EFFECTS OF TRICAINE METHANESULFONATE IN A MANAGED COLLECTION OF MOON JELLYFISH (AURELIA AURITA).

The moon jellyfish (Aurelia aurita) is a scyphozoan frequently maintained in public and private aquaria. Little research has been conducted to investigate the effects of various drugs, such as anesthetics, in this species. Tricaine methanesulfonate (MS-222), a common immersion anesthetic for fish and amphibians, was evaluated in a managed population of moon jellyfish. Twenty-four clinically healthy jellyfish were assigned into three groups of eight for trials of 0.3 g/L MS-222 (low concentration [LC]), 0.6 g/L MS-222 (high concentration [HC]), and a saltwater control. The goal was to evaluate the effects of MS-222 administration on moon jellyfish movement and response to stimuli. Movement and response to stimuli were measured via rocking and probe stimulus tests and observations of bell contraction quality and body tone. These tests were performed at baseline and throughout both drug exposure and recovery periods. A threshold drug effect was defined based on systematic scoring criteria. Additionally, elastomer tags were administered to four of eight animals in each MS-222 group to evaluate response to tag placement after drug exposure. Threshold drug effect was achieved in six of eight individuals in the LC group and eight of eight individuals in the HC group. The LC group had median threshold and recovery times of 12.2 and 10.1 min, respectively, while the HC group had median threshold and recovery times of 4.0 and 19.9 min, respectively. The HC group had significantly faster time to threshold drug effect (P < 0.001) and longer recovery times (P= 0.005) than the LC group. In both the LC and HC tagged group, three of four jellyfish had no reaction to tag placement. All animals recovered uneventfully, and there were no mortalities. MS-222 at 0.3 and 0.6 g/L decreased movement and response to stimuli in moon jellyfish.

Retrospective Analysis of Cataract Formation and Nutritional Etiology in a Managed Collection of Parakeet Auklets (Aethia psittacula).

The parakeet auklet (Aethia psittacula) is a piscivorous seabird with a natural diet of various invertebrate and teleost species, which is challenging to replicate in a managed collection. A high prevalence of early onset cataracts was observed in a managed collection of parakeet auklets at the North Carolina Zoo (Asheboro, NC, USA), which was hypothesized to be related to inappropriate vitamin A and E levels. From 1994 to 2002, these parakeet auklets were offered dietary supplementation comprising Vita-Zu small bird tablets. In June 2002, the birds were transitioned to only Thiamin-E paste (vitamin E and thiamin only). Plasma samples were collected from birds with and without cataracts from 1998 to 2005 and submitted for vitamin A (retinol) and vitamin E (α-tocopherol) analysis. Food items comprising the birds' diet were also evaluated for vitamin content. This information was combined with clinical and necropsy data from medical records from 1994 to 2015. A total of 78% of birds (39/50) developed cataracts, with a median age of onset of 7 years (range, 2-12 years). Cataracts ranged from incipient to hypermature during both routine ophthalmic examinations and postmortem evaluations. The median (range) of plasma retinol and α-tocopherol values were 1.99 µg/mL (0.20-6.68 µg/mL) and 15.39 µg/mL (3.40-96.27 µg/mL), respectively. There were no significant differences in plasma concentrations of vitamins based on the animals' sex, origin, presence of cataracts, or administered vitamin supplementation product. No other etiologies for cataract development were identified in the population. Further research in free-ranging parakeet auklet nutrition and cataract occurrence is warranted for continued species collection management.

EVALUATION OF THE OPHTHALMIC DISEASE AND HISTOPATHOLOGIC EFFECTS DUE TO THE OCULAR TREMATODE PHILOPHTHALMUS ZALOPHI ON JUVENILE GALAPAGOS SEA LIONS ( ZALOPHUS WOLLEBAEKI).

The Galapagos sea lion ( Zalophus wollebaeki) is an otariid species endemic to the Galapagos archipelago and is currently listed as endangered. The ocular trematode Philophthalmus zalophi was recently reported to affect the survival of juvenile Galapagos sea lions on Santa Cruz Island, resulting in marked ophthalmic changes. This study evaluated the ophthalmic disease and histopathologic effects of P. zalophi on juvenile Galapagos sea lions in the largest rookery located on San Cristóbal Island. Twenty juvenile Galapagos sea lions (10 male and 10 female) were evaluated among five sites in the rookery El Malecón. Ophthalmic examination, including fluorescein staining and evaluation of the adnexa, cornea, and sclera, were performed on each eye. The presence, number, and location of ocular parasites were determined, and parasites were collected for identification. Conjunctival biopsy was performed on 11 animals: 2 that lacked parasites and gross lesions and 9 with both parasites and gross lesions. All parasites collected were confirmed as P. zalophi and identified in 80% (16/20) of the study animals and 70% (28/40) of the examined eyes. Philophthalmus zalophi was most frequently found attached to the nictitating membrane but also located on the palpebral conjunctiva or cornea. The most common clinical signs were varying degrees of conjunctival hyperemia (28/40 eyes), most frequently of the nictitating membrane and mucoid ocular discharge (12/40 eyes). The number of parasites was significantly associated with the degree of conjunctival hyperemia ( P < 0.001). Histopathology of conjunctival biopsies revealed organized lymphoid follicles and lymphoplasmacytic infiltrates. The histopathologic changes and gross lesions were likely due to the parasite's attachment to the conjunctiva. This study provides additional details of P. zalophi infection in juvenile Galapagos sea lions. Further research is warranted to detail the life cycle of this parasite, transmission to sea lions, and potential treatment protocols.

