Hermanus B. Groenewald

The structure of the cushions in the feet of African elephants (Loxodonta africana).

The uniquely designed limbs of the African elephant, Loxodonta africana, support the weight of the largest terrestrial animal. Besides other morphological peculiarities, the feet are equipped with large subcutaneous cushions which play an important role in distributing forces during weight bearing and in storing or absorbing mechanical forces. Although the cushions have been discussed in the literature and captive elephants, in particular, are frequently affected by foot disorders, precise morphological data are sparse. The cushions in the feet of African elephants were examined by means of standard anatomical and histological techniques, computed tomography (CT) and magnetic resonance imaging (MRI). In both the forelimb and the hindlimb a 6th ray, the prepollex or prehallux, is present. These cartilaginous rods support the metacarpal or metatarsal compartment of the cushions. None of the rays touches the ground directly. The cushions consist of sheets or strands of fibrous connective tissue forming larger metacarpal/metatarsal and digital compartments and smaller chambers which were filled with adipose tissue. The compartments are situated between tarsal, metatarsal, metacarpal bones, proximal phalanges or other structures of the locomotor apparatus covering the bones palmarly/plantarly and the thick sole skin. Within the cushions, collagen, reticulin and elastic fibres are found. In the main parts, vascular supply is good and numerous nerves course within the entire cushion. Vater–Pacinian corpuscles are embedded within the collagenous tissue of the cushions and within the dermis. Meissner corpuscles are found in the dermal papillae of the foot skin. The micromorphology of elephant feet cushions resembles that of digital cushions in cattle or of the foot pads in humans but not that of digital cushions in horses. Besides their important mechanical properties, foot cushions in elephants seem to be very sensitive structures.

Technique for the collection of clear urine from the Nile crocodile (Crocodylus niloticus).

Urine samples can be a very useful diagnostic tool for the evaluation of animal health. In this article, a simple technique to collect urine from the Nile crocodile (Crocodylus niloticus) was described, based on a similar unpublished technique developed for the American alligator (Alligator mississippiensis) using a canine urinary catheter. With this technique, it was possible to collect relatively clean urine samples from Nile crocodiles of different sizes using canine urinary catheters or small diameter stomach tubes. Based on the gross anatomical features of the cloaca of the Nile crocodile, it was confirmed that urine accumulates in a chamber consisting of the urodeum and coprodeum. Faecal material is stored temporarily in the very short rectum, which is separated from the urinary chamber by the rectocoprodeal sphincter.

The effects on steroidogenesis and histopathology of adult male Japanese quails (Coturnix coturnix japonica) testis following pre-pubertal exposure to di(n-butyl) phthalate (DBP)

In the present study, we have investigated the effects of 30-day dietary (pre-pubertal) exposure to different doses (0 (control), 1, 10, 50, 200 and 400 mg/kg bodyweight/day) of di(n-butyl) phthalate (DBP) on Leydig cells of adult male Japanese quails by quantifying the transcript levels for P450 side-chain cleavage (p450scc), P450c17 (CYP17), and 3β- and 17β-hydroxysteroid dehydrogenase (hsd) using quantitative (real-time) polymerase chain reaction (qRT-PCR). In addition, the plasma testosterone levels were analysed using radioimmunoassay (RIA) and testis was examined for evidence of gross pathology and histopathology. Our data showed that pre-pubertal exposure to DBP produced alterations in testicular architecture as evident by poorly developed or mis-shaped testis, and altered spermatogenesis due to tubular degeneration and atrophy of seminiferous tubules especially in the high DBP dose (200 and 400 mg/kg) treated groups. In addition, DBP altered several key enzymes involved in testicular steroidogenesis pathways in an apparent dose-dependent manner. For example, biphasic effects of DBP were observed for P450scc and 3β-hsd mRNA, that were generally increasing at low dose 10 mg/kg, and thereafter, an apparent dose-dependent decrease between 50 and 400mg/kg. The steroidogenic acute regulatory (StAR) protein was at the lowest detectable limits and therefore not quantifiable. These effects did not parallel the non-significant changes observed for plasma testosterone levels. The present data is consistent with previous reports showing that DBP modulates Leydig cell steroidogenesis in several species, with a potential negative effect on reproduction in those avian species that are vulnerable to endocrine disrupting chemicals.

