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.
Ultrasound-assisted injection of the centrodistal joint in the horse. Injection of the centrodistal (CD) joint in the horse is a commonly performed procedure for both diagnostic and therapeutic purposes. This procedure can be technically challenging, and while radiographic guidance has been previously used, ultrasound localised injection of the CD joint has not been described. Objective: The purpose of this study was to explore the feasibility of using ultrasound localisation to increase the accuracy of CD joint injection. Methods: Experimental method assessment. Methods: One operator performed the ultrasound and injection of 24 CD joints in 12 sedated horses. T...
Lamellar perfusion and energy metabolism in a preferential weight bearing model. Supporting limb laminitis (SLL) is suspected to be caused by lamellar ischaemia as a consequence of increased mechanical load. Objective: Examine the effects of prolonged preferential weight bearing (PWB) on lamellar perfusion and metabolism. Methods: In vivo experiment. Methods: Microdialysis probes were inserted in the lamellar and sublamellar dermis of one forelimb in 13 Standardbred horses. In six horses, a platform shoe (contralateral forelimb) was used to induce increased load on the microdialysis-instrumented forelimb (PWB). The remaining seven horses were controls (CON). All horses wer...
Comparison of histomorphometric characteristics of dorsal colon and pelvic flexure biopsy specimens obtained from horses with large colon volvulus that underwent resection. To determine the degree of histomorphometric damage in dorsal colon and pelvic flexure biopsy specimens (DCBSs and PFBSs, respectively) obtained from horses with large colon volvulus (LCV) and assess the accuracy of predicting short-term outcome for those horses on the basis of DCBS or PFBS characteristics. Methods: 18 horses with ≥ 360° LCV that underwent large colon resection. Methods: During surgery, biopsy specimens from the dorsal colon resection site and the pelvic flexure (when available) were collected from each horse. Interstitial-to-crypt (I:C) ratio (ratio of the lamina propria s...
Computed Tomographic Assessment of Individual Paranasal Sinus Compartment and Nasal Conchal Bulla Involvement in 300 Cases of Equine Sinonasal Disease. Computed tomographic (CT) imaging has allowed new anatomical studies and detailed clinical imaging of the complex, overlapping equine sinonasal structures. Despite the widespread use of CT, no study has specifically identified which compartments are most commonly affected with sinus disorders. CT has also shown the presence of intercurrent, ipsilateral nasal disorders, especially infection of the nasal conchal bullae (NCB) in many cases of sinus disease, but the frequency of intercurrent NCB infections has not been reported. To identify which sinus compartments are most commonly affected in ...
Immunohistochemical analysis of laryngeal muscle of horses clinically affected with recurrent laryngeal neuropathy. As myosin heavy chain (MyHC) profile of muscle fibres is heavily influenced by neural input, changes in MyHC expression are expected in horses clinically affected with recurrent laryngeal neuropathy (RLN) yet, this has not been thoroughly investigated. Objective: To describe the changes in MyHC and fibre diameter in left cricoarytenoideus dorsalis (L-CAD) muscle of horses with clinical signs of RLN. Methods: Observational cohort study. Methods: Immunohistochemistry was used to assess the MyHC-based fibre-type proportion, size and grouping in the L-CAD of 10 Thoroughbred horses, five clinically...
An Unusual Case of Testicular Disorder in Sex Development of Arabian Mare (64,XX SRY-Negative). A 3-year-old Arabian mare underwent medical examinations due to the presence of abnormalities of the reproductive apparatus and stallion behavior (nervous temperament, aggressiveness, masculine attitude). During the clinical visit, an anovulvar distance shorter than normal was observed; moreover, vulvar lips were dorsally fused except for the lower neckline, showing a blind ending from which a penis-like structure protruded. The ultrasound examination revealed the presence of a cervix and corpus of a uterus, hypoplastic uterine horns, and small gonads with an echogenicity similar to a testis. ...
Diagnostic needle arthroscopy of the scapulohumeral joint in standing sedated horses. To describe the technique to perform diagnostic standing scapulohumeral joint needle arthroscopy with a 1.2-mm-diameter arthroscope in horses. Methods: Experimental study. Methods: Eight thoracic limbs in phase 1 and six horses in phase 2. Methods: In phase 1, the feasibility of the technique was evaluated by using a craniolateral arthroscopic approach. An evaluation of the visible structures of the scapulohumeral joint was performed with both a needle arthroscope and a 4-mm-diameter arthroscope. In phase 2, the technique was performed in six healthy sedated horses to validate the technique in...
Radiographic parameters of the digit in a cohort population of Amiata donkeys. The most common musculoskeletal conditions reported in donkeys are related to the foot. Radiographic examinations are clinically important in the diagnosis of foot abnormalities and are commonly used. However, few studies have been conducted to establish the normal radiographic appearance of a donkey's foot. To determine the radiographic features of the front digit in healthy Amiata donkeys. Radiographic examinations were performed on 56 forefeet of 28 Amiata donkeys. Three radiographic views of each front foot were taken: lateromedial, dorsopalmar and dorso-65°proximal/palmarodistal oblique....
Primary Hyperparathyroidism in a Quarter Horse Mare Associated With a Chief Cell Adenoma. Primary hyperparathyroidism is rare in large animal species, and little is known regarding its pathophysiology, endocrine and electrolyte derangements, diagnosis, medical management, and prognosis. This report describes the clinicopathologic diagnosis of a parathyroid (PT) gland chief cell adenoma in a 12-year-old Quarter Horse mare, including PT hormone (PTH) and electrolyte disarrangements associated with the neoplasia, the surgical removal of the adenoma, and medical management of the case. This report also describes for the first time the use PTH immunohistochemistry to confirm the nature ...
