVE To compare perceptions related to veterinary anesthesiologist involvement with anesthesia and pain management, benefits of a preanesthetic consultation (PAC) with an anesthesiologist, and quality of patient care between clients who did and did not participate in a PAC prior to their dogs’ elective orthopedic surgery. SAMPLE 80 dog owners. PROCEDURES Owners of dogs undergoing elective stifle joint surgery participated in the study. Participants were randomly assigned to PAC and control groups (n = 40 participants/group). The PAC group participated in a PAC with an anesthesiologist and completed a written survey (12 items with Likert-type response options). The control group completed a similar survey (identical except for 2 statements related to the PAC experience) without participating in a PAC. Results were compared between groups by statistical methods. RESULTS The proportion of clients in the PAC group who strongly agreed with the statements that a PAC was beneficial, their questions about the pet's anesthesia and pain management plan were answered, they knew who would perform anesthesia and what safeguards were in place, veterinary specialty hospitals should have an anesthesiologist on staff, they were willing to pay more to have an anesthesiologist supervise the anesthesia and pain management, and a PAC with an anesthesiologist should be standard of care in veterinary medicine was greater than that for control group clients. Responses to quality-of-care items did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE Participating in a PAC was associated with more positive perceptions of anesthesiologists and knowledge about the anesthesia plan. Further research with a validated survey instrument is needed to confirm these findings.

Introduction: In 2020, a coronavirus pandemic resulted in a worldwide ventilator shortage In response, a device with a continuous positive airway pressure (CPAP) machine was developed as a ventilator Methods: A goat (89 kg) and a sheep (86 kg) were used for testing Midazolam (0 25 mg kg -1), morphine (0 25 mg kg-1), propofol (3 5 mg kg-1, 0 2 mg kg-1 min-1) and atracurium (0 25 mg kg-1) were administered, and animals were intubated and attached to the device breathing circuit A CPAP machine delivered constant circuit pressure Fraction of inspired oxygen (FIO2) was adjusted with a flow meter Electronic control of one-way valves allowed for adjustment of breaths minute-1 (BPM), and inspiratory:expiratory ratio (I:E) An expiratory valve allowed for adjustment of positive end expiratory pressure (PEEP) Various BPM, I:E, peak inspiratory pressure (PIP), and PEEP were tested in each animal PIP, PEEP, tidal volume via Wright respirometer (VT) and arterial partial pressure of oxygen (PaO2) were measured to determine device limits Results: Animals were anesthetized for 2 hours and recovered uneventfully Attained range of parameters were: FIO 2 0 22 to 0 5, BPM 8 to 20, I:E 1:3 to 2:1, PEEP 2 to 20 cm H2O, VT 300 to 1200 ml, and PaO2 68 to 99 mm Hg PIP in the first animal was 18 cm H2O In the second animal, a second CPAP machine was added and a maximum PIP of 38 cm H2O was achieved Conclusion: The device demonstrated effective ventilation in a range of parameters that may be necessary for treatment of virus-affected humans

Objective To evaluate cardiopulmonary and recovery characteristics of horses administered total intravenous anesthesia (TIVA) with xylazine and ketamine combined with midazolam or propofol. Study design Randomized crossover study. Animals A group of eight adult horses, aged 7–22 years, weighing 493–740 kg. Methods Horses were administered xylazine (1 mg kg−1) intravenously (IV), and anesthesia was induced with ketamine (2.2 mg kg−1) IV. Anesthesia was maintained for 45 minutes via IV infusion of xylazine (0.016 mg kg−1 minute−1) and ketamine (0.03 mg kg−1 minute−1) combined with midazolam at 0.002 mg kg−1 minute−1 (MKX), propofol at 0.05 mg kg−1 minute−1 (PKXlow) or propofol at 0.1 mg kg−1 minute−1 (PKXhigh). Additional ketamine was administered if a horse moved spontaneously. Cardiopulmonary variables, blood gases, lactate concentration, packed cell volume and total solids were recorded before sedation (baseline), at 10, 20, 30 and 45 minutes during TIVA and 10 minutes after standing. Recovery variables and quantitative recovery scores were compared. Significance was set at p Results Additional ketamine was required for 50% of MKX horses. Systolic arterial pressure was elevated in MKX at 20 minutes compared with baseline (p = 0.043), at 10 and 20 minutes compared with PKXhigh (p = 0.007, p = 0.024) and at 20 and 30 minutes compared with PKXlow (p = 0.009, p = 0.02). MKX horses (5/8) were hypertensive compared with PKXlow (1/8; p = 0.017). All horses became hypoxemic (PaO2 ≤80 mmHg; 10.7 kPa) during TIVA. Recovery variables did not differ among treatments. Conclusions and clinical relevance PKXlow and PKXhigh had similar cardiopulmonary and recovery performance compared with MKX. PKX combinations provided superior quality of anesthesia to that of MKX. A combination of propofol, ketamine and xylazine administered as TIVA can be used in horses to provide anesthesia for short procedures. Supplemental oxygen is recommended.

