Radiological Anatomy of the Pelvis and Pelvic Limb of the Greater Cane Rat (Thryonomys swinderianus)

Greater cane rats (Thryonomys swinderianus) are now being captive reared and domesticated in the sub-Saharan Africa because of increase in their demand for biomedical research and traditional medicine and as a source of meat. This research was performed to provide the normal radiological anatomy of the pelvis and pelvic limb in greater cane rats for a reference in biomedical research, in anatomical studies, and in clinical use. Radiological examination of the pelvis and right pelvic limb was done in five greater cane rats. Radiological results were correlated with bones of the pelvis and right pelvic limb. The pelvic bone had a prominent caudoventral iliac spine. The pelvic symphysis was long and obturator foramina appeared teardrop-shaped elongated craniocaudally. The prominent major trochanter extended proximally higher than the femoral head. The middle third of the body of the tibia presented a very prominent tuberosity. In all specimens, the tarsal sesamoid bone was visualised. Mineralised popliteal sesamoid bone was not visualised. In male greater cane rats, the os penis was visualised. The lateral and medial menisci of the stifle joint were seen with ossicles. The first metatarsal bone was rudimentary with greater plantar divergence. Despite of the pelvic limb and pelvis of greater cane rats sharing anatomical structures with other rodents, it retains some exceptional anatomical features. Findings of this study will serve as a reference for anatomical studies, clinical veterinary practice, and in biomedical research.

Postcranial skeleton of Goodwin's brush-tailed mouse (Calomyscus elburzensis Goodwin, 1939) (Rodentia: Calomyscidae): Shape, size, function, and locomotor adaptation

Goodwin's brush-tailed mouse (Calomyscus elburzensis Goodwin, 1939) is a poorly known small rodent that occupies rocky habitats in Iran, Turkmenistan, Afghanistan, Pakistan, Azerbaijan, and Syria. Herein, a detailed description of the shape, size, and function of the postcranial skeleton of this species is presented for the first time. Trapping was carried out in eastern Iran between the years 2013 and 2015. Skeletal parts of 24 adult male specimens were removed using the papain digestion protocol, and several postcranial morphological characteristics and measurements were examined. We attempted to achieve a morpho-functional characterization of Goodwin's brush-tailed mouse and to match morphological specializations with previous information on the ecology, behavior, and phylogenetic inferences of this rodent. Goodwin's brush-tailed mouse has extended transverse processes and long zygapophyses in the first five caudal vertebrae along with a good innervation of the caudal vertebrae, which has resulted in a well-developed basal musculature of the tail. It has extended forelimb, long ilium, and short post-acetabular part of the innominate bone, loose hip joint with high degree of lateral movement of the hindlimb, and long distal elements of the hindlimb. These features have resulted in fast terrestrial movements in open microhabitats, including climbing and jumping. Although superficial scratching of the ground is observed, the species is incapable of digging burrows. Evaluation of postcranial morphological characteristics and character states further indicated the basal radiation of the genus Calomyscus among other Muroidea. Findings constitute a source of information for morpho-functional and phylogenetic comparisons between Calomyscidae and other mouse-like muroids.

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.

Morphology of the stifle in agouti (Dasyprocta prymnolopha, Wagler 1831)

The agouti (Dasyprocta prymnolopha, Wagler 1831) is a wild rodent of great zootechnical potential, a fact that enables anatomical and morphological studies to support management actions with this animal. In this perspective, this study aimed to describe the anatomy and histology of the agouti stifle joint. Four adult agoutis were used, two females and two males. The animals were submitted to dissection and identification of the structures of the stifle joint. For light microscopy study, samples of the patellar ligament, cranial and caudal cruciate ligaments, medial and lateral collateral ligaments were used. Agouti has a highly congruent patellofemoral joint; elongated patella; medial and lateral fabellae at the proximal insertion of the gastrocnemius muscle; medial and lateral meniscus with lunula; in addition to the presence of the following ligament structures: patellar ligament, cranial and caudal cruciate ligaments, medial and lateral collateral ligaments, meniscofemoral ligament, caudal meniscal ligament of the medial meniscus, and medial and lateral cranial ligaments. The patellar ligament presents bundles of parallel collagen fibers with a straight path and coated fibroblasts; collateral and cruciate ligaments had loose and dense connective tissue, coated fibroblasts and collagen bundle undulations, the latter most expressive in the caudal cruciate ligament. Thus, except for the shape and angulation of the stifle, which allows specific movements, the agouti stifle has structures analogous to that of other rodents and domestic animals.

