The Gross and Micro Anatomy of the Accessory Sex Glands of the Male Agouti (Dasyprocta leporina)

This study was a follow up to the study on the gross anatomy of the male agouti ( Dasyprocta leporina ) reproductive system. The seminal vesicles of the agouti are lobulated structures. The mean diameter of the large lumen is 883.6 ± 76.83 μm. The mucosa (24.1 ± 0.92 μm), which is lined by pseudo-stratified columnar epithelium is thrown into folds, which often branch. The lamina muscularis mucosa is thin and is made of loose connective tissue containing blood vessels. The mucosa of the leaf-like coagulating glands of the agouti is folded. The mean diameter of the lumen is 488.3 ± 41.96 μm. The mucosa contains tubuloalveolar glands, which have a mean length of 199.5 ± 28.83 μm. The thin epithelium, 15.0 ± 1.25-μm wide, consists mostly of pseudo-stratified columnar cells. The epithelium also has surface modifications in the form of apical blebs and cilia. The epithelium of the agouti's lobulated prostate gland is also folded creating a large lumen with a mean diameter of 995.5 ± 55.70 μm. The mucosa contains tubular and tubuloalveolar glands, each having a mean length of 134.4 ± 13.59 μm. The epithelium (13.9 ± 1.16 μm) consists of pseudo-stratified columnar cells. The pea-shaped bulbourethral gland (BG) of the agouti consists of convoluted tubular, mucous secretory units, which are irregularly shaped each with a mean length of 177.9 ± 7.10 μm and a mean width of 63.5 ± 3.97 μm. The BG of the agouti are ventro-lateral to the rectum and dorsally positioned to the pubic symphysis, and connected to the urethra by short ducts.     

Collateral arteries of the aortic arch of the red-rumped agouti (Dasyprocta leporina Linnaeus, 1758)

Detailed knowledge of the arterial system is an important prerequisite when interpreting experimental data in research, as well as in the diagnosis of cardiovascular disease using imaging techniques such as Doppler echocardiography and contrast radiography. Thus, considering the importance of the aortic arrangement, the objective of this study was to describe the collateral arteries of the aortic arch of agoutis in order to establish the standard model, and therefore contribute to studies involving research related to heart disease, and produce information for a more accurate diagnosis in complementary imaging examinations. In this study, 14 adult animals were used, comprising eight males and six females. The vascular system was washed with 0.9% aqueous saline solution and perfused with Neoprene 450 latex coloured with yellow or red pigment, which was subsequently dissected and analysed. One male animal was used for the digital contrast radiography technique perfused with a liquid barium sulphate solution (Bariogel^®) (1 g/ml) and Neoprene 450 latex, both diluted 1/3. The aortic arch of the agouti presented with only the brachiocephalic trunk as collateral branch in all the animals studied. Thus, agouti falls into type 1 for mammalian aortic arch vascular arrangements.     

Interactions Among Different Devices and Electrical Stimulus on the Electroejaculation of Captive Agoutis (Dasyprocta leporina)

The interactions among different electroejaculation devices associated with serial or continuous stimuli were investigated to improve the efficiency of the electroejaculation for semen collection in agoutis. Ten sexually matured male Dasyprocta leporina were restrained by the intramuscular administration of xylazine–ketamine association. Each individual was randomly subjected to four electroejaculation protocols, by combining two devices (one presenting longitudinal electrodes emitting square waves and other presenting ring electrodes emitting sine waves) and two electrical stimuli protocols (serial or continuous). A total of 40 attempts for electroejaculation were conducted in agoutis, being 10 per treatment. The most efficient treatment in providing ejaculates containing sperm (p < 0.05) was that using and electroejaculator connected to a probe with ring electrodes and associated with serial stimuli (4/7; 57%). In spite of semen parameters obtained by sine waves were adequate for using the samples for assisted reproduction, higher values for sperm motility and functional membrane integrity were obtained in the use of the square wave, independently of the electric stimulation protocol used (p < 0.05). In conclusion, we verified that the use of a device presenting a probe with ring electrodes and emitting sine waves, associated with a serial stimuli protocol, improves the efficiency for semen obtaining by electroejaculation in adults D. leporina.     

