Identification of a new Sarcocystis sp. in marsh deer (Blastocerus dichotomus) from wetlands of Argentina.

The marsh deer (Blastocerus dichotomus) is the largest South American native deer species and is listed as "Vulnerable" by IUCN due to the population reduction. As part of a conservation and disease surveillance program, muscle samples from 14 marsh deer found dead in 2016 and 2017 in northeast Argentina were obtained at necropsy. Samples from each animal were processed as pooled muscles (heart, diaphragm, tongue and hindlimb) by homogenization and direct microscopical observation to detect intracellular Sarcocystis spp. cysts. Sarcocysts were observed in six samples, and several cysts recovered from two samples were processed by transmission electron microscopy. The cysts were thin-walled and showed a cyst-wall ultrastructure with ribbon-like protrusions similar to other species using cervids as intermediate host and canids as definitive hosts. Genomic DNA from individual sarcocysts from three marsh deer were successfully amplified by PCR of 18S rRNA and COI gene fragments and further sequenced. Sequence comparison revealed a 99.3-100% identity among them and only 93.7-96.6% and 88.8-89.7% identity at 18S rRNA and COI markers, respectively, with other Sarcocystis spp. Despite morphological similarities, the high sequence divergence at 18S rRNA and COI fragments allowed the assumption that Sarcocystis sp. from marsh deer is a different species from others using cervids as intermediate hosts. Therefore, we propose the name Sarcocystis blastoceris n. sp. for the species infecting marsh deer.

Oral affections in an ex situ population of marsh deer (Blastocerus dichotomus): a retrospective study (1990-2020) / Afecções bucais em uma população ex situ de cervos-do-pantanal (Blastoceru dichotomus): um estudo retrospectivo (1990-2020)

Oral diseases are limiting to health, welfare, and conservation practices, especially in the case of endangered animals. In this retrospective study, a survey on oral health-related conditions noted in the clinical records for 261 deer comprised in an ex situ population of the Marsh Deer Conservation Center (CCCP) over 30 years (1990-2020) was carried out. Of these, 49 (18.77%) marsh deer (31 females - 63.27% and 18 males - 36.73%) had clinical oral affections; the affected deer's mean age was 8.9 years. Logistic regression analysis was performed, and the variable age was significantly associated with the presence of dental affections. Thus, with a change in the age category, a deer had eight times the chance of manifesting oral affections; therefore, age can be considered a risk factor for the manifestation of oral affections in the species. Increased facial volume (65.3%), accumulation of food in the mouth (36.7%), tooth loss (22.4%), fistulas (22.4%), mucosal or palatal lesions (22.4%), tooth wear (20.4%), and tooth root exposure (18.3%) were the most frequently recorded lesions. The relatively high occurrence of oral affections in Blastocerus dichotomus reiterates the importance of oral health care when deer are kept in human care.

As doenças bucais são limitantes para as práticas de saúde, bem-estar e conservação, especialmente no caso de animais ameaçados de extinção. Neste estudo retrospectivo, realizou-se um levantamento sobre condições relacionadas à saúde bucal observadas nos registros clínicos de 261 cervídeos que compunham uma população ex situ do Centro de Conservação do Cervo-do-Pantanal durante um período de 30 anos (1990-2020). Destes, 49 (18,77%) cervos-do-pantanal (31 fêmeas (63,27%) e 18 machos (36,73%)) apresentavam afecções clínicas bucais; e a idade média dos cervídeos afetados foi de 8,9 anos. Realizou-se a análise de regressão logística e a variável idade mostrou associação significativa com a presença de afecções dentárias. Assim, com a mudança de categoria de idade, um cervídeo teve oito vezes mais chances de manifestar afecções bucais; portanto, a idade pode ser considerada como fator de risco para manifestação de afecções bucais na espécie. Aumento de volume facial (65,3%), acúmulo de alimentos na boca (36,7%), perda dentária (22,4%), fístulas (22,4%), lesões nas mucosas ou palatinas (22,4%), desgaste dentário (20,4%) e exposição de raiz (18,3%) foram as lesões mais registradas. A ocorrência relativamente alta de afecções bucais em Blastocerus dichotomus reitera a importância dos cuidados com a saúde bucal quando os cervídeos são mantidos sob cuidados humanos.

