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Polyomaviruses (PyVs) are small double-stranded DNA viruses able to infect species across all vertebrate taxa. In cetaceans, PyVs have been reported only in short-beaked common dolphin ( Delphinus delphis ), common bottlenose dolphin ( Tursiops truncatus ) and killer whale ( Orcinus orca ). Herein, we surveyed PyV in 119 cetaceans (29 mysticetes and 90 odontocetes) stranded along the Brazilian coast, from 2002 to 2022, comprising 18 species. DNA extracted from the lungs was tested using a nested PCR targeting the major capsid protein gene of PyV. Polyomavirus was detected in lung samples of 1.7% (2/119) cetaceans: two juvenile female Guiana dolphins ( Sotalia guianensis ) stranded in Rio de Janeiro (Rio de Janeiro state) and Guriri (Espírito Santo state), in 2018. Both retrieved sequences were identical and presented 93.3% amino acid identity with Zetapolyomavirus delphini , suggesting a novel species. On histopathology, one of the PyV-positive individuals presented basophilic intranuclear inclusion bodies morphologically consistent with polyomavirus in the lungs. Other available tissues from both cases were PyV-PCR-negative; however, both individuals tested positive for Guiana dolphin morbillivirus. To our knowledge, this is the first report of PyV infection in cetaceans of the Southern Hemisphere and the first description of a co-infection with morbillivirus.

Clade 2.3.4.4b highly pathogenic avian influenza (HPAI) H5N1 virus was detected in the South American sea lions found dead in Santa Catarina, Brazil, in October 2023. Whole genome sequencing and comparative phylogenetic analysis were conducted to investigate the origin, genetic diversity, and zoonotic potentials of the H5N1 viruses. The H5N1 viruses belonged to the genotype B3.2 of clade 2.3.4.4b H5N1 virus, which was identified in North America and disseminated to South America. They have acquired new amino acid substitutions related to mammalian host affinity. Our study provides insights into the genetic landscape of HPAI H5N1 viruses in Brazil, highlighting the continuous evolutionary processes contributing to their possible adaptation to mammalian hosts., (© 2024. The Author(s).)

Long-standing reports of open sores on the hind legs of moose (Alces alces) have been recorded in Alaska (as well as Canada, Europe, and Michigan), eliciting concerns about causes and infection. We used histological and genomic methods to investigate the sores from 20 adult moose on the Kenai Peninsula, Alaska. We paired this with thermal imagery and molt scoring of adult moose to further describe sore formation and understand its timing. Severe, ulcerative and eosinophilic dermatitis was found in all moose with sores present, and microfilariae within intraepidermal pustules were additionally found in four samples. Genetic analysis of sores from moose revealed a previously unknown genetic lineage of Onchocerca. Adult moose molt and lose their barrier of protection against flies in June and July during peak fly activity, leaving them vulnerable and allowing the development of sores. In summary, our results indicate that the cause for the sores on the hindleg of moose is a previously unknown genetic lineage of Onchocerca, probably transmitted by black flies, in timing with the molt cycle of adult moose. These sores leave moose exposed to pathogens, making them vulnerable, and challenging their health and fitness., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Benedict et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

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., (© Wildlife Disease Association 2022.)

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., (© 2021 The Authors.)

The humpback whale (HW; Megaptera novaeangliae) population that seasonally resides along the Brazilian coast concentrates in the Abrolhos Bank (Bahia and Espírito Santo states) for breeding during austral winter and spring. Cetacean morbillivirus (CeMV, Paramyxoviridae family) is currently one of the most significant biological threats to cetaceans worldwide with high infection and mortality rates. CeMV is pleiotropic yet it has special tropism for the respiratory, lymphoid and nervous system and is primarily transmitted by the aerogenous route. A new lineage of CeMV, the Guiana dolphin morbillivirus (GDMV), is known to affect cetaceans off Brazil. GDMV was first detected in a Guiana dolphin (Sotalia guianensis) stranded in the Abrolhos Bank region, in 2010. In addition to pathologic examinations on stranded HW, pathogen survey of free-ranging HW may provide valuable insight into the epidemiology of diseases. We hypothesized that HW in the Brazilian breeding ground could be exposed to CeMV. Thus, in the present study, we investigated the presence of CeMV in exhaled breath condensates (EBC) of HW in the Abrolhos Bank. Overall, 73 samples of EBC from 48 groups of HW were collected during the breeding seasons of 2011 (n = 16) and 2012 (n = 57). One sample failed to have the reference gene amplified and was excluded from the study. CeMV was detected by a RT-qPCR method in 2 EBC samples, representing 2 whale groups. Phylogenetic analysis of partial morbillivirus phosphoprotein gene showed 100% homology to GDMV. Our results show that HW in Brazil are infected by CeMV with a relative prevalence of 4.3% (2/47) and demonstrate the suitability of using EBC and RT-qPCR as a non-invasive tool for CeMV survey in free-ranging whales. This pioneer study provides scientific basis for non-invasive CeMV monitoring of HW, suggests HW may play a role in the dynamics of CeMV and raises concern for potential conservation implications for this species., (© 2020 Wiley-VCH GmbH.)

