A case of epiglottic entrapment in a cat.

OBJECTIVE: The objective of this study was to describe a case of epiglottic entrapment in a cat. CASE SUMMARY: A 5-month-old male neutered Russian Blue cat was evaluated for progressive stertorous upper airway sounds, acute onset vestibulopathy and abnormal laryngeal anatomy. Endotracheal intubation was only able to be achieved using videoscopic guidance and identified concern for severe nasopharyngeal stenosis. A computerized tomography scan revealed otitis interna, narrowed nasopharynx and no definitive cause for the stertorous breathing. The cat recovered very slowly from anaesthesia due to concern for airway obstruction following extubation. It was discharged the following day and then passed away at home 2 weeks later. Necropsy revealed that the epiglottis was obscured by 2 cm of redundant mucosal tissue extending from the base of the tongue to the larynx resulting in epiglottic entrapment. Also noted was chronic, severe otitis interna and externa. Upper airway obstruction is suspected to be the cause of sudden death. NEW OR UNIQUE INFORMATION: To the authors' knowledge, this is the first report of these oropharyngeal anatomic abnormalities in a cat.

Effect of the reverse Trendelenburg position on the incidence of gastroesophageal reflux in dogs anesthetized for elective stifle surgery.

OBJECTIVE: To determine if a 15° reverse Trendelenburg position decreases the incidence of gastroesophageal reflux (GER) compared with a horizontal position in dogs anesthetized for stifle surgery. STUDY DESIGN: Prospective, randomized parallel-arm study. ANIMALS: A total of 44 healthy client-owned dogs were enrolled and data from 36 dogs were analyzed. METHODS: Dogs requiring preoperative radiographs under anesthesia, or with a history of gastrointestinal signs or administered gastroprotectant therapy within 1 month of surgery were excluded. Anesthesia protocol was standardized to include hydromorphone, dexmedetomidine, ketamine, propofol and isoflurane. Dogs were randomly assigned at enrollment to be positioned in a 15° reverse Trendelenburg or a horizontal position for surgery. Continuous pH monitoring was documented throughout the procedure with a 6.4 Fr (2.13 mm) esophageal pH probe positioned in the distal esophagus via the oral cavity. GER was defined as pH < 4.0 (acidic) or > 7.5 (alkaline) for more than 30 seconds. The proportions of dogs developing GER were compared between groups using Fisher's exact test. Time to reflux was compared using survival curves and the Gehan-Breslow-Wilcoxon test. Statistical significance was set as p < 0.05. RESULTS: An episode of GER occurred in 11/36 (30%) dogs. Reflux was alkaline in two dogs and acidic in nine dogs. The proportion of dogs with GER was 5/18 (28%) and 6/18 (33%) for dogs in the reverse Trendelenburg position and horizontal position, respectively, and was not statistically significant (p > 0.99). Median (range) time until reflux was 44 (23-135) and 44.5 (9-56) minutes when dogs were positioned in reverse Trendelenburg position and horizontal position, respectively (p = 0.66; two-tailed Mann-Whitney U test). CONCLUSIONS AND CLINICAL RELEVANCE: Positioning the surgery table in a 15° rostral elevation for dogs anesthetized for elective stifle surgical procedures did not decrease the incidence of GER.

Species Differences in Metabolism of Soluble Epoxide Hydrolase Inhibitor, EC1728, Highlight the Importance of Clinically Relevant Screening Mechanisms in Drug Development.

There are few novel therapeutic options available for companion animals, and medications rely heavily on repurposed drugs developed for other species. Considering the diversity of species and breeds in companion animal medicine, comprehensive PK exposures in the companion animal patient is often lacking. The purpose of this paper was to assess the pharmacokinetics after oral and intravenous dosing in domesticated animal species (dogs, cats, and horses) of a novel soluble epoxide hydrolase inhibitor, EC1728, being developed for the treatment of pain in animals. Results: Intravenous and oral administration revealed that bioavailability was similar for dogs, and horses (42 and 50% F) but lower in mice and cats (34 and 8%, respectively). Additionally, clearance was similar between cats and mice, but >2× faster in cats vs. dogs and horses. Efficacy with EC1728 has been demonstrated in mice, dogs, and horses, and despite the rapid clearance of EC1728 in cats, analgesic efficacy was demonstrated in an acute pain model after intravenous but not oral dosing. Conclusion: These results demonstrate that exposures across species can vary, and investigation of therapeutic exposures in target species is needed to provide adequate care that addresses efficacy and avoids toxicity.