A participatory surveillance of marsh deer (Blastocerus dichotomus) morbidity and mortality in Argentina: first results.

BACKGROUND: In an era of unprecedented socio-ecological changes, managing wildlife health demands high-quality data collection and the engagement of local communities. Blastocerus dichotomus, the largest South American deer, is Vulnerable to extinction mainly due to habitat loss. Diseases have been recognised as a potential threat, and winter mortality has been historically described in marsh deer populations from Argentina. Field difficulties have, however, prevented in-depth studies of their health status. RESULTS: Between May 2014 and April 2017, we investigated marsh deer morbidity and mortality in the two largest populations in Argentina. We collected data by means of a passive surveillance system that involved a network of researchers, field partners (veterinarians, park rangers, and local community), and decision makers. We sampled marsh deer during as well as outside mortality events. A total of 44 marsh deer with different body condition scores were evaluated. We obtained haematology and biochemistry values from animals with good body condition score. Marsh deer with poor body condition had a high burden of the ticks Amblyomma triste and Rhipicephalus microplus. Vector-borne agents such as Theileria cervi, Trypanosoma theileri, Trypanosoma evansi, Ehrlichia chaffeensis, Anaplasma platys, Anaplasma odocoilei, Anaplasma marginale, and Candidatus Anaplasma boleense were also found. Haemonchus spp., Ostertagia spp., and Trichostrongylus spp. were the most frequent gastrointestinal parasites in deer with poor body condition. A Multiple Correspondence Analysis reinforced a possible association of winter period with lower body score condition, high tick loads, infection with E. chaffeensis, and presence of harmful gastrointestinal parasites. CONCLUSIONS: Our approach allowed the establishment of a participatory surveillance network of marsh deer morbidity and mortality in Argentina. We report and analyse the first data obtained opportunistically within the framework of this network, providing information on the infectious and parasitic agents in marsh deer populations. The occurrence of Fasciola hepatica and Leptospira interrogans serovar pyrogenes is reported for the first time in wild marsh deer from Argentina. Our data will be useful to improve the interpretation of future mortality events. The field implementation of a surveillance network is key to a holistic approach to wildlife diseases.

Evidence of Ehrlichia chaffeensis in Argentina through molecular detection in marsh deer (Blastocerus dichotomus).

Vector-borne pathogens are responsible for serious emerging diseases and have been widely described in wildlife. Ehrlichia chaffeensis causes the zoonotic "monocytic ehrlichiosis" in humans, is transmitted by the tick Amblyomma americanum and its reservoir host is the white-tailed deer (Odocoileus virginianus) in North America. Little is known about the native reservoir and the tick vectors involved in the transmission cycle in South America. We report here the detection of E. chaffeensis in a study on marsh deer (Blastocerus dichotomus) mortality in Argentina, in different time periods between 2007 and 2016. Four deer, from two distinct populations, were positive for E. chaffeensis through molecular methods. Additionally, the variable-length PCR target (VLPT) region of positive samples was genotyped. Our results provide the first evidence of E. chaffeensis in autochthonous Cervidae from Argentina, contributing to uncover the distribution of this tick-borne infection in South America.

Morfologia da língua do cervo do pantanal (Blastocerus dichotomus) / Morphology of the tongue of the Marsh deer (Blastocerus dichotomus)