Anatomy of the vertebral column,ribs and sternum in orange rumped agouti (Dasyprocta leporina Linnaeus, 1758): Structural and Functional perspectives

The axial skeleton of orange rumped agouti, Dasyprocta leporina, was studied for better understanding of its locomotor behaviour. The bones from eight adult agoutis of both sexes were observed for their anatomical features and functional significance. The vertebral formula was found to be C₇T₁₂L₇S₅Cy_5–6. The well-developed occipital crest, caudally oriented prominent axis spine and well-developed transverse processes from C₃–C₇ indicated a highly flexible neck with greater sagittal mobility. Articular facets were horizontal in anterior series while oblique in the posterior series, which enabled them to perform both lateral and sagittal movements during locomotion. The caudally directed thoracic spines, T₁₂ as anticlinal vertebra and prominent mamillary process in the posterior series were suggestive of strong dorso-ventral flexion/extension and rotation. The robust lumbar vertebrae, well-developed transverse processes with cranio-ventral extension, were the feature for powerful sagittal/dorsoventral movement. The presence of spinous processes and well-developed transverse processes in all caudal vertebrae was an indication of a highly movable tail. The ribs were 13 pairs with first seven as sternal and six as asternal. They were laterally compressed in the anterior series as a cursorial adaptation. A strong muscular attachment to vertebrae provides this rodent speed, agility, dexterity and strength suitable for survival in food chain.     

Treatment of Intraoperative Persistent Penile Erection in a Stallion

This case report describes the occurrence of persistent penile erection in a breeding stallion that occurred while the horse was under inhalant anesthesia for a carpal arthroscopy. The horse had no history of breeding problems, and no abnormalities were detected on physical examination, complete blood count, or serum chemistry tests performed prior to surgery. Anesthesia was induced with guaifenesin and ketamine after sedation with xylazine and was maintained with isoflurane in 100% oxygen. Penile erection developed approximately 35 minutes after induction and persisted for over 2 hours despite various physical and pharmacological attempts to alleviate it (massage, cold compresses, intravenous benztropine administration, and intracavernosal phenylephrine). Successful resolution of the erection was obtained by cannulation and drainage of blood from the corpus cavernosum and subsequent irrigation with heparinized sterile saline and infusion of phenylephrine in the corpus cavernosum. The detumescent penis was placed back into the sheath, and purse string sutures were placed in the sheath to ensure the penis would remain inside the sheath during recovery. The stallion's recovery from anesthesia was uneventful, the sutures were removed, and the horse was fitted with a penile sling to prevent additional edema or trauma. The stallion recovered completely from the persistent penile erection. Semen was collected 6 days after the event, and he returned to normal pasture breeding 6 weeks after surgery.     

Arterial supply of the penis in agoutis (Dasyprocta prymnolpha, Wagler, 1831)

The arterial vascularization of agoutis’ penis (Dasyprocta prymnolopha) were analysed using ten male adults from ‘Núcleo de Estudos e Preservação de Animais Silvestres da Universidade Federal do Piauí’ (FUFPI/IBAMA n° 02/99). Among the total number of specimens, six animals had natural death and were members of the research collection of the Laboratory of Anatomy, and four were killed after anaesthesia. Stained bi‐centrifugated‐Cis‐I‐4 latex was injected in arterial vessels responsible for penis vascularization throughout the abdominal portion of aorta. The samples were fixed in 10% formaldehyde solution and arteries were dissected. The penile artery is originated as a branch of internal pudendal artery. At the level of ischiatic arch, the penile artery project two branches, the penile dorsal and the deep arteries; those arteries irrigates the penile dorsal surface and the corpus cavernosum penis. The penile dorsal arteries have an independent course up to the glans penis. Based on the conditions of this work a remarkable similarity regarding the distribution of vessels destined to the agouti penis when compared to other domestic, wild and lagomorph rodents as rabbits.     

