Abstract: Veterinary practice commonly involves caring for domestic and companion animal. Since the trend of owning exotic pets is rapidly increasing, veterinarians often treat exotic patients as well. As a result, veterinarians are facing increased demands for specialized skills and knowledge. This article aims to provide a concise review of the anatomy of the vascular system in exotic animals and its relevance in clinical practice. Snakes, lizards and chelonians have 3-chambered heart with 2 atria and one partially divided ventricle whereas crocodiles have 4-chambered heart. It is important to consider these characteristics during the anesthesia in reptiles since blood shunting affects changes in blood pressure, oxygen level and other anesthetic parameters. In birds, the cardiovascular system is crucial in enduring the exhausting physical activities such as swimming, flying or diving and running. Birds have renal portal system which consists of cranial and caudal renal portal vein. The recommendation of avoiding drug application in the hindlimbs of birds is present for a long time. This is valid not only for birds, but for reptiles, amphibians and most fish. The ventricle of amphibians is trabeculated, which minimizes blood shunting through various anatomical and physiological features. During biphasic systole, the left and right side of the ventricle contract separately, directing blood in different parts of aortic arches. Due to the complexity of the exotic animals, thorough education added in veterinary curricula is needed. Keywords: amphibians, birds, cardiovascular, clinical, reptiles

Simple Summary The aim of this study was to analyze and compare the morphology of root canals in the carnassial teeth of German shepherds and mixed-breed dogs. Knowledge of the morphology of root canals is essential for a successful endodontic procedure. It has been determined that an apical delta, which represents a complex structure that consists of multiple cavities whose purpose is to allow the passing of nerves and blood vessels from the pulp cavity to the apex of the root, was present in 247 roots. There are four main types of apical delta. The most common type in superior fourth premolars was type II, with up to 10 apical ramifications, whereas type IIIA, with 10–20 apical ramifications, was most commonly present in inferior first molars. Abstract Root canal treatment of carnassial teeth in dogs is a common endodontic technique which aims to re-establish or maintain the health of the periapical tissues. In total, 43 dogs were used in this study. Root canal morphology was evaluated in 86 superior fourth premolars and 86 inferior first molars. Apical delta was present in 247 roots, while obliteration of the root canal was found in 11 roots. The most common type of apical delta of the roots of superior fourth premolars was type II, with up to 10 apical ramifications, while type IIIA, with 10–20 apical ramifications, was most commonly present in the roots of inferior first molars. Considering that knowledge of the morphology of root canals is essential for a successful endodontic procedure, the aim of this study was to analyze and compare the morphology of root canals in the carnassial teeth of German shepherds and mixed-breed dogs. Apical resection for the purpose of endodontic therapy of the superior fourth premolar and the inferior first molar is indicated at a length of 4 to 6 mm from the anatomical tip of the roots, which would completely remove the apical delta of these two teeth.

Simple Summary The aim of the study was to determine the morphological and morphometrical features of the auditory ossicles in the red fox. Moreover, for the first time, shape analysis was performed on all the middle ear bones by geometric morphometry. The auditory ossicles play a vital role in transmitting sound waves through the middle ear. The malleus was considered to be the largest bone, with three distinctive processes. The overall shape of the incus was found to be similar to that in other mammals. The presence of a prominent muscular process was noted on the head of the stapes and the convex base which closes the window of the inner ear. Abstract The use of carnivores as experimental models in auditory biology has led to a significant improvement regarding our understanding of the structure and function of the ear. Considering that data regarding the anatomy of the middle ear in the red fox are rare, this study aimed to describe the morphological and morphometrical features of the auditory ossicles in the red fox, as well as to provide their shape characteristics by geometric analysis. Nine adult red foxes were used in the study. The malleus, incus and stapes were extracted from the middle ear, prepared, photographed and measured using the software. For the geometric analysis, 19 landmarks were used. Following Principal Component Analysis (PCA), PC1 was found to explain approximately half of all variance (incus: 49.97%; malleus: 49.93%; stapes: 58.49%). The study demonstrated the similar anatomical organization of the auditory ossicles in line with important morphometric and basic geometric data, which can contribute to this field and add a useful perspective to the literature.