Dramatic declines in amphibians worldwide highlight the need for a better understanding of diseases affecting these species. To delineate the health issues of amphibians submitted to Texas A&M University System (2016-2020), the databases were queried on the basis of defined selection criteria. A total of 502 anurans (157 frogs [44 species] and 345 toads [10 species]) and 30 caudatans (23 salamanders [6 species] and 7 newts [4 species]) were reviewed. A most likely cause of death or major pathological finding (CD-MPF) leading to euthanasia was identified in 295 (55%) Anura cases and 15 (50%) Caudata cases. Of the 532 records reviewed, anurans included 492 captive, seven free-ranging and three undetermined specimens. All caudatans were captive. The most common CD-MPF in anurans was infectious/inflammatory (228/295; 77%), involving mycobacteriosis (73/228; 32%), chlamydiosis (44/228; 19%) and mycosis (32/228; 14%). Neoplasia was less common (28/295; 9%). Infectious/inflammatory lesions (14/15; 93%) were the main CD-MPFs in caudatans. Infectious diseases are a significant threat to captive amphibians in Texas and these results may aid personnel involved in amphibian conservation programmes, veterinarians and diagnosticians., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Keratinocyte organoids can be used as a tool to evaluate epidermal structure, function and dysfunction., Objectives: To optimize the canine keratinocyte organoid system and produce organoids that are structurally equivalent to in vivo canine epidermis, in order to enable studies that focus on epidermal diseases and diseases resulting from an impaired epidermal barrier., Animals: Skin biopsies were obtained from five recently euthanized dogs of different breeds with no skin abnormalities., Methods and Materials: Cells derived from microdissected interfollicular epidermis were seeded in basement membrane extract and epidermal organoids were grown under different media conditions. Organoids were characterized to assess cell morphology and architecture in haematoxylin and eosin-stained slides and expression of selected epidermal markers (keratin 5, keratin 10, loricrin and filaggrin) by immunohistochemical analysis and quantitative reverse transcription PCR., Results: The selected epidermal markers were expressed in the same epidermal layers in the organoids cultured in expansion medium and differentiation medium as in normal interfollicular epidermis, yet restriction to the distinct layers was best achieved with expansion medium. Comparison of the mRNA expression levels of these markers revealed that relative expression is similar in organoids cultured in expansion medium and normal canine epidermis, while it differs in organoids cultured in differentiation medium., Conclusion and Clinical Importance: Organoids cultured in expansion medium have an equivalent structure to the interfollicular epidermis and express key marker proteins in similar proportions. Epidermal organoids are therefore a promising in vitro model to study epidermal structure, function and dysfunction., (© 2020 the European Society of Veterinary Dermatology and the American College of Veterinary Dermatology.)

We report the epidemiological, clinical and pathological features of an outbreak of Paranannizziopsis australasiensis (order Onygenales) in captive African bush vipers (Atheris squamigera) (ABVs) that died suddenly. The snakes had multifocal, raised, white-grey to dark brown discoloured cutaneous patches. Microscopically, all had integumentary lesions characterized by multifocal to coalescent necroheterophilic epidermitis with superficial and intraepidermal fungal elements and bacteria. Concurrent epidermal hyperplasia, hyperkeratosis and intracellular and intercellular oedema, often leading to vesiculation, and fasciitis/superficial myositis, were consistent findings in all snakes, while ulceration (9/11) and dysecdysis (5/11) varied. A panfungal polymerase chain reaction targeting the internal transcribed spacer-2 region, and gene sequencing, confirmed P. australasiensis infection in three cases. This is the first report of P. australasiensis in the USA and the first record of paranannizziopsis infection in African bush vipers. P. australasiensis should be considered in the differential diagnosis of dermatomycosis in snakes and represents a potential threat to reptile conservation programmes., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Cetacean morbillivirus (CeMV; Paramyxoviridae ) is the most significant pathogen of cetaceans worldwide. The novel "multi-host" Guiana dolphin ( Sotalia guianensis ; GD)-CeMV strain is reported in South American waters and infects Guiana dolphins and southern right whales ( Eubalaena australis ). This study aimed to describe the pathologic findings, GD-CeMV viral antigen distribution and detection by RT-PCR (reverse transcriptase polymerase chain reaction), and infectious comorbidities in 29 Guiana dolphins that succumbed during an unusual mass-mortality event in Rio de Janeiro state, Brazil, between November 2017 and March 2018. The main gross findings were lack of ingesta, pulmonary edema, ascites, icterus, hepatic lipidosis, multicentric lymphadenomegaly, as well as pneumonia, polyserositis, and multiorgan vasculitis caused by Halocercus brasiliensis . Microscopically, the primary lesions were bronchointerstitial pneumonia and multicentric lymphoid depletion. The severity and extent of the lesions paralleled the distribution and intensity of morbilliviral antigen. For the first time in cetaceans, morbilliviral antigen was detected in salivary gland, optic nerve, heart, diaphragm, parietal and visceral epithelium of glomeruli, vulva, and thyroid gland. Viral antigen within circulating leukocytes suggested this as a mechanism of dissemination within the host. Comorbidities included disseminated toxoplasmosis, mycosis, ciliated protozoosis, and bacterial disease including brucellosis. These results provide strong evidence for GD-CeMV as the main cause of this unusual mass-mortality event.