A morphological study of simple testicular cysts in the ostrich (Struthio camelus)

Simple testicular cysts are rare in mammals and of unknown aetiology, but dietary conditions have been implicated in this phenomenon in poultry. This study characterises the structural features of simple intratesticular cysts in the ostrich. Seven testes from a total of 15 sexually mature ostriches slaughtered during the breeding season were used. The testes contained multifocal, fluid-filled, unilocular cysts which were lined by a simple squamous or low cuboidal epithelium and surrounded by a thick layer of fibrous connective tissue. The cysts developed within seminiferous tubules and displayed morphological features similar to those reported in man and domestic poultry. The testis parenchyma revealed several foci composed of intermingled normal seminiferous tubules and variably sized intratesticular cysts. The atrophic tubules lay within a mass of hyperplastic, fibroblastic intertubular connective tissue in the proximity of large cysts and their formation appeared to result from hydrostatic pressure exerted by cysts. Morphological evidence supports a continuous process of cyst formation in the affected testis and a concomitant progressive loss of atrophic seminiferous tubules. A pathogenetic scenario of cyst formation and the effect of simple cysts on testicular histology has been proposed. Although the course of this phenomenon remains unknown, its impact on the fertility of this economically important bird deserves closer scrutiny.

Radiographic thoracic anatomy of the ring-tailed lemur (Lemur catta)

The ring‐tailed lemur (Lemur catta) is a quadruped arboreal primate primarily distributed in south and south‐western Madagascar. This study was carried out to describe the normal radiographic thoracic anatomy of the ring‐tailed lemur as a reference for clinical use.

Histomorphometrical and ultrastructural study of the effects of carbendazim on the magnum of the Japanese quail (Coturnix coturnix japonica).

The study investigated the effect of various doses of carbendazim on the morphology of the magnum of the Japanese quail. No morphological changes were observed in the magnum in birds treated with carbendazim at doses of 25 mg/kg and 100 mg/kg bodyweight. A carbendazim dose of 400 mg/kg bodyweight was the lowest dose which caused morphological changes in the magnum. Histologically, carbendazim caused pyknosis and glandular atrophy in the magnum mucosa. Carbendazim also caused significant decreases in the height of the mucosal folds, epithelial height, glandular width and glandular luminal diameter at 400 mg/kg and 800 mg/kg (p < 0.05). At ultrastructural level, dose-dependent deciliation was observed. Pyknotic nuclei, dilated cisternae of rough endoplasmic reticulum, swollen mitochondria, numerous vacuoles and lysosomes in the luminal and glandular epithelia were identified. The observed degenerative changes could be due to cytoskeletal disruption caused by carbendazim toxicity. Degeneration of the luminal and glandular cells in the magnum pose a potential threat to the egg production and reproduction of exposed birds.

Kupffer cell structure in the juvenile Nile crocodile, Crocodylus niloticus

The morphology of Kupffer cells was examined in the liver of the juvenile Nile crocodile using light microscopy and transmission electron microscopy. Pleomorphic Kupffer cells were located in the sinusoids, in the space of Disse, in the hepatic parenchyma and often connected adjacent sinusoids. The cell surfaces were irregular due to the presence of filopodia and lamelliapodia with phagocytosis of white blood cells, red blood cells and thrombocytes being evident. The cells were in close contact with endothelial cells and pit cells in the sinusoidal lumen and with stellate cells in the space of Disse. The cytoplasm contained large phagosomes comprising a combination of ceroid pigment, melanosomes and siderosomes. The nuclei were often indented and eccentrically placed due to the presence of the phagosomes. Conspicuous clusters of membrane‐bound tubular organelles with a filamentous or crystalline interior were observed in the cytoplasm. The clusters were sometimes separated into smaller groups around phagosomes. A clear zone existed between the limiting membrane and the interior of these tubular organelles with the electron‐dense interior profiles being, respectively, circular, angular or divided. The tubular organelles have not previously been described in Kupffer cells and possibly represent lysosomes with specialized functions. Mitochondria, microtubules, Golgi profiles, granular and smooth endoplasmic reticulum, and a few cytoplasmic lipid droplets were also present. The presence of the tubular organelles and the occurrence of the Kupffer cells in different locations in the liver of the juvenile Nile crocodile are indicative of particularly active and mobile cells. J. Morphol. 275:1–8, 2014.

Ultrasonographic abdominal anatomy of healthy captive caracals (Caracal caracal)

Abdominal ultrasonography was performed in six adult captive caracals (Caracal caracal) to describe the normal abdominal ultrasonographic anatomy. Consistently, the splenic parenchyma was hyperechoic to the liver and kidneys. The relative echogenicity of the right kidneys cortex was inconsistent to the liver. The gall bladder was prominent in five animals and surrounded by a clearly visualized thin, smooth, regular echogenic wall. The wall thickness of the duodenum measured significantly greater compared with that of the jejunum and colon. The duodenum had a significantly thicker mucosal layer compared with that of the stomach. Such knowledge of the normal abdominal ultrasonographic anatomy of individual species is important for accurate diagnosis and interpretation of routine health examinations.