Fatal anemia and dermatitis in captive agoutis (Dasyprocta mexicana) infested with Echidnophaga fleas

Two captive agoutis (Dasyprocta mexicana) died of anemia with centrilobular hepatocellular necrosis (2/2), severe flea ectoparasitism (2/2), and cardiomegaly attributed to anemia (1/2). Other agoutis were similarly parasitized and one had anemia. Fleas were manually removed and all agoutis treated topically with propoxur and selamectin and moved to another enclosure. No additional cases of fatal anemia were seen. Cutaneous lesions suggestive of hypersensitivity were observed in three additional agoutis with dorsal alopecia (3/3), a penetrating wound associated with pruritus and self-mutilation in the flank (2/3), flea ectoparasitism at the time of morphologic diagnosis (1/3), and hyperplastic perivascular dermatitis (3/3). One of these died of bacterial infection of the wound. Similar but milder skin disease was seen in 3 out of over 30 maras (Dolichotis patagonum) housed in the same exhibit. Fleas collected from all the fatal agouti cases and maras were classified in the genus Echidnophaga based on the angular front margin of head, contracted thorax, absence of genal and pronotal combs, and the fact that fleas did not jump. These findings suggest that flea ectoparasitism may be an important cause of morbidity and mortality in captive rodents.     

The gross anatomy of the male reproductive system of a neotropical rodent: the agouti (Dasyprota leporina)

The literature available on the agouti (Dasyprocta leporina) is very limited. The agouti is a Neotropical rodent found in Trinidad and Tobago, Central and South America. This study focuses on one of the many unexplored areas relating to the species, the male reproductive system. The results showed that the mean testicular length, diameter and weight was 3.67 +/- 0.12 cm, 1.67 +/- 0.04 cm and 5.03 +/- 0.52 g respectively. The paired testes and epididymis were found in contact with the abdominal muscles within scrotal pouches, which are evaginations of the caudoventral abdominal wall. The caput epididymis is enclosed by a fat body. The ductus deferens has a mean length and diameter of 10.98 +/- 0.40 cm and 0.14 +/- 0.01 cm respectively. At the urethral end of the ductus deferens the diameter of each duct expends to form the ampulla. The mean diameter of each of the ampulla was 0.25 cm. The accessory sex organs of the male agouti (D. leporina) include the vesicular glands, the coagulating glands, the prostate glands and the bulbourethral glands. The penis of the agouti is U-shaped with a mean length of 9.90 +/- 0.43 cm. The glans penis contains an os penis, a pair of lateral penile cartilages and paired ventral keratinaceous styles.     

Multicentric squamous cell carcinona in a paca (Agouti paca) resembling Bowen's disease

An 8-yr-old female paca (Agouti paca) was admitted at the Veterinary Hospital of the Belo Horizonte Zoo (Brazil) with an ulcerated cutaneous nodule of approximately 1.5 cm in diameter in the left ear. One week later, other cutaneous nodules were detected in various body locations. The animal died during a surgical procedure to remove the tumors. All cutaneous nodules were histologically similar with features of squamous cell carcinoma. Considering the predominant in situ nature of the lesion as well as its multicentric localization, the disease reported here closely resembles Bowen's disease, which has been described in humans and which has been identified as a rare neoplastic disease of cats, with one single report in a dog. This is the first report of a neoplastic disease in Agouti     

Anatomical Evidence of Electroreception in the Coelacanth (Latimeria chalumnae)

Serial sections of an immature female Latimeria brain were studied to describe the octavolateral area. Sections were stained with cresyl violet (for cell bodies) and with Klüver-Barrera method for myelinated fibers. The presence of a well-developed dorsal nucleus of the octavolateral area suggests that Latimeria probably possesses the electroceptive capacity with ampullary organs.     

Anatomoradiographic description of the teeth of pacas bred in captivity (Agouti paca, Linnaeus, 1766)

Two newborn males, two adult males 9 and 72 months old, one newborn female and two adult females of 30 and 54 months old pacas were used. Animals were radiographed on lateral recumbency, teeth were extracted and the vestibulolingual and mesiodistal lengths were achieved at the occlusal surface, besides the longitudinal length. The lower incisors presented greater length in relation to the other ones and sinuous shape; the upper incisors, relatively smaller, are practically straight. There is no canine tooth, and after a great diastema there is one premolar and three molars in each hemiarcade. In adult pacas, the enamel of incisors presents yellowish colour, mainly in the labial surface; in the premolars and molars, the enamel is present as internal sheets disposed nearly in a parallel way and in vestibulolingual direction, through practically all the dental length, which provides several joined teeth aspect.     

