Gastrointestinal nematodes in Cuniculus paca (Linnaeus, 1766) from hunting fauna in the Western Amazonian region.

Cuniculus paca, commonly known as the paca, is a rodent of the Cuniculidae family that is widely distributed throughout the Americas, including all Brazilian territories, and is abundant in the Amazon region. It is one of the most hunted species and faces significant predation in the extreme western Amazon region of Brazil because it constitutes a staple in the diet of local communities, for subsistence and commercial purposes. Understanding the helminthic fauna of these animals is of paramount importance, given that some nematodes have zoonotic potential and may pose risks to consumer health. This study aimed to contribute to the records of the nemtodes of this highly consumed species in the Amazon region, highlighting the occurrence of gastrointestinal parasites in free-living pacas intended for human subsistence consumption. The study was conducted in the Paranã da Floresta community, located in the municipality of Guajará, Amazonas from 2022 to 2023. The community members hunted this rodent for consumption and voluntarily provided the viscera for analysis. Nematodes were extracted from each organ. The organs were opened, and the contents were processed using a sieve (0.15 mm) and subsequently evaluated separately. In total, 10,157 nematodes were found in the 14 pacas. Based on morphological analyses, the nematodes were identified as Heligmostrongylus sedecimradiatus (n = 10,068), Trichuris sp. (n = 85), and Physaloptera sp. (n = 4). This study provides insights into the nematodes diversity of free-living pacas in the extreme Western Amazon region, emphasizing the importance of sanitary surveillance and public awareness of the risks associated with bushmeat consumption.

Rabbits as reservoirs: An updated perspective of the zoonotic risk from Cryptosporidium and Giardia.

Rabbits are highly abundant in many countries and can serve as reservoirs of diseases for a diversity of pathogens including the enteric protozoan parasites, Cryptosporidium and Giardia. Both parasites shed environmentally robust environmental stages (oo/cysts) and have been responsible for numerous waterborne outbreaks of diseases. Cryptosporidium hominis and C. parvum are responsible for most infections in humans, while Giardia duodenalis assemblages A and B, cause most human cases of giardiasis. Cryptosporidium cuniculus, the dominant species infecting rabbits, is the only spceies other than C. hominis and C. parvum to have caused a waterborne outbreak of gastritis, which occurred in the United Kingdom in 2008. This review examines the prevalence of Cryptosporidium and Giardia species in rabbits to better understand the public health risks of contamination of water sources with Cryptosporidium and Giardia oo/cysts from rabbits. Despite the abundance of C. cuniculus in rabbits, reports in humans are relatively rare, with the exception of the United Kingdom and New Zealand, and reports of C. cuniculus in humans from the United Kingdom have declined substantially since the 2008 outbreak. Subtyping of C. cuniculus has supported the potential for zoonotic transmission. Relatively few studies have been conducted on Giardia, but assemblage B dominates. However, improved typing methods are required to better understand the transmission dynamics of Giardia assemblages in rabbits. Similarly, it is not well understood if pet rabbits or contaminated water are the main source of C. cuniculus infections in humans. Well-planned studies using high-resolution typing tools are required to understand the transmission dynamics better and quantify the public health risk of Cryptosporidium and Giardia from rabbits.

Abdominal aortic branches of red-rumped agouti (Dasyprocta leporina Linnaeus, 1758).

Understanding the cardiovascular system is fundamental in diagnosing pathologies and interpreting exams, such as contrast radiographs. In this context, the present study describes the collateral abdominal aorta artery branches of red-rumped agouti. Ten red-rumped agoutis, six males and four females, were assessed. The vascular system was perfused with Neoprene 450 latex coloured with a yellow pigment, dissected and analysed. Three euthanized animals were perfused with a barium sulfate solution (1 g mL-1 ) associated with latex Neoprene 450 at a 1:3 ratio to obtain contrast-enhanced radiographs. The abdominal aorta emitted the celiac artery, which in turn originated the left gastric, hepatic and splenic arteries. The second collateral branch comprised the cranial mesenteric artery, followed by the renal arteries, which emitted the adrenal arteries, with the caudal emergence of the gonadal arteries. The caudal mesenteric artery appeared in a caudal direction. The abdominal aorta divided after reaching the pelvic cavity entrance, originating the right and left common iliac arteries. Before its bifurcation, the abdominal aorta dorsocaudally emitted its last collateral branch, the median sacral artery. The collateral branches of the aorta, therefore, resemble previously described rodent patterns, with few variations.

