Pathology of "double scale" skin defect in farmed American alligators (Alligator mississippiensis) and the possible association with hepatic fibrosis.

"Double scale" is a poorly characterized skin defect of crocodilians that drastically reduces the economic value of crocodilian skin. This study investigated the morphology and pathogenesis of double scale in a ranching farm of American alligators (Alligator mississippiensis). We compared the histopathology of skin and selected organs (liver, lung, kidney, heart, spleen, intestine, and brain) of alligators with double scale against healthy control animals, together with serum and liver vitamin and mineral levels. Skin affected with double scale had statistically significant hyperkeratosis, epidermal atrophy, and increased basal cell degeneration compared with control alligators (P < .0001). Interestingly, all alligators with double scale had varying degrees of hepatic fibrosis. Feed analysis showed that alligators that had double scale and hepatic fibrosis had prolonged dietary exposure to high levels of vitamin A, iron, and copper. Serum analysis indicated that levels of zinc (p < .0001), copper (P < .05), and vitamin E (P < .002) were significantly lower in alligators with hepatic fibrosis and double scale compared with controls. Finally, immunohistochemical analysis of skin with double scale showed a marked reduction in immunolabeling with the zinc-binding protein metallothionein. These results suggest that zinc deficiency, in combination with other micronutrient anomalies, may play a role in the pathogenesis of double scale in alligators with liver fibrosis.

Wound recovery efficacy of retinol based-micellar formulations in an organotypic skin wound model.

Impairment of the skin's structural integrity initially results in acute wounds which can become chronic if timely wound closure is not achieved. Chronic wounds (CWs) affect more than 1% of the global population with increasing cases of this condition due to the ageing population. Current wound management relies on debridement, hyperbaric oxygen, antibiotics, and wound dressings, which lack early intervention and specificity. Herein, antibiotics-free retinol-based micellar formulations (RMF) were made and their wound healing efficacy were investigated in vitro. Five different formulations with retinol contents of 0.3% and 1% against a placebo were topically applied to an organotypic full-thickness skin wound model (FT-SWM, MatTek®) with a 3 mm punch wound, and maintained in an incubator for 6 days. The histological analysis of the FT-SWM was conducted at depths of 60 µm and 80 µm. It was found that all the micellar retinol formulations accelerated wound bed contraction, with 0.3% RMF demonstrating the highest efficacy. At the depths of 60 µm and 80 µm, the 0.3% RMF exhibited inner wound diameter contraction of 58% and 77%, respectively, in comparison to the placebo showing 15% and 8%. The RMF significantly accelerated wound healing and can thus be a potential early intervention for speedy wound recovery. It should be pointed out that these results were obtained based on a small sample size and a large sample size will be explored to further validate the results.

Cetacean Intracytoplasmic Eosinophilic Globules: A Cytomorphological, Histological, Histochemical, Immunohistochemical, and Proteomic Characterization.

The nature, etiopathogenesis, and clinicopathologic relevance of the prevalent intracytoplasmic eosinophilic globules (IEGs) within hepatocytes of cetaceans are unknown. This study aims to evaluate the presence and characterize the IEGs in the hepatocytes of cetaceans using histochemical and immunohistochemical electron microscopy, Western blot, lectin histochemistry, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry techniques. A total of 95/115 (83%) animals (16 species) exhibited histologically evident intracytoplasmic round to oval, single to multiple, hyaline eosinophilic globules within the hepatocytes. These globules were largely PAS-positive, diastase resistant, and were immunopositive for fibrinogen (FB, 97%), albumin (Alb, 85%), and α1-antitrypsine (A1AT, 53%). The IEG positivity for FB and A1AT were correlated with live-stranding, hepatic congestion and a good nutritional status. The cetaceans lacking IEGs were consistently dead stranded and had poor body conditions. The IEGs in 36 bycaught cetaceans were, all except one, FB-positive and A1AT-negative. The IEGs exhibited morphologic and compositional variations at the ultrastructural level, suggesting various stages of development and/or etiopathogenesis(es). The glycocalyx analysis suggested an FB- and A1AT-glycosylation pattern variability between cetaceans and other animals. The proteomic analyses confirmed an association between the IEGs and acute phase proteins, suggesting a relationship between acute stress (i.e., bycatch), disease, and cellular protective mechanisms, allowing pathologists to correlate this morphological change using the acute hepatocytic cell response under certain stress conditions.

