Diakoudi G, Buonavoglia A, Pellegrini F, Capozza P, Vasinioti VI, Cardone R, Catella C, Camero M, Parisi A, Capozzi L, Mendoza-Roldan JA, Otranto D, Bànyai K, Martella V, Lanave G. 2023. Identification of new astroviruses in synanthropic squamates. Res Vet Sci, 161:103–109. Gainor K, Stewart KM, Picknell A, Russ M, Makela N, Watson K, Mancuso DM, Malik YS, Ghosh S. 2023. First report on detection and complete genomic analysis of a novel CRESS DNA virus from sea turtles. Pathogens (Basel, Switzerland), 12(4):601. Kuhn JH, Schmaljohn CS. 2023. A brief history of bunyaviral family Hantaviridae. Diseases (Basel,VIRUSES
Reptiles
Ophidian serpentoviruses, initially referred to as nidoviruses, were first documented in captive pythons nearly 10 yr ago. Since then, much has been learned about these important pathogens, now classified in the subfamily Serpentovirinae of the family Tobaniviridae and representing important emerging pathogens that threaten captive snakes. Serpentoviral infections are best characterized in pythons (family Pythonidae), but have also been documented in boas (family Boidae) and colubrids (family Colubridae), as well as shingleback skinks (Tiliqua rugosa), veiled chameleons (Chamaeleo calyptratus), and Bellinger River snapping turtles (Myuchelys georgesi). Clinical signs include increased oral mucous secretion, oral mucosal reddening, dyspnea, anorexia, and weight loss. Subclinical infections can also occur, and multiple studies report a lack of correlation between clinical signs and the presence of serpentoviral nucleic acids in snakes. Lesions associated with serpentoviral infections predominantly occur in the upper respiratory and gastrointestinal tracts, but can also extend to the lungs. Microscopically, these lesions may consist of inflammation, epithelial proliferation, and proliferative interstitial pneumonia, which can be complicated by concurrent bacterial bronchopneumonia. The most common method of diagnosis is reverse transcriptase polymerase chain reaction to detect viral RNA, and oral/choanal swabs are reliable samples for ante- or postmortem diagnosis. Specific treatment protocols have not yet been described, and management is based on supportive care. This paper presents a narrative review of all serpentovirus publications to date with perspective from researchers working to further characterize these pathogens, with the goal of serving as a comprehensive clinical and diagnostic overview for clinicians, zoological curatorial staff, wildlife biologists, and hobbyists.Abstract
A 5-yr-old male central bearded dragon (Pogona vitticeps) presented with a 3 day history of left forelimb lameness, minimal muscle tone, and absent pain sensation distal to the midhumerus. Computed tomography (CT) revealed thickened and hypoattenuating soft tissues adjacent to the left scapulohumeral and left neck regions with no abnormal contrast enhancement. The suspected left external jugular vein in this region was ill defined and small, with filling defects, consistent with the appearance of a venous thrombus. Focal ultrasound of the left side of the neck confirmed a thrombus in this location, just cranial to a jugular venous valve. The patient was treated with supportive care and started on clopidogrel as an antithrombotic treatment. Clinical improvement was minimal following this visit, and the patient presented again 5 months later after declining significantly. On follow-up imaging at this visit, a suspected cardiac mass was seen on echocardiography. A fine-needle aspirate of the mass at that time was suspicious for a sarcoma; however, the sample was nondiagnostic. The previously identified thrombus could not be detected on ultrasonography at this visit. The owner ultimately decided to pursue hospice care at home and no additional imaging or further workup was performed. This is the first report in reptiles describing a venous thrombus using diagnostic imaging. Given the reported occurrence of aneurysms and thrombi in bearded dragons in clinical practice, this case demonstrates the use of an important tool for diagnosis of these conditions.Abstract
A 2-yr-old female African side-neck turtle (Pelomedusa subrufa) housed at a pet store in Illinois, USA presented for evaluation of nasal discharge and an ulcerative skin lesion. Molecular diagnostics for Mycoplasma spp., herpesviruses, and frog virus 3 (ranavirus) were negative, and cytologic evaluation of the ulceration showed nonseptic inflammation without fungal elements. A presumptive diagnosis of a bacterial upper respiratory infection was treated with ceftazidime (20 mg/kg SC every 72 h) and husbandry improvements were recommended. One month later, the turtle re-presented; physical examination revealed diffuse skin sloughing and severe dehydration, and the animal was euthanized. Necropsy and histopathology revealed multiple fungal granulomas throughout the liver, gastrointestinal tract, and lungs. Heavy growth of a white powdery fungal organism was obtained from culture. Four gene targets (D1/D2 domains of the 28S ribosomal DNA, 18S-28S ribosomal internal transcribed spacer region, actin, and β-tubulin) were sequenced from the fungal isolate and each was >98% identical to Nannizziopsis arthrosporioides. A maximum-likelihood phylogenetic tree constructed from concatenated D1/D2, ITS, actin, and β-tubulin sequences from Nannizziopsis spp. placed the new fungal isolate in a highly supported (99% bootstrap support) monophyletic group with two N. arthrosporioides isolates. This case report describes the first known N. arthrosporioides infection in an aquatic turtle species and adds to the growing literature surrounding N. arthrosporioides infections in nonsquamate reptilian patients.Abstract