Urogenital development and sexual differentiation in males of the species Dasyprocta fuliginosa.

Thirteen black agouti (Dasyprocta fuliginosa) male fetuses, acquired in two areas of the Amazon Forest, were used for the purpose of morphologically describing the fetal male urogenital organs with a focus on addressing histological and macroscopic aspects. The organs of interest were dissected and photographed in situ and ex situ. Fragments were collected and subjected to routine histological processing for inclusion in paraffin, which was cut and stained by haematoxylin and eosin and Gomori's Trichrome methods and subsequently analysed in a light microscope. The results showed that the urinary tract is like that of domestic animals and is composed of smooth unilobed kidneys covered by a dense capsule of connective tissue and divided into two well-defined regions, cortical and medullary. Ureters, urethra and urinary bladder also showed macroscopic and microscopic characteristics similar to those of domestic animals. The penis of these animals has fibroelastic characteristics, with numerous keratinized structures at its apex. In the middle third of the penis, a "U" shaped penile flexure was seen; the glans penis is covered by a keratinized epidermis containing horny spicules. The presence of a penile bone in an endochondral ossification process was observed, being more developed in gestational ages greater than 76 days. The annex glands were not observed, probably because they were fetuses; only the ampulla of the ductus deferens was identified.

[Overview of infectious and non-infectious diseases in French Guiana in 2022]. / Panorama des pathologies infectieuses et non infectieuses de Guyane en 2022.

Source of many myths, French Guiana represents an exceptional territory due to the richness of its biodiversity and the variety of its communities. The only European territory in Amazonia, surrounded by the Brazilian giant and the little-known Suriname, Ariane 6 rockets are launched from Kourou while 50% of the population lives below the poverty line. This paradoxical situation is a source of health problems specific to this territory, whether they be infectious diseases with unknown germs, intoxications or chronic pathologies.Some infectious diseases such as Q fever, toxoplasmosis, cryptococcosis or HIV infection are in common with temperate countries, but present specificities leading to sometimes different management and medical reasoning. In addition to these pathologies, many tropical diseases are present in an endemic and / or epidemic mode such as malaria, leishmaniasis, Chagas disease, histoplasmosis or dengue. Besides, Amazonian dermatology is extremely varied, ranging from rare but serious pathologies (Buruli ulcer, leprosy) to others which are frequent and benign such as agouti lice (mites of the family Trombiculidae) or papillonitis. Envenomations by wild fauna are not rare, and deserve an appropriate management of the incriminated taxon. Obstetrical, cardiovascular and metabolic cosmopolitan pathologies sometimes take on a particular dimension in French Guiana that must be taken into account in the management of patients. Finally, different types of intoxication are to be known by practitioners, especially due to heavy metals.European-level resources offer diagnostic and therapeutic possibilities that do not exist in the surrounding countries and regions, thus allowing the management of diseases that are not well known elsewhere.Thanks to these same European-level resources, research in Guyana occupies a key place within the Amazon region, despite a smaller population than in the surrounding countries. Thus, certain pathologies such as histoplasmosis of the immunocompromised patient, Amazonian toxoplasmosis or Q fever are hardly described in neighboring countries, probably due to under-diagnosis linked to more limited resources. French Guiana plays a leading role in the study of these diseases.The objective of this overview is to guide health care providers coming to or practicing in French Guiana in their daily practice, but also practitioners taking care of people returning from French Guiana.

Subsistence hunting and the introduction of Neotropical echinococcosis into the domestic environment in the Brazilian Amazon / Caça de subsistência e a introdução da equinococose neotropical no ambiente doméstico na Amazónia brasileira

The present study recorded the consumption of paca and agouti meat and revealed the presence of hydatid cysts in the livers of these rodents in extractivist communities in Brazilian Amazonia. A total of 42 families (with a median four of members per household) were interviewed, of which 98% (n=41) reported the consumption of paca and 86% (n=36) the consumption of agouti. Structures consistent with hydatid cysts were detected more frequently in the liver tissue of the pacas (74% ­ 31 of 42 samples) than the agoutis (26% ­ 11/42). The parasitological analysis of a paca liver confirmed the presence of E. vogeli. The consumption of the meat of these rodents and the confirmation of infection by E. vogeli represent preoccupying risk factors for the inhabitants of these forest communities, given that the uncooked viscera of both rodents are often fed to domestic dogs.