Fatal cerebrovascular accident in a captive red panda (Ailurus fulgens fulgens) with concurrent amdoparvovirus infection.

We report the pathological and molecular findings in an adult male Himalayan red panda (Ailurus fulgens fulgens) whose death was attributed to parenchymal brain haemorrhage (PBH) of the thalamus. Post-mortem examination revealed severe, acute PBH and intraventricular haemorrhage with major involvement of the thalamus, as well as scattered chronic microinfarctions. Vascular disease in the brain and other organs was suggestive of systemic hypertension. Histological lesions included arteriolar hyalinosis and varying degrees of arteriosclerosis, arterial tunica media hypertrophy and hyperplasia and infiltration of arterial walls by lipid-laden macrophages. Other relevant findings included marked myocardial fibrosis, lymphoplasmacytic tubulointerstitial nephritis, lymphoplasmacytic meningoencephalitis and chronic mitral valve degeneration. The changes in the cerebral vasculature were consistent with hypertensive encephalopathy and a cerebrovascular accident, specifically PBH, which has not been previously reported in this species. Additionally, polymerase chain reaction analysis for red panda amdoparvovirus (RPAV) was positive in the brain and kidneys. Preceded by hypertensive vascular changes and brain microinfarctions, sudden death in this animal likely resulted from fatal PBH with intraventricular haemorrhage. The clinicopathological role of RPAV infection is unknown in this case, although its contribution to the chronic renal disease is considered possible in the context of our current understanding of RPAV-associated pathology.

Deer mastadenovirus B pneumonia in a white-tailed deer fawn.

A 7-mo-old farmed white-tailed deer fawn (Odocoileus virginianus) died after several weeks of progressive deterioration associated with endoparasitism and respiratory signs. A field autopsy was performed, and lung tissue was submitted for histologic examination. The findings were consistent with necrosuppurative bronchointerstitial pneumonia with intranuclear viral inclusions. Immunofluorescence using fluorescently labeled polyclonal antibodies to bovine adenovirus 3 and 5 was positive. To rule out cross-reactivity with other adenoviruses, formalin-fixed, paraffin-embedded tissue sections were submitted for genome sequence analysis, which revealed a 99.6% match to Deer mastadenovirus B (formerly Odocoileus adenovirus 2, OdAdV2). To our knowledge, natural clinical disease associated with OdAdV2 has not been reported previously.

RETROSPECTIVE REVIEW OF NEUROLOGIC DISEASE IN STRANDED ATLANTIC HARBOR SEALS (PHOCA VITULINA CONCOLOR) ALONG THE NEW ENGLAND COAST.

Harbor seals (Phoca vitulina) are a common species admitted to marine mammal rehabilitation facilities. As important indicators of marine ecosystem health, monitoring trends of disease in harbor seal populations is critical. However, few studies have evaluated neurologic disease in this species. The general objective of this study was to retrospectively review and delineate neurologic disease in free-ranging Atlantic harbor seals (P. vitulina concolor) that stranded along the New England (United States) coast and entered a rehabilitation facility between 2006 and 2019. Any Atlantic harbor seal that stranded live along the New England coast during the study period and was diagnosed with neurologic disease on either antemortem or postmortem evaluation was included; medical records and pathologic reports were reviewed. From 211 records, 24 animals met the inclusion criteria. Prevalence of neurologic disease was 11% in the study population and six major categories of neurologic disease were identified including: inflammatory (54%), idiopathic (33%), trauma (4%), congenital (4%), and degenerative (4%). Of the seals diagnosed with neurologic disease, 13 (54%) seals died during rehabilitation, 10 (42%) seals were euthanized, and 1 (4%) seal survived to release. Unique cases seen included a seal with Dandy-Walker-like malformation and another seal with histopathologic findings compatible with neuroaxonal dystrophy, a degenerative process that has not been previously reported in marine mammals. This study contributes to the overall knowledge of the health of free-ranging Atlantic harbor seals and may aid clinicians in characterizing neurologic conditions that may be present in seals undergoing rehabilitation.

