Otariid gammaherpesvirus 1 in South American fur seals (Arctocephalus australis) and a novel related herpesvirus in free-ranging South American sea lions (Otaria byronia): Prevalence and effects of age, sex, and sample type.

Otariid gammaherpesvirus 1 (OtGHV1) is associated with high rates of urogenital carcinoma in free-ranging California sea lions (Zalophus californianus; CSL), and until recently was reported only in the Northern Hemisphere. The objective of this study was to survey free-ranging South American sea lions (Otaria byronia; SASL) and South American fur seals (Arctocephalus australis: SAFS) in Punta San Juan, Peru for OtGHV1 and to determine prevalence characteristics. Twenty-one percent (14/67) of urogenital swabs collected over three years (2011, 2014, 2015) from live pinnipeds of both species tested positive with a pan-herpesvirus conventional PCR. Sequencing of SAFS amplicons revealed 100% homology to OtGHV1 at the DNA polymerase, glycoprotein B, and viral bcl2-like genes. Sequencing of SASL amplicons revealed a novel related virus, herein called Otariid gammaherpesvirus 8 (OtGHV8). For comparison of sample sites, urogenital, conjunctival, and oropharyngeal swabs collected from 136 live pinnipeds of both species at Punta San Juan between 2011-2018 were then assayed using quantitative PCR for a segment of the OtGHV1/8 DNA polymerase gene using a qPCR assay now determined to cross-react between the two viruses. In total, across both species, 38.6% (51/132) of urogenital swabs, 5.6% (4/71) of conjunctival swabs, and 1.1% (1/90) of oropharyngeal swabs were positive for OtGHV1/8, with SASL only positive on urogenital swabs. Results from SASL were complicated by the finding of OtGHV8, necessitating further study to determine prevalence of OtGHV1 versus OtGHV8 using an alternate assay. Results from SAFS suggest a potential relationship between OtGHV1 in SAFS and CSL. Though necropsy surveillance in SAFS is very limited, geographic patterns of OtGHV1-associated urogenital carcinoma in CSL and the tendency of herpesviruses to cause more detrimental disease in aberrant hosts suggests that it is possible that SAFS may be the definitive host of OtGHV1, which gives further insight into the diversity and phyogeography of this clade of related gammaherpesviruses.

NALTREXONE AS A PROMISING TREATMENT FOR CLINICAL SIGNS OF LATERAL LINE DEPIGMENTATION IN PALETTE SURGEONFISH (PARACANTHURUS HEPATUS).

Lateral line depigmentation (LLD) is a common condition in managed tropical saltwater fish, and treatment is somewhat elusive. Naltrexone, an opioid receptor antagonist, enhances epithelial cell replication, cytokine production, and angiogenesis to stimulate wound healing in mice. A treatment trial with 11 palette surgeonfish with LLD was performed. Seven fish underwent a single topical treatment of a mixture of 4 mg naltrexone and 10 g iLEX petroleum paste applied topically to LLD lesions. Four additional fish served as controls: two received only topical iLEX and two received no treatment. Severity of disease was scored on a 0-3 scale. Inflammatory response was gauged on a separate 0-3 scale for 5 d after treatment based on severity of erythema, as seen in a clinical case performed prior to this study. After 11 days, four affected animals that lacked an inflammatory response after naltrexone topical treatment were administered a single dose of intralesional 0.04% naltrexone (4 mg diluted into 10 ml saline). Lesions on all fish were photographed and measured at day 33. Clinical improvements in lesion size and pigmentation were apparent following topical naltrexone therapy in fish with severe lesions. Although these cases are promising, more data are needed to further evaluate the effectiveness of naltrexone 0.04% in treating LLD lesions in palette surgeonfish.

Bioencapsulation is a feasible method of terbinafine administration in Emydomyces testavorans-infected western pond turtles (Actinemys marmorata).