O presente estudo registrou o consumo de carne de paca e cutia e revelou a presença de cistos hidáticos nos fígados desses roedores em comunidades extrativistas da Amazônia brasileira. Foram entrevistadas 42 famílias (mediana quatro membros/família), destas 98% (n=41) informaram o consumo de paca e 86% (n=36) o consumo de cutia. Estruturas compatíveis com cistos hidáticos foram relatadas com maior frequência em fígados de pacas 74% (31/42) do que em cutias 26% (11/42). A análise parasitológica de um fígado de paca confirmou a presença de E. vogeli. O consumo da carne desses roedores e a confirmação da infecção por E. vogeli representam fatores de risco preocupantes para os moradores dessas comunidades florestais, uma vez que as vísceras cruas de ambos os roedores são utilizadas na alimentação de cães domésticos.

Organization of Somatosensory Cortex in the South American Rodent Paca (Cuniculus paca).

INTRODUCTION: The study of non-laboratory species has been part of a broader effort to establish the basic organization of the mammalian neocortex, as these species may provide unique insights relevant to cortical organization, function, and evolution. METHODS: In the present study, the organization of three somatosensory cortical areas of the medium-sized (5-11 kg body mass) Amazonian rodent, the paca (Cuniculus paca), was determined using a combination of electrophysiological microelectrode mapping and histochemical techniques (cytochrome oxidase and NADPH diaphorase) in tangential sections. RESULTS: Electrophysiological mapping revealed a somatotopically organized primary somatosensory cortical area (S1) located in the rostral parietal cortex with a characteristic foot-medial/head-lateral contralateral body surface representation similar to that found in other species. S1 was bordered laterally by two regions housing neurons responsive to tactile stimuli, presumably the secondary somatosensory (S2) and parietal ventral (PV) cortical areas that evinced a mirror-reversal representation (relative to S1) of the contralateral body surface. The limits of the putative primary visual (V1) and primary auditory (A1) cortical areas, as well as the complete representation of the contralateral body surface in S1, were determined indirectly by the histochemical stains. Like the barrel field described in small rodents, we identified a modular arrangement located in the face representation of S1. CONCLUSIONS: The relative location, somatotopic organization, and pattern of neuropil histochemical reactivity in the three paca somatosensory cortical areas investigated are similar to those described in other mammalian species, providing additional evidence of a common plan of organization for the somatosensory cortex in the rostral parietal cortex of mammals.

Anthelmintic usage on the performance of the Agouti (Dasyprocta leporina) reared intensively in Trinidad and Tobago, West Indies / Uso de anti-helmíntico no desempenho da cutia (Dasyprocta leporina) criada intensivamente em Trinidad e Tobago, Índias Ocidentais

Abstract Anthelmintic drugs have been used strategically in livestock reared in the tropics. These drugs have been used in the treatment of endoparasitism which have resulted in an increase in the animals' performance. The agouti (Dasyprocta leporina) is a neo-tropical rodent with the potential for domestication and has been farmed intensively in Trinidad. However, the objective of this research was to investigate the effect of anthelmintic use of the growth performance of the agouti. In searching the literature, it was found that this type of study on the agouti has not been done. In this experiment fourteen weaned agoutis weighing 1kg were divided into two groups randomly. The first group (T1) was not given any anthelmintic treatment but the second group (T2) was treated with Endovet Ces® subcutaneously every three months. There were no significant differences (p > 0.05) between the two groups in the carcass weight, weight gain, dressing percentage (hot and cold), heart, lungs, skin, head and feet. However, a significant difference (p < 0.05) was seen between groups in the weight of liver and pluck. To the authors knowledge this is the first time that carcass parameters has been presented in literature. The live weight of the animals at the end of the experiment ranged from 2.4 kg to 2.6 kg and animals had a dressing percentage of 57% to 55%. The results are suggestive that the use of anthelmintic drugs in agoutis reared intensively had no significant effect on weight gain and dressing percentage.