We provide pathological, immunohistochemical and molecular evidence of cetacean morbillivirus (CeMV) infection in a live-stranded adult female killer whale (Orcinus orca), which stranded alive in Espírito Santo State, Brazil, in 2014. Although attempts were made to release the animal, it stranded again and died. The main pathological findings were severe pulmonary oedema, pleural petechiation, multifocal, lymphoplasmacytic meningoencephalitis and leptomeningomyelitis with perivascular cuffing and gliosis, chronic lymphocytic bronchointerstitial pneumonia and multicentric lymph node and splenic lymphoid depletion. Other pathological findings were associated with the 'live-stranding stress response'. Immunohistochemical analysis revealed multifocal morbilliviral antigen in neurons and astrocytes, and in pneumocytes, histiocytes and leukocytes in the lung. CeMV was detected by a novel reverse transcriptase polymerase chain reaction method in the brain and kidney. Phylogenetic analysis of part of the morbillivirus phosphoprotein gene indicates that the virus is similar to the Guiana dolphin (Sotalia guianensis) morbillivirus strain, known to affect cetaceans along the coast of Brazil. To the authors' knowledge, this is the first report of morbillivirus disease in killer whales., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Cetacean morbillivirus (CeMV, family Paramyxoviridae) is a re-emergent pathogen associated with severe epizootic outbreaks causing high mortality among cetaceans worldwide. Recently, CeMV caused an unusual mortality event of Guiana dolphins (Sotalia guianensis) in Brazil. Partial sequence of the viral phosphoprotein (P) gene showed that the Guiana dolphin morbillivirus (GDMV) might represent a new lineage of CeMV. This study aimed to develop a molecular technique to detect the most common CeMV strains known to circulate in the Atlantic Ocean: GDMV, Dolphin morbillivirus (DMV) and Pilot-whale morbillivirus (PWMV). A sensible real-time reverse transcription polymerase chain reaction (RT-qPCR) method based on intercalating dye, targeting the P gene was described. This assay successfully detected GDMV, PWMV and DMV from field samples. Its performance was compared to a RT-qPCR method that specifically detects GDMV. Both assays had high sensibility and excellent intra- and inter-assay reproducibility. A total of 109 field samples from 32 Guiana dolphins were screened for CeMV by conventional RT-PCR in parallel with the RT-qPCR assay. The detection rate increased from 32% to 60% by use of the novel RT-qPCR. The RT-qPCR assay described herein allows rapid and sensitive detection of Atlantic CeMV strains, and is potentially suitable for screening of CeMV globally., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The transcriptome profile and differential gene expression in telogen and late anagen microdissected hair follicles and the interfollicular epidermis of healthy dogs was investigated by using RNAseq. The genes with the highest expression levels in each group were identified and genes known from studies in other species to be associated with structure and function of hair follicles and epidermis were evaluated. Transcriptome profiling revealed that late anagen follicles expressed mainly keratins and telogen follicles expressed GSN and KRT15 . The interfollicular epidermis expressed predominately genes encoding for proteins associated with differentiation. All sample groups express genes encoding for proteins involved in cellular growth and signal transduction. The expression pattern of skin-associated genes in dogs is similar to humans. Differences in expression compared to mice and humans include BMP2 expression mainly in telogen and high KRT17 expression in the interfollicular epidermis of dogs. Our data provide the basis for the investigation of the structure and function of canine skin or skin disease and support the use of dogs as a model for human cutaneous disease by assigning gene expression to specific tissue states.

While the health effects of trypanosomes in Australian mammals in their native range are not fully understood, there is evidence of an impact in those species introduced to other geographical regions. Here we report the pathological and molecular features of concurrent fatal trypanosomiasis and toxoplasmosis in an adult female captive red-necked wallaby (syn. Bennett's wallaby; Macropus rufogriseus) from Bee County, Texas, USA. The animal exhibited no clinical signs prior to sudden death. On necropsy, the main findings were generalized organ congestion and bilateral renal petechiation. Microscopically, the main finding was lymphohistiocytic and necrotizing pancarditis with intrasarcoplasmic protozoal pseudocysts containing amastigotes and occasional intrahistiocytic amastigotes, morphologically compatible with Trypanosoma cruzi, as well as rare intrasarcoplasmic protozoal tissue cysts with zoites morphologically compatible with Toxoplasma gondii. Other lesions included acute centrilobular to panlobular necrotizing hepatitis with intrahepatocellular T. gondii cysts, necrotizing splenitis, pulmonary oedema with fibrin, histiocytosis and rare fibrin microthrombi, and acute renal tubular degeneration with proteinosis and pigmented casts suggestive of haemoglobinuria or myoglobinuria. Immunohistochemical labelling confirmed intralesional T. gondii cysts and molecular analyses identified T. cruzi genotype I and T. gondii. This is a unique case that, to the best of our knowledge, represents the first description of T. cruzi and T. gondii co-infection, as well as the first record of naturally occurring infection T. cruzi genotype I infection in macropodids. This case adds to the epidemiological knowledge on Chagas disease in the USA, particularly in Texas where there is a high prevalence of human and canine trypanosomiasis., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The leatherback sea turtle (LST; Dermochelys coriacea) is highly migratory and is primarily distributed throughout tropical and subtropical regions. The LST populations found in Brazil are critically endangered. An unusual mortality event occurred between August and November 2016 with 23 LSTs stranded along a 100 km coastal segment in Iguape, Ilha Comprida and Ilha do Cardoso in southern São Paulo state. This study investigated the pathological findings and most likely causes of death of 10 LSTs. Male (n = 9) and adult (n = 9) animals predominated. All but one animal was in good body condition and all were found dead. The most prevalent gross findings were suggestive of bycatch, namely cutaneous erosions, abrasions and/or lacerations around the neck and flippers (n = 9), generalized congestion (n = 8) and pulmonary oedema (n = 6). Other prevalent gross findings were: cutaneous epibiosis by Stomatolepas elegans (n = 7); ileocecal diverticulitis (n = 7); distal oesophagitis (n = 5); and fibrinous coelomitis (n = 5). Microscopically, the most prevalent findings were: hepatic melanomacrophage centre hypertrophy or hyperplasia (n = 9); interstitial pneumonia (n = 8); multisystemic congestion (n = 6); pulmonary oedema with or without aspirated material (n = 5); adrenal coccidiosis (n = 5) with variable multiorgan involvement; and multiorgan bacterial disease (n = 5). Five animals had food ingesta (cnidarians, crustaceans) in the oesophagus or stomach; only one had evident plastic foreign bodies. Asphyxia due to entanglement in nets was the most frequently identified cause of death (n = 8); a cause of death was not identified in two animals. Our findings provide evidence of the severe negative impact of entanglement in fishing nets in LSTs, raising concerns for conservation. These findings also contribute to knowledge of the pathology of LSTs in South American populations., Competing Interests: Conflict of Interest Statement The authors declare no potential conflicts of interest with respect to the research, authorship or publication of this article., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This study investigated the repertoire, call-type variability and call rates of southern right whales on a calving ground off Brazil in the western South Atlantic. Acoustic tag data were collected from four lactating females and one juvenile. Pulsive, hybrid, and upcalls showed the greatest variability among call-types with up to 23% of non-standard forms detected. Quiet sounds (grunt, single, and double pulse) were detected for the first time in this species on the calving grounds. Although the sample size was limited, results suggest that social interaction increased call-type diversity and call rates, in line with other acoustic studies on right whales.