The use of digital teaching resources became widespread and very helpful during the COVID‐19 pandemic as an alternative to a traditional course with cadavers. Technologies such as augmented reality (AR), virtual reality (VR), 3D models, video lectures and other online resources enable three‐dimensional visualization of the anatomical structures and allow students to learn more interactively. The aim of this study was to compare students' performance in the traditional anatomical courses in teaching neuroanatomy and technology‐based learning methods such as video lectures, 3D models and 3D printed specimens. Four groups of first‐year students of Veterinary Faculty established for the practical classes during the academic year 2021/2022 took part in this research. The total number of students participating in this research was 72. Each group attended separately the theoretical lecture with a demonstration based on a different technique; the control group used formalized specimens, while the three experimental groups used video lectures, 3D models and 3D printed specimens, respectively. Subsequently, all groups completed the same questionnaire testing their short‐term memory of the neuroanatomical structures. After four weeks students were tested for their long‐term memory of the neuroanatomy lecture with the follow‐up test containing an identical list of questions. The test scores using video lectures and 3D printed models were significantly higher compared with the group that learned in the traditional way. This study suggests that alternative approaches such as technology‐based digital methods can facilitate memorization of anatomical terms and structures in a more interactive and sensory engaging way of learning.

Microvascularization of domestic fowl kidneys was studied using scanning electron microscopy (SEM) of vascular corrosion casts (VCCs). Two types of nephrons, mammalian‐type (MT) and reptilian‐type (RT) nephrons and their glomerular structure were analysed quantitatively by 3D morphometry. A significant difference in shape and size between the MT and RT glomeruli was found. The mean diameter of the RT glomeruli was about 56 µm, while that of MT glomeruli was significantly larger, namely about 80 µm. The afferent arterioles in mammalian‐type glomeruli usually bifurcated into two lobular branches and formed a complex glomerular capillary network with numerous loops. Reptilian‐type glomeruli consisted of a single capillary forming few loops and leaving the glomerulus as efferent arteriole. Diameters of afferent and efferent arteriolar replicas were similar in all three kidney divisions of MT and RT nephrons. The absence of the interconnecting branches between the MT nephron capillaries at the gross inspection suggests that the mammalian‐type nephron glomeruli, although more complex than the reptilian type, are not equivalent to those in mammalian kidneys.

This paper presents a comprehensive anatomic overview of normal pulmonary vascularization in an American mink (Neovison vison), with emphasis on venous and arterial peculiarities as regards its course and potential disruptions. The study is designed as macro-morphological and vascular network analysis of lungs of fifteen minks of different age and gender. Dissection is conducted along with injection corrosion method in order to clearly visualize the vascular topology, bronchial tree, arterial and venous trees, and their interconnections. The specimens exhibit consistence in the arterial branching pattern with negligible range of alterations. It was noticed that upon leaving the right ventricle of heart, pulmonary trunk divides ventrally from the site of tracheal bifurcation. The divisions were identified as left and right pulmonary arteries, which then ramified in the left and right lung, respectively. Left a. pulmonalis further divides into two major branches ramus lobi cranialis and ramus lobi caudalis, while the right a. pulmonalis gives five major branches for lobes in the right lung. Total of five pulmonary veins leave pulmonary lobes and enter left atrium of the heart. Mink has a distinct niche in biomedical research, proving as a suitable model to enhance the understandings of the various diseases. Gained insights are valuable as reference values for examination of the vasculature in other Mustelidae species, recognition of potential deviations and vascular remodeling due to respiratory diseases.