Effects of alfaxalone administered intravenously to healthy yearling loggerhead sea turtles (Caretta caretta) at three different doses.

OBJECTIVE To compare physiologic and anesthetic effects of alfaxalone administered IV to yearling loggerhead sea turtles (Caretta caretta) at 3 different doses. DESIGN Randomized crossover study. ANIMALS 9 healthy yearling loggerhead sea turtles. PROCEDURES Animals received each of 3 doses of alfaxalone (3 mg/kg [1.4 mg/lb], 5 mg/kg [2.3 mg/lb], or 10 mg/kg [4.5 mg/lb]) administered IV in randomly assigned order, with a minimum 7-day washout period between doses. Endotracheal intubation was attempted following anesthetic induction, and heart rate, sedation depth, cloacal temperature, and respirations were monitored. Times to first effect, induction, first voluntary muscle movement, first respiration, and recovery were recorded. Venous blood gas analysis was performed at 0 and 30 minutes. Assisted ventilation was performed if apnea persisted 30 minutes following induction. RESULTS Median anesthetic induction time for all 3 doses was 2 minutes. Endotracheal intubation was accomplished in all turtles following induction. Heart rate significantly increased after the 3- and 5-mg/kg doses were administered. Median intervals from alfaxalone administration to first spontaneous respiration were 16, 22, and 54 minutes for the 3-, 5-, and 10-mg/kg doses, respectively, and median intervals to recovery were 28, 46, and 90 minutes, respectively. Assisted ventilation was required for 1 turtle after receiving the 5-mg/kg dose and for 5 turtles after receiving the 10-mg/kg dose. The 10-mg/kg dose resulted in respiratory acidosis and marked hypoxemia at 30 minutes. CONCLUSIONS AND CLINICAL RELEVANCE IV alfaxalone administration to loggerhead sea turtles resulted in a rapid anesthetic induction and dose-dependent duration of sedation. Assisted ventilation is recommended if the 10 mg/kg dose is administered.

Comparison of hematology, plasma biochemistry, and blood gas variables between 2 venipuncture sites in Southern Stingrays (Dasyatis americana).

BACKGROUND: The Southern Stingray (Dasyatis americana) is a batoid elasmobranch frequently exhibited in zoological institutions. Blood is commonly collected from the caudal hemal arch at the tail base in stingrays for the purpose of health assessment and clinical pathology tests. An alternative site that allows a dorsal or ventral approach without necessitating puncture of a cartilaginous structure has been identified between the cartilaginous pectoral fin rays (ceratotrichia). OBJECTIVES: The purpose of the study was to compare CBC, plasma biochemistry analytes, and blood gas variables between blood samples collected from the caudal and pectoral fin vasculature sites of the Southern Stingray. METHODS: Fifteen captive Southern Stingrays (10 females, 5 males) from 4 zoo and aquarium facilities were sampled. Lithium heparinized blood samples were collected from the caudal and pectoral venipuncture sites of each animal. Values from estimated total and differential leukocyte counts, plasma biochemistry analytes, and blood gas variables were compared. RESULTS: There were no statistically significant differences between venipuncture sites for the measured analytes except for CK activity, which was statistically significantly higher in the pectoral site samples. Levels of agreement between sites were good or moderate for 22 analytes and poor for ALT, AST, CK, pO2 , lactate, monocytes, and eosinophils. CONCLUSIONS: The good agreement between sampling sites for the majority of the measured analytes and the lack of differences that would alter clinical interpretation support the use of the pectoral site as an alternative to the traditional caudal fin venipuncture site in Southern Stingrays.

Population pharmacokinetics of enrofloxacin in purple sea stars (Pisaster ochraceus) following an intracoelomic injection or extended immersion.