A 15-yr-old, male, captive red-tailed boa (Boa constrictor constrictor) was submitted for postmortem examination after it was euthanized after becoming nonresponsive and laterally recumbent. The snake had a history of respiratory disease, coelomic swelling, leukocyte intracytoplasmic inclusion bodies, and an antemortem negative Reptarenavirus PCR. At necropsy, there were solid white masses in the lungs and throughout the alimentary tract, and firm, smooth yellow masses in the pericardium and adventitia of heart base vessels. Histopathology revealed an anaplastic large-cell lymphoma that infiltrated multiple tissue types, most severely the lungs and esophagus. Neoplastic lymphocytes were negative for CD3 and positive for Pax5, consistent with a B-cell lymphoma. The yellow pericardial masses were composed of neoplastic neuroendocrine cells with moderate amounts of vacuolated cytoplasm and small, ovoid nuclei with finely stippled chromatin arranged in packets separated by fine fibrovascular stroma. Neoplastic cells were positive for β-endorphin consistent with a diagnosis of paraganglioma. Additionally, many cell types, including neoplastic lymphocytes and neuroendocrine cells, contained cytoplasmic viral eosinophilic inclusions, and Reptarenavirus PCR on spleen detected a virus in the species Reptarenavirus giessenae. This snake was diagnosed with concurrent paraganglioma, inclusion body disease, and anaplastic lymphoma, morphologically represented as a diffuse lymphoma of B-cell phenotype. Whether Reptarenavirus predisposes to neoplasia in snakes is debated. This case describes multiple neoplasms in a snake with a concurrent Reptarenavirus infection.Abstract
Historically, juvenile and subadult green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) sea turtles have been observed in the waters surrounding St. Kitts, West Indies, year-round; however, no formal population or health assessment for these species and cohorts in St. Kitts has been previously conducted. During the study period (2004–2017), 211 juvenile sea turtles (158 hawksbills and 53 greens) were captured at 16 different capture sites in St. Kitts. Once turtles were on shore and restrained, morphometric measurements and mass were collected, untagged animals were tagged, and a health assessment was performed. Blood samples were collected and used to establish reference intervals for hematological and biochemical parameters. These reported reference intervals make it possible to incorporate monitoring programs for infectious diseases and to identify any trends in population and health status. The morphometrics, mass, and number of animals captured enable sound decision-making as it relates to conservation policy development and implementation, which is especially important in countries such as St. Kitts and Nevis where an open harvest for sea turtles still exists.Abstract
There is limited knowledge on amphibian sedation, and drug doses appear to be species-specific and affected by the administration route. Alfaxalone, a neuroactive steroid, has gained popularity in veterinary medicine and has been evaluated in some amphibian species. Previous studies in amphibians have demonstrated a sedative dose range of 10–30 mg/kg IM. No peer--reviewed publication has investigated this drug in Sonoran Desert toads (Incilius alvarius) specifically. Therefore, the purposes of this study were 1) to determine the effective dose 50 (ED50) of IM alfaxalone for sedation, and 2) to determine the cardiopulmonary effects of the effective dose 99 (ED99) in 13 Sonoran Desert toads. Using Dixon's up-and-down method, the ED50 was calculated as 9.02 mg/kg, and using a nonlinear regression, the calculated ED50 was 9.65 mg/kg, and the ED99 was 9.91 mg/kg. Based on these results, 10 mg/kg IM was administered, and its cardiovascular effects were determined for 120 min postinjection. The 10 mg/kg IM dose resulted in significant transient cardiorespiratory depression in all toads, with most toads (11/13) showing signs of sedation (recumbency and/or loss of righting reflex) within 30–40 min postinjection. There was no associated mortality with this study, and the side effects associated with this dosage (cardiorespiratory depression, ventral erythema, and dysphoric behavior such as rolling and head pressing) resolved in all toads prior to the end of the 120 min observation window. This study hopes to increase the understanding of the clinical application and limitations of this drug for sedation of Sonoran Desert toads.Abstract
This paper presents novel baseline health parameters on the Española lava lizard (Microlophus delanonis). Blood samples and morphological measurements were taken on 51 lizards (21 males, 30 females) captured from three locations on the island of Española. Morphological parameters measured included body weight, snout–vent length, and temperature. Blood samples were analyzed approximately 8 h after collection using an i-STAT portable blood analyzer that measured hemoglobin, total CO2, glucose, lactate, sodium, potassium, and ionized calcium. Hematologic characterization data were obtained using standard laboratory techniques. There were significant differences found in snout–vent length, weight, heart rate, respiratory rate, total CO2, and heterophil percentage between males and females. The data presented herein can be used to monitor the health of this population of Española lava lizards as well as help to understand the health of a related species, the San Cristóbal lava lizard (Microlophus bivittatus), which faces different evolutionary pressures including the presence of humans and feral cats. This study continues to widen our understanding of the genus Microlophus; however, further research should characterize the remaining species that inhabit the islands in the Galápagos archipelago.Abstract
Sex determination in reptiles is important for implementing appropriate husbandry, successful pairing for breeding programs, and reproductive medical care. In reptile species that are not sexually dimorphic, accuracy in sex determination is dependent upon methods other than physical observation. Preferred sexing techniques should be quick, noninvasive, and reliable, and they should be able to be performed by veterinarians with a broad range of reptile experience. Vast anatomical differences among reptiles make the efficacy of these techniques highly variable between species. This study evaluated hemipenis contrast radiography and computed tomography techniques, previously described in other Heloderma species, to determine reliability in sexing 23 Gila monsters (Heloderma suspectum). The results were compared to the sex determined by coelomic ultrasound, which indicated that there were 8 females and 15 males. Identification of hemipenes in males was shown in 1/15 (7%) by contrast radiography and 9/15 (60%) by hemipenis contrast computed tomography. Outline of the cloacal rim in females was seen in 100% (8/8) by contrast radiography and 100% (8/8) by contrast computed tomography. Our findings suggest that contrast radiography and computed tomography are not reliable methods for sex determination in Gila monsters, and that coelomic ultrasound is currently the most reliable, noninvasive technique for this species.Abstract