OBJECTIVE To report complication rates following elective arthroscopy in horses and determine whether postoperative complication rates are higher for outpatient procedures, compared with inpatient procedures. DESIGN Retrospective cohort study. ANIMALS 357 client-owned horses that had undergone 366 elective arthroscopic procedures between January 2008 and February 2015. PROCEDURES Medical records were retrospectively reviewed. Data collected included signalment, travel time to the hospital, clinical signs, joints treated, lesions diagnosed, medications administered, anesthesia and surgery times, details of the procedure (including closure method and surgeons involved), and hospitalization status (inpatient or outpatient). Inpatients were horses that remained hospitalized overnight, and outpatients were horses that were discharged in the afternoon of the day of surgery. The collected data were analyzed along with follow-up information to identify factors associated with postoperative complications and potentially associated with hospitalization status. RESULTS Data were collected on 366 elective arthroscopic procedures (outpatient, n = 168 [46%]; inpatient, 198 [54%]). Complications that occurred included bandage sores, catheter problems, colic, diarrhea, postoperative discomfort, esophageal impaction, fever, incisional drainage, postanesthetic myopathy, persistent synovitis, persistent lameness, septic arthritis, and osteochondral fragments not removed during the original surgery. None of these complications were associated with hospitalization status (outpatient vs inpatient). However, Standardbreds were overrepresented in the outpatient group, and anesthesia and surgery times were longer for the inpatient group. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that outpatient elective arthroscopy in healthy horses could be performed safely and without a higher risk of complications, com pared with similar procedures performed on an inpatient basis.

Objective To compare the biomechanical properties and healing of ventral midline celiotomies (VMC) closed with a self-locking knot combination and forwarder start and Aberdeen end (F-A) vs a traditional knot combination and surgeon's start and end (S-S). Study design In vivo, experimental. Animals Twenty-one horses. Methods Fourteen horses underwent VMC, which was closed with either an F-A (n = 7) or an S-S (n = 7) knot combination. Incisions were subjectively graded by masked evaluators for dehiscence, edema, and drainage. Biomechanical testing was performed on three abdominal segments, and histology was performed on one segment from each animal after humane euthanasia 10 days post-VMC. The abdominal wall of control horses (n = 7, no celiotomy) was collected for biomechanical testing. Results Forwarder start and Aberdeen end and S-S horses had less tensile strength compared with control horses (P ≤ .001). No differences were detected between treatment groups for any variable evaluated, including tensile strength (P = .975), location of failure (P = .240), and histologic healing at the knot (P = .600). Conclusion Closure of VMC with self-locking knots resulted in biomechanical and healing features similar to those with a traditional closure technique, with neither restoring the tensile strength of the linea alba. Clinical significance Results of this study provide evidence to support a clinical trial to evaluate long-term performance of the F-A self-locking knot closure in horses.

Objectives To determine the physiologic and behavioral effects and pharmacokinetic profile of hydromorphone administered intravenously (IV) to horses. Study design Prospective, randomized, crossover study. Animals A group of six adult healthy horses weighing 585.2 ± 58.7 kg. Methods Each horse was administered IV hydromorphone (0.025 mg kg–1; treatment H0.025), hydromorphone (0.05 mg kg–1; treatment H0.05) or 0.9% saline in random order with a 7 day washout period. For each treatment, physiologic, hematologic, abdominal borborygmi scores and behavioral data were recorded over 5 hours and fecal output was totaled over 24 hours. Data were analyzed using repeated measures anova with significance at p Results Hydromorphone administration resulted in a dose-dependent increase in heart rate (HR) and systolic arterial pressure (SAP). HR and SAP were 59 ± 17 beats minute–1 and 230 ± 27 mmHg, respectively, in treatment H0.05 at 5 minutes after administration. No clinically relevant changes in respiratory rate, arterial gases or temperature were observed. The borborygmi scores in both hydromorphone treatments were lower than baseline values for 2 hours. Fecal output did not differ among treatments and no evidence of abdominal discomfort was observed. Recorded behaviors did not differ among treatments. For hydromorphone, mean ± standard deviation for volume of distribution at steady state, total systemic clearance and area under the curve until the last measured concentration were 1.00 ± 0.29 L kg–1, 106 ± 21 mL minute–1 kg–1 and 8.0 ± 1.5 ng hour mL–1, respectively. Conclusions and clinical relevance Hydromorphone administered IV to healthy horses increased HR and SAP, decreased abdominal borborygmi and did not affect fecal output.

Objective To evaluate the pharmacokinetics (PK) of platinum (Pt) and safety of carboplatin-impregnated calcium sulfate hemihydrate (C-I CSH) beads after implantation in healthy cats. Study design In vivo experimental study. Animals Six healthy adult cats. Methods Three C-I CSH beads were implanted in muscle pockets over the right and left hemithoraces of each cat (~3.9 mg/kg of Pt; 60.4 mg/m2 of calculated carboplatin). Hematology and blood chemistry were tested at baseline and 3, 7, 14, and 21 days postimplantation. Serum was analyzed for Pt at specific times from 1 hour to 21 days. Tissue was obtained for histopathology and analysis of Pt at 3, 7, 14, and 21 days at standardized distances from implantation sites. Results Platinum was detected in tissues at all times and distances (range, 0.1-4.19 μg/g). Serum Pt increased up to 2.6 hours (3.25 μg/mL) then decreased sharply. Samples containing muscle had higher Pt compared with samples without muscle (P = .004). Mild hypercalcemia was noted in four cats, and mild inflammatory reaction was noted on histopathology of all samples. Conclusion Platinum was released from C-I CSH beads differentially into surrounding tissues over 21 days. Systemic absorption of Pt was minimal, but mild hypercalcemia occurred. Clinical significance Implantation was well tolerated by healthy adult cats. Securing beads within muscle may limit Pt diffusion to targeted tissue. Although Pt concentrations did not achieve levels reported to be cytotoxic for feline sarcoma cells in culture, results provide evidence to support evaluation of efficacy in the tumor microenvironment of cats with locally invasive cancers.