Resumo Drogas anti-helmínticas têm sido usadas estrategicamente em rebanhos criados nos trópicos. Essas drogas têm sido utilizadas no tratamento do endoparasitismo, o que resultou em um aumento no desempenho dos animais. A cutia (Dasyprocta leporina) é um roedor neotropical com potencial para domesticação e tem sido criada intensivamente em Trinidad. Porém, o objetivo desta pesquisa foi investigar o efeito do uso de anti-helmínticos no desempenho de crescimento da cutia. Através de uma busca na literatura, constatou-se que esse tipo de estudo na cutia não foi realizado. Neste experimento, quatorze cutias desmamadas pesando 1kg foram divididas em dois grupos aleatoriamente. O primeiro grupo (T1) não recebeu nenhum tratamento anti-helmíntico, mas o segundo grupo (T2) foi tratado com Endovet Ces® por via subcutânea a cada três meses. Não houve diferenças significativas (p> 0,05) entre os dois grupos no peso da carcaça, ganho de peso, porcentagem de cobertura (quente e frio), coração, pulmão, pele, cabeça e pés. No entanto, uma diferença significativa (p <0,05) foi observada entre os grupos no peso do fígado e depenagem. Para os autores, esta é a primeira vez que parâmetros de carcaça são apresentados na literatura. O peso vivo dos animais ao final do experimento variou de 2,4 kg a 2,6 kg e os animais tinham uma porcentagem de curativo de 57% a 55%. Os resultados sugerem que o uso de anti-helmínticos em cutias criadas intensivamente não teve efeito significativo no ganho de peso e na porcentagem de curativo.

Effect of Long-Term Treatment with Dexamethasone on the Liver and Kidney Histopathology, as well as Blood Biochemistry in Male Rabbits (Lepus Cuniculus).

Glucocorticoids have a wide range of pharmacological activities. Generally speaking, the steroid drugs, such as dexamethasone (DEX) can have severe side effects on the histology of different organs. In fact, glucocorticoids have been known as powerful medicines which can cure inflammation and work with the immune system to treat a wide range of health problems. Therefore, this study aimed to investigate the effects of DEX on the histological changes of the liver and kidney, as well as blood biochemical parameters. In total, 13 specific pathogen-free male Lepus Cuniculus rabbits aged 8-10 months old, with a mean weight of 1.12±0.13 kg were randomly divided into three groups. Group I (n=3) did not receive DEX, and they only received saline solution as a placebo (control). In Group II (n=5), the animals received 0.25 mg DEX/kg body weight/day for a period of 56 days, and the animals in Group III (n=5) received 0.5 mg DEX/kg body weight/day for 56 days. Blood was aspirated from the rabbit's marginal ear vein. All blood samples were centrifuged at 3000×g for 10 min to separate serum samples. Blood lipids and trace elements (zinc, copper, calcium, and iron) were measured. The microscopical analyses of the liver and kidney tissues were performed through the observation of the histological changes in the tissues. The results showed a significant (P≤0.05) decrease in the body and organ weight, as well as serum concentrations for the trace elements. On the other hand, lipid profile showed a significant increase (P≤0.05) in cholesterol, triglycerides, and low-density lipoprotein. However, a significant decrease was recorded in high-density lipoprotein in both treated groups with DEX, compared to the control group. The results of the histological evaluation showed some degrees of degeneration, necrosis, cell vacuolation, and lymphocyte infiltration in the kidney and liver tissues in the treatment groups.

Morphological, morphometric, ultrastructural, and functional evaluation of red-rumped agouti (Dasyprocta leporina) sperm during epididymal transit.

