ADVANCED DIAGNOSTIC IMAGING AND PATHOLOGIC FINDINGS OF THYROID LESIONS IN TWO SHORT-BEAKED ECHIDNAS (TACHYGLOSSUS ACULEATUS).

Two zoo-maintained short-beaked echidnas (Tachyglossus aculeatus) had long histories of intermittent anorexia and lethargy. Case 1 presented with a recurrence of these signs after transfer to another facility and died shortly after arrival. A focal area of hyperattenuation within the paratracheal tissue of the cranial mediastinum was noted antemortem on CT. Postmortem, this corresponded with severe thyroid follicular hyperplasia with lymphoplasmacytic thyroiditis. Additional findings included a systemic fungal infection without an inflammatory response, suggesting underlying factors such as torpor or immunosuppression. In Case 2, an intrathoracic mass was identified during a preshipment examination. CT confirmed a contrast-enhanced mass compressing the cranial vena cava and right atrium, and the animal was euthanized. The mass was diagnosed histologically as thyroid adenocarcinoma. These cases report thyroiditis and thyroid adenocarcinoma in echidna and describe the use of IV contrast and CT as a diagnostic aid in this species.

CLINICAL AND PATHOLOGIC FINDINGS IN IGUANIDS WITH SODIUM URATE CHOLELITHIASIS.

Four green iguanas (Iguana iguana) and one blue iguana (Cyclura lewisi) from five facilities were diagnosed with sodium urate cholelithiasis. One case was diagnosed antemortem via ultrasonography, and the iguana underwent a choledochotomy for treatment. The other four cases were identified at necropsy. Pathologic hepatic and biliary changes were present in four of the five cases at necropsy. Histologically, four iguanas had hepatic fibrosis, three had bile duct hyperplasia, and one had cholangiohepatitis and pancreaticocholedochitis. Two iguanas had pathologic renal changes. This is the first report of sodium urate cholelithiasis in reptiles. This case series highlights the potential significant clinical disease caused by sodium urate cholelithiasis and the importance of biliary system evaluation. Further investigation is recommended to explore the pathogenesis of reptilian sodium urate cholelith formation.

RETROSPECTIVE ANALYSIS OF MORTALITY CAUSES IN MANAGED KIRK'S DIK-DIKS (MADOQUA KIRKII) IN NORTH AMERICA FROM 1988 to 2019.

Kirk's dik-diks (Madoqua kirkii) are the most common dik-dik species managed in North American zoological institutions, but their numbers are declining at a concerning rate, with less than 40 individuals currently housed in accredited institutions. This retrospective study reports the causes of mortality in Kirk's dik-diks in North American zoological institutions from 1988 to 2019. Out of 15 institutions accredited by the Association of Zoos and Aquariums (AZA) currently housing Kirk's dik-diks, nine contributed to this study (60% participation). Eighty-four necropsy records were reviewed to determine the primary affected body system and etiological cause of death across and within age categories. Neonatal death (prior to 1 mon of age) was most common (38.1%), followed by death in adults (29.8%), geriatric animals (19.0%), and juveniles (13.1%). As a whole population, causes of death by body system were multisystemic (47.6%), musculoskeletal (15.5%), respiratory (8.3%), and digestive (8.3%). Neonatal complications accounted for 50.0% of all deaths in animals prior to 1 mon of age. In juveniles, a nutritional cause of death was most common (27.3%) and significantly higher compared to measures of this cause within other age categories. In adults, metabolic etiologies and trauma each accounted for 28.0% of deaths. Degenerative etiologies were most common in geriatric individuals, representing 31.3% of the deaths. Death from infectious disease was found across all ages, representing 11.9% of all mortalities. Results from this study provide a baseline reference for this species and may aid clinicians in decision-making as it relates to the medical care and management of this species during different life stages.

Correction: Turner et al. Steatitis in Cold-Stunned Kemp's Ridley Sea Turtles (Lepidochelys kempii). Animals 2021, 11, 898.