Objective To investigate the effects of intravenous (IV) administration of terbutaline on PaO2, PaCO2, pH, heart rate (HR) and arterial pressures in healthy, laterally recumbent horses breathing ambient air under total intravenous anesthesia (TIVA). Study design Prospective experimental study. Animals Eight healthy adult horses were enrolled. Six horses, four mares and two geldings weighing 433-624 kg, completed the study. Methods Horses were sedated with xylazine (1.0 mg kg−1) IV for placement of arterial and venous catheters. Anesthesia was induced with midazolam (0.1 mg kg−1) and ketamine (2.2 mg kg−1) IV and maintained with an IV infusion of guaifenesin (50 mg mL−1), ketamine (2 mg mL−1) and xylazine (0.5 mg mL−1) at 1.9 ± 0.3 mL kg−1 hour−1. Horses were in left lateral recumbency and breathed air spontaneously. Arterial blood was collected for pH and blood gas analysis during xylazine sedation, 15 minutes after induction of anesthesia, immediately before and 5, 15 and 30 minutes after administration of terbutaline (2 μg kg−1), and when the horse was standing after recovery from anesthesia. HR, systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures were recorded at 5 minute intervals during anesthesia. Normal data were analyzed with anova and non-normal data were analyzed with a Friedman test with a p Results The mean PaO2 decreased from baseline to Conclusions and clinical relevance Terbutaline (2 μg kg−1) IV did not improve PaO2 and was associated with adverse cardiovascular effects during TIVA in healthy, laterally recumbent horses breathing air.

OBJECTIVE: To determine the intracoelemic (ICe) dose of alfaxalone required to induce loss of righting reflex (LRR) in garter snakes (Thamnophis sirtalis) and to evaluate the tactile stimulus response in unanesthetized and alfaxalone-anesthetized snakes. ANIMALS: 8 healthy mature garter snakes. PROCEDURES: During the first of 3 phases, snakes received each of 3 doses (10, 20, and 30 mg/kg) of alfaxalone, ICe, with a 2-week washout period between treatments. Times to LRR and return of righting reflex were determined after each dose. During phase 2, unanesthetized snakes underwent tactile stimulation testing with Semmes-Weinstein monofilaments once daily for 3 consecutive days to determine the baseline tactile pressure required to elicit purposeful movement. During phase 3, snakes were anesthetized with alfaxalone (30 mg/kg, ICe), and the tactile pressure required to induce purposeful movement was assessed at predetermined times after LRR. RESULTS: Intracoelomic administration of alfaxalone at doses of 10, 20, and 30 mg/kg induced LRR in 0, 5, and 8 snakes, respectively. For snakes with LRR, median time to LRR following the 30-mg/kg dose (3.8 minutes) was significantly shorter than that following the 20-mg/kg dose (8.3 minutes); median time to return of righting reflex did not differ between the 2 doses. Mean ± SD tactile pressure that resulted in purposeful movement in unanesthetized snakes was 16.9 ± 14.3 g. When snakes were anesthetized, the mean tactile pressure that resulted in purposeful movement was significantly increased from baseline at 10, 20, and 30 minutes after LRR. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested ICe administration of alfaxalone might be effective for anesthetizing garter snakes.

OBJECTIVE To evaluate agreement among diplomates of the American College of Veterinary Anesthesia and Analgesia for scores determined by use of a simple descriptive scale (SDS) or a composite grading scale (CGS) for quality of recovery of horses from anesthesia and to investigate use of 3-axis accelerometry (3AA) for objective evaluation of recovery. ANIMALS 12 healthy adult horses. PROCEDURES Horses were fitted with a 3AA device and then were anesthetized. Eight diplomates evaluated recovery by use of an SDS, and 7 other diplomates evaluated recovery by use of a CGS. Agreement was tested with κ and AC1 statistics for the SDS and an ANOVA for the CGS. A library of mathematical models was used to map 3AA data against CGS scores. RESULTS Agreement among diplomates using the SDS was slight (κ = 0.19; AC1 = 0.22). The CGS scores differed significantly among diplomates. Best fit of 3AA data against CGS scores yielded the following equation: RS = 9.998 × SG0.633 × ∑UG0.174, where RS is a horse's recovery score determined with 3AA, SG is acceleration of the successful attempt to stand, and ∑UG is the sum of accelerations of unsuccessful attempts to stand. CONCLUSIONS AND CLINICAL RELEVANCE Subjective scoring of recovery of horses from anesthesia resulted in poor agreement among diplomates. Subjective scoring may lead to differences in conclusions about recovery quality; thus, there is a need for an objective scoring method. The 3AA system removed subjective bias in evaluations of recovery of horses and warrants further study.