The red-rumped agouti (Dasyprocta leporina) is a hystricognath rodent with reproductive anatomical peculiarities presenting as an intra-abdominal testes-epididymis complex. This study was carried out to describe, for the first time, details related to the morphological and functional changes in sperm along the epididymal transit in agoutis. The testes-epididymal complexes were sampled from seven sexually mature agoutis. Sperm from different epididymal regions (caput, corpus, and cauda) were collected using the floating technique, and their morphology, morphometry, ultrastructure, mitochondrial activity, membrane structural integrity, and kinetic parameters were determined. The number of sperm collected (823.5 ×106 sperm) was higher in the epididymis cauda. No significant differences in normal sperm morphology among the different epididymal regions (caput, 82.42%; corpus, 86.71%; and cauda, 88.86 %) were observed. The mean head length, head width, and tail length were highest in the caput (5.15 µm, 3.44 µm, and 32.04 µm, respectively), decreasing along the epididymal transit. Ultrastructure by scanning electron microscopy (SEM) revealed agglomeration of spermatozoa from caput and corpus, thus, enabling analysis of the gametes from only the epididymal cauda with clarity. Sperm from epididymis cauda showed the greatest proportion of membrane integrity and mitochondrial activity, followed by those from corpus and caput (79.71 %, 58.9 %, 47.7 %, respectively). Significant increase in total motility, progressive motility, velocity average pathway -VAP, velocity straightline - VSL, velocity curvilinear - VCL, and rapid sperm in the caput-corpus-cauda direction were observed. These novel data contribute to the knowledge of sperm maturation in the red-rumped agouti.

Evaluation of sperm membrane functionality during epididymal transit in red-rumped agouti (Dasyprocta leporina).

We studied the sperm membrane functionality through the epididymal transit by comparing different hypoosmotic solutions and verifying possible associations among osmotic response and functional parameters of sperm in red-rumped agouti (Dasyprocta leporina). For this purpose, epididymal sperm from six sexually mature male agoutis were collected via flotation. Then, analyses of sperm parameters and hypoosmotic swelling test using different hypoosmotic solutions (0, 50 and 200 mOsm/L) in different regions of the epididymis (caput, corpus and cauda) were performed. There was an increase (p < .05) in the values for sperm concentration, the total number of sperm recovered, total and progressive motility, average path velocity, straight-line velocity, curvilinear velocity, and rapid and medium subpopulations following the caput-corpus-cauda direction. Regardless of the hypoosmotic solution, the agouti sperm membrane presented similar functional integrity in all the epididymal regions. Moreover, the highest (p < .05) osmotic responses were reached with the use of 50 mOsm/L solution in comparison to 0 and 200 mOsm/L for all the regions. Significant correlations among osmotic response and some sperm kinetic parameters were observed, especially in epididymal caput, while no correlations were found in the region of the cauda. In summary, red-rumped agouti sperm present similar membrane functionality during epididymal transit, but there are evident correlations among such functionality and sperm kinetic parameters, especially in the caput region. Moreover, we indicate the use of a 50 mOsm/L hypoosmotic solution for the analysis of this parameter through the hypoosmotic swelling test.

Opportunistic pneumonia caused by E. cuniculi in mice immunosuppressed with cyclophosphamide.

Opportunistic fungal pneumonia is a cause of concern in immunocompromised patients due to its high morbidity and mortality rates. One such opportunistic agent affecting immunocompromised patients is the microsporidia called Encephalitozoon cuniculi. This study aimed to evaluate pneumonia caused by E. cuniculi in mice treated with the immunosuppressive agent cyclophosphamide (Cy). This study also aimed to describe the immune cells associated with the microsporidial pneumonia. C57BL/6 mice were infected intravenously with E. cuniculi spores and treated with Cy (75 mg/kg/week, intraperitoneally). Thirty days post-infection, the fungal burden (qPCR), histopathological lesions, cytokine production, and the phenotype of the immune cells in the lung parenchyma were evaluated. Histologically, interstitial pneumonia with lymphocytic infiltrate was observed in the infected animals. The infiltrate mainly consisted of CD8+ and CD4+ T lymphocytes, with reduced populations of B lymphocytes and macrophages. The production of tumor necrosis factor-alpha (TNF-α) was significant in the animals of the infected groups. Also, the fungal burden was higher in the Cy-treated animals, which was confirmed by the immunohistochemical observation of spores. These results demonstrated that E. cuniculi infection of C57BL/6 mice caused lymphocytic interstitial pneumonia (characterized by a predominant lymphocytic infiltrate), which was aggravated by Cy-induced immunosuppression. Thus, these results can be used to understand the different pathological, immunological, and therapeutic aspects of lymphocytic interstitial pneumonia.

Immunocompetent rabbits infected with Cryptosporidium cuniculus as an animal model for anti-cryptosporidial drug testing.