In the original publication [...].

COMPARISON OF DIAGNOSTIC PREDICTORS OF NEONATAL SURVIVABILITY IN NONDOMESTIC CAPRINAE.

This retrospective study evaluated whether six methods (glutamyltransferase, glutaraldehyde coagulation test, sodium sulfite precipitation test, total serum protein, glucose, and fibrinogen) used to assess passive transfer status in ruminants were predictive of survival of nondomestic Caprinae neonates in a zoological collection. A total of 184 neonates from 10 nondomestic Caprinae species had one or more testing methods performed within 7 d of birth. Results of each test were compared with the clinical condition (alive or dead) at 7, 30, and 90 d of age. Total protein (TP) results were not considered for statistical significance in this study. No statistical correlations between results of the serum gamma glutamyltransferase (GGT), glutaraldehyde coagulation test, or sodium sulfite precipitation test (BOVA-S) and survival at any age were found. A higher glucose level within 7 d of birth was associated with a greater probability of survival. Fibrinogen levels were found to have a strong negative association with survival at 30 and 90 d. Increased glucose concentration was negatively associated with the probability of an infectious cause of mortality and the need for medical intervention. In contrast, increased fibrinogen levels were associated with higher probabilities of infectious death and the need for major medical care. Neonates who were confirmed to have nursed had a lower likelihood of requiring major medical intervention. These findings suggest that glucose and fibrinogen levels are better predictors of neonatal survival in nondomestic Caprinae when compared to the other three tests reviewed in this study. Using survival as an indicator of adequate passive transfer in this group of neonates failed to identify a gold standard of diagnosis of failure of passive transfer, so more than one diagnostic test should be utilized.

Steatitis in Cold-Stunned Kemp's Ridley Sea Turtles (Lepidochelys kempii).

The pathogenesis of steatitis that infrequently occurs in cold-stunned Kemp's ridley sea turtles (KRT; Lepidochelys kempii) has been undetermined. The objectives of this study were to investigate the clinical (n = 23) and histologic findings (n = 11) in cold-stunned KRT, and to compare plasma concentrations of α-tocopherol (vitamin E), thiobarbituric acid reactive substances (TBARS), and the TBARS to vitamin E (T/E) ratio (an assessment of oxidative stress) between cold-stunned KRT with clinically and/or histologically confirmed steatitis (n = 10) and free-ranging KRT (n = 9). None of the cold-stunned turtles had clinically detectable steatitis at admission, and the median number of days to diagnosis of steatitis was 71 (range 33­469). Histologic findings of affected adipose tissue included heterophilic (n = 9) and/or histiocytic (n = 5) steatitis, fat necrosis (n = 7), myonecrosis (n = 2), and intralesional bacteria (n = 6). Cold-stunned KRT had significantly lower plasma vitamin E concentrations (median = 3.5 nmol/g), lower plasma TBARS concentrations (median = 1.6 nmol/g), and higher T/E ratios (median = 0.50), than controls (62.3 nmol/g; 2.1 nmol/g; 0.03, respectively). These results suggest a multifactorial etiology for the development of steatitis in KRT during rehabilitation, including tissue injury, septicemia, and various factors resulting in imbalances of anti-/oxidative status. By highlighting the need to provide more effective vitamin E supplementation, and the need to re-assess specific components of the diet, this study may lead to reduced incidence and improved medical management of steatitis in cold-stunned sea turtles.

Fatal Sarcocystis falcatula Infection in Three Penguins.