We report the pathological features of a facial squamous cell carcinoma (SCC) and an abdominal peripheral nerve sheath tumour (PNST) with rhabdomyoblastic differentiation in an aged free-ranging rough-toothed dolphin (Steno bredanensis). The animal was found stranded dead in poor body condition. On external examination, there was a 25 × 7 × 3 cm extensively ulcerated area on the right maxillary region of the rostrum, involving the oral mucocutaneous junction with prominent nodular edges, severe soft tissue loss and extensive maxillary and premaxillary bone lysis. On abdominal dissection, a 5 × 4 × 3.5 cm pale tan to red, raised mass expanded the inner aspect of the right transverse abdominis muscle. Microscopically, the aggressive facial lesion was an acantholytic SCC with extensive osteolysis; there was no evidence of metastasis in the tissues examined. The abdominal mass had cytohistomorphological features compatible with a localized PNST, including whorling, Antoni A and Antoni B areas and Verocay bodies intermixed with rhabdomyoblastic components, as suggested by phosphotungstic acid haematoxylin stain. This neoplasm was locally infiltrative, yet no metastases were observed in the tissues examined. No immunohistochemical investigations could be performed due to lack of tissue availability. Total DNA from the formalin-fixed and paraffin wax-embedded SCC was extracted and tested by polymerase chain reaction for herpesvirus and papillomavirus genetic material. There was no amplification for either of these genera. Other pathological findings observed in this animal were related to the 'live-stranding stress response'. The severity and extent of the facial SCC likely related to anorexia and poor body condition and might have played a role in the stranding and death of this dolphin. These two tumour subtypes add to the relatively uncommon reports of neoplasia in cetaceans. Specifically, these appear to be the first neoplasia records for rough-toothed dolphins, including the first documentation of a PNST with features compatible with rhabdomyoblastic differentiation in a marine mammal., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii. In cetaceans, T. gondii infection is a significant cause of morbidity and mortality. Despite the worldwide range and broad cetacean host record of T. gondii infection, there is limited information on toxoplasmosis in cetaceans from the Southern hemisphere. We investigated the occurrence of T. gondii by histopathology and immunohistochemistry in tissue samples of 185 animals comprising 20 different cetacean species from Brazil. Three out of 185 (1.6%) animals presented T. gondii-associated lesions: a captive killer whale Orcinus orca, a free-ranging common bottlenose dolphin Tursiops truncatus and a free-ranging Guiana dolphin Sotalia guianensis. The main lesions observed in these animals were necrotizing hepatitis, adrenalitis and lymphadenitis associated with protozoal cysts or extracellular tachyzoites presenting immunolabeling with anti-T. gondii antibodies. This study widens the spectrum of species and the geographic range of this agent in Brazil, and provides the first reports of T. gondii infection in a captive killer whale and in a free-ranging common bottlenose dolphin in South America.

A juvenile subantarctic fur seal (Arctocephalus tropicalis) found dead in Santa Catarina state, southern Brazil, presented with disseminated verminous pneumonia due to Parafilaroides sp. A concomitant infection with two different gammaherpesviruses was identified by PCR in different tissues; one of them possibly a novel species (tentatively named Otariid herpesvirus 7). Sarcocystis sp. DNA was identified molecularly in skeletal muscle samples with intrasarcoplasmic bradyzoites and no apparent tissue response. All analyzed samples (mandibular, laryngeal, tracheal, and mesenteric lymph nodes, and lung) were PCR-negative for Brucella spp. The most likely cause of death was severe pulmonary parafilaroidiasis. The pathogenic role of the gammaherpesviruses in several of the tissues was not evident. This study describes the pathogenicity of Parafilaroides sp. in a subantarctic fur seal, widens the host range of herpesvirus in pinnipeds, and reports the first molecular identification of Sarcocystis sp. in this species.

Brucella-exposure and infection is increasingly recognized in marine mammals worldwide. To better understand the epidemiology and health impacts of Brucella spp. in marine mammals of Brazil, molecular (conventional PCR and/or real-time PCR), serological (Rose Bengal Test [RBT], Competitive [c]ELISA, Serum Agglutination Test [SAT]), pathological, immunohistochemical (IHC) and/or microbiological investigations were conducted in samples of 129 stranded or by-caught marine mammals (orders Cetartiodactyla [n = 124], Carnivora [n = 4] and Sirenia [n = 1]). Previous serological tests performed on available sera of 27 of the 129 animals (26 cetaceans and one manatee), indicated 10 seropositive cetaceans. Conventional PCR and/or real-time PCR performed in cases with available organs (n = 119) and/or blood or swabs (n = 10) revealed 4/129 (3.1%) Brucella-infected cetaceans (one of them with positive serology; the remaining three with no available sera). Pathological, IHC and/or microbiological analyses conducted in PCR/real-time PCR and/or seropositive cases (n = 13) revealed Brucella-type lesions, including meningitis/meningoencephalitis, pneumonia, necrotizing hepatitis, pericarditis and osteoarthritis in some of those animals, and positive IHC was found in all of them (excepting two live-stranded animals without available organs). Brucella spp. culture attempts were unsuccessful. Our results demonstrated exposure, asymptomatic, acute and chronic Brucella sp. infection in several cetacean species in the Brazilian coast, highlighting the role of this pathogen in stranding and/or death, particularly in Clymene dolphin (Stenella clymene) and short-finned pilot whale (Globicephala macrorhynchus) off Ceará State. Novel hosts susceptible to Brucella included the franciscana (Pontoporia blainvillei), the Guiana dolphin (Sotalia guianensis) and the spinner dolphin (Stenella longirostris). Additionally, three coinfection cases involving Brucella spp. and cetacean morbillivirus, Edwarsiella tarda and Proteus mirabilis were detected. To the best of our knowledge, this is the first long-term and large-scale survey of Brucella spp. in marine mammals of South America, widening the spectrum of susceptible hosts and geographical distribution range of this agent with zoonotic potential., (© 2019 Blackwell Verlag GmbH.)