2020 AAHA Anesthesia and Monitoring Guidelines for Dogs and Cats.

Risk for complications and even death is inherent to anesthesia. However, the use of guidelines, checklists, and training can decrease the risk of anesthesia-related adverse events. These tools should be used not only during the time the patient is unconscious but also before and after this phase. The framework for safe anesthesia delivered as a continuum of care from home to hospital and back to home is presented in these guidelines. The critical importance of client communication and staff training have been highlighted. The role of perioperative analgesia, anxiolytics, and proper handling of fractious/fearful/aggressive patients as components of anesthetic safety are stressed. Anesthesia equipment selection and care is detailed. The objective of these guidelines is to make the anesthesia period as safe as possible for dogs and cats while providing a practical framework for delivering anesthesia care. To meet this goal, tables, algorithms, figures, and "tip" boxes with critical information are included in the manuscript and an in-depth online resource center is available at aaha.org/anesthesia.

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

OBJECTIVE: To compare postanesthetic xylazine and dexmedetomidine on recovery characteristics from sevoflurane anesthesia in horses. STUDY DESIGN: Randomized, crossover study. ANIMALS: Six geldings, mean±standard deviation (SD) (range), 17±4 (11-24) years and 527±80 (420-660) kg. METHODS: Horses were anesthetized with sevoflurane for 60 minutes under standardized conditions for a regional limb perfusion study. In recovery, horses were administered either xylazine (200 µg kg-1) or dexmedetomidine (0.875 µg kg-1) intravenously. Recoveries were unassisted and were video-recorded for later evaluation of recovery events and quality by two individuals unaware of treatment allocation. Recovery quality was assessed using a 100 mm visual analog scale (VAS) (0=poor recovery, 100=excellent recovery), the Edinburgh Scoring System (ESS) (0-100; 100=excellent recovery) and the mean attempt interval (MAI) (longer=better). Data are mean±SD. RESULTS: All recovery quality assessments (xylazine and dexmedetomidine, respectively: VAS: 71±21 mm, 84±13 mm; ESS: 65±22, 67±30; MAI: 52±24 minutes, 60±32 minutes) and events (first limb movement: 37±8 minutes, 42±10 minutes; first attempt to lift head: 44±12 minutes, 48±9 minutes; first attempt to sternal posture: 57±28 minutes, 50±7 minutes; number of head bangs: 2.0±3.0, 0.5±0.5; time to first attempt to stand: 72±6 minutes, 78±13 minutes; time to standing: 79±14 minutes, 84±13 minutes) did not differ significantly between treatments (p>0.05). CONCLUSIONS AND CLINICAL RELEVANCE: Recovery characteristics did not differ significantly between postanesthetic xylazine and dexmedetomidine following 1 hour of sevoflurane anesthesia in horses in this study. Further evaluations in more horses and in younger horses are required to confirm these results.

Cardiovascular, respiratory and metabolic responses to apnea induced by atlanto-occipital intrathecal lidocaine injection in anesthetized horses.

OBJECTIVE: To determine physiologic responses to apnea-induced severe hypoxemia in anesthetized horses. STUDY DESIGN: Prospective experimental study. ANIMALS: Six university-owned horses with a median (range) body weight of 500 (220-510) kg and aged 13.5 (0.8-24.0) years scheduled for euthanasia. METHODS: Xylazine-midazolam-ketamine-anesthetized horses breathing room air spontaneously were instrumented with a facial artery catheter for pressure measurement and blood sampling, and were made apneic with atlanto-occipital intrathecal lidocaine (4 mg kg-1 ). Cardiopulmonary, biochemical and hematologic variables were recorded before (baseline) and every minute for 10 minutes after lidocaine injection. RESULTS: PaO2 values were: baseline, 55 mmHg (7.3 kPa); 1 minute, 28 mmHg (3.8 kPa); 2 minutes, 18 mmHg (2.4 kPa); 3 minutes, 15 mmHg (2.0 kPa), and 4-10 minutes, (8-11 mmHg (1.1-1.5 kPa). PaCO2 values were: baseline, 50 mmHg (6.7 kPa); 1 minute, 61 mmHg (8.1 kPa), and 2-10 minutes, 64-66 mmHg (8.5-8.8 kPa). Base excess values at baseline, 1 minute and 2-10 minutes were 5.3 mmol L-1 , 6.5 mmol L-1 and 7.0-8.1 mmol L-1 , respectively. Pulse rates at baseline, 1 minute and 2-7 minutes were 36, 53 and 54-85 beats minute-1 , respectively. Asystole occurred at 8 minutes. Pulse pressures were 50 mmHg at baseline and 1 minute, and 39 mmHg, 31 mmHg, 22 mmHg, 17 mmHg and 1-9 mmHg at 2, 3, 4, 5 and 6-10 minutes, respectively. Lactate was 0.9 mmol L-1 at baseline, progressively increasing to 1.7-2.4 mmol L-1 at 7-10 minutes. Packed cell volume increased after 7 minutes of apnea. There were no other major changes. CONCLUSIONS AND CLINICAL RELEVANCE: Apnea immediately exacerbated hypoxemia and hypercapnia and rapidly caused hemodynamic instability. Apnea in hypoxemic anesthetized horses is associated with a serious risk for progress to cardiovascular collapse.

