Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Anatomy
Anatomy in horses encompasses the study of the structural organization of the equine body, including the bones, muscles, organs, and systems that function together to sustain life and enable movement. Understanding equine anatomy is important for veterinarians, equine scientists, and horse owners, as it provides insights into how horses move, how they respond to external stimuli, and how various conditions can affect their health and performance. Key anatomical features in horses include the musculoskeletal system, which provides support and locomotion; the cardiovascular system, which circulates blood and nutrients; and the respiratory system, which facilitates gas exchange. This page compiles peer-reviewed research studies and scholarly articles that explore the detailed anatomy of horses, focusing on the structure and function of different body systems, their interrelationships, and their relevance to equine health, performance, and veterinary care.
The pathophysiology of chronic laminitis. Pain and anatomic pathology. The potential pathologic manifestations of chronic laminitis are just as varied, and possibly more so, than the list of possible inciting agents of the disease itself. The extent to which rehabilitation and return to normal function can be attained, cannot always be accurately determined by physical examination. It should be remembered that significant physiologic and pathologic alterations occur in chronic laminitis; thus, even if radiographically the patient returns to a normal appearance, residual morphologic and structural defects are likely to remain.
Identification of an ossicle associated with the palmar aspect of the carpus in the horse. An ossicle associated with the palmar aspect of the carpus is described in five horses. The size of the ossicle varied from 3 x 4 mm to approximately 12 x 10 mm. The ossicles were located at the junction of the proximal and distal rows of carpal bones, between the palmaromedial aspect of the fourth carpal bone and the ulnar carpal bone. In 3 horses they were bilateral, in one horse unilateral, and only one limb was examined in the remaining horse. In all horses it was an incidental finding and not regarded to be a pathologic entity.
A congenital malformation of the maxilla of a horse. A 1-month-old male American Paint Horse was evaluated for a hard swelling on the right side of the maxillary region. On radiographs there was a large, expansile outpouching of the right maxillary bone between the second and third premolar teeth. Computed tomography further characterized the expansile lesion to have a soft tissue component and to originate in the region of a caudal maxillary tooth. Surgical reconstruction of the defect was unsuccessful and the animal was euthanetized. Based on failure to find histopathologic evidence of a neoplasm or cyst, the diagnosis was a congenital malform...
Persistent vitelline vein in a foal. A three-day-old foal died from intestinal strangulation due to a remnant of vitelline vein which extended between the umbilicus and the portal vein. The strangulating vein was identified on the basis of its morphological and histological structure. This finding, which is the first reported case of a persistent vitelline vein in a horse, is discussed in relation to the normal development and involution of the vitelline circulation.
Characterisation of the type and location of fractures of the third metacarpal/metatarsal condyles in 135 horses in central Kentucky (1986-1994). The objective of this retrospective study was to provide a detailed description of the characteristics of condylar fractures represented in a population of 135 horses who sustained 145 fractures. Records and radiographic studies were examined. Fifty-nine percent of the horses were male and the majority Thoroughbreds. The distribution of fractures was 37% incomplete-nondisplaced, 30% complete-nondisplaced and 32% complete-displaced. The right front was more likely to sustain a complete-displaced fracture, whereas the left front was more likely to sustain an incomplete-nondisplaced fracture. For...
Equine castration: review of anatomy, approaches, techniques and complications in normal, cryptorchid and monorchid horses. Complications associated with equine castration are the most common cause of malpractice claims against equine practitioners in North America. An understanding of the embryological development and surgical anatomy is essential to differentiate abnormal from normal structures and to minimise complications. Castration of the normal horse can be performed using sedation and regional anaesthesia while the horse is standing, or under general anaesthesia when it is recumbent. Castration of cryptorchid horses is best performed under general anaesthesia at a surgical facility. Techniques for castratio...
The use of postmortem radiography as an aid in diagnosing, documenting, and understanding disease in animals. Postmortem radiography can be a valuable supplement to traditional necropsy. This article provides examples where postmortem radiographs have been useful in diagnosing and documenting lesions in animals, and have helped demonstrate important principles of the pathology and the pathogenesis of lesions identified at necropsy. This article also discusses additional circumstances where the application of postmortem radiography might be worthwhile.
