Gross Osteology and digital radiography of the common Capybara (Hydrochoerus hydrochaeris), Carl Linnaeus, 1766 for scientific and clinical application / Osteologia bruta e radiografia digital da capivara comum (Hydrochoerus hydrochaeris), Carl Linnaeus, 1766 para aplicação científica e clínica

Being able to study anatomical structures of wildlife species for science and clinical practice is of great importance. We aimed to describe the normal gross osteology of the common adult capybara Hydrochoerus hydrochaeris (Linnaeus, 1766), using macerated bone specimens and high-resolution digital radiography. The complete axial and appendicular skeleton was further compared with previously reported anatomical findings. For this purpose, we used three adult capybara cadavers (two females and one male), with a mean bodyweight of ±50 kg. Some H. hydrochaeris-specific morphological characteristics, especially in the skull region, show evidence of adaptation to aquatic life, such as an elongated head shape, with eyes, ears, and nose, located dorsally, to stay above water. Additionally, the entire bone structure demonstrates the size and weight support of the largest rodent and its adaptation with respect to foraging and locomotion behaviors. As a semi-aquatic herbivore, classified as cursorial (having limbs adapted for running), the authors believe it should be reclassified as cursorial-swimming/diving. Moreover, we argue to consider a differentiation between H. hydrochaeris silvestris to H. hydrochaeris synanthrope, due to substantial weight variation, in some cases > 100%. This inevitably has an impact on the development of bone structure, thus influencing habitual adaptation, and consequently, its clinical implications and animal handling. Radiography exams helped in the identification of bone structures, which otherwise were not observed in anatomical specimens, such as ossa sesamoidea, including the ossiclelunulae. Likewise, the radiographs were particularly helpful in overall better comprehension of the intubation and catheterization procedures. We believe this work can contribute as a reference to anatomical studies for students and professionals acting in clinic, surgery, and research.(AU)

Ser capaz de estudar estruturas anatômicas dos animais da fauna para fins científicos e prática clínica é de grande importância. Objetivamos descrever a osteologia geral normal de capivaras adultas Hydrochoerus hydrochaeris (Linnaeus, 1766), usando amostras de ossos macerados e radiologia digital de alta resolução. O esqueleto axial e apendicular foi posteriormente comparado a achados anatômicos reportados anteriormente. Para esse fim, nós utilizamos de três cadáveres de capivaras adultas (duas fêmeas e um macho) com peso médio de cerca de 50 kg. cada. Algumas características morfológicas de cavidade específicas, especialmente na região do crânio, evidenciam a adaptação à vida aquática, como o formato alongado da cabeça, com olhos, orelhas e nariz localizados dorsalmente, para permanência sobre a água. O completo desenvolvimento morfológico ósseo é evidência de tamanho e suporte de peso do maior roedor, assim como de seus hábitos de alimentação e locomoção, sendo um herbívoro semiaquático, classificado como cursório (tendo membros adaptados à corrida), caso em que os autores acreditam deveria ser reclassificado como cursorial-natação/mergulho. Além disso, argumentamos que deve ser considerada uma diferenciação entre H. hydrochaeris silvestris e H. hydrochaeris sinantropo, devido ao fato da variação substancial de peso, em alguns casos> 100%, inevitavelmente terá um impacto no desenvolvimento da estrutura óssea, influenciando, assim, a adaptação habitual e, consequentemente, suas implicações clínicas e manejo animal. A radiografia auxiliou na correlação e identificação de estruturas ósseas que não observadas em espécimes anatômicos, como o osso sesamóide, incluindo o ossículo lunar. Ademais, as radiografias foram particularmente úteis para uma melhor compreensão geral de procedimentos de intubação e cateterização. Acreditamos que este trabalho possa contribuir como referência de estudos anatômicos para estudantes e profissionais atuantes em clínica, cirurgia e pesquisa.(AU)

Brazilian Spotted Fever Prevention through a Nonlethal Capybara Population Control Strategy.

INTRODUCTION: Brazilian spotted fever (BSF), a lethal tick-borne Rickettsioses (2000 - 2018 >600 human deaths) involving synanthropic capybara as host. METHODS: We introduced an alternative to mitigate human-capybara conflicts and epidemiologic concerns of BSF. Complex aspects like transmission dynamics, risk areas, host mobility, and birth rate control, were considered to develop a prevention strategy using an anti-GnRH vaccine. RESULTS: The propositioned immunocontraceptive potentially remove and prevent the spread of BSF from endemic areas. CONCLUSIONS: We propose the anti-GnRH vaccine as a BSF prevention strategy based on these favorable results.