We describe the gross, microscopical, histochemical and immunohistochemical features of a sclerosing pneumopathic disease process resembling primary multicentric pulmonary low-grade fibromyxoid sarcoma in a juvenile female leatherback sea turtle (Dermochelys coriacea). The animal was fresh, presented in good body condition and stranded dead in Aracaju, Sergipe state, Brazil, in September, 2017. Grossly, the lungs were enlarged bilaterally and the parenchyma was replaced by large, coalescing, white, firm masses that extended into the bronchi and bronchioles and to the pleura. Microscopically, these masses consisted of paucicellular populations of well-differentiated, spindle-shaped fibroblasts with low pleomorphism and low mitotic count, but tissue invasion. Abundant collagen in compact areas merged with peripheral fibromyxoid foci and inflamed stroma. Antibodies specific for cytokeratins AE1/AE3 and smooth muscle actin (SMA) labelled pneumocytes lining the remaining distorted alveoli and the hypertrophied and hyperplastic bronchial muscles, respectively. Tumour cells were negative for SMA; neither neoplastic nor normal tissues cross-reacted with antibodies specific for vimentin or Ki67. Chelonid alphaherpesvirus 5 (ChHV5) polymerase chain reaction analysis from formalin-fixed, paraffin wax-embedded lung tissue sections amplified a 450 base pair fragment of DNA-polymerase (UL30 region) that had 100% homology to sequences previously detected in green sea turtles (Chelonia mydas) on the Brazilian coast. Enterocolitis was a concomitant condition that likely caused morbidity in this case. These findings contribute to the body of knowledge on sea turtle health and expand the known geographical range for ChHV5 in the southern hemisphere., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Cetacean morbillivirus (CeMV) is a major natural cause of morbidity and mortality in cetaceans worldwide and results in epidemic and endemic fatalities. The pathogenesis of CeMV has not been fully elucidated, and questions remain regarding tissue tropism and the mechanisms of immunosuppression. We compared the histopathologic and viral immunohistochemical features in molecularly confirmed CeMV-infected Guiana dolphins (Sotalia guianensis) from the Southwestern Atlantic (Brazil) and striped dolphins (Stenella coeruleoalba) and bottlenose dolphins (Tursiops truncatus) from the Northeast-Central Atlantic (Canary Islands, Spain) and the Western Mediterranean Sea (Italy). Major emphasis was placed on the central nervous system (CNS), including neuroanatomical distribution of lesions, and the lymphoid system and lung were also examined. Eleven Guiana dolphins, 13 striped dolphins, and 3 bottlenose dolphins were selected by defined criteria. CeMV infections showed a remarkable neurotropism in striped dolphins and bottlenose dolphins, while this was a rare feature in CeMV-infected Guiana dolphins. Neuroanatomical distribution of lesions in dolphins stranded in the Canary Islands revealed a consistent involvement of the cerebrum, thalamus, and cerebellum, followed by caudal brainstem and spinal cord. In most cases, Guiana dolphins had more severe lung lesions. The lymphoid system was involved in all three species, with consistent lymphoid depletion. Multinucleate giant cells/syncytia and characteristic viral inclusion bodies were variably observed in these organs. Overall, there was widespread lymphohistiocytic, epithelial, and neuronal/neuroglial viral antigen immunolabeling with some individual, host species, and CeMV strain differences. Preexisting and opportunistic infections were common, particularly endoparasitism, followed by bacterial, fungal, and viral infections. These results contribute to understanding CeMV infections in susceptible cetacean hosts in relation to factors such as CeMV strains and geographic locations, thereby establishing the basis for future neuro- and immunopathological comparative investigations., Competing Interests: The authors have declared that no competing interests exist.