Ultrastructural aspects of feeding and secretion-excretion by the equine parasite Strongylus vulgaris. Light, scanning, and transmission electron microscopy were employed to provide further data on the putative origins of the immunogenic secretory-excretory product (ESP) of Strongylus vulgaris (Looss 1900). The sharply delineated but superficial attachment to the equine caecum by the mouth leaves behind an oval area devoid of epithelial cells. Attachment does not extend deeply enough to reach the muscularis mucosa layer of the equine intestine. The progressive digestion of the ingested plug of tissue (epithelial cells, blood cells and mucous) was visualized. The coelomocytes, floating cells and...
Morphological character of the shoulder and leg skeleton in Przewalski’s horse (Equus przewalskii). The skeletal feature was observed in Przewalski's horse (Equus przewalskii) and the domestic horse (E. caballus). As results of the observations, remarkable differences were found in the scapula. The caudal border of the scapula in Przewalski's horse is curved in the caudal direction more than that of the domestic horse. Moreover, in the domestic horse, the sharp caudal border is formed by the shift of the outer muscular line (Linea muscularis) to the border. In Przewalski's horse, however, the caudal border is rounded because the outer muscular line does not shift to the border but lies besid...
Persistent frenulum of the epiglottis in four foals. To report the clinical signs and management of 4 foals with persistent frenulum of the epiglottis. Methods: Case report. Methods: Four newborn foals. Methods: Foals were admitted with a complaint of oronasal reflux after nursing. Variable systemic signs of aspiration pneumonia were evident. Nasal endoscopy confirmed persistent dorsal displacement of the soft palate. Persistent frenulum of the epiglottis, confirmed by oral endoscopic examination, was transected. Results: After surgery, all foals had the epiglottis positioned normally, dorsal to the soft palate. Clinical signs of oronasal reflux...
Near infrared spectroscopy in large animals: optical pathlength and influence of hair covering and epidermal pigmentation. The effects of epidermal pigmentation and hair covering on the relative transparency of various animal tissues to near infrared (NIR) light were examined, and the pathlengths of NIR light through tissues at four wavelengths in the NIR range were subsequently determined. Black hair covering and black or dark-coloured hooves prevented NIR light from penetration sufficient for conduction of pathlength or NIR spectroscopy measurements. Non-pigmented hair covering of the head did not appear to be a barrier to successful NIR light transmission. Tissues sufficiently transparent to NIR light had the d...
Malignant rhabdoid tumour in the orbit of a horse. A malignant rhabdoid tumour was diagnosed in the orbit of a 2-year-old Thoroughbred filly. The neoplasm, which was very aggressive, was present in nearly every part of the ocular and periocular structures and had spread to the lymph nodes of the head and neck, the salivary glands and the subcutaneous tissues around the eye. The neoplasm was composed of polygonal cells with abundant eosinophilic cytoplasm. Many cells had a large, vesiculate, indented nucleus and contained a paranuclear globular inclusion. Ultrastructurally, the inclusions were seen to consist of whorls of intermediate filaments...
Ultrasonographic anatomy of the accessory ligament of the superficial digital flexor tendon in horses. The ultrasonographic anatomy of the accessory ligament of the superficial digital flexor tendon (AL-SDFT) in the horse is presented. Comparison between anatomical sections of isolated limbs and ultrasound scans of the distal antebrachium in sound horses enabled the authors to establish the normal reference ultrasonographic images of this structure. The AL-SDFT inserts 7-14 cm above the antebrachiocarpal joint on the palmaromedial aspect of the radius. Ultrasonographically it appears as an uniformly echogenic structure located deep to the median artery. The knowledge of ultrasonographic anatomy...
A method for determination of equine hoof strain patterns using photoelasticity: an in vitro study. During impact, equine hooves undergo viscoelastic deformations which may result in potentially harmful strains. Previous hoof strain studies using strain gauges have been inconclusive due to arbitrary gauge placement. Photoelastic stress analysis (PSA) is a full-field technique which visually displays strains over entire loaded surfaces. This in vitro study identifies normal hoof strain patterns using PSA. Custom-made photoelastic plastic sheets were applied to the hoof surface. The hooves were axially loaded (225 kg) under level and varus/valgus conditions. Strain patterns were video-recorded...
Endoscopic examination of the tarsal sheath of the lateral digital flexor tendon in horses. This study was designed to develop a reliable technique for endoscopic examination of the tarsal sheath of the lateral digital flexor tendon of horses. The anatomy of the tendon sheath and associated structures was studied in detail in cadavers before determining portals for the insertion of an arthroscope into the sheath. Approaches into the sheath through the proximal pouch and through the flexor retinaculum, at the level of the sustentaculum tali, were performed and compared in cadavers. The proximal pouch portal permitted visualisation only of the proximal half of the sheath, while the app...