Sarcocystis falcatula is a well-known cause of fatal pneumonia in some birds, particularly Old World psittacines. Here we describe fatal sarcosystosis due to S. falcatula in 3 penguins (Family Spheniscidae) under managed care, including one African penguin (Spheniscus demersus), and two Southern rockhopper penguins (Eudyptes chrysocome). Randomly distributed foci of necrosis, inflammatory cell infiltrates, edema, and variable numbers of round to elongated protozoal schizonts were observed in sections of lung. Protozoal organisms exhibited strong immunoreactivity for Sarcocystis sp. antigen by immunohistochemistry. Apicomplexan and Sarcocystis genus-specific PCR assays and sequence analysis confirmed S. falcatula as the etiologic agent. These cases of fatal pneumonia attributed to S. falcatula expand the list of aberrant intermediate avian hosts, with particular implications for penguins.

Cutaneous squamous cell carcinoma associated with Zalophus californianus papillomavirus 1 in a California sea lion.

Papillomaviruses (PVs) are found in many species and infect epithelial cells at both mucosal and cutaneous sites. PVs are generally species-specific and cause benign epithelial proliferations, often forming papillomas or plaques. Rarely, these infections can persist, allowing progression to in situ and invasive cancers. We describe herein a case of multiple cutaneous pigmented plaques from a California sea lion ( Zalophus californianus) that progressed to in situ and invasive squamous cell carcinoma (SCC). The lesions were characterized by epithelial hyperplasia, hyperkeratosis, and hypergranulosis that bordered more dysplastic areas, and, at one site, bordered an invasive SCC. Immunohistochemistry for papillomavirus antigen revealed strong nuclear immunoreactivity within keratinocytes in the hyperplastic epidermis. PCR was performed using degenerate and specific primers to detect papillomavirus DNA. Specific primers were used to amplify Zalophus californianus papillomavirus 1 (ZcPV-1), the only sea lion papillomavirus known to date. We detected ZcPV-1 DNA within the pigmented plaque, and in both in situ and invasive SCC samples.

Multi-locus sequence typing provides epidemiological insights for diseased sharks infected with fungi belonging to the Fusarium solani species complex.

Fusarium spp. are saprobic moulds that are responsible for severe opportunistic infections in humans and animals. However, we need epidemiological tools to reliably trace the circulation of such fungal strains within medical or veterinary facilities, to recognize environmental contaminations that might lead to infection and to improve our understanding of factors responsible for the onset of outbreaks. In this study, we used molecular genotyping to investigate clustered cases of Fusarium solani species complex (FSSC) infection that occurred in eight Sphyrnidae sharks under managed care at a public aquarium. Genetic relationships between fungal strains were determined by multi-locus sequence typing (MLST) analysis based on DNA sequencing at five loci, followed by comparison with sequences of 50 epidemiologically unrelated FSSC strains. Our genotyping approach revealed that F. keratoplasticum and F. solani haplotype 9x were most commonly isolated. In one case, the infection proved to be with another Hypocrealian rare opportunistic pathogen Metarhizium robertsii. Twice, sharks proved to be infected with FSSC strains with the same MLST sequence type, supporting the hypothesis the hypothesis that common environmental populations of fungi existed for these sharks and would suggest the longtime persistence of the two clonal strains within the environment, perhaps in holding pools and life support systems of the aquarium. This study highlights how molecular tools like MLST can be used to investigate outbreaks of microbiological disease. This work reinforces the need for regular controls of water quality to reduce microbiological contamination due to waterborne microorganisms.

Cerebral Angiostrongylus cantonensis infection in a captive African pygmy falcon (Polihierax semitorquatus) in southern California.

A 10-month-old, female African pygmy falcon (Polihierax semitorquatus) hatched and housed at the San Diego Zoo developed neurologic signs and died from a cerebral infection with the rat lungworm Angiostrongylus cantonensis. There was an associated mild nonsuppurative meningoencephalitis. This infection was diagnosed on histology and confirmed by detection of species-specific A. cantonensis DNA in formalin-fixed and frozen brain tissue by a polymerase chain reaction assay. To the authors' knowledge, this infection has not previously been reported in a bird in the United States and has not been known to be naturally acquired in any species in this region of the world. The source of the infection was not definitively determined but was possibly feeder geckos (Hemidactylus frenatus) imported from Southeast Asia where the parasite is endemic.