Objetivou-se descrever a morfologia da língua do cervo do pantanal (Blastocerus dichotomus), o maior cervídeo da fauna brasileira, pois poucas são as informações detalhadas sobre sua morfologia. Línguas e fragmentos linguais de oito cervos do pantanal, adultos, provenientes do Projeto Cervo-do-Pantanal de Porto Primavera foram analisados quanto aos seus aspectos macroscópicos e à microscopia de luz. A língua do cervo do pantanal ocupa grande parte da cavidade oral, onde a raiz e o corpo estão fixados caudalmente pelo osso hióide e, em sua porção média, pelo frênulo lingual; seu ápice, achatado e plano é livre; apresenta torus lingual pouco proeminente, não havendo delimitação da fossa lingual. Na superfície dorsal encontram-se as seguintes papilas: filiformes, cônicas, lenticulares, fungiformes e valadas. Histologicamente verificou-se que a mucosa reveste-se de epitélio estratificado pavimentoso queratinizado, a lâmina própria constitui-se de tecido conjuntivo, rico em fibras colágenas dispostas em várias direções, onde se verifica abundante vascularização, além de acúmulo de tecido linfático.

The aim was to describe the morphology of the tongue of the Marsh deer (Blastocerus dichotomus), the largest deer of the Brazilian fauna, since there is little detailed information on their morphology. Tongues of eight adult Marsh deers, belonging to Projeto cervo-do-pantanal de Porto Primavera were analyzed for their macroscopic aspects and by light microscopy. The Marsh deer tongue occupies most of the oral cavity, where the root and body are fixed caudally by the hyoid bone, and in its middle portion by the frenulum linguae; its free apex is flat and plane, has little prominent torus lingae and there is no demarcation of fossa linguae. The lateral and ventral surfaces are covered by a thin mucosa; however the dorsal surface is covered by thick mucosa, although soft. On the dorsal surface are the papillae: filiform, conical, lenticular, fungiform and vallate. Histologically was found that the mucosa has a stratified squamous epithelium, the lamina propria consists of connective tissue rich in collagen fibers arranged in several directions, where there is abundant vascularization and accumulation of lymphoid tissue.

Morfologia da língua do cervo do pantanal (Blastocerus dichotomus) / Morphology of the tongue of the Marsh deer (Blastocerus dichotomus)

Objetivou-se descrever a morfologia da língua do cervo do pantanal (Blastocerus dichotomus), o maior cervídeo da fauna brasileira, pois poucas são as informações detalhadas sobre sua morfologia. Línguas e fragmentos linguais de oito cervos do pantanal, adultos, provenientes do Projeto Cervo-do-Pantanal de Porto Primavera foram analisados quanto aos seus aspectos macroscópicos e à microscopia de luz. A língua do cervo do pantanal ocupa grande parte da cavidade oral, onde a raiz e o corpo estão fixados caudalmente pelo osso hióide e, em sua porção média, pelo frênulo lingual; seu ápice, achatado e plano é livre; apresenta torus lingual pouco proeminente, não havendo delimitação da fossa lingual. Na superfície dorsal encontram-se as seguintes papilas: filiformes, cônicas, lenticulares, fungiformes e valadas. Histologicamente verificou-se que a mucosa reveste-se de epitélio estratificado pavimentoso queratinizado, a lâmina própria constitui-se de tecido conjuntivo, rico em fibras colágenas dispostas em várias direções, onde se verifica abundante vascularização, além de acúmulo de tecido linfático.(AU)

The aim was to describe the morphology of the tongue of the Marsh deer (Blastocerus dichotomus), the largest deer of the Brazilian fauna, since there is little detailed information on their morphology. Tongues of eight adult Marsh deers, belonging to Projeto cervo-do-pantanal de Porto Primavera were analyzed for their macroscopic aspects and by light microscopy. The Marsh deer tongue occupies most of the oral cavity, where the root and body are fixed caudally by the hyoid bone, and in its middle portion by the frenulum linguae; its free apex is flat and plane, has little prominent torus lingae and there is no demarcation of fossa linguae. The lateral and ventral surfaces are covered by a thin mucosa; however the dorsal surface is covered by thick mucosa, although soft. On the dorsal surface are the papillae: filiform, conical, lenticular, fungiform and vallate. Histologically was found that the mucosa has a stratified squamous epithelium, the lamina propria consists of connective tissue rich in collagen fibers arranged in several directions, where there is abundant vascularization and accumulation of lymphoid tissue.(AU)