Abstract The study has aimed to investigate and determine the anatomical position, shape, size, and histological features of the ductus venosus, and its role as a shunt in the fetal circulatory system in domestic ruminants. The research was conducted on 19 bovine, 11 sheep and 5 goat fetuses, aborted at the late stage of pregnancy or deceased just after delivery. The general anatomy of the ductus venosus was investigated by in-situ dissection of the corrosive cast obtained by injection of 25% solution of Vinylite mass through the umbilical vein. For histological examination, the fetal tissue samples were stained with Hematoxylin and Eosin, Masson’s trichrome, Verhoeff-Van Gieson and Gomoriꞌs silver stain. The results showed that ruminant fetal ductus venosus is a curved, trumpet-shaped vessel, situated in the central part of the liver, above the porta hepatis. Its ventral part is constricted in the form of an isthmus, having a prominent lip-like thickening at the junction with the portal sinus. Histological examination showed the dominant presence of collagen and elastic fibers in its tunica media, with thin bands of smooth muscle fibers oriented in a longitudinal and circular direction indicating ability for vasoconstriction and vasodilatation.

Spondyloarthropathy is a form of arthritis that affects spine, especially sacroiliac joint leading to the severe, chronic pain and over time, can cause complete fusion of the sacroiliac (SI) joint. The present report describes a case of spondyloarthropathy in a captive female brown bear ( Ursus arctos ) from Sarajevo zoo, Bosnia and Herzegovina. Morphological inspection and radiograph of the macerated sacral and coxal bone specimen was performed. Both examinations showed complete bilateral symmetrical fusion of the sacral and coxal bone with syndesmophyte formation. Animals residing in zoos are kept under specific conditions which lead to inactivity and possible mobility problems caused by some sort of spondyloarthropathy.

Ultrastructure of plasma cells in Harderian gland was investigated using the transmission electron microscopy. For this research, we examined the glands of 32 laying hens collected at 1, 7, 20 and 40 days and 4, 6, 8 and 12 months of the birds' ages. The research showed that the stroma of the gland contains a large number of lymphocytes and plasma cells. Most of the plasma cells are mature, but morphologically do not show productive activity. Only some individual plasma cells, situated under the secretory epithelium of primary and secondary ducts, have extremely dilated cisternae of rough endoplasmic reticulum which contain moderately dense, granular material. The morphology of these cells indicates that they are in active stage of immunoglobulin production. Also, we identified plasma cells with two types of Russell bodies. One type of these bodies was small, round or oval, while the other had irregular, angular shape. It was noted that one plasma cell never contains both type of Russell bodies at the same time. These cells were often affected by apoptosis. Among them, in deeper part of the stroma, were situated the small plasmablast cells.

Abstract This paper presents the results of the research on renal blood vessels of the mink. The main goal of this research is to provide a unique insight in renal vessel constellation and thereby contributes to the amount and quality of the available data on the cardiovascular system of the mink, since the data found in the available literature regarding this specific field is rather poorly documented. Blood vessels of the mink kidney were studied by dissection and corrosion injection technique. The renal artery and its branches, and the lobar, interlobar and interlobular arteries are terminal arteries and they do not anastomose between each other. The arterial system is characterized by two independent vascular areas, supplied by the dorsal and ventral lobar artery. Lobar arteries divide the kidney horizontally into a dorsal and ventral half, while lobar veins divide it vertically into the cranial and caudal half. The renal vein is formed from the cranial and caudal lobar vein. The obtained results are compared with relevant literature findings on renal blood supply of a dog and other sympatric carnivores.

Bosnia and Herzegovina has always had a developed sheep production, at least from the aspect of the number of sheep per capita. Today, the ratio is 1 sheep per 4 persons, because the cattle production, globally looking, is decimated by war. Thanks to the geographic location of the country, the quality of mountain pastures and environment that is still healthy, we believe that with increased investments in sheep production we could increase the number of heads, which would have positive effects on production of meat and milk of exceptional quality. The study involving the uterus of Dubska pramenka during sexual season under nomadic conditions of holding, demonstrated that, in adequate zoo hygiene conditions (holding, feeding, treatment of animal), the sheep showed increased reproductive parameters as well as parameters manifested in meat and milk production. In our studies, microstructure of uterus of Dubska pramenka during sexual season shows extremely positive characteristics for nidation of the egg cell and normal development of the embryo. Epithelium of the uterus is in a form of high-prismatic cells, which points to significant cell activity; perfusion and development of myometrium are visible. The uterine glands are extremely well developed and their histological structure indicates increased secretion and preparation of the uterus for gravidity.