Cetacean morbillivirus (CeMV; Paramyxoviridae ) causes epizootic and interepizootic fatalities in odontocetes and mysticetes worldwide. Studies suggest there is different species-specific susceptibility to CeMV infection, with striped dolphins ( Stenella coeruleoalba ), bottlenose dolphins ( Tursiops truncatus ), and Guiana dolphins ( Sotalia guianensis ) ranking among the most susceptible cetacean hosts. The pathogenesis of CeMV infection is not fully resolved. Since no previous studies have evaluated the organ-specific immunopathogenetic features of CeMV infection in tissues from infected dolphins, this study was aimed at characterizing and comparing immunophenotypic profiles of local immune responses in lymphoid organs (lymph nodes, spleen), lung and CNS in CeMV-molecularly (RT-PCR)-positive cetaceans from Western Mediterranean, Northeast-Central, and Southwestern Atlantic. Immunohistochemical (IHC) analyses targeted molecules of immunologic interest: caspase 3, CD3, CD20, CD57, CD68, FoxP3, MHCII, Iba1, IFNγ, IgG, IL4, IL10, lysozyme, TGFβ, and PAX5. We detected consistent CeMV-associated inflammatory response patterns. Within CNS, inflammation was dominated by CD3 + (T cells), and CD20 + and PAX5 + (B cells) lymphocytes, accompanied by fewer Iba1 + , CD68 + , and lysozyme + histiocytes, mainly in striped dolphins and bottlenose dolphins. Multicentric lymphoid depletion was characterized by reduced numbers of T cells and B cells, more pronounced in Guiana dolphins. Striped dolphins and bottlenose dolphins often had hyperplastic (regenerative) phenomena involving the aforementioned cell populations, particularly chronically infected animals. In the lung, there was mild to moderate increase in T cells, B cells, and histiocytes. Additionally, there was a generalized increased expression of caspase 3 in lymphoid, lung, and CNS tissues. Apoptosis, therefore, is believed to play a major role in generalized lymphoid depletion and likely overt immunosuppression during CeMV infection. No differences were detected regarding cytokine immunoreactivity in lymph nodes, spleen, and lung from infected and non-infected dolphins by semiquantitative analysis; however, there was striking immunoreactivity for IFNγ in the CNS of infected dolphins. These novel results set the basis for tissue-specific immunophenotypic responses during CeMV infection in three highly susceptible delphinid species. They also suggest a complex interplay between viral and host's immune factors, thereby contributing to gain valuable insights into similarities, and differences of CeMV infection's immunopathogenesis in relation to body tissues, CeMV strains, and cetacean hosts.

Herpesvirus (HV) infections in cetaceans are frequently associated with skin and mucosal lesions. Although HV infections have been reported worldwide, their occurrence in southern Atlantic marine mammals is still poorly understood. We tested skin, oral and genital mucosal beta-actin PCR-positive samples from 109 free-ranging Brazilian cetaceans using a universal herpesvirus DNA polymerase PCR. Herpesvirus-positive skin samples from a Guiana dolphin (Sotalia guianensis), a dwarf sperm whale (Kogia sima), a Bolivian river dolphin (Inia boliviensis), and a lingual sample from an Atlantic spotted dolphin (Stenella frontalis) were histologically evaluated. Additional tissue samples from these animals were also PCR-positive for HV, including a novel sequence obtained from the dwarf sperm whale's stomach and mesenteric lymph node. Four novel HV species were detected in the Guiana dolphin (one), the dwarf sperm whale (two) and the Bolivian river dolphin (one). The cutaneous lesions (marked, focally extensive, chronic proliferative dermatitis) of the Guiana dolphin and the Bolivian river dolphin were similar to previous HV reports in cetaceans, despite the absence of intranuclear inclusion bodies. This is the largest HV survey in South American cetaceans and the first detection of HV infection in riverine dolphins worldwide., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Strandings of live new-born West Indian manatees (WIMs; Trichechus manatus) are one of the main challenges for the conservation of this species in Brazil, particularly in the northeastern states. Congenital malformations (CMs) are rare in sirenians. We identified CMs in two of 19 stranded WIMs that were rescued, rehabilitated and subjected to complete pathological examinations in Ceará and Rio Grande do Norte States between 1992 and 2017. In case 1, dilation of the cerebral lateral and fourth ventricles with abundant cerebrospinal fluid (internal hydrocephalus), was diagnosed. Furthermore, this animal developed necrotizing enterocolitis associated with pneumatosis intestinalis and aspiration pneumonia late during rehabilitation. Cardiac malformations in case 2 included: right ventricle hypoplasia with marked stenosis of the tricuspid outflow, high ventricular septal defect, segmental pulmonary artery aneurysm, mitral valve haemocyst and left ventricular hypertrophy. Herein, we provide the first description of a neural tube defect, specifically a developmental internal hydrocephalus, and multiple cardiac congenital anomalies, together with their respective clinicopathological features in manatees. Although the aetiology of the CMs remains unknown in these cases, a genetic basis is plausible given the low genetic variability in this population. These cases add to the body of knowledge on health and disease aspects of manatees and may provide scientific basis for future medical and conservation efforts on neonatal WIMs., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Cetacean morbillivirus (CeMV) has caused repeated epizootics and interepizootic fatalities in a variety of cetacean species worldwide. Recently, a novel CeMV strain (GD-CeMV) was linked to a mass die-off of Guiana dolphins (Sotalia guianensis) in Brazil. Southern right whales (SRWs; Eubalaena australis) migrate to the southern Brazilian coast during austral winter and spring (June through November) for breeding and calving. Because unexplained high calf mortality rates have recurrently been documented in SRWs, we hypothesized they could be infected with CeMV. We developed a novel real-time RT-PCR method based on SYBR ® GREEN for detection of CeMV and identified the virus in three out of five stranded SRWs from Santa Catarina state, Brazil. The partial sequences of the morbillivirus phosphoprotein gene suggest that the virus is similar to the GD-CeMV strain. Our results indicate CeMV can infect SRWs and should be considered in the differential aetiologic diagnosis of infectious diseases in this species. It also raises concern for potential conservation implications for this species in its main coastal breeding area off Southern Brazil., (© 2018 Blackwell Verlag GmbH.)

North Atlantic right whales (NARW), Eubalaena glacialis , were nearly exterminated by historical whaling. Their abundance slowly increased up until 2010, to a maximum of fewer than 500 whales, and since then they have been in decline. We assessed the extent to which the relatively slow increase demonstrated by NARW was intrinsic, and how much could be due to anthropogenic impacts. In order to do so, we first compared calf counts of three populations of Southern right whales (SRW), E. australis , with that of NARW, over the period 1992-2016. By this index, the annual rate of increase of NARW was approximately one-third of that of SRW. Next we constructed a population projection model for female NARW, using the highest annual survival estimates available from recent mark-resight analysis, and assuming a four-year calving interval. The model results indicated an intrinsic rate of increase of 4% per year, approximately twice that observed, and that adult female mortality is the main factor influencing this rate. Necropsy records demonstrate that anthropogenic mortality is the primary cause of known mortality of NARW. Anthropogenic mortality and morbidity has limited the recovery of NARW, and baseline conditions prior to their recent decline were already jeopardizing NARW recovery., Competing Interests: We have no competing interests.