Change in body temperature (BT), serum biochemistry and recovery variables were compared after infusion of amino acids (AA) or lactated Ringer’s solution (LRS) in dogs undergoing ovariohysterectomy. Dogs received eight parts 10 per cent AA and two parts LRS (AA, n=10) or only LRS (CG, n=10) at 10 ml/kg/hour during 90 minutes of anaesthesia. BT was measured during anaesthesia and 60 minutes of recovery. Extubation time and shivering were noted. Serum samples were obtained before anaesthesia (T0), end of anaesthesia (T90) and 18 hours after (T18h). Friedman, Mann-Whitney, Kruskal-Wallis or Fisher’s exact tests were used for analysis. A decrease in BT of −2.16 (−1.59 to −3.24)°C for group AA and −2.79 (−1.98 to −4.52)°C for group CG was different (P=0.02). Time to extubation was 5 (3–9) minutes for group AA and 9 (5–15) minutes for group CG and was different (P=0.01). Only 30 per cent of dogs in group AA and 100 per cent of dogs in group CG shivered during recovery (P=0.003). Glucose, insulin and blood urea nitrogen at T90 were higher than T0 and T18h for group AA. Dogs receiving intraoperative infusion of AA had a higher BT, extubated sooner and shivered less than control dogs at recovery from anaesthesia.

A 10-yr-old female spayed mixed breed tiger presented for a 9-day history of acute and nonprogressive paralysis of the pelvic limbs. Magnetic resonance imaging revealed a lesion suggestive of fibrocartilaginous embolic myelopathy with regional spinal cord edema, decreased disk signal intensity at L2-L3, and mild intervertebral disk protrusion at L1-L2 and L2-L3. Cerebral spinal fluid analysis showed no overt evidence of infection or neoplasia. Medical therapy was instituted, including corticosteroids and gastroprotectants as well as nursing care and physical therapy. The tiger began showing clinical improvement 2 wk after initiating treatment, progressing to the point where the animal was standing and intermittently walking. Three months after diagnosis, the tiger had regained muscle strength of its hind limbs and walked regularly with improving coordination. This case is the first report of antemortem diagnosis and successful medical management of suspected fibrocartilaginous embolic myelopathy in a large exotic felid.

Objective—To qualitatively describe lung CT images obtained from sedated healthy equine neonates (≤ 14 days of age), use quantitative analysis of CT images to characterize attenuation and distribution of gas and tissue volumes within the lungs, and identify differences between lung characteristics of foals ≤ 7 days of age and foals > 7 days of age. Animals—10 Standardbred foals between 2.5 and 13 days of age. Procedures—Foals were sedated with butorphanol, midazolam, and propofol and positioned in sternal recumbency for thoracic CT. Image analysis software was used to exclude lung from nonlung structures. Lung attenuation was measured in Hounsfield units (HU) for analysis of whole lung and regional changes in attenuation and lung gas and tissue components. Degree of lung attenuation was classified as follows: hyperinflated or emphysema, −1,000 to −901 HU; well aerated, −900 to −501 HU; poorly aerated, −500 to −101 HU; and nonaerated, > −100 HU. Results—Qualitative evidence of an increase in lung attenuation and patchy alveolar patterns in the ventral lung region were more pronounced in foals ≤ 7 days of age than in older foals. Quantitative analysis revealed that mean ± SD lung attenuation was greater in foals ≤ 7 days of age (−442 ± 28 HU) than in foals > 7 days of age (−521 ± 24 HU). Lung aeration and gas volumes were lower than in other regions ventrally and in the mid lung region caudal to the heart. Conclusions and Clinical Relevance—Identified radiographic patterns and changes in attenuation were most consistent with atelectasis and appeared more severe in foals ≤ 7 days of age than in older neonatal foals. Recognition of these changes may have implications for accurate CT interpretation in sedated neonatal foals with pulmonary disease.

Objective To compare a towel under, a warm water pad under or a forced warm air blanket over dogs as techniques to reduce heat loss during a standardized anesthetic. Study design Prospective, randomized, crossover study. Animals Eight, healthy, mixed breed dogs weighing 16.3–19.6 kg. Methods Dogs were anesthetized four times for 90 minutes. Dogs were placed on a steel table (treatment TA), with a cotton towel (treatment TO) or a circulating warm water pad (treatment WP) between the dog and the table, or with, a towel under the dog and covered with a forced warm air blanket (treatment WAB). Rectal temperature (RT) was recorded at 5 minute intervals. Changes in temperature (ΔRT) were calculated as the RT at a given point subtracted from the RT before anesthesia (baseline) and compared over time. Results After 90 minutes of anesthesia, the ΔRT was 3.42 °C ± 0.29 for TA, 2.78 °C ± 0.43 for TO, 1.98 °C ± 0.29 for WP, and 0.91 °C ± 0.27 for WAB. Significant differences in ΔRT occurred between TA and WAB at 20 minutes (0.94 °C ± 0.42, p = 0.0206), between TO and WAB at 30 minutes (1.16 °C ± 0.62, p = 0.0063), between WP and WAB at 50 minutes (0.96 °C ± 0.98, p = 0.0249), between TA and WP at 35 minutes (1.19 °C ± 0.54, p = 0.0091), between TO and WP at 70 minutes (1.12 °C ± 0.56, p = 0.0248), and between TA and TO at 75 minutes (0.96 °C ± 0.62, p = 0.0313). These differences in ΔRT between each treatment persisted from the times indicated until the end of the anesthesia. Conclusion and clinical relevance During anesthesia, forced warm air blankets were superior to other methods tested for limiting heat loss. An efficient heat loss technique should be used for anesthesia longer than 20 minutes duration in medium sized dogs.