Cryptosporidium is one of the leading causes of diarrheal disease in humans and animals, which can be severe and deadly in neonates and immunocompromised hosts. Studies on the biology of Cryptosporidium and drug discovery efforts have been hindered by a number of factors including the limited availability of animal models. Here, we report the establishment and characterization of an immunocompetent rabbit model for infection with Cryptosporidium cuniculus. By testing four known anti-cryptosporidial compounds (nitazoxanide, baicalein, curcumin and matrine), we showed that the rabbit could be used as an alternative animal model for evaluating anti-cryptosporidial drug efficacy in vivo.

Approach to the humerus and femur of the paca (Cuniculus paca, Linnaeus 1766).

The paca (Cuniculus paca, Linnaeus 1766) is a rodent species, typical of tropical regions. It is important that in addition to its commercial value as a protein source, it can be used as a scientific scope. The objective of this study was to describe the morphology of the thigh and the arm of the paca by anatomical and imaging methodology with radiography (X-ray), computed tomography (CAT scan) and magnetic resonance imaging (MRI) to determine the surgical approach of the bones of these regions. It was concluded that the imaging study through X-ray, CAT scan and MRI are reliable methods for anatomical description of wild animals that have little known about their morphology. Finally, similarly to dogs, it was determined that lateral access is the best approach to the femoral diaphysis and the medial access is the best approach to the humerus diaphysis of the paca.

Anthelmintic usage on the performance of the Agouti (Dasyprocta leporina) reared intensively in Trinidad and Tobago, West Indies.

Anthelmintic drugs have been used strategically in livestock reared in the tropics. These drugs have been used in the treatment of endoparasitism which have resulted in an increase in the animals' performance. The agouti (Dasyprocta leporina) is a neo-tropical rodent with the potential for domestication and has been farmed intensively in Trinidad. However, the objective of this research was to investigate the effect of anthelmintic use of the growth performance of the agouti. In searching the literature, it was found that this type of study on the agouti has not been done. In this experiment fourteen weaned agoutis weighing 1kg were divided into two groups randomly. The first group (T1) was not given any anthelmintic treatment but the second group (T2) was treated with Endovet Ces® subcutaneously every three months. There were no significant differences (p > 0.05) between the two groups in the carcass weight, weight gain, dressing percentage (hot and cold), heart, lungs, skin, head and feet. However, a significant difference (p < 0.05) was seen between groups in the weight of liver and pluck. To the authors knowledge this is the first time that carcass parameters has been presented in literature. The live weight of the animals at the end of the experiment ranged from 2.4 kg to 2.6 kg and animals had a dressing percentage of 57% to 55%. The results are suggestive that the use of anthelmintic drugs in agoutis reared intensively had no significant effect on weight gain and dressing percentage.

Molecular eco-epidemiology of Paracoccidioides brasiliensis in road-killed mammals reveals Cerdocyon thous and Cuniculus paca as new hosts harboring this fungal pathogen.

Wild animals infected with Paracoccidioides brasiliensis represent important indicators of this fungal agent presence in the environment. The detection of this pathogen in road-killed wild animals has shown to be a key strategy for eco-epidemiological surveillance of paracoccidioidomycosis (PCM), helping to map hot spots for human infection. Molecular detection of P. brasiliensis in wild animals from PCM outbreak areas has not been performed so far. The authors investigated the presence of P. brasiliensis through nested-PCR in tissue samples obtained from road-killed animals collected nearby a human PCM outbreak spot, Rio de Janeiro state, Brazil and border areas. Eighteen species of mammals were analyzed: Dasypus novemcinctus (nine-banded armadillo, n = 6), Cerdocyon thous (crab-eating fox, n = 4), Coendou spinosus (hairy dwarf porcupine, n = 2), Lontra longicaudis (Neotropical river otter, n = 1), Procyon cancrivorus (crab-eating raccoon, n = 1), Galactis cuja (lesser grison, n = 1), Tamandua tetradactyla (collared anteater, n = 1), Cuniculus paca (paca, n = 1), and Bradypus variegatus (brown-throated three-toed sloth, n = 1). Specific P. brasiliensis sequences were detected in the liver, spleen, and lymph node samples from 4/6 (66.7%) D. novemcinctus, reinforcing the importance of these animals on Paracoccidioides ecology. Moreover, lymph nodes samples from two C. thous, as well as lung samples from the C. paca were also positive. A literature review of Paracoccidioides spp. in vertebrates in Brazil indicates C. thous and C. paca as new hosts for the fungal pathogen P. brasiliensis.