Levantamento populacional do cervo-do-pantanal Blastocerus dichotomus (Mammalia, Cervidae) no Parque Nacional de Ilha Grande e entorno: implicações para a conservação

We conducted an aerial survey of the marsh deer population Blastocerus dichotomus (Illiger, 1815) in the Ilha Grande National Park and its surroundings, on the border between the states of Paraná and Mato Grosso do Sul, Brazil, during the dry season. We used the double-counting technique, resulting in a population estimate of 1079 ± 207 marsh deers in a sampled area of 1081 km², corresponding to an estimated density of 0.998 ± 0.192 ind/km². The population was mostly concentrated inside the park, but also occupied altered wetlands outside its limits. The results should be used to support population management and conservation measures at the national park and its surroundings, due to the enormous anthropogenic pressure upon the marsh deer population in the region.

Nós conduzimos um levantamento populacional aéreo do cervo-do-pantanal, Blastocerus dichotomus (Illiger, 1815), no Parque Nacional de Ilha Grande e seu entorno, entre os estados do Paraná e Mato Grosso do Sul, Brasil, na estação seca. Utilizamos a técnica da contagem dupla, e a população foi estimada em 1.079 ± 207 cervos em uma área amostral de 1.081 km², corresponde a uma densidade de 0,998 ± 0,192 ind/km². A população mostrou-se mais concentrada no interior do parque, ocupando também várzeas alteradas fora dos limites do parque. Estes resultados devem subsidiar medidas de manejo e conservação da população no parque nacional e seu entorno, devido à enorme pressão antrópica sobre a população de cervos na região.

Levantamento populacional do cervo-do-pantanal Blastocerus dichotomus (Mammalia, Cervidae) no Parque Nacional de Ilha Grande e entorno: implicações para a conservação

We conducted an aerial survey of the marsh deer population Blastocerus dichotomus (Illiger, 1815) in the Ilha Grande National Park and its surroundings, on the border between the states of Paraná and Mato Grosso do Sul, Brazil, during the dry season. We used the double-counting technique, resulting in a population estimate of 1079 ± 207 marsh deers in a sampled area of 1081 km², corresponding to an estimated density of 0.998 ± 0.192 ind/km². The population was mostly concentrated inside the park, but also occupied altered wetlands outside its limits. The results should be used to support population management and conservation measures at the national park and its surroundings, due to the enormous anthropogenic pressure upon the marsh deer population in the region.

Nós conduzimos um levantamento populacional aéreo do cervo-do-pantanal, Blastocerus dichotomus (Illiger, 1815), no Parque Nacional de Ilha Grande e seu entorno, entre os estados do Paraná e Mato Grosso do Sul, Brasil, na estação seca. Utilizamos a técnica da contagem dupla, e a população foi estimada em 1.079 ± 207 cervos em uma área amostral de 1.081 km², corresponde a uma densidade de 0,998 ± 0,192 ind/km². A população mostrou-se mais concentrada no interior do parque, ocupando também várzeas alteradas fora dos limites do parque. Estes resultados devem subsidiar medidas de manejo e conservação da população no parque nacional e seu entorno, devido à enorme pressão antrópica sobre a população de cervos na região.

Transferability of microsatellite loci from Cervidae species to the endangered Brazilian marsh deer, Blastocerus dichotomus

Blastocerus dichotomus, the marsh deer, is the largest Brazilian Cervidae species. The species is endangered because of hunting and loss of its natural habitat, i.e., flood plain areas, because of hydroelectric power station construction and agricultural land expansion. In the present study, we tested 38 microsatellite loci from four Cervidae species: Odocoileus virginianus (7), Rangifer tarandus (17), Capreolus capreolus (7), and Mazama bororo (7). Eleven loci showed clear amplification, opening a new perspective for the generation of fundamental population genetic data for devising conservation strategies for B. dichotomus.