Recovery from anesthesia can be one of the most dangerous and unpredictable elements of providing anesthesia to horses. Strategies to quiet, control, and improve the quality of recovery of horses can be implemented in most situations and circumstances. This article provides an overview of the recovery period and areas where interventions may be practical to clinicians to provide improved care for their equine patients.

Effective delivery of local anesthesia is essential for successful standing surgical procedures in the horse. Local anesthesia can be used to facilitate examination of the eye, diagnostic procedures, therapeutic techniques, and surgical procedures. Understanding the relevant clinical anatomy and techniques for performing local anesthesia is critical to delivering successful local and regional anesthesia and analgesia.

OBJECTIVE To evaluate use of single manual alveolar recruitment maneuvers (ARMs) to eliminate atelectasis during CT of anesthetized foals. ANIMALS 6 neonatal Standardbred foals. PROCEDURES Thoracic CT was performed on spontaneously breathing anesthetized foals positioned in sternal (n = 3) or dorsal (3) recumbency when foals were 24 to 36 hours old (time 1), 4 days old (time 2), 7 days old (time 3), and 10 days old (time 4). The CT images were collected without ARMs (all times) and during ARMs with an internal airway pressure of 10, 20, and 30 cm H2O (times 2 and 3). Quantitative analysis of CT images measured whole lung and regional changes in attenuation or volume with ARMs. RESULTS Increased attenuation and an alveolar pattern were most prominent in the dependent portion of the lungs. Subjectively, ARMs did not eliminate atelectasis; however, they did incrementally reduce attenuation, particularly in the nondependent portion of the lungs. Quantitative differences in lung attenuation attributable to position of foal were not identified. Lung attenuation decreased significantly (times 2 and 3) and lung volume increased significantly (times 2 and 3) after ARMs. Changes in attenuation and volume were most pronounced in the nondependent portion of the lungs and at ARMs of 20 and 30 cm H2O. CONCLUSIONS AND CLINICAL RELEVANCE Manual ARMs did not eliminate atelectasis but reduced attenuation in nondependent portions of the lungs. Positioning of foals in dorsal recumbency for CT may be appropriate when pathological changes in the ventral portion of the lungs are suspected.

Anaesthetic chamber concentrations of isoflurane, sevoflurane and desflurane that resulted in loss of righting reflex within 15 minutes in 50 per cent of toads (Rhinella marina) exposed (ED50-LRR

Objective To evaluate efficacy of a topical epidural analgesia used alone, or in combination with hydromorphone, against a standard pain protocol for the 48 hours immediately after hemilaminectomy. Study Design Randomized, blinded, controlled, clinical trial. Animals Dogs (n = 30) with thoracolumbar intervertebral disc disease treated with hemilaminectomy. Methods Dogs were randomly divided into 3 groups: group 1 received intermittent hydromorphone postoperatively, group 2 received a topical epidural of preservative-free morphine and dexmedetomidine administered via gel foam, group 3 received both forms of analgesia. All dogs were monitored and assessed for pain for 48 hours immediately postoperatively. Data were analyzed using MANOVA and Wilcoxon Rank Sum Tests. Results There was a significant temporal difference in treatment groups 1 and 3 when using a 0–10 pain scale (MANOVA, P = .02). There was also a significant difference at the 48th hour postoperatively between groups 1 and 3 (Wilcoxon Rank Sum Test). Conclusion Topical epidural of preservative-free morphine and dexmedetomidine administered via gelfoam is not sufficient analgesia alone post hemilaminectomy but in conjunction with other opioid administration may lead to superior pain relief.

Objective To determine endogenous production of L-lactate and the clearance of exogenous sodium L-lactate (ExLC) in healthy adult horses. Design A sodium L-lactate solution (1 mmol/kg body weight qs to 500 mL final volume in 0.9% NaCl) was adminstered IV over 15 minutes. Blood samples for L-lactate concentration [LAC] measurement were collected immediately prior to infusion, at 5, 10, and 15 minutes during infusion and at 1 minute intervals for 15 minutes, at 30, 45, 60, 120, and 180 minutes postinfusion. Disposition modeling and pharmacokinetic analysis was performed using proprietary software. Setting University Teaching Hospital. Animals Six clinically healthy adult horses. Measurements and Main Results Median (range) baseline [LAC] was 0.43 (0.20–0.72) mmol/L for samples obtained every 3 hours over the 24 hours prior to ExLC and demonstrated variability primarily associated with horse. Median [LAC] immediately prior to ExLC was 0.43 (0.35–0.52) mmol/L. A 2-compartment model was used to specify the pharmacokinetic parameters. Median (range) ExLC was 1.05 (0.073–1.75) L·h−1·kg−1 and t1/2 β was 29.54 (20.8–38.6) min. Median lactate production based on basal [LAC] immediately prior to ExLC was was 0.49 (0.31–0.93) mmol·h−1·kg−1. Conclusions ExLC in healthy adult horses is greater than that of hyperlactemic human patients but similar to normolactemic-sick human patients examined using the same model, supporting development of species, and disease specific ExLC parameters.