During November-December 2017, a mass die-off of Guiana dolphins (Sotalia guianensis) began in Rio de Janeiro, Brazil. Molecular and pathologic investigations on 20 animals indicated that cetacean morbillivirus played a major role. Our findings increase the knowledge on health and disease aspects of this endangered species.

A considerable amount of knowledge on natural and anthropogenic pathologic conditions affecting different cetacean species has been gained over the last decades. Nonetheless, the immunopathological bases for most of these processes have been poorly documented or remain unknown. Comparative immunopathological investigations in these species are precluded by the limited number of specific antibodies, most of which are not commercially available, and the reduced spectrum of validated and/or cross-reactive ones. To partially fill in this gap of knowledge, a set of commercially available primary antibodies were tested for cross-reactivity against leukocytes and cytokines in formalin-fixed, paraffin-embedded (FFPE) lymphoid tissues (lymph nodes, spleen and thymus) of three bycaught, apparently healthy and fresh Franciscanas (Pontoporia blainvillei) using immunohistochemistry. On the basis of similar region specificity within the lymphoid organs, cellular morphology and staining pattern with human control tissues, 13/19 primary antibodies (caspase 3, CD3, CD57, CD68, FoxP3, HLA-DRα, IFNγ, IgG, IL4, IL10, Lysozyme, TGFβ and PAX-5) exhibited satisfactory cross-reactivity. Our results expand the spectrum of suitable cross-reactive primary antibodies in FFPE cetacean tissues. Further comparative immunopathological studies focused on infectious diseases and ecotoxicology may benefit from establishment of baseline expression of immunologically relevant molecules in various cetaceans species., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This study describes the pathologic findings of 24 humpback whales (Megaptera novaeangliae) found stranded along the Brazilian coast from 2004 to 2016. Eighteen (75%) animals evaluated were found stranded alive. From these, 13 died naturally on shore and five were euthanized. Six died at sea and were washed ashore. Of the 24, 19 (79.2%) were calves, four (16.7%) were juveniles, and one (4.2%) was an adult. The most probable cause of stranding and/or death (CSD) was determined in 23/24 (95.8%) individuals. In calves, CSD included neonatal respiratory distress (13/19; 68.4%), infectious disease (septicemia, omphaloarteritis and urachocystitis; 3/19; 15.8%), trauma of unknown origin (2/19; 10.5%), and vehicular trauma (vessel strike; 1/19; 5.3%). In juveniles and adult individuals, CSD was: emaciation (2/5; 40%), sunlight-thermal burn shock (1/5; 20%); and discospondylitis (1/5; 20%). In one juvenile, the CSD was undetermined (1/5; 20%). This study integrates novel findings and published case reports to delineate the pathology of a South-western Atlantic population of humpback whales. This foundation will aid in the assessment of the population health and establish a baseline for development of conservation policies.

The occurrence of accessory spleens in cetacean species is high yet confirmed reports of intrapancreatic accessory spleen, a congenital malformation, remain undescribed. The current study provides the gross, microscopical, histochemical and immunohistochemical features of an intrapancreatic accessory spleen in a harbor porpoise (Phocoena phocoena). Grossly, a 17 × 18 × 9 mm well-demarcated, dark brown to red mass expanded the left pancreatic lobe. Microscopically, this mass consisted of mature splenic tissue interspersed with exocrine pancreatic acini. Intrapancreatic accessory spleens should be considered in the list of differential diagnoses for intrapancreatic nodular lesions in cetaceans.