OBJECTIVE: To evaluate the pharmacokinetics of terbinafine administered to western pond turtles (Actinemys marmorata) via oral gavage and bioencapsulated in earthworms. ANIMALS: 7 western pond turtles. PROCEDURES: A randomized complete crossover single-dose pharmacokinetic study was performed. Compounded terbinafine (25 mg/mL; 30 mg/kg) was administered through oral gavage (OG) directly into the stomach or bioencapsulated (BEC) into an earthworm vehicle. Blood (0.2 mL) was drawn from the jugular vein at 0, 0.5, 1, 2, 4, 8, 12, 24, 48, 72, and 120 hours after administration. Plasma terbinafine levels were measured using high-performance liquid chromatography. RESULTS: Peak plasma terbinafine concentrations of 786.9 ± 911 ng/mL and 1,022.2 ± 911 were measured at 1.8 ± 2.8 and 14.1 ± 12.3 hours after OG and BEC administration, respectively. There was a significant (P = .031) increase in area under the curve with BEC compared to OG. Using steady-state predictions, with once-daily terbinafine administration, 3/7 and 7/7 turtles had plasma concentrations persistently greater than the minimum inhibitory concentration (MIC) for Emydomyces testavorans for the OG and BEC administration routes of administration, respectively. With administration every 48 hours, 3/7 turtles for the OG phase and 6/7 turtles for the BEC phase had concentrations greater than the E. testavorans MIC throughout the entire dosing interval. CLINICAL RELEVANCE: Administration of terbinafine (30 mg/kg) every 24 or 48 hours via earthworm bioencapsulation in western pond turtles may be appropriate for the treatment of shell lesions caused by E. testavorans. Clinical studies are needed to assess the efficacy of treatment.

SAFETY AND EFFICACY OF MILBEMYCIN OXIME AND LUFENURON TO TREAT ARGULUS SPP. INFESTATION IN SMOOTH BACK RIVER STINGRAYS (POTAMOTRYGON ORBIGNYI) AND MAGDALENA RIVER STINGRAYS (POTAMOTRYGON MAGDALENAE).

Fish lice, ectoparasites of the genus Argulus, are branchurian crustaceans that can significantly impact fish health by causing mechanical damage to cutaneous barriers and increasing susceptibility to other infections. While many treatments have been reported in teleosts and invertebrates, there are no published treatments for elasmobranchs. This study evaluated the safety and efficacy of a commercial formulation of milbemycin oxime and lufenuron in freshwater stingrays for treatment of Argulus spp. Seven juvenile Magdalena river stingrays (Potamotrygon magdalenae) and 10 juvenile smooth back river stingrays (Potamotrygon orbignyi) had severe infestations of Argulus spp. that were identified visually and microscopically. Animals were treated with milbemycin oxime and lufenuron (at 0.015 mg/L and 0.30 mg/L, respectively) in a 6-hr immersion once weekly for two treatments. They were visually examined for skin lesions as well as behavior and appetite daily by animal care staff. A subset of animals was euthanized and necropsied on days 8, 9, 43, and 78 after treatment initiation. There were no Argulus spp. detected at the time of the second treatment. Complete gross and histologic evaluations were completed for all animals. At all time points, no gross abnormalities were detected with the exception of thin body condition in some animals; no Argulus spp. were noted. Histologic lesions were all attributed to poor nutritional state at the time of acquisition. No histologic evidence of acute or chronic toxicosis was detected. The commercial formulation of milbemycin oxime and lufenuron, applied at the dose and for the exposure time used in this study, effectively eradicated Argulus spp. in a population of juvenile P. magdalenae and P. orbignyi, and did not cause mortality or clinical gross or histologic evidence of acute or chronic toxicity.

ECHOCARDIOGRAPHIC PARAMETERS IN AFRICAN WHITE-BELLIED PANGOLINS (PHATAGINUS TRICUSPIS) WITHOUT CARDIAC DISEASE.