Experimental ethology of intensively reared lowland pacas (Cuniculus paca).

The objective of this study was to evaluate and to describe the main behaviors of family groups of lowland pacas (Cuniculus paca) raised in a commercial breeding facility. We used 24 adult pacas, 16 females and 8 males, with a mean live weight of 8.2 kg and age ranging from 2 to 4 years. The animals were kept in groups of two females and one male per enclosure. Cameras were used to monitor the animals. The behaviors identified were divided into five categories (maintenance, exploratory, social interaction, reproductive, and environmental interaction). A completely randomized design in a split-split plot arrangement with three treatment factors was used: sex, period of the day, and season. The frequencies of the maintenance and environmental interaction behavioral categories were significantly higher during the day compared to the nocturnal period (P < 0.05). The duration of each behavioral category differed significantly (P < 0.05) between day and night. The frequencies of the maintenance and reproductive behavioral categories were significantly higher during the dry season compared to the rainy season (P < 0.05) and the relative duration of behaviors of the environmental interaction category was shorter during the dry season (P < 0.05). Females exhibited a significantly higher frequency of maintenance and environmental interaction than males (P < 0.05) and the duration of environmental interaction was shorter (P < 0.05) in females. The present results add to the existing knowledge on the behavior of lowland pacas raised in captivity for production of this wild species which is in the stage of domestication.

The macro and micro-structure of the celiac and cranial mesenteric ganglia in a long-lived rodent - paca (Cuniculus paca, Linnaeus 1766) / La macro y micro estructura de los ganglios mesentéricos celíacos y craneales en un roedor longevo - paca (Cuniculus paca, Linnaeus 1766)

SUMMARY: The celiac, cranial mesenteric and celiacomesenteric ganglia of the paca (Cuniculus paca) were found between the celiac and cranial mesenteric arteries. Two predominant patterns were found: isolated celiac and cranial mesenteric ganglion and the celiacomesenteric ganglion. At the microscopic level, the ganglia are constituted by an agglomeration of neurons surrounded by capsule of connective tissue. Most of these neurons had a single eccentric nucleus. Satellite cells and mast cells were found around the soma. The mast cells were also found ar ound blood vessels and in the capsule of the ganglia.

RESUMEN: Los ganglios celíacos, mesentérico-craneales y celíaco mesentéricos de la paca (Cuniculus paca) se encontraron entre las arterias celíaca y mesentérica craneal. Se visalizaron dos patrones predominantes: celiaca aislada y ganglio mesentérico craneal y ganglio celiaco mesentérico. A nivel microscópico, los ganglios están constituidos por una aglomeración de neuronas rodeadas por una cápsula de tejido conectivo. La mayoría de estas neuronas tenían un solo núcleo excéntrico. Se encontraron células satélites y mastocitos alrededor del soma. Los mastocitos también se encontraron alrededor de los vasos sanguíneos y en la cápsula de los ganglios.

Anatomic and histologic analysis of paca larynx (Cuniculus paca, Linnaeus 1766) / [Análise anatômica e histológica da laringe da paca (Cuniculus paca, Linnaeus 1766)]

Paca (Cuniculus paca) has encouraged research as an experimental model both in the human medicine and veterinary, as well as the economic exploitation of its meat cuts, which favored its zootechnical use. There are no anatomical, microscopic descriptions and measurements of the larynx in this rodent. Eight pacas were dissected from the wild animal's sector of the Faculty of Agricultural and Veterinary Sciences of the University of the State of São Paulo. The larynx was observed located in the ventral region of the neck, ventral to the esophagus, connecting the pharynx to the trachea, with cylindrical and irregular shape. Laryngeal cartilages (epiglottic, thyroid, cricoid and arytenoid) are interconnected and have different shapes. Thyroid showed greater length and width, compared to the others. Laryngeal cartilages were submitted to histological processing and stained with hematoxylin-eosin and Masson's trichrome. The epiglottic cartilage was stained with toluidine blue. Laryngeal cartilages thyroid, cricoid and the lower portion of the arytenoids are of hyaline origin and, in contrast, the epiglottis and the upper portion of the arytenoids are elastic. This latter cartilage demonstrated taste buds. The results will be able to auxiliate in veterinary care and as well as the conservation programs for this rodent.(AU)