Objective To determine whether experimentally induced acute moderate hyperglycemia is associated with coagulation activation in healthy adult horses. Design Prospective experimental study. Setting University veterinary teaching hospital. Animals Six healthy adult horses. Interventions Hyperglycemia (10.0–13.3 mmol/L [180–240 mg/dL]) was induced and maintained for 6 hours using a hyperglycemic clamp technique. Blood glucose concentrations were assessed using a point of care (POC) glucometer at 10- and 20-minute intervals throughout the hyperglycemic clamp procedure. Platelet count, fibrinogen concentration, prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin antithrombin complex level (TAT), and thromboelastometry (TEM) were determined before and after jugular catheter placement, prior to glucose administration, and at 3 and 6 hours of sustained hyperglycemia. Data were analyzed by repeated measures analysis of variance with significance defined as P < 0.05. Measurements and Main Results All horses maintained blood glucose concentration >10.0 mmol/L (>180 mg/dL) throughout the duration of the hyperglycemic clamp with a mean concentration of 11.9 ± 0.3 mmol/L [216 ± 6 mg/dL] as measured by the POC glucometer. No significant difference was found for any evaluated parameter associated with sustained hyperglycemia. Intravenous catheter placement resulted in a significant increase in mean TAT (0.8 ± 0.3 μg/L pre-catheter, 2.3 ± 0.8 μg/L post-catheter; P = 0.008). Conclusions Acute, moderate hyperglycemia in healthy adult horses does not have a detectable effect on coagulation based on evaluated parameters. Jugular catheter placement results in a transient increase in thrombin generation as determined by increased TAT concentrations.

The effect of a proton pump inhibitor on gastrointestinal (GI) microbiota was evaluated. Eight healthy 9-month-old dogs (four males and four females) received omeprazole (1.1 mg kg−1) orally twice a day for 15 days. Fecal samples and endoscopic biopsies from the stomach and duodenum were obtained on days 30 and 15 before omeprazole administration, on day 15 (last day of administration), and 15 days after administration. The microbiota was evaluated using 16S rRNA gene 454-pyrosequencing, fluorescence in situ hybridization, and qPCR. In the stomach, pyrosequencing revealed a decrease in Helicobacter spp. during omeprazole (median 92% of sequences during administration compared to > 98% before and after administration; P = 0.0336), which was accompanied by higher proportions of Firmicutes and Fusobacteria . FISH confirmed this decrease in gastric Helicobacter ( P < 0.0001) and showed an increase in total bacteria in the duodenum ( P = 0.0033) during omeprazole. However, Unifrac analysis showed that omeprazole administration did not significantly alter the overall phylogenetic composition of the gastric and duodenal microbiota. In feces, qPCR showed an increase in Lactobacillus spp. during omeprazole ( P < 0.0001), which was accompanied by a lower abundance of Faecalibacterium spp. and Bacteroides-Prevotella-Porphyromonas in the male dogs. This study suggests that omeprazole administration leads to quantitative changes in GI microbiota of healthy dogs.

Objective—To assess the clinical differences between induction of anesthesia in ball pythons with intracardiac administration of propofol and induction with isoflurane in oxygen and to assess the histologic findings over time in hearts following intracardiac administration of propofol. Design—Prospective randomized study. Animals—30 hatchling ball pythons (Python regius). Procedures—Anesthesia was induced with intracardiac administration of propofol (10 mg/kg [4.5 mg/lb]) in 18 ball pythons and with 5% isoflurane in oxygen in 12 ball pythons. Induction time, time of anesthesia, and recovery time were recorded. Hearts from snakes receiving intracardiac administration of propofol were evaluated histologically 3, 7, 14, 30, and 60 days following propofol administration. Results—Induction time with intracardiac administration of propofol was significantly shorter than induction time with 5% isoflurane in oxygen. No significant differences were found in total anesthesia time. Recovery following intracardiac administration of propofol was significantly longer than recovery following induction of anesthesia with isoflurane in oxygen. Heart tissue evaluated histologically at 3, 7, and 14 days following intracardiac administration of propofol had mild inflammatory changes, and no histopathologic lesions were seen 30 and 60 days following propofol administration. Conclusions and Clinical Relevance—Intracardiac injection of propofol in snakes is safe and provides a rapid induction of anesthesia but leads to prolonged recovery, compared with that following induction with isoflurane. Histopathologic lesions in heart tissues following intracardiac injection of propofol were mild and resolved after 14 days.