Interactions between straw size and thawing rates on the cryopreservation of agouti (Dasyprocta aguti) epididymal sperm

This study verifies the interactions between straw size and thawing rates and their impact on the epididymal sperm from this species. Caudae epididymidum from 10 agoutis were subjected to retrograde washing using a coconut water extender (ACP‐109c^®). Epididymal sperm were evaluated and extended in ACP‐109c^® plus egg yolk (20%) and glycerol (6%). The samples were packaged in 0.25‐ or 0.50‐ml straws, frozen in liquid nitrogen and thawed at 37°C/1 min or 70°C/8 s, followed by a re‐evaluation. The use of 0.25‐ml straws thawed at 37°C/1 min provided a value of 26.6% for sperm motility. No interactions between straw size and thawing rates were verified on agouti sperm (p > 0.05), but when 0.5‐ml straws were thawed at 70°C/8 s, sperm vigour decreased significantly (p < 0.05). It is recommended that the agouti epididymal sperm cryopreserved in ACP‐109c^® extender should be packaged in 0.25‐ or 0.50‐ml straws and thawed at 37°C/60 s.     

Anatomical Atlas of the Quail's Ear (Coturnix coturnix)

This study aims to enhance the anatomical knowledge of the ear of the adult quail (Coturnix coturnix) through the creation of a scaled 3D model utilizing data from micro‐CT images. In addition, 17 annotated histological sections of the quail's ear are aligned to their 3D position in the model. The resulting anatomical atlas provides an intuitive insight into the 3D anatomy and can be used for medical education. The model also allows measuring anatomical structures and can thus serve as reference for the quail's auricular anatomy and as a basis to evaluate clinical diagnostic imaging results.     

Anatomical Structure of the Brachial Plexus in the Merlin (Falco columbarius)

This study aimed to document the detailed features of the morphological structure and the innervation areas of the brachial plexus in Merlin (Falco columbarius). The skin and muscles of five adult male Merlins were dissected under the stereo microscope. The Merlin had two plexus trunks. The accessory brachial plexus consisted of ventral rami C10 and C11. C11 was divided into two branches: the cranial and caudal. The brachial plexus was composed of a rather complex network involving the ventral rami of C11‐C13, T1 and T2. In addition, a thin branch from the last two cervical sympathetic nerves participated in the plexus formation. C12, C13 and T1 had rather thick trunk. C12, C13 and T1 were also involved in the formation of the brachial plexus emerging after 1 cm from the foramen inter‐vertebrale as three trunk roots.     

双峰驼跖趾关节解剖结构

采用大体解剖学方法,研究了成年双峰驼的８个跖趾关节,并与马、牛、羊、猪、犬等动物的对等器官进行了比较。结果发现,双峰驼跖趾关节的形态结构有以下显著特征：（１）跖骨远端关节面后部有矢状嵴,近趾节骨近端关节面后部有与之相对应的矢状沟,这种结构与跖行动物和趾行动物相类似;（２）籽骨上没有对应近趾节骨近端的关节面;（３）籽骨间韧带只连接同一趾上的２个籽骨,与牛的将２趾的４个近籽骨连在一起的结构不同;（４）轴侧侧副韧带不像牛的那样与对侧的同名韧带共同起始于跖骨远端滑车间切迹,而是分别起始于此切迹的轴侧韧带窝及韧带结节;（５）轴侧侧副韧带仅为１层,而远轴侧侧副韧带分为２层;（６）籽骨直韧带、趾间趾节骨籽骨韧带及趾间近韧带均缺如。     

Anatomical study of the diaphragm of the opossum (Didelphis albiventris)

The anatomical characteristics of the South American opossum diaphragm were described. Five male and seven female adult opossums, weighing between 700 and 1110 g, were used. Animals were killed by ether inhalation saturation. The abdominal and thoracic walls were dissected and opened, the viscerae were removed and the diaphragm anatomy was described and photographed in situ. After diaphragm removal, some dimensional data were taken and tabled. Primary branches of the phrenic nerves were dissected under a surgical microscope. The secondary branches were studied and described by transillumination after clarification in acetic acid. The opossum diaphragm is domed and has a mean area of 54.33 +/- 3.8 cm2. Well-identified costal, sternal and lumbar parts form the peripheral muscular region. The central tendinous region presents with a V-like form. Three folioles comprise the phrenic centre and present different dimensions. The caudal vena cava passes through its foramen between the ventral and right dorsal folioles. Both right and left phrenic nerves present one ventral branch and one dorsolateral trunk in 50.0% and 66.67% of the cases, respectively.