Characterization of Traumatic Injuries Due to Motor Vehicle Collisions in Neotropical Wild Mammals.

Motor vehicle collisions (MVCs) are a severe threat to wildlife biodiversity worldwide and most vertebrate species are at risk. However, there is a considerable knowledge gap on the traumatic features and potential patterns of MVCs in wildlife. We investigated traumatic injuries (TIs) caused by MVCs (MVCs-TIs) in 430 neotropical wild mammals representing 44 species from Brazil. Injuries were classified topographically into four categories: abdomen/pelvis (AP), chest (TX), head/neck (HN) and extremities (EX). We also determined the prevalence of pathological changes in MVC fatalities. AP (n = 381; 89%) was the most affected body segment, followed by TX (n = 372; 87%), HN (n = 363; 84%) and EX (n = 288; 67%). The most prevalent gross pathological findings were single or multiple bone fractures (n = 397; 92%), visceral organ rupture (n = 371; 86%), haemothorax (n = 220; 51%) and pulmonary haemorrhage (n = 212; 49%). Microscopically, pulmonary oedema (n = 324; 82%) and haemorrhage (n = 272; 69%) were the most prevalent lesions. No distinct TI patterns were evident across the various taxonomic groups, although trends were found in some taxa, such as armadillos. These results may help clinicians performing emergency care on MVC wildlife patients and may be of value in pathological and forensic investigations where a MVC has been deemed a likely contributory factor to death.

Erysipelas in a stranded common bottlenose dolphin: first report in a South American odontocete.

Erysipelas is a zoonotic disease caused by Erysipelothrix rhusiopathiae. In cetaceans, this disease has two main clinical forms: a cutaneous one, grossly characterized by rhomboid lesions, and a septicemic and often fatal form. Erysipelas is considered an important cause of morbidity and mortality in captive cetaceans; however, information in free-ranging cetaceans is limited. An adult common bottlenose dolphin (Tursiops truncatus) was found dead and in advanced autolysis in Paraíba state, northeastern Brazil, on July 19th, 2020. Upon gross examination, 80% of the body surface presented disseminated rhomboid cutaneous lesions ranging from 4 to 6 cm-width, characterized by well-defined edges and occasional ulceration, consistent with erysipelas. Additionally, anthropic-made postmortem linear cuts and partial mechanical removal of the flank musculature were noted. Skin samples were collected for histopathologic and molecular analyses. Microscopically, it was possible to observe multifocal dermatitis with vasculitis. Erysipelothrix sp. was detected by PCR. Despite previous reports of human consumption of cetacean meat in northeastern Brazil, the observed marks and advanced carcass autolysis suggested that the animal was most likely used as bait for fishing instead of human intake. This case highlights the value of postmortem examination and PCR even in poorly preserved cadavers and contributes to the understanding of the epidemiology of cutaneous erysipelas in free-ranging cetaceans (first report in an odontocete from the Southern Hemisphere). Due to the zoonotic potential of certain Erysipelothrix species (i.e., E. rhusiopathiae), active public health policies are required to inform field professionals and the general public about the health threats associated with marine mammal manipulation and consumption.

Ovarian Filariasis in a Wild Southern Tamandua (Tamanduatetradactyla; Mammalia: Myrmecophagidae).

Knowledge of reproductive health in wild southern tamanduas (Tamandua tetradactyla; Mammalia: Myrmecophagidae) is fragmentary. During necropsies of roadkill xenarthran species in Brazil, a case of ovarian filariasis in an adult female southern tamandua was observed. Macroscopically, both ovaries were irregularly enlarged and had numerous smooth protuberances. Histologically, the affected ovarian parenchyma presented adult nematodes (including females with microfilaria) surrounded by pleocellular inflammatory infiltrates. The morphological characteristics of the nematodes were consistent with the superfamily Filarioidea (order Spirurida). The adjacent ovarian parenchyma had developing and atretic follicles at different stages of maturation. Filarial nematodes were not observed in other tissues. The cause of death of this tamandua was fatal acute polytrauma as a consequence of the motor vehicle collision. This case adds to a prior report of ovarian filariasis in two southern tamanduas in Nicaragua and Guatemala, dating back almost 100 years, and suggests filarial infections could potentially have an impact on reproductive success in southern tamanduas and possibly other xenarthrans. Several xenarthran species are under different levels of threat and knowledge of their basic reproductive health is crucial for conservation programs.