Pulmonary neoplasia is rare among wild New World primates. We report the gross, microscopical, and immunohistochemical features of a primary multicentric pulmonary adenosquamous carcinoma in a free-living black capuchin monkey (Sapajus nigritus). Herein, the spectrum of pulmonary neoplasms in non-human primates is widened and briefly reviewed., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The opossum (family Didelphidae) is a marsupial endemic to the Americas. Apart from the South American short-tailed opossum (Monodelphis domestica) and the Virginia opossum (Didelphis virginiana), there is considerable lack of knowledge about the health and diseases of most opossum species. Among these, the big-eared opossum (Didelphis aurita) is found in Argentina, Brazil and Paraguay. Natural and experimental studies have shown this species to be susceptible to infectious agents with zoonotic potential and the animals may play a role in transmission of such agents. However, neoplasia appears to be uncommon in this species. We describe the gross, microscopical and immunohistochemical features of a parotid salivary gland basal cell adenocarcinoma in a free-living big-eared opossum. This case represents the first report of salivary gland neoplasia in opossums., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Neuroectodermal developmental anomalies are reported rarely in cetaceans and central nervous system cysts are not described. We describe the gross, microscopical, histochemical and immunohistochemical features of a neuraxial myelencephalic cyst in a stranded neonatal Burmeister's porpoise (Phocoena spinipinnis). Grossly, a subdural, extra-axial, well-demarcated, yellow fluid-filled cystic structure (1.9 × 1.6 × 1 cm) expanded the left foramen of Luschka, the left caudolateral cerebellar recess and the left cranioventral myelencephalon. The cyst displaced the ipsilateral ventral paraflocculus and distended the underlying cranial nerves IX, X, XI and XII. Microscopically, the cystic structure was lined by a monolayer of low cuboidal to flattened epithelium supported by a thin fibrovascular matrix. Immunohistochemistry (IHC) revealed strong and diffuse expression of AE1/AE3 and focal positivity for vimentin. IHC for epithelial membrane antigen, glial fibrillary acid protein, synaptophysin and S100 was negative. Based on these findings, an extra-axial cyst of the choroid plexus of the fourth ventricle (CCPFV) was diagnosed. The pathological relevance of the CCPFV in this case is uncertain. The cause of death involved severe perinatal interspecific (shark) trauma. The present case provides the first evidence of a neuroepithelial cyst in cetacean species., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The vascular system of Cuvier's beaked whales (CBW) (Ziphius cavirostris; family Ziphiidae), an extremely deep, prolonged-diving cetacean, is increasingly receiving anatomic and physiologic study due to possible anthropogenic interactions; however, vascular pathology rarely has been reported in this species. Thirteen CBW stranded in the Canary Islands from June 2008 to June 2014 were autopsied. A careful dissection of the thoracic and abdominal vasculature was performed on these animals. All had moderate to severe and extensive chronic fibrosing arteritis with aneurysms, hemorrhages, and thrombosis primarily involving the mesenteric and gastroepiploic arteries and the thoracic and abdominal aorta. Microscopically, the lesions varied from subacute subintimal hemorrhages and severe neutrophilic, eosinophilic, and histiocytic dissecting arteritis with intralesional nematode larvae to marked, chronic, fibrosing arteritis with thickening and distortion of the vascular wall with calcification and occasional cartilage metaplasia. In addition, adult nematodes in renal arteries and veins, renal parenchyma and/or ureter were identified morphologically as Crassicauda sp. Nucleic acid sequenced from renal nematodes from 2 animals yielded closest nucleotide identity to C. magna The pathogenesis is proposed to involve a host response to larval migration from the intestine to the kidney through the mesenteric arteries, abdominal aorta, and renal arteries. Severe consequences for such lesions are possible and could vary from reduced vascular compliance to chronic renal disease and predisposition to the development of disseminated intravascular coagulation and multiorgan failure. Severe chronic arteritis in CBW is associated with renal parasitism by Crassicauda spp., (© The Author(s) 2016.)

Aiming to gather information on southern right whale (Eubalaena australis) mother-calf pairs' vocal behavior, archival acoustic recorders were deployed at a calving area off Brazil. Manual inspection of spectrograms revealed seven call classes: upcall, downcall, down-upcall, tonal variable, tonal constant, hybrid, and pulsive calls, which are consistent with those previously described for this species in Argentina. Gunshots and warbles, vocalizations described from other right whale species, were not detected. Mean values of start, end, maximum, minimum and peak frequencies, frequency bandwidth and duration were calculated for each call class. Start and end frequencies, frequency bandwidth and duration of upcalls recorded off Brazil were compared to those from other right whale populations and species. Only mean duration of upcalls from Brazil were significantly different from upcalls from all other populations. Differences in call duration may be driven by differences in demographic factors or background noise features among study areas. The repertoire characterization presented in this study will contribute to increase the utility of passive acoustic monitoring as a tool for conservation and research of southern right whales off Brazil as it provides important baseline information on the vocal behavior of this species.

Cetacean morbillivirus (CeMV) is considered one of the most important viral pathogens in cetaceans. CeMV outbreaks of lethal disease have repeatedly been observed in Europe, the Americas, and Australia, while large herds of gregarious species were found to be the likely reservoirs and sources of CeMV infection to susceptible species in the Atlantic and Pacific Oceans. Furthermore, three new strains were detected recently in Hawaii, Brazil and Australia. To clarify the real global distribution of CeMV and possible carriers, we showed a novel technique successfully diagnosing and distinguishing different virus strains (DMV, PWMV and novel CeMVs) using FFPE samples from 1996 to 2011. This efficient method that combines qRT-PCR and high resolution melting (HRM) could be applied to the future retrospective global studies for better understanding of different prevalence and outbreak conditions among ocean basins and the mechanism of variable host response to pathogens.

The reproductive success of southern right whale (Eubalaena australis) depends on body condition and, therefore, on foraging success. This, in turn, might be affected by climatically driven change in the abundance of the species main prey, krill (Euphausia superba), on the feeding grounds. Annual data on southern right whale number of calves were obtained from aerial surveys carried out between 1997 and 2013 in southern Brazil, where the species concentrate during their breeding season. The number of calves recorded each year varied from 7 to 43 ( = 21.11 ± 11.88). Using cross-correlation analysis we examined the response of the species to climate anomalies and krill densities. Significant correlations were found with krill densities (r = 0.69, p = 0.002, lag 0 years), Oceanic Niño Index (r = -0.65, p = 0.03, lag 6 years), Antarctic Oscillation (r = 0.76, p = 0.01, lag 7 years) and Antarctic sea ice area (r = -0.68, p = 0.002, lag 0 years). Our results suggest that global climate indices influence southern right whale breeding success in southern Brazil by determining variation in food (krill) availability for the species. Therefore, increased frequency of years with reduced krill abundance, due to global warming, is likely to reduce the current rate of recovery of southern right whales from historical overexploitation.

A uterine prolapse associated with a leiomyoma (fibroid) was observed in a live-stranded Atlantic spotted dolphin (Stenella frontalis). A 7 cm segment of the reproductive tract including the cervix, uterine neck and caudal uterine body had intussuscepted and prolapsed into the cranial vaginal vault. In the leading edge of the intussuscepted/prolapsed uterine wall was a 6 × 3 × 3.5 cm leiomyoma expanding the myometrium. The leiomyoma and prolapse were associated with necrotizing exposure endometritis. This is the first report of a uterine prolapse associated with a leiomyoma in a cetacean. This lesion was believed to be the underlying cause of the live stranding., (Copyright © 2015 Elsevier Ltd. All rights reserved.)