Hind foot drumming: morphological adaptations of the muscles and bones of the hind limb in three African mole-rat species

Seismic signalling in the form of hind foot drumming plays an integral role in the communication of several species of African mole-rats (Bathyergidae). To produce these vibrational signals, alternating hind limbs strike the ground repetitively at high speeds by flexion and extension of the hip and knee. This descriptive study aimed to determine whether anatomical differences in hind limb osteology and/or musculature between drumming and non-drumming species of three Bathyergidae species could be detected. Formalin-fixed left and right hind limbs of 24 animals (N = 48) consisting of three species (n = 16 each) of two drumming species, Georychus capensis and Bathyergus suillus, and one non-drumming species, Cryptomys hottentotus natalensis, were dissected to determine the origins and insertions of individual muscles. After dissection, all soft tissue was removed by maceration. Hind limb bones, including the pelvis, were photographed, and the exact muscle origin and insertion points were electronically mapped onto the images using imaging software. On lateral view, the acetabular position was parallel to the sacrum in G. capensis, while being more ventral in position in the other two species. The shape of the femur head was spherical and the neck defined in all species. The distal shaft of the femur was gracile and the epicondyles were robust and prominent in the non-drumming C. h. natalensis compared with the drumming species. Shallow and relatively wide patellar grooves were observed in all three species. In the two drumming species, m. gracilis was single, whereas it was double in C. h. natalensis. In all three species, m. tensor fasciae latae was absent. The more dorsal positioning of the acetabulum in G. capensis may be needed to increase the stability of the spine and allow for more force to be exerted on the pelvis during drumming. It is unlikely that m. gracilis plays a role in drumming, as the singularity or doubling thereof is variable among rodents. It is additionally postulated that m. gluteus superficialis has taken the hip rotator role of m. tensor fasciae latae as it partially inserted onto the lateral fascia of the thigh. The more robust ilia, femoral shafts and tibiae observed in the two drumming species studied here are possible adaptations for hind foot drumming, as robust bones are able to withstand the additional biomechanical loading during drumming.

Origem e distribuição das principais artérias do membro torácico de Cuniculus paca (Linnaeus, 1766)

RESUMO: Objetivou-se descrever as artérias do membro torácico da paca (Cuniculos paca Linanaeus, 1766), mediante a dissecação da região. Para tanto, foram utilizadas 10 pacas adultas, machos ou fêmeas, pesando entre cinco e 10 kg do plantel de pacas do setor de Animais Silvestres da FCAV, Unesp, Jaboticabal-SP. Nos animais, injetou-se látex pela artéria carótida comum esquerda para preencher e corar todo o sistema arterial, seguido pela fixação em formaldeído a 10% e conservação em solução salina a 30% para dissecação anatômica das principais artérias do arco aórtico, braço e antebraço, identificando-se a origem e distribuição destes vasos. Os resultados foram foto documentados e discutidos com base na literatura sobre os animais domésticos, e roedores selvagens. De forma geral, as artérias do membro torácico da paca, assemelham-se com as dos carnívoros domésticos, do rato e da cobaia.

Osteology and radiographic anatomy of the hind limbs in Marshdeer (Blastocerus dichotomus)

Abstract: The knowledge of anatomical structures found in wild animals is important for the practice of medical and surgical clinic. Thus, the aim of this study was to describe the osteology and radiographic anatomy of the femur, patella, tibia, fibula, tarsal, metatarsal and phalanges of the Marshdeer Blastocerus dichotomus as a reference for clinical use and species identification. Most structures were similar to those found in domestic animals, with special features of this species. Noteworthy is, for example, the absence of the third trochanter of the femur. Although a ruminant, the Marshdeer has a fibuyla similar to the one described for the horse. B. dichotomus has four fingers on each limb, formed through three phalanges, only the third and fourth finger touch the ground, and the second and fifth finger is rudimentary. It has four proximal and two distal sesamoid bones, and sesamoid bones near the gastrocnemius muscle do not exist.

Morphology of the pelvis and hind limb of the red panda (Ailurus fulgens) evidenced by gross osteology, radiography and computed tomography

The red panda (Ailurus fulgens) is a quadrupedal arboreal animal primarily distributed in the Himalayas and southern China. It is a species commonly kept in zoological collections. This study was carried out to describe the morphology of the pelvis and hind limb of the red panda evidenced by gross osteology, radiography and computed tomography as a reference for clinical use and identification of skeletons. Radiography of the pelvis and right hind limb was performed in nine and seven animals, respectively. Radiographic findings were correlated with bone specimens from three adult animals. Computed tomography of the torso and hind limb was performed in one animal. The pelvic bone had a wide ventromedial surface of the ilium. The trochlea of the femur was wide and shallow. The patella was similar to that seen in feline species. The medial fabella was not seen radiographically in any animal. The cochlea grooves of the tibia were shallow with a poorly defined intermediate ridge. The trochlea of the talus was shallow and presented with an almost flattened medial ridge. The tarsal sesamoid bone was always present. The lateral process of the base of the fifth metatarsal (MT) bone was directed laterally. The MT bones were widely spaced. The morphology of the pelvis and hind limb of the red panda indicated flexibility of the pelvis and hind limb joints as an adaptation to an arboreal quadrupedal lifestyle.