Budd-Chiari-like pathology in dolphins.

Nearly two decades ago, pathologic examination results suggested that acoustic factors, such as mid-frequency active naval military sonar (MFAS) could be the cause of acute decompression-like sickness in stranded beaked whales. Acute systemic gas embolism in these whales was reported together with enigmatic cystic liver lesions (CLL), characterized by intrahepatic encapsulated gas-filled cysts, tentatively interpreted as "gas-bubble" lesions in various other cetacean species. Here we provide a pathologic reinterpretation of CLL in odontocetes. Among 1,200 cetaceans necropsied, CLL were only observed in four striped dolphins (Stenella coeruleoalba), with a low prevalence (2%, N = 179). Together, our data strongly suggest that CLL are the result of the combination of a pre-existing or concomitant hepatic vascular disorder superimposed and exacerbated by gas bubbles, and clearly differ from acute systemic gas embolism in stranded beaked whales that is linked to MFAS. Budd-Chiari-like syndrome in dolphins is hypothesized based on the present pathologic findings. Nonetheless, further researched is warranted to determine precise etiopathogenesis(es) and contributing factors for CLL in cetaceans.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Nocardiosis in Free-Ranging Cetaceans from the Central-Eastern Atlantic Ocean and Contiguous Mediterranean Sea.

We report the pathologic features of nocardiosis in five free-ranging delphinids from the Canary Islands and Andalusia, namely four striped dolphins (Stenella coerulealba) and one bottlenose dolphin (Tursiops truncatus). All animals had a multiorgan (disseminated) pattern of infection involving suppurative to pyogranulomatous and thromboembolic lesions in two or more organs. Most affected organs were (by decreasing order) lung, pulmonary lymph nodes, liver, kidney, adrenal glands, and central nervous system. Typical intralesional and intravascular branched and filamentous bacteria were highlighted by Grocott's methenamine silver and Gram stains. Bacterial analysis including 16S rRNA gene sequencing identified Nocardia farcinica in two striped dolphins and Nocardia otitidiscaviarum in one striped dolphin and the bottlenose dolphin. All dolphins tested (n = 4) for cetacean morbillivirus were negative; one dolphin had concurrent cutaneous herpesvirosis. These results provide the first record of N. otitidiscaviarum in cetaceans, the first account of N. farcinica in free-ranging dolphins, and confirmation of nocardiosis in central eastern Atlantic Ocean. These results expand the known geographic range of nocardiosis in cetaceans.

Yokenella regensburgei, a novel pathogen in farmed American alligators.

Increased acute mortality of farmed American alligators (Alligator mississippiensis) was observed in various pens from 2 different farms in Louisiana over 2 years (2019-2021). A total of 14 alligators from multiple events of increased mortality were subjected to postmortem investigations. Except for one alligator with acute neurologic signs, no premonitory signs were observed. All animals had pneumonia (14/14), coelomitis (14/14), and intravascular short Gram-negative bacilli (14/14). Myocarditis (13/14) was common. Yokenella regensburgei was isolated from all alligators tested (13/13). These data suggest the respiratory tract may be a primary target system and could be involved in transmission, either through exhaled bacteria or through swallowing of contaminated respiratory fluids with passage through the feces. Available sensitivity data for Y. regensburgei in this study indicates in vitro sensitivity to aminoglycosides, fluoroquinolones, chloramphenicol, and trimethoprim/sulphamethoxazole antibiotics. Yokenella regensburgei should be included in the differential diagnosis of septicemia and acute death in alligators.

Immunophenotype of the inflammatory response in the central and enteric nervous systems of cockatiels (Nymphicus hollandicus) experimentally infected with parrot bornavirus 2.