Case Description—A 5-year-old castrated male domestic shorthair cat was examined because of presumptive lidocaine intoxication. Thirty minutes earlier, the cat had received an SC injection of approximately 140 mg of lidocaine hydrochloride (20 mg/kg [9.1 mg/lb]) to facilitate closure of a wound on the left pelvic limb. Clinical Findings—Initial physical examination revealed severe lethargy and respiratory distress; erratic, poor-quality pulses with severe hypotension; and pulmonary edema. Treatment and Outcome—Initial supportive treatment included administration of oxygen and IV administration of lactated Ringer's solution. Additional treatment with a 20% lipid emulsion (1.5 mL/kg [0.68 mL/lb], IV) delivered over a 30-minute period resulted in dramatic improvement in cardiovascular and behavioral variables. No adverse effects from lipid emulsion were detected on routine hematologic evaluation, thoracic radiography, or computed tomography. Clinical Relevance—IV administration of a lipid emulsion was used in the treatment of lidocaine intoxication in a cat. Rapid infusion of a lipid emulsion may be a therapeutic option for veterinary patients with toxicosis attributable to local anesthetics or other lipid-soluble drugs.

Objective To assess whether recovery from general anesthesia, in an illuminated or a darkened stall, has an effect on time to first movement, time to standing, and recovery score. Study design Prospective randomized clinical study. Animals Twenty-nine healthy, 2- to 5-year-old horses undergoing surgical correction of dorsal displacement of the soft palate. Methods Each horse was assigned randomly to recover in either an illuminated (n = 15) or a darkened stall (n = 14). For pre-anesthetic medication, all horses received intravenous (IV) xylazine (0.4 mg kg−1) and butorphanol (0.02 mg kg−1). Anesthesia was induced with midazolam (0.1 mg kg−1) and ketamine (2.2 mg kg−1) IV and maintained on isoflurane in oxygen. Vital parameters, end-tidal CO2 and isoflurane were recorded at 5-minute intervals. At the conclusion of anesthesia, horses were placed in either an illuminated or a darkened stall and xylazine (0.2 mg kg−1) IV was administered at extubation. Video cameras were used to record the horses while they were allowed to recover undisturbed. Video recordings were later viewed and recoveries were evaluated on a 100-point scale by three graders. Results Horses in illuminated and darkened recovery stalls were evaluated on total anesthesia time, minimum alveolar concentration hours of isoflurane, time to first movement, time to standing, and total recovery score. There were no significant differences between the two groups in any of the measured parameters. Conclusion Recovering horses in a darkened versus an illuminated recovery stall may provide no benefit. Clinical relevance Darkening the recovery stalls for horses recovering from general anesthesia may be unnecessary.

Anesthetizing the neonatal foal presents significant challenges as a result of physiologic differences from the adult equine. This article gives the reader an overview of these differences and the impact they have on anesthetic drug selection, monitoring, and support of the equine neonate. Special emphasis is directed to the sick neonate and appropriate preparation and maintenance of anesthesia in the face of commonly presented disease conditions.

Inadvertent perianesthetic hypothermia is one of the most common complications in anesthesia of dogs and cats. Hypothermia during anesthesia can lead to altered pharmacokinetics of anesthetic and analgesic drugs, dysfunction of organ systems, increased patient susceptibility to infection, reduced wound healing, altered coagulation, hypotension, and delayed recovery. An understanding of the pathophysiology, complications, and techniques to minimize hypothermia during anesthesia can help veterinarians optimize care of patients. This article provides an overview of inadvertent perianesthetic hypothermia.

A 6-month-old male Quarter Horse was evaluated for chronic respiratory tract disease. Diagnostic investigations revealed pulmonary inflammation; Pneumocystis carinii was detected within macrophages. Lymphocyte subpopulation phenotyping and immunoglobulin concentration analysis were performed and results suggested immune suppression. Trimethoprim-sulfamethoxazole administration was initiated; the colt was discharged but was reexamined 8 days later because of profuse diarrhea and endotoxemia. Bacterial culture of feces recovered Salmonella spp resistant to trimethoprim-sulfamethoxazole, and a diagnosis of antimicrobial-associated colitis was made. Bilateral fibrinous hypopyon developed and was treated with topical medication and intracameral injections of human recombinant tissue plasminogen activator. Dapsone (3 mg/kg [1.4 mg/lb], PO, q 24 h; dose extrapolated from human data) was administered for treatment of P carinii pneumonia (56-day treatment period). The colt recovered from the pneumonia and diarrhea. Dapsone may be a useful adjunct to traditional treatment for P carinii pneumonia in horses or as a sole medication for horses that cannot tolerate other treatments.