Results of screw fixation combined with cortical drilling for treatment of dorsal cortical stress fractures of the third metacarpal bone in 56 Thoroughbred racehorses. The purpose of this study was to evaluate screw fixation with cortical drilling as a surgical treatment for dorsal cortical stress fractures of MCIII in the Thoroughbred racehorse. Details of age, sex, limb affected, fracture assessment, and post operative recommendations were obtained from medical records and radiographs. Fracture healing was assessed radiographically at the time of screw removal. Performance evaluation was determined from race records obtained from The Jockey Club Information System, Lexington, Kentucky. Fifty-six Thoroughbred racehorses were treated surgically for stress fr...
Physeal growth retardation leads to correction of intracarpal angular deviations as well as physeal valgus deformity. Retrospective analysis of the radiographs of horses with carpal valgus, presented to the Iowa State University Veterinary Teaching Hospital from 1987-1996, were used to compare 2 methods of geometric analysis for finding the total angle of deviation. The pivot point angle method and the individual joint angle method were found to be comparable for determining the total angle of deviation. The individual joint angle method was used to analyse individual carpal joint angles and physis angle in joints with carpal valgus, as well as the changes that occurred in response to surgical correction. Mul...
Distribution of fast myosin heavy chain-based muscle fibres in the gluteus medius of untrained horses: mismatch between antigenic and ATPase determinants. The distribution of muscle fibres classified on the basis of their content of different myosin heavy chain (MHC) isoforms was analysed in muscle biopsies from the gluteus medius of adult untrained horses by correlating immunohistochemistry with specific anti-MHC monoclonal antibodies and standard myofibrillar ATPase (mATPase) histochemistry. Percutaneous needle biopsies were taken at 3 depths (20, 40 and 60 mm) from 4 4-y-old Andalusian stallions. The percentage of 'pure' I MHC fibres increased whereas that for pure IIX MHC fibres decreased from the most superficial to the deepest sampling sit...
Dental wear in horses in relation to the microhardness of enamel and dentine. The microhardness of enamel, primary dentine and secondary dentine was determined in the incisor teeth of 39 horses of three different breeds, trotter horses, Belgian draft horses and Arab horses. Using a microhardness tester fitted with a Knoop diamond indenter, the overall Knoop Hardness Number was determined for each tissue, and the influence of breed and age on the hardness were evaluated. Enamel and secondary dentine were significantly harder in Arab horses than in trotters and Belgian draft horses, but there were no significant differences between draft horses and trotter horses in the h...
[Effect of common head gear on horses]. The functions of the most common head-gears for horses are analysed from a biomechanical point of view. With the exception of the stable halter are all of them designed to enlarge the tensile forces transmitted through the reins or the longe, and to concentrate the enlarged forces on sensitive parts of the horse's head: the nose, or the lips, mandible and tongue. Since the direction, duration and size of these tensile forces are the essential factors to modulate signals for controlling the horse, a device has been developed to measure, or at least roughly quantify these forces. The mechanical ...
Lectin histochemistry and identification of O-acetylated sialoderivatives in the horse sublingual gland. This study was aimed at characterizing the glycoconjugates produced by the horse sublingual gland and, in particular, at discriminating between the sialoderivatives by means of differential oxidation and saponification combined with lectin histochemistry and enzymatic degradation. The results showed a predominance of sialoglycoconjugates with beta-galactose as acceptor sugar in the salivary mucins produced by the sublingual gland. Besides being the most represented terminal residue, sialic acid was also expressed in a great variety of derivatives distinguishable on the basis of acceptor sugars...
An immunohistochemical study of interstitial cells of Cajal (ICC) in the equine gastrointestinal tract. The interstitial cells of Cajal (ICC) are c-kit immunoreactive cells of the gastrointestinal tract which are suggested to have a role in the control of intestinal motility. Cells with c-kit immunoreactivity have not been previously described in the gastrointestinal tract of the horse. Immunoreactivity for c-kit was revealed using immunohistochemical labelling with an anti-c-kit polyclonal antibody. Sections of normal gastrointestinal tissue were examined from 13 anatomically defined sites from stomach to small colon taken from horses free from gastrointestinal disease. Three types of c-kit imm...