Proventricular dilatation disease is a lethal disease of psittacine birds. In this study, we characterized the local cellular immune response in the brain, proventriculus, and small intestine of 27 cockatiels (Nymphicus hollandicus) experimentally infected with parrot bornavirus 2 (PaBV-2). Perivascular cuffs in the brain were composed of CD3+ T-lymphocytes and Iba1+ macrophages/microglia in most cockatiels (n = 26). In the ganglia of the proventriculus, CD3+ T-lymphocytes (n = 17) and Iba1+ macrophages (n = 13) prevailed. The ganglia of the small intestine had a more homogeneous distribution of these leukocytes, including PAX5+ B-lymphocytes (n = 9), CD3+ T-lymphocytes (n = 8), and Iba1+ macrophages (n = 8). Our results indicate that perivascular cuffs in the brain and the inflammatory infiltrate in the proventriculus of PaBV-2-infected cockatiels is predominately composed of T-lymphocytes, while the inflammatory infiltrates in the ganglia of the small intestine are characterized by a mixed infiltrate composed of T-lymphocytes, B-lymphocytes, and macrophages.

CLINICO-PATHOLOGIC FINDINGS AND PATHOGEN SCREENING IN FUR SEALS (ARCTOCEPHALUS AUSTRALIS AND ARCTOCEPHALUS TROPICALIS) STRANDED IN SOUTHEASTERN BRAZIL, 2018.

Among pinnipeds, four Otariidae species (eared seals) have been reported as occasional or frequent vagrants along the coast of Brazil, mainly in the southern region. These animals usually arrive debilitated during winter and are directed to rehabilitation. Nevertheless, available information on sanitary aspects of stranded pinnipeds in Brazil is limited. Increased fur seal strandings (n=23) were recorded during the 2018 winter season in southeast Brazil (Iguape, Ilha Comprida, and Ilha do Cardoso, Sao Paulo State) compared to 2017 (n=2). Of these 23 fur seals, two were found dead and were in a good postmortem condition, and four died during rehabilitation and were subsequently necropsied. The remaining fur seals were not analyzed due to advanced decomposition (9/23) or successful rehabilitation (8/23). Herein, we report the antemortem hematology (n=4) and postmortem pathologic, parasitologic, and molecular analysis results as well as the most likely cause of stranding and/ or death (CSD) in five free-ranging juvenile South American fur seals (Arctocephalus australis) and one free-ranging juvenile subantarctic fur seal (Arctocephalus tropicalis). All animals were males, and all but one had poor body condition. Pathologic examinations revealed a variety of lesions, predominantly hemodynamic disturbances, endoparasitism, and inflammatory disease processes of suspected infectious nature. Molecular analyses detected gammaherpesvirus infections in two South American seals and one subantarctic fur seal, Sarcocystis sp. in one subantarctic fur seal, and Neospora spp. in two South American fur seals. All seals were PCR-negative for morbillivirus, flavivirus, and Toxoplasma gondii. The most likely CSDs were: starvation (2), aspiration pneumonia (1), asphyxia (1), predator attack (1), and presumed systemic infectious disease (1). These findings expand the geographic range of various pathogens of pinnipeds and may be of value to first responders, clinicians, and diagnosticians.

Novel gammaherpesvirus associated with primary gastric T-cell lymphoma in a free-ranging giant armadillo in Brazil.

The number of viral-associated neoplasms reported in wildlife has increased over the last decades, likely because of growing research efforts and a potentially greater burden of carcinogenic pathogens. Herein, we describe a primary gastric T-cell lymphoma in one free-ranging giant armadillo (Priodontes maximus) from Brazilian Pantanal infected by a novel gammaherpesvirus, proposed as Cingulatid gammaherpesvirus 1 (CiHV-1). By chromogenic in situ hybridisation against Epstein-Barr virus some neoplastic cells were labeled. Subsequently, a molecular screening was carried out to detect the occurrence of this pathogen in other giant armadillos in the same region. Overall, this novel virus was detected in 14.3% (3/21) of the tested giant armadillos. We suggest this herpesvirus, the first in Xenarthra, as a plausible aetiology of the neoplasm. The implications of CiHV-1 for this species are uncertain; while no outbreaks of disease have been recorded, the present study raises concerns. Further research is warranted to assess the real significance of CiHV-1 and its potential oncogenic role in this species.