Cardiovascular effects of equipotent doses of isoflurane alone and isoflurane plus fentanyl in New Zealand White rabbits (Oryctolagus cuniculus).

OBJECTIVE To determine effects of equipotent concentrations of fentanyl and isoflurane, compared with isoflurane alone, on cardiovascular variables in New Zealand White rabbits (Oryctolagus cuniculus). ANIMALS 6 adult female New Zealand White rabbits. PROCEDURES Rabbits were anesthetized with isoflurane, and lungs were mechanically ventilated. The minimum alveolar concentration (MAC) of isoflurane alone (baseline) and with fentanyl administered IV to achieve 3 targeted plasma concentrations was determined for each rabbit by means of an electrical stimulus. Cardiovascular variables were measured in a separate experiment at 1.3X isoflurane MAC and equipotent doses of isoflurane plus fentanyl at the same 3 targeted plasma concentrations. Blood samples were collected for measurement of blood gas variables and plasma fentanyl concentrations. Treatment effects were evaluated by repeated-measures ANOVA followed by 2-tailed paired t tests with sequentially rejective Bonferroni correction. RESULTS Mean ± SD MAC of isoflurane was 1.95 ± 0.27%. Mean measured plasma fentanyl concentrations of 4.97, 8.93, and 17.19 ng/mL reduced isoflurane MAC by 17%, 37%, and 56%, respectively. Mean measured plasma fentanyl concentrations during cardiovascular measurements were 5.49, 10.26, and 18.40 ng/mL. Compared with baseline measurements, heart rate was significantly lower at all 3 plasma fentanyl concentrations, mean arterial blood pressure and systemic vascular resistance were significantly higher at mean fentanyl concentrations of 10.26 and 18.40 ng/mL, and cardiac output was significantly higher at 18.40 ng of fentanyl/mL. CONCLUSIONS AND CLINICAL RELEVANCE Administration of fentanyl in isoflurane-anesthetized rabbits resulted in improved mean arterial blood pressure and cardiac output, compared with isoflurane alone. This balanced anesthesia technique may prove useful in the management of clinical cases in this species.

Evaluation of trends in marijuana toxicosis in dogs living in a state with legalized medical marijuana: 125 dogs (2005-2010).

OBJECTIVE: To report a correlation between the increased number of medical marijuana licenses and marijuana toxicosis in dogs in a state with legalized marijuana for medical use. DESIGN: Retrospective case series from January 1, 2005 to October 1, 2010. SETTING: Private specialty referral hospital and a university teaching hospital. ANIMALS: A total of 125 client-owned dogs presenting for known or suspected marijuana toxicosis with or without a urine drug screening test (UDST). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: During the study period, 125 dogs were evaluated including 76 dogs with known marijuana exposure or a positive UDST (group 1), 6 dogs with known marijuana ingestion and a negative UDST (group 2), and 43 dogs with known marijuana ingestion that were not tested (group 3). The incidence of marijuana toxicosis presenting to both hospitals increased 4-fold, while the number of people registered for medical marijuana in the state increased 146-fold in the last 5 years. A significant positive correlation was detected between the increase in known/suspected marijuana toxicosis in dogs (groups 1-3) and the increased number of medical marijuana licenses (correlation R coefficient = 0.959, P = 0.002). Two dogs that ingested butter made with medical grade marijuana in baked products died. CONCLUSIONS: A significant correlation was found between the number of medical marijuana licenses and marijuana toxicosis cases seen in 2 veterinary hospitals in Colorado. Ingestion of baked goods made with medical grade tetrahydrocannabinol butter resulted in 2 deaths. UDST may be unreliable for the detection of marijuana toxicosis in dogs.

Ultrasound-guided transversus abdominis plane block in the dog: an anatomical evaluation.

OBJECTIVE: To describe the ultrasound-guided technique to the transversus abdominis plane (TAP) block in the dog and evaluate the spread of a local anesthetic/methylene blue solution. STUDY DESIGN: Prospective experimental trial. ANIMALS: Ten adult Beagle cadavers weighing 11.1 ± 1.1 kg (mean ± SD). METHODS: Transversus abdominis plane (TAP) blocks were performed bilaterally by a single trained individual on unpreserved cadaver dogs using 10 mL of methylene blue/bupivacaine solution per site. Dissection of the abdominal wall was performed within 15-55 minutes of block to determine distribution of injectate and nerve involvement in the transversus abdominis fascial plane. RESULTS: The transversus abdominis fascial plane was adequately visualized via ultrasound and injected in twenty hemi-abdominal walls. Segmental branches of T11, T12, T13, L1, L2, and L3 were adequately stained in 20%, 60%, 100%, 100%, 90%, and 30% of injections, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: This anatomical study suggests that the transversus abdominis plane (TAP) block would provide adequate regional anesthesia of the abdomen, potentially extending to the cranial and caudal limits of the abdomen. This supports the clinical potential of this block in veterinary medicine.