A paca (Cuniculus paca) tem encorajado inúmeras pesquisas, tornando-a modelo experimental tanto em humanos como na veterinária, além da exploração econômica de seus cortes cárneos, que favoreceu diretamente sua importância zootécnica. Não há descrições anatômicas, microscópicas e mensurações da laringe desse roedor. Foram dissecadas oito laringes de pacas, provenientes do setor de Animais Silvestres da Faculdade de Ciências Agrárias e Veterinárias - Universidade Estadual Paulista. Observou-se que a laringe localiza-se na região ventral do pescoço, ventral ao esôfago, conectando a faringe à traqueia, possuindo formato cilíndrico e irregular. As cartilagens laríngeas (epiglote, tireóide, cricóide e aritenóidea) são interligadas e possuem formatos variados. A cartilagem tireóide demonstrou-se maior em comprimento e largura, comparativamente às demais. As cartilagens laríngeas foram submetidas a processamento histológico e coradas em hematoxilina-eosina e tricrômio de Masson. A cartilagem epiglote foi corada em azul de toluidina. As cartilagens laríngeas tireóide, cricóide e a porção inferior das aritenóides são de origem hialina; em contrapartida, a epiglote e a porção superior das aritenóides, de origem elástica. Esta última cartilagem demonstrou corpúsculos gustativos. Os resultados poderão auxiliar tanto nos atendimentos veterinários quanto nos programas de conservação desse roedor.(AU)

Evaluation of chemical restraint, isoflurane anesthesia and methadone or tramadol as preventive analgesia in spotted pacas (Cuniculus paca) subjected to laparoscopy.

OBJECTIVE: To evaluate the efficacy and cardiopulmonary effects of ketamine-midazolam for chemical restraint, isoflurane anesthesia and tramadol or methadone as preventive analgesia in spotted pacas subjected to laparoscopy. STUDY DESIGN: Prospective placebo-controlled blinded trial. ANIMALS: A total of eight captive female Cuniculus paca weighing 9.3 ± 0.9 kg. METHODS: Animals were anesthetized on three occasions with 15 day intervals. Manually restrained animals were administered midazolam (0.5 mg kg-1) and ketamine (25 mg kg-1) intramuscularly. Anesthesia was induced and maintained with isoflurane 30 minutes later. Tramadol (5 mg kg-1), methadone (0.5 mg kg-1) or saline (0.05 mL kg-1) were administered intramuscularly 15 minutes prior to laparoscopy. Heart rate (HR), respiratory rate, mean arterial pressure (MAP), peripheral oxygen saturation (SpO2), end-tidal CO2 partial pressure (Pe'CO2), end-tidal concentration of isoflurane (Fe'Iso), pH, PaO2, PaCO2, bicarbonate (HCO3-), anion gap (AG) and base excess (BE) were monitored after chemical restraint, anesthesia induction and at different laparoscopy stages. Postoperative pain was assessed by visual analog scale (VAS) for 24 hours. Variables were compared using anova or Friedman test (p < 0.05). RESULTS: Chemical restraint was effective in 92% of animals. Isoflurane anesthesia was effective; however, HR, MAP, pH and AG decreased, whereas Pe'CO2, PaO2, PaCO2, HCO3- and BE increased. MAP was stable with tramadol and methadone treatments; HR, Fe'Iso and postoperative VAS decreased. VAS was lower for a longer time with methadone treatment; SpO2 and AG decreased, whereas Pe'CO2, PaCO2 and HCO3- increased. CONCLUSIONS AND CLINICAL RELEVANCE: Ketamine-midazolam provided satisfactory restraint. Isoflurane anesthesia for laparoscopy was effective but resulted in hypotension and respiratory acidosis. Tramadol and methadone reduced isoflurane requirements, provided postoperative analgesia and caused hypercapnia, with methadone causing severe respiratory depression. Thus, the anesthetic protocol is adequate for laparoscopy in Cuniculus paca; however, methadone should be avoided.