Hepatitis and splenitis due to systemic tetratrichomoniasis in an American white pelican (Pelecanus erythrorhynchos).

A free-ranging, young adult, female American white pelican (Pelecanus erythrorhynchos), found dead on the grounds of the San Diego Zoo Safari Park in Southern California, had severe multifocal to coalescing necrotizing hepatitis and splenitis on postmortem examination. Histologically, within the large areas of necrosis were myriad pleomorphic, 5-20 µm in diameter, protozoal organisms with 1 to multiple nuclei. Ultrastructurally, the organisms were consistent with a trichomonad flagellate. Polymerase chain reaction and sequencing of the small subunit ribosomal RNA gene identified nucleotide sequences with 99% identity to Tetratrichomonas gallinarum, which is a common inhabitant of the intestinal tract of galliform and anseriform birds that has occasionally been associated with disease, including typhlitis and hepatitis. Damage to the cecal mucosa in the pelican from trematodes and secondary bacterial infection could have allowed invasion and systemic dissemination of the organism. Exposure of the pelican to a variety of native and exotic anseriform and galliform birds at the zoological institution could have led to cross-species infection and severe manifestation of disease in a novel host.

Histologic and molecular correlation in shelter cats with acute upper respiratory infection.

This is a descriptive study designed to correlate diagnostic real-time PCR results with histopathologic lesions in cats with clinical signs of upper respiratory infection (URI). The study occurred over a 9-month period in a single open-intake animal shelter. Cats that were selected for euthanasia by the shelter staff and additionally had URI were included in the study, for a total of 22 study cats. Combined conjunctival and oropharyngeal swab specimens were tested by quantitative real-time PCR (qPCR) for feline herpesvirus type 1 (FHV-1), feline calicivirus (FCV), Mycoplasma felis, Chlamydophila felis, and Bordetella bronchiseptica. Necropsy was performed on all cats, and a complete set of respiratory tract tissues was examined by histopathology. Among 22 cats, 20 were qPCR positive for FHV-1, 7 for M. felis, 5 for FCV, 1 for C. felis, and 0 for B. bronchiseptica. Nine cats were positive for two or more pathogens. Histopathologic lesions were present in all cats, with consistent lesions in the nasal cavity, including acute necroulcerative rhinitis in 16 cats. Histologic or antigenic detection of FHV-1 was seen in 18 of 20 cats positive for FHV-1 by qPCR. No lesions that could be specifically attributed to FCV, M. felis, or C. felis were seen, although interpretation in this cohort could be confounded by coinfection with FHV-1. A significant agreement was found between the amount of FHV-1 DNA determined by qPCR and the presence of specific histopathologic lesions for FHV-1 but not for the other respiratory pathogens.

Glomus tumours in the skin and subcutis of three horses.

Three horses presented with variably painful, nonulcerated masses of the head or neck that were diagnosed as glomus tumours. Grossly, they were fleshy, pink to tan masses ranging from 0.4 to 9 cm in diameter, involving either the deep dermis and subcutis or the subcutis and underlying skeletal muscle. Microscopically, neoplastic epithelioid cells were arranged in sheets, cords and packets within lobules. The neoplastic cells frequently abutted and formed nodular bulges into large endothelium-lined vascular spaces, especially around the tumour periphery. Large nerve branches were associated with each tumour. As determined by immunohistochemistry, the neoplastic cells consistently expressed α-smooth muscle actin and vimentin, and some cells in two of the cases expressed desmin. A laminin- or collagen IV-positive basement membrane was demonstrated around individual tumour cells or small groups of cells in all three cases. Morphological features and immunohistochemistry supported the diagnosis of glomus tumour, most consistent with the solid type in humans. Applying a classification system used in humans, two of these tumours met criteria of malignancy (glomangiosarcomas). One horse was euthanized due to complications associated with recurrence and treatment-related necrosis and secondary infection.