RADIOGRAPHIC AND ULTRASONOGRAPHIC ABDOMINAL ANATOMY IN CAPTIVE RING-TAILED LEMURS (LEMUR CATTA)

Abstract The ring-tailed lemur (Lemur catta) is primarily distributed in south and southwestern Madagascar. It is classified as an endangered species by the International Union for Conservation of Nature. Various abdominal diseases, such as hepatic lipidosis, intestinal ulcers, cystitis, urinary tract obstruction, and neoplasia (e.g., colonic adenocarcinoma and cholangiocarcinoma), have been reported in this species. The aim of this study was to describe the normal radiographic and ultrasonographic abdominal anatomy in captive ring-tailed lemurs to provide guidance for clinical use. Radiography of the abdomen and ultrasonography of the liver, spleen, kidneys, and urinary bladder were performed in 13 and 9 healthy captive ring-tailed lemurs, respectively, during their annual health examinations. Normal radiographic and ultrasonographic reference ranges for abdominal organs were established and ratios were calculated. The majority (12/13) of animals had seven lumbar vertebrae. The sacrum had mainly (12/13) three segments. Abdominal serosal detail was excellent in all animals, and hypaxial muscles were conspicuous in the majority (11/13) of animals. The spleen was frequently (12/13) seen on the ventrodorsal (VD) view and rarely (3/13) on the right lateral (RL) view. The liver was less prominent and well contained within the ribcage. The pylorus was mostly (11/13) located to the right of the midline. The right and left kidneys were visible on the RL and VD views, with the right kidney positioned more cranial and dorsal to the left kidney. On ultrasonography, the kidneys appeared ovoid on transverse and longitudinal views. The medulla was hypoechoic to the renal cortex. The renal cortex was frequently (8/9) isoechoic and rarely (1/9) hyperechoic to the splenic parenchyma. The liver parenchyma was hypoechoic (5/5) to the renal cortex. Knowledge of the normal radiographic and ultrasonographic abdominal anatomy of ring-tailed lemurs may be useful in the diagnosis of diseases and in routine health examinations.

Thoracic limb morphology of the red panda (Ailurus fulgens) evidenced by osteology and radiography.

The red panda (Ailurus fulgens) is distributed primarily in the Himalayas and southern China. It is classified as a vulnerable species by the International Union for Conservation of Nature. The aim of this study was to describe the normal osteology and radiographic anatomy of the thoracic limb of the red panda. Radiography of the right thoracic limb was performed in seven captive adult red pandas. Radiographic findings were correlated with bone specimens from three adult animals. The scapula was wide craniocaudally and presented with a large area for the origin of the teres major muscle. The square-shaped major tubercle did not extend proximal to the head of the humerus. The medial epicondyle was prominent. A supracondylar foramen was present. The radial tuberosity and sesamoid bone for the abductor digiti I longus were prominent. The accessory carpal bone was directed palmarolaterally. Metacarpal bones were widely spread. The thoracic limb morphology of the red panda evidenced by osteology and radiography indicated flexibility of the thoracic limb joints and well-developed flexor and supinator muscles, which are important in arboreal quadrupedal locomotion. Knowledge gained during this study may prove useful in identifying skeletal material or remains and diagnosing musculoskeletal diseases and injuries of the thoracic limb.The red panda (Ailurus fulgens) is distributed primarily in the Himalayas and southern China. It is classified as a vulnerable species by the International Union for Conservation of Nature. The aim of this study was to describe the normal osteology and radiographic anatomy of the thoracic limb of the red panda. Radiography of the right thoracic limb was performed in seven captive adult red pandas. Radiographic findings were correlated with bone specimens from three adult animals. The scapula was wide craniocaudally and presented with a large area for the origin of the teres major muscle. The square-shaped major tubercle did not extend proximal to the head of the humerus. The medial epicondyle was prominent. A supracondylar foramen was present. The radial tuberosity and sesamoid bone for the abductor digiti I longus were prominent. The accessory carpal bone was directed palmarolaterally. Metacarpal bones were widely spread. The thoracic limb morphology of the red panda evidenced by osteology and radiography indicated flexibility of the thoracic limb joints and well-developed flexor and supinator muscles, which are important in arboreal quadrupedal locomotion. Knowledge gained during this study may prove useful in identifying skeletal material or remains and diagnosing musculoskeletal diseases and injuries of the thoracic limb.