Marsh deer (Blastocerus Dichotomus) reintroduction in the Jataí Ecological Station (Luís Antônio, SP): spatial preferences

Throughout the latter half of the twentieth century, wildlife habitat destruction and species extinctions have greatly increased. As the number of endangered species grows, the use of reintroduction as a conservation tool against species extinction increases. This study focuses on a 16-month study on marsh deer reintroduced in the Jataí Ecological Station. The animals were radio tagged and tracked daily between December 1998 and April 2000. Displacement activity and spatial preferences were monitored by triangulation. The animals wandered the floodplains inside the protected area and also a floodplain that is part of privately owned property on the western edge of the Jataí Ecological Station. During the study, most of the reintroduced marsh deer preferred the private floodplain area more than the floodplains inside the protected area. This preference revealed the ecological importance of the area and the necessity of its incorporation into the Jataí Ecological Station.

A destruição dos habitats naturais e a extinção de espécies têm crescido muito a partir da última metade do século XX. Nesse contexto, o aumento do número de espécies ameaçadas tem proporcionado maior uso da reintrodução como estratégia de conservação no combate à atual taxa de extinção. O presente trabalho focaliza um estudo de 16 meses realizado com cervos-do-pantanal reintroduzidos na Estação Ecológica de Jataí. Os animais foram marcados com rádio-colares e monitorados diariamente entre dezembro de 1998 e abril de 2000, tendo suas atividades de deslocamento e uso do espaço acompanhadas por triangulação. Os animais exploraram várzeas dentro da unidade de conservação e também uma área de várzea pertencente a uma propriedade particular localizada na fronteira oeste da estação. Durante o período de estudo, a maioria dos cervos reintroduzidos utilizou a área de várzea particular mais intensivamente que as várzeas da unidade de conservação. A preferência demonstrada por essa área confirmou sua importância ecológica, evidenciando a necessidade de proteção por meio de sua incorporação aos limites da Estação Ecológica de Jataí.

Retroflexão de bexiga: relato de caso em Blastocerus dichotomus (Cervo-do-Pantanal) / Bladder retroflexion: a case report in Blastocerus dichotomus (Cervo-do-Pantanal)

A retroflexão de bexiga foi objeto de estudo em cervídeo atendido no Hospital Veterinário da FCAV-Unesp-Jaboticabal-SP. Uma fêmea gestante do criatório da Faculdade apresentou prolapso de bexiga e de reto. A cesariana foi efetuada, porém sem sucesso para ambos. Após esse procedimento, o animal foi sacrificado devido ao comprometimento total da bexiga. (AU)

A bladder retroflexion was reported in Blastocerus dichotomus at The Veterinary Hospital of FCAV Jaboticabal-SP. A pregnat female from University breeder showed a retal and bladder prolapse. A cesarean were applied but not sucsseful for both. Then, the female was euthanized because the bladder had no conditions to be back again. (AU)

Intramyocardial course of the coronary arteries in the marsh deer (Blastocerus dichotomus) / Trajeto intramiocárdico das artérias coronárias no cervo-do-pantanal (Blastocerus dichotomus)

The course of the coronary arteries was studied in marsh deers for comparison with domestic ruminants. The left coronary artery is originated from the aorta in the cardiac auricular surface and divides into paraconal and circumflex branches, which fit the paraconal interventricular sulcus and the subsinuous sulcus, respectively; this artery also gives off a branch to the conus arteriosus just before penetrating the myocardium. The right coronary artery arises from the aorta, in the heart cranial border and ends in this border, close to the subsinuous interventricular sulcus, perhaps without fitting it.

O trajeto das artérias coronárias foi estudado no cervo-do-pantanal para comparação com os ruminantes domésticos. A artéria coronária esquerda se origina na aorta, na superfície auricular cardíaca e divide-se em ramos paraconal e circunflexo, os quais preenchem o sulco paraconal interventricular e sulco subsinuoso, respectivamente; esta artéria também origina um ramo para o conus arteriosus imediatamente antes de entrar no miocárdio. A artéria coronária direita surge da aorta, na borda cranial cardíaca e termina nesta borda, próximo ao sulco subsinuoso interventricular, entretanto, sem preenche-lo.