Positive-reinforcement strategies to reduce capture-stress in Capybaras

Prior to the administration of any anesthetics, capturing the semi-aquatic capybara (Hydrochoerus hydrochaeris) demands physical restraint, which presents immense challenges. Traditional methods, such as lassoing and traps, are prone to induce acute stress, may result in injury, and can even have fatal outcomes. As part of a larger population control project using contraceptive methods, frequent capture-induced stress and injury may directly affect normal reproductive physiology. Thus, choosing a less stress-inducing method was imperative. In this report, we describe methods of conditioning to enable frequent capture and manipulation, using bait as a positive reinforcement associated with a special click-sound, in a free-ranging populationof 40 capybaras. The objectives were to attract, herd, and allow capybaras to voluntarily enter a coral. We evaluated the conditioning effect on individual and group behaviors, interpreting vocal and body language manifestations during the processes of conditioning, herding, capture, and recovery (post procedure/chemical restraint), with the aim of minimizing capture-related stress and injuries. Based on our observations, we report that conditioning, used as part of the capture strategies, noticeably facilitated physical restraint and manipulation throughout the procedures, while apparently maintaining the animals’ overall welfare as it relates to conditioning and capture.

Brazilian spotted fever prevention through a nonlethal capybara population control strategy

Abstract INTRODUCTION: Brazilian spotted fever (BSF), a lethal tick-borne Rickettsioses (2000 - 2018 >600 human deaths) involving synanthropic capybara as host. METHODS: We introduced an alternative to mitigate human-capybara conflicts and epidemiologic concerns of BSF. Complex aspects like transmission dynamics, risk areas, host mobility, and birth rate control, were considered to develop a prevention strategy using an anti-GnRH vaccine. RESULTS: The propositioned immunocontraceptive potentially remove and prevent the spread of BSF from endemic areas. CONCLUSIONS: We propose the anti-GnRH vaccine as a BSF prevention strategy based on these favorable results.

Wildlife population control ­ reproductive physiology under the influence of contraceptive methods in mammalian wildlife, with emphasis on immunocontraception: the best choice? A literature review / Controle da população em animais selvagens ­ fisiologia reprodutiva sob a influência de métodos anticoncepcionais em animais mamíferos, com ênfase na imunocontracepção: a melhor escolha? Uma revisão da literatura

Human-wildlife conflicts, a growing and sad reality worldwide, makes population control of wildlife and feral animals one of the biggest challenges in wildlife management, especially due to the rapidly expanding human population, and consequently the ever-diminishing natural habitats of animals. Human activities and the destruction of nature forcing wildlife to move inevitably into urban and agricultural areas, causing "conflicts", such as the risk of zoonosis and traffic accidents, as well as damage to crops in the search for food, whose losses reach millions of dollars. For decades, science has been engaged in extensive efforts to develop methods of "humane" population control methods, and many techniques are being employed in order to control wildlife population. In this article, we present an overview of applied contraceptive methods with simplified graphic demonstrations of their interactions with reproductive physiology, furthermore relating pro and contra of utilized antifertility agents. These are being compared to a set of desired characteristics for free-ranging wildlife for in-field applications, with emphasis on reversible immunocontraception ­ concluding, therefore, the reasons why this concept is becoming the most appropriate and promising for free-ranging wildlife.(AU)

Os conflitos Humanos-Animais Selvagens são uma realidade crescente e triste no mundo inteiro, tornando o controle populacional da fauna silvestre e animais ferais o maior desafio, principalmente diante do crescimento da população humana e, consequentemente, da diminuição dos habitats naturais dos animais. As atividades humanas e a destruição da natureza, forçam os animais de vida livre a se dirigirem para áreas urbanas e agrícolas, inevitavelmente, causando conflitos, como o risco de zoonoses, acidentes de trânsito, bem como danos às plantações, quando em busca de alimentos, cujo prejuízo chega a milhões de dólares. Durante décadas, a ciência esteve empenhada em esforços extensivos para desenvolver métodos de controle populacional "humano"; e muitas técnicas foram utilizadas, a fim de se realizar um controle populacional destes animais silvestres. Neste artigo será apresentada uma visão geral dos métodos anticoncepcionais aplicados, com demonstrações gráficas simplificadas de suas interações com a fisiologia reprodutiva, bem como relacionando os prós e os contras dos agentes antifertilidade empregados; também serão comparados com um conjunto de características desejadas para as aplicações em fauna a campo, com ênfase em imunocontracepção reversível, concluindo assim, com as razões do porque este conceito torna-se o mais apropriado e promissor para animais silvestres de vida livre.(AU)