RETROSPECTIVE REVIEW OF PROPOFOL ANESTHESIA IN MULTIPLE ELASMOBRANCH SPECIES AT GEORGIA AQUARIUM, 2010-2022.

General anesthesia is often required in elasmobranch species for medical procedures. A variety of anesthetic drugs have been administered to elasmobranchs with wide variability in efficacy and safety. A retrospective review of 47 anesthetic procedures using IV propofol in eight different elasmobranch species at the Georgia Aquarium from 2010 to 2022 was performed. Cases involving seven sand tiger sharks (Carcharias taurus), four largetooth sawfish (Pristis perotteti), one longcomb sawfish (Pristis zijsron), four blacktip reef sharks (Carcharhinus melanopterus), three silvertip sharks (Carcharhinus albimarginatus), one sandbar shark (Carcharhinus plumbeus), five cownose rays (Rhinoptera bonasus), and one blotched fantail stingray (Taeniura meyeni) were evaluated. Induction dose of IV propofol (median: 2.5; 25-75%: 2.3-3.0; range: 1.7-4.0 mg/kg), time to desired effect (median: 4.0; 25-75%: 2.0-5.0; range: 0.5-15.0 min) and anesthetic duration (median: 76.0; 25-75%: 61.5-119.0; range: 27-216 min) were reported in all species. In six procedures (12.7%), maintenance of desired anesthetic plane required a supplemental dose of propofol IV (1 mg/kg) or addition of tricaine methanesulfonate (70 mg/L) as an immersion bath. The most common side effects were apnea and prolonged recovery. The IV propofol was efficacious and provided a procedural plane of anesthesia for a clinically relevant period of time in the majority of elasmobranch species, but observation for and management of complications is warranted.

Clinical tolerance of dexamethasone in New Zealand white rabbits.

Rabbits have been a popular pet and research species world-wide. In many clinical and research situations, controlling inflammation is necessary for the health of these animals. One of the first drugs commonly employed in veterinary medicine to suppress inflammatory responses is corticosteroids. Unfortunately, steroid use in rabbits is not universally accepted as they are perceived, based on their potent immunosuppressant activity, to negatively impact quality of life. This is may be due, in part, to the lack of well-developed dosing protocols in these animals. This study evaluated the impact of a 5-day IM dexamethasone (Dex, 0.5 mg/kg) protocol on the immunity and clinical health of the New Zealand rabbit. Through two experiments separated by a 10-day washout period, experiment 1 comprised 5-days of dosing with bleedings on day 0, 3, 5 and 7, where experiment 2 consisted of 5-days of dosing with bleedings on day 0, 3 and 5. Animals were monitored twice daily for changes in clinical health. Hematology, T cell subset phenotype, leukocyte cell cycle, histopathology, phagocytosis and oxidative formation were evaluated. Consistent with other species, 5-day dosing with Dex suppressed leukocytes, in particular the T cells (p ≤ 0.003). Interestingly, rabbits failed to show any adverse clinical signs throughout the entire study. This would imply that a 5-day IM Dex (0.5 mg/kg) dosing protocol is well tolerated by New Zealand white rabbits and could be used in rabbits suffering from inflammatory conditions or disease as long as the animal's immune status is closely monitored.

Measurements of the radiographic cardiac silhouette of ospreys (Pandion haliaetus).

OBJECTIVE: To evaluate and report measurements of the radiographic cardiac silhouette of healthy juvenile and adult ospreys (Pandion haliaetus). ANIMALS: 54 ospreys (22 adults, 19 juveniles, and 13 birds of undetermined age) without clinical signs of cardiac disease and with adequate ventrodorsal radiographic images for cardiac silhouette assessment. PROCEDURES: Radiographs of ospreys were assessed to determine cardiac width at the widest point as well as sternal width and thoracic width at the same level. Two-way mixed-effects models were used to evaluate interrater reliability for mean rating. Multivariable linear regression analysis was used to create predictive models of cardiac width and to establish a theoretical reference range for healthy ospreys. RESULTS: Cardiac width of healthy ospreys was approximately 90% to 92% of sternal width and 67% to 69% of thoracic width. Both sternal width and thoracic width were significant predictors of cardiac width in independent predictive models as well as in a combined model after controlling for age. Thirty-four of 41 (83%) measured cardiac widths were within the theoretical reference range. CONCLUSIONS AND CLINICAL RELEVANCE: Ospreys are sentinels used in monitoring environmental health. Environmental factors may have an impact on the cardiac health of ospreys, but reference values for healthy ospreys have not been established for use in assessing cardiomegaly in this species. The radiographic ratios and predictive model obtained in this study may be useful for objective evaluation of cardiomegaly in ospreys.