Relatively little is known about pangolin care and physiology, and it has become increasingly important to have a better understanding of normal health parameters for evaluation of free-ranging, rehabilitating, and managed populations. Echocardiograms were performed on six African white-bellied pangolins (Phataginus tricuspis) under professional care at a single institution. Because of the propensity of pangolins to roll up with only thick keratinized scales exposed, the pangolins were anesthetized with either isoflurane or sevoflurane. All echocardiograms were performed and evaluated by a board-certified cardiologist. None of the pangolins had any evidence of prior cardiac disease. All standard measurements were obtained. Four pangolins (66.7%) had trace to mild mitral regurgitation, six (100%) had trace to mild tricuspid regurgitation, and two (33.3%) had trace to mild pulmonic regurgitation. All examinations were determined to be normal, with no evidence of valvular structural abnormalities, cardiac dysfunction, chamber enlargement, or cardiac hypertrophy. This report broadens understanding of normal echocardiogram parameters in pangolin species and contributes techniques and baseline data for veterinarians caring for these vulnerable populations.

REPEATED ANESTHESIA IN A BLACK RHINOCEROS ( DICEROS BICORNIS) TO MANAGE UPPER RESPIRATORY OBSTRUCTION.

This report describes weekly repeated anesthesia in a 7-yr-old, 1,030 kg, female Eastern black rhinoceros ( Diceros bicornis michaeli), that was immobilized six times using a combination of 2 mg etorphine (0.002 mg/kg), 5 mg medetomidine (0.005 mg/kg), 25 mg midazolam (0.024 mg/kg), and 300 mg ketamine (0.29 mg/kg) delivered intramuscularly (IM) via remote dart to facilitate long-term medical care of a bilateral, obstructive Actinomyces sp. rhinitis. The drug combination described in this study resulted in reliable, rapid recumbency of the animal within 2-8 min after initial administration via dart and produced deep anesthesia for 34-78 min without supplemental anesthetic administration. Antagonist drugs (100 mg naltrexone [0.1 mg/kg] and 25 mg atipamezole [0.024 mg/kg] IM) produced reliable and uneventful recoveries in all the procedures. During each anesthetic procedure, the animal was intubated and provided intermittent positive pressure ventilation with a megavertebrate demand ventilator. Tachycardia and hypoxia noted after induction resolved after positive pressure ventilation with oxygen. This report provides useful information on a novel anesthetic protocol used repeatedly for intensive medical management in a black rhinoceros.

SERUM COBALAMIN AND FOLATE CONCENTRATIONS AS INDICATORS OF GASTROINTESTINAL DISEASE IN KILLER WHALES ( ORCINUS ORCA).

Cobalamin and folate are water-soluble vitamins that are useful indicators of chronic gastrointestinal (GI) function in humans and some animal species. Serum cobalamin and folate concentrations in an ex situ population of killer whales ( Orcinus orca) were measured and factors that may affect their serum concentrations were identified. Serum samples ( n = 104) were analyzed from killer whales ( n = 10) both while clinically healthy and during periods of clinical GI disease as defined by clinical signs and fecal cytology. To characterize serum cobalamin and folate concentrations in clinically healthy animals, a mixed-model regression was used, with cobalamin and folate both significantly affected by weight (cobalamin: P < 0.0001, folate: P = 0.006) and season (cobalamin: P < 0.0001, folate: P < 0.0001). The marginal mean concentrations for cobalamin and folate across weight and season were 742 ± 53.6 ng/L and 30.2 ± 2.6 µg/L, respectively. The predicted 95% confidence intervals (CI) for these analytes were then compared with samples collected during periods of GI disease. Across individuals, 22% (2/9) of the folate and 80% (8/10) of the cobalamin samples from the animals with GI disease fell outside the 95% CI for the population. When comparing samples within an individual, a similar pattern presented, with 100% of cobalamin of the observed abnormal samples reduced compared to healthy animal concentration variability. The same was not true for folate. These results suggest that serum concentrations of cobalamin and folate may be useful minimally invasive markers to identify GI disease in killer whales, especially when values are compared within an individual.