OBJECTIVE To determine population pharmacokinetics of enrofloxacin in purple sea stars (Pisaster ochraceus) administered an intracoelomic injection of enrofloxacin (5 mg/kg) or immersed in an enrofloxacin solution (5 mg/L) for 6 hours. ANIMALS 28 sea stars of undetermined age and sex. PROCEDURES The study had 2 phases. Twelve sea stars received an intracoelomic injection of enrofloxacin (5 mg/kg) or were immersed in an enrofloxacin solution (5 mg/L) for 6 hours during the injection and immersion phases, respectively. Two untreated sea stars were housed with the treated animals following enrofloxacin administration during both phases. Water vascular system fluid samples were collected from 4 sea stars and all controls at predetermined times during and after enrofloxacin administration. The enrofloxacin concentration in those samples was determined by high-performance liquid chromatography. For each phase, noncompartmental analysis of naïve averaged pooled samples was used to obtain initial parameter estimates; then, population pharmacokinetic analysis was performed that accounted for the sparse sampling technique used. RESULTS Injection phase data were best fit with a 2-compartment model; elimination half-life, peak concentration, area under the curve, and volume of distribution were 42.8 hours, 18.9 µg/mL, 353.8 µg•h/mL, and 0.25 L/kg, respectively. Immersion phase data were best fit with a 1-compartment model; elimination half-life, peak concentration, and area under the curve were 56 hours, 36.3 µg•h/mL, and 0.39 µg/mL, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the described enrofloxacin administration resulted in water vascular system fluid drug concentrations expected to exceed the minimum inhibitory concentration for many bacterial pathogens.

POPULATION PHARMACOKINETICS OF ENROFLOXACIN AND ITS METABOLITE CIPROFLOXACIN IN THE GREEN SEA URCHIN (STRONGYLOCENTROTUS DROEBACHIENSIS) FOLLOWING INTRACOELOMIC AND IMMERSION ADMINISTRATION.

Sea urchin mass mortality events have been attributed to both infectious and noninfectious etiologies. Bacteria, including Vibrio spp. and Pseudoalteromonas spp., have been isolated during specific mortality events. Aquarium collection sea urchins are also subject to bacterial infections and could benefit from antimicrobial treatment, but pharmacokinetic studies have been lacking for this invertebrate group until recently. This study evaluated the pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin in the green sea urchin (Strongylocentrotus droebachiensis) after intracoelomic injection and medicated bath immersion administration. The utility of a population pharmacokinetic method using nonlinear mixed effects modeling (NLME) was also evaluated. Thirty sea urchins were assigned to either the injection or immersion group. Twelve study animals and three untreated controls were utilized for each administration method: enrofloxacin 10 mg/kg intracoelomic injection or a 6-hr enrofloxacin 10 mg/L immersion. Each animal was sampled four times from 0 to 120 hr. Water samples were collected during immersion treatment and posttreatment time points in both groups. Hemolymph and water sample drug concentrations were analyzed using high-performance liquid chromatography, and pharmacokinetic parameters were determined using an NLME population pharmacokinetic method. Enrofloxacin concentrations were fit to a two-compartment model with first-order input for the intracoelomic injection group. The enrofloxacin elimination half-life (t½), peak hemolymph concentration (CMAX), and area under the curve (AUC) were 38.82 hr, 90.92 µg/ml, and 1,199 hr·µg/ml, respectively. Enrofloxacin was modeled to a one-compartment model with first-order input for the immersion treatment. The enrofloxacin t½, CMAX, and AUC were 33.46 hr, 0.48 µg/ml, and 32.88 hr·µg/ml, respectively. Ciprofloxacin was detected in trace concentrations in all hemolymph samples, indicating minimal production of this metabolite. The concentrations of enrofloxacin achieved far exceeded minimum inhibitory concentrations reported for teleost pathogens. No adverse effects were associated with enrofloxacin administration by either treatment method or from hemolymph sampling.

Preliminary investigation of bottlenose dolphins (Tursiops truncatus) for hfe gene-related hemochromatosis.

Hemochromatosis (iron storage disease) has been reported in diverse mammals including bottlenose dolphins (Tursiops truncatus). The primary cause of excessive iron storage in humans is hereditary hemochromatosis. Most human hereditary hemochromatosis cases (up to 90%) are caused by a point mutation in the hfe gene, resulting in a C282Y substitution leading to iron accumulation. To evaluate the possibility of a hereditary hemochromatosis-like genetic predisposition in dolphins, we sequenced the bottlenose dolphin hfe gene, using reverse transcriptase-PCR and hfe primers designed from the dolphin genome, from liver of affected and healthy control dolphins. Sample size included two case animals and five control animals. Although isotype diversity was evident, no coding differences were identified in the hfe gene between any of the animals examined. Because our sample size was small, we cannot exclude the possibility that hemochromatosis in dolphins is due to a coding mutation in the hfe gene. Other potential causes of hemochromatosis, including mutations in different genes, diet, primary liver disease, and insulin resistance, should be evaluated.