West Nile virus infection in a green-winged macaw (Ara chloropterus).

A 29-year-old female green-winged macaw (Ara chloropterus) was presented for acute pelvic limb lameness. On physical examination the bird was found to be mildly dehydrated with paraparesis and proprioceptive deficits of the pelvic limbs. Antemortem diagnostics included a complete blood count and plasma biochemistry panel, fecal Gram and Ziehl-Neelsen acid fast stains, plasma heavy metal concentrations, reverse transcriptase (RT)-PCR testing for West Nile virus (WNV) RNA and PCR testing for Chlamydophila psittaci DNA from choanal/cloacal swabs, and survey radiography. Abnormal findings included a heterophilic leukocytosis, elevated kidney and muscle enzyme values, and a positive RT-PCR result for West Nile viral RNA. Although the bird showed some improvement with supportive care, on the fourth day it began having seizures and was euthanatized. There were no abnormal findings detected on gross necropsy; however, histopathology revealed mononuclear inflammatory cell infiltration in multiple organs including brain, heart, and pancreas. WNV antigen and RNA were detected using immunohistochemistry and RT-PCR in various tissues including brain, pancreas, and spleen. WNV was successfully isolated from brain, pancreas, spleen, and liver. To our knowledge, this is the first report characterizing WNV disease in a green-winged macaw and one of few reports of this disease in a psittacine bird.

Preventive medicine success: thymoma removal in an African spot-necked otter (Lutra maculicollis).

During a preventive medicine examination on a 13-yr-old intact female African spot-necked otter (Lutra maculicollis), radiographs were obtained and a cranial thoracic mass was noted. Cytology from an ultrasound-guided fine-needle aspirate was suggestive of a thymoma. Surgical removal was performed and this diagnosis was confirmed by histopathology. At a recheck examination 6 mo postsurgery, there was no evidence of recurrence. This case highlights the value of a comprehensive preventive medicine program that resulted in the early detection of a subclinical thymoma and its successful removal.

Squamous cell carcinoma.

Squamous cell carcinoma (SCC) is a relatively common, malignant neoplasm of dogs and cats that can arise in a variety of locations. The gross appearance of SCC can be variable and nonspecific, so definitive diagnosis requires microscopic examination of the tissue (cytology or histology). Several treatment modalities exist, but surgical excision, if possible, is regarded as the best treatment option. Early diagnosis and treatment of SCC are key because small, early-stage tumors are the most amenable to treatment and carry the best prognosis.

Persistence of H5 and H7 avian influenza viruses in water.

Although fecal-oral transmission of avian influenza viruses (AIV) via contaminated water represents a recognized mechanism for transmission within wild waterfowl populations, little is known about viral persistence in this medium. In order to provide initial data on persistence of H5 and H7 AIVs in water, we evaluated eight wild-type low-pathogenicity H5 and H7 AIVs isolated from species representing the two major influenza reservoirs (Anseriformes and Charadriiformes). In addition, the persistence of two highly pathogenic avian influenza (HPAI) H5N1 viruses from Asia was examined to provide some insight into the potential for these viruses to be transmitted and maintained in the environments of wild bird populations. Viruses were tested at two temperatures (17 C and 28 C) and three salinity levels (0, 15, and 30 parts per thousand sea salt). The wild-type H5 and H7 AIV persistence data to date indicate the following: 1) that H5 and H7 AIVs can persist for extended periods of time in water, with a duration of infectivity comparable to AIVs of other subtypes; 2) that the persistence of H5 and H7 AIVs is inversely proportional to temperature and salinity of water; and 3) that a significant interaction exists between the effects of temperature and salinity on the persistence of AIV, with the effect of salinity more prominent at lower temperatures. Results from the two HPAI H5N1 viruses from Asia indicate that these viruses did not persist as long as the wild-type AIVs.