A 2-year-old female Quarter Horse was evaluated for hind limb lameness, fever (40 degrees C [104 degrees F]), and lethargy of 2 weeks' duration. Hypoproteinemia characterized by hypoalbuminemia and hyperfibrinogenemia was detected. Abdominal ultrasonography revealed thickening of the right dorsal colon wall. Treatment was instituted for putative right dorsal coliis. Lameness evaluation localized signs of pain to the lumbar vertebrae or pelvis. Radiography performed with the horse standing and nuclear scintigraphy revealed no abnormalities. Ventrodorsal pelvic radiography revealed a focal area of bony lysis and proliferation involving the cranial portion of the pubic symphysis. Aspiration yielded purulent exudate containing Rhodococcus equi, which was susceptible to erythromycin. Treatment included surgical debridement of the abscess and oral administration of erythromycin and rifampin. The horse's hind limb lameness completely resolved within 20 days. Infections of the pubic symphysis should be considered when lameness localized to the pelvis is associated with fever and an inflammatory leukogram.

Anesthesia for mice is commonly performed through the injection of parenteral agents via the intraperitoneal (IP) route. Variability in anesthetic sensitivities has been noted in mice resulting in inconsistencies in anesthetic depth and/or mortality. Anesthetic protocols that improve consistency and safety are needed. The objectives of this study were to assess the effects of intraperitoneal (IP) ketamine (95 mg/kg) and xylazine (7 mg/kg) alone or combined with lidocaine at 4, 8, or 16 mg/kg on time to loss (LRR) and return (RRR) of righting reflex, duration of immobilization and loss of pedal withdrawal response (PWR), body weight and histopathology in CD-1 mice. In a prospective, randomized trial, 36 male CD-1 mice, 4-6 weeks of age were randomly assigned to 5 groups: saline (SA, n = 4); ketamine-xylazine (KX, n = 8); ketamine-xylazine-lidocaine 4 mg/kg (KXL4, n = 8); ketamine-xylazine-lidocaine 8 mg/kg (KXL8, n = 8); ketamine-xylazine-lidocaine 16 mg/kg (KXL16, n = 8). Two mice in each group were euthanized at day 2 post-injection and the remaining mice were euthanized at day 11 post-injection. After IP injection, LRR and RRR, duration of immobilization and loss of PWR, body weight and histopathology were evaluated. LRR occurred sooner in mice receiving KXL16 compared with KX, with median (range) times of 78 (62-104) and 107 (91-298) seconds, respectively. Loss of PWR occurred in 1, 5, 4, 6 mice for groups KX, KXL4, KXL8, and KXL16 respectively. Median (range) duration of absent PWR was longer in mice receiving KXL16 at 13 (0-30) minutes, compared to KX at 0 (0-9) minutes. Duration of immobilization and RRR were not different between groups. Weight loss occurred 2 days following anesthesia but was not different between groups. Weight gain was significantly greater in all lidocaine groups 11 days post-injection compared to KX. No mortality or histopathologic abnormalities were observed in any group. Lidocaine administered with ketamine and xylazine shortens the onset of anesthesia in mice and improves anesthetic depth without prolonging recovery time.

OBJECTIVE To compare CT and radiographic images of the lungs in sedated healthy foals positioned in sternal recumbency and to investigate whether a relationship exists between CT-derived measurements of lung attenuation and Paco2 and Pao2. ANIMALS 6 healthy Standardbred foals < 14 days of age. PROCEDURES Thoracic CT images were acquired followed by radiographic views with each foal sedated and positioned in sternal recumbency. For each foal, both CT and radiographic images were evaluated for severity and extent of changes by lung regions on the basis of a subjective scoring system by 3 investigators. Quantitative analysis of CT images was also performed. Assessments of Pao2 and Paco2 were performed before sedation, following sedation prior to CT, and after CT prior to radiography. RESULTS Interobserver agreement for CT and radiographic image scoring was strong (0.73) and fair (0.65), respectively; intraobserver agreement was near perfect for CT (0.97) and radiographic (0.94) image scoring. Increased CT attenuation and radiographic changes were identified for all foals and were preferentially distributed in the caudoventral portion of the lungs. Radiographic scores were significantly lower than CT image scores. A positive correlation (r = 0.872) between lung attenuation and CT image score was identified. A significant increase in Paco2 was not considered clinically relevant. Significant changes in Pao2 were not observed. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that interpretation of CT images may be less subjective, compared with interpretation of radiographic images. These findings may aid in the evaluation of CT and radiographic images of neonatal foals with respiratory tract disease.

Objective—To determine the safety, efficacy, and effects on hemolymph gas analysis variables of sevoflurane anesthesia in Chilean rose tarantulas (Grammostola rosea). Animals—12 subadult Chilean rose tarantulas of unknown sex. Procedures—Spiders were anesthetized in a custom chamber with sevoflurane (5% in oxygen [1.0 L/min]), then allowed to recover in 100% oxygen. Righting reflex was evaluated every 3 minutes during anesthesia to determine time to anesthetic induction and recovery. Hemolymph samples were collected from an intracardiac location prior to and after induction of anesthesia and evaluated to determine various gas analysis variables. Results—Mean ± SD induction and recovery times were 16 ± 5.91 minutes and 29 ± 21.34 minutes, respectively. Significant differences were detected for Po2, base excess, and glucose and ionized magnesium concentrations between hemolymph samples obtained before anesthesia and those obtained after induction of anesthesia. Conclusions and Clinical Relevance—Results of this study suggested that the use of sevoflurane as an anesthetic agent for Chilean rose tarantulas was safe and effective. Various hemolymph sample gas analysis values changed during anesthesia.