Assessment of Lung Disease in Finishing Pigs at Slaughter: Pulmonary Lesions and Implications on Productivity Parameters.

Swine respiratory disease is associated with productive losses. We evaluated the prevalence of lung lesions with an emphasis on Mycoplasma hyopneumoniae (Mh), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV), as well as the impact on productive parameters in 108 finishing pigs at slaughter. Pathologic, immunohistochemical (IHC) and serologic analyses were performed. Pneumonic processes were observed in 73.1% of the animals. They mainly consisted of cranioventral bronchopneumonia (CBP) (46.3%) and pleuritis (17.6%). Microscopically, bronchointerstitial pneumonia (67.4%) was common and was occasionally combined (27.9%) with interstitial pneumonia (IP). Mh and PCV2-antigens were detected in bronchointerstitial pneumonia (70.7%) and IP cases (33.3%). There were low titers against Mh (18%) and high titers against PRRSV (100%) and PCV2 (65%). Animals with CBP remained at the farm longer; those with >10% of lung parenchyma involvement were sent later (208.8 days old) and had a lower average carcass weight (74.1 kg) and a lower daily weight gain (500.8 gr/day) compared with animals without lesions (567.2 gr/day, 77.7 kg, 200.8 days old). We suggest that animals that do not reach the weight at slaughter should be sent to slaughter regardless to avoid further negative impacts of respiratory disease in productive parameters.

Crassicaudiasis in three geographically and chronologically distant Cuvier's beaked whales (Ziphius cavirostris) stranded off Brazil.

The Cuvier's beaked whale (CBW; Ziphius cavirostris) is a cosmopolitan marine mammal found in deep tropical and temperate waters of all oceans. CBW strandings have been recorded sporadically in Brazil; however, there is lack of information available regarding their causes of stranding and/or death. Herein, we report the epidemiologic, pathologic, morphologic parasitologic features and molecular identification of arterial and renal crassicaudiasis by Crassicauda sp. in three geographically and chronologically distant CBW stranded off Brazil. CBW-1 was an adult male stranded dead in Rio Grande do Sul State. CBW-2 was an adult female that stranded alive in Sergipe State and died shortly after. CBW-3 was and adult male that stranded dead in Santa Catarina State. The most relevant pathologic findings in these three CBW were severe, chronic proliferative mesenteric and caudal aortic endarteritis and chronic granulomatous and fibrosing interstitial nephritis with renicular atrophy and loss, and numerous intralesional Crassicauda sp. nematodes. Furthermore, CBW-1 had concomitant gram-negative bacterial pneumonia and pulmonary and hepatic thromboembolism. Morphologic analysis of renal adult nematodes identified Crassicauda sp. in the three CBW. Molecular analyses targeting the 18S and ITS-2 ribosomal loci of renal nematodes in CBW-2 and CBW-3 identified C. anthonyi. It is believed that severe arterial and renal crassicaudiasis likely resulted or contributed significantly to morbidity and death of these animals. These results expand the known geographical range of occurrence of crassicaudiasis in CBW. Specifically, the present study provides the first accounts of arterial and renal crassicaudiasis in CBW off the southern hemisphere, specifically in CBW off Brazil, and to the authors' knowledge, it is the first record of C. anthonyi in the southern Atlantic Ocean.

Pathologic features and molecular identification of parelaphostrongylosis in a sitatunga (Tragelaphus spekii).

We report the pathologic features, local inflammatory response immunophenotype, and molecular identification results of cerebral nematodiasis in a young sitatunga (Tragelaphus spekii) from Texas. To the authors' knowledge, this is the first report of cerebral nematodiasis by Parelaphostrongylus tenuis in a sitatunga, a bovid species introduced into the USA, and the first characterization of the local inflammatory response immunoprofile in this condition. A molecular identification method based on formalin-fixed and paraffin-embedded-polymerase chain reaction was described. These results contribute to knowledge on geographical distribution and host spectrum of P. tenuis, and highlight the relevance of this nematodiasis in naïve translocated or introduced bovid species into endemic areas.