Equine Sinus Surgery. The anatomy of the equine paranasal sinuses is critical to understand to assess the extent of the disease process, the optimal surgical approach, and the ability to drain through the normal nasomaxillary pathway. By following established anatomic landmarks, direct sinus access can be used to further explore the sinus compartments, remove compromised cheek teeth, remove any purulent debris or feed contamination, and establish drainage. Many complications can be avoided or minimized by thoroughly evaluating all sinus compartments and critically assessing the ability of the sinus to drain.
Dental Radiography and Radiographic Signs of Equine Dental Disease. Radiography is an important imaging modality and is available to most equine veterinarians providing primary care. Diagnostic radiographic imaging of the equine skull and dentition requires careful positioning and technique. This article is aimed at providing the veterinarian with instructions and guidelines for obtaining diagnostic skull and dental radiographs and a discussion of the radiographic signs of dental disease with case-based examples. The limitations of radiography are discussed with regard to determining the need for adjunct diagnostic techniques and more advanced imaging techniqu...
Arthroscopic removal of a solitary osteochondroma interfering with the podotrochlear apparatus in a foal. To report the diagnostics, surgical treatment, and outcome of a juvenile foal with solitary osteochondroma (SO) interfering with the podotrochlear apparatus. Methods: Case report ANIMAL: One 36-day-old Arabian colt. Methods: Clinical, radiographic, ultrasonographic, computed tomographic, and histopathologic examinations were required to characterize and treat an SO located at the palmar aspect of the diaphysis of the second phalanx of the left forelimb. This SO caused severe distal interphalangeal joint (DIPJ) inflammation, marked interference with the podotrochlear apparatus, and associated l...
Equine Oral Endoscopy. Oral endoscopy is a valuable addition to the equine dental examination process. It enables veterinarians to visualize subtle oral disorders and is a useful client education tool. There are several commercially available oral endoscopic systems on the market. Practitioners can also assemble their own systems. An oral endoscope is used to perform a thorough and systematic oral examination and to visualize normal oral structures as well as oral disorders. It is also used to guide instrument placement during oral surgeries and other dental procedures.
Adjunct Extraction Techniques in Equine Dentistry. Adjunct extraction techniques are used when the shape or integrity of the tooth, the shape or size of the patient's oral cavity, the location of the tooth, or the location of the proximal teeth prevents or complicates standard oral extraction. Techniques described and discussed include partial coronectomy, tooth sectioning, minimally invasive buccotomy, transbuccal screw extraction, and commissurotomy.
Equine Imaging: Computed Tomography Interpretation. Computed tomography (CT) has revolutionized the veterinarian's ability to image the equine skull and led to improved diagnostic accuracy and clarity for surgical planning. The increased cost for this evaluation is offset by more accurate diagnosis and targeted therapy. As novel technology is developed that allows for increased availability of equine head, the price will continue to decrease and more examinations will be performed. New skills are needed for the veterinarian to accurately interpret this modality. This article reviews the normal CT appearance of the equine skull and presents exam...
Equine Nasal Endoscopy: Treating Bullae Disease and Sinus Disease. The nasal conchal bullae (dorsal and ventral) are separate, air-filled structures within their respective dorsal and ventral nasal conchae. Computed tomography scans have assisted with the increasing diagnosis of empyema of the nasal conchae. This condition is usually associated with dental or sinus disease. Drainage of affected bullae is considered critical for resolution of clinical signs. The ventral conchal bullae can be easily viewed with a standard 10 mm diameter flexible endoscopy via the middle nasal meatus. This approach can also be used for fenestration of the bullae, using a diode ...
Equine Dental Floating (Crown Osontoplasty). Odontoplasty (floating and occlusal equilibration) is the most commonly performed procedure in equine dentistry. From an anatomic perspective, an irregular occlusal surface, prominent cingula, transverse ridges, and enamel points all contribute to the function, form, and longevity of the equine cheek tooth. With limited reserve crown available and an average functional life range between 18 and 25 years, removal of tooth structure should be conservative. The authors consider a quality oral examination to be the most important dental procedure performed in the horse. Individual tooth evaluatio...
Cervical disc width index is a reliable parameter and consistent in young growing Dutch Warmblood horses. Intervertebral disc disease, as well as the associated alteration of the radiographic intervertebral disc space width, has been reported in horses. Disc height index (DHI) has proven to be an accurate and objective parameter in other species but data related to this parameter are lacking in horses. Therefore, the aims of this retrospective longitudinal diagnostic accuracy study were (a) to evaluate the reliability of measurements within and between observers of the equine Disc Width Index (EDWI) as a parameter for radiographic equine cervical intervertebral disc space width, and (b) to evaluat...
Horse welfare at slaughter: A novel approach to analyse bruised carcasses based on severity, damage patterns and their association with pre-slaughter risk factors. The study presents a novel veterinary forensic approach to analyse the bruising of horse carcasses, based on the nature of the bruises and how they are grouped in certain anatomical areas. Data on pre-slaughter logistics was obtained for 113 journeys with horses that travelled from Mexico and the USA to a Mexican abattoir. We found that carcass bruising was a highly prevalent problem (79% of carcasses had bruising) and was especially problematic in journeys lasting longer than 12 h, independently of the animal's country of origin, sex, age, lairage time or vehicle type. Multivariable logistic...
Ultrasonographic evaluation of the width, thickness, and length of the normal linea alba in standing and dorsal recumbent horses. To determine the variability in length, width, and thickness of the equine linea alba (LA) and the effect of a standing vs dorsal recumbent position on these measurements. Methods: Descriptive anatomical comparative study. Methods: Standing horses (N = 75; in 30 horses, measurements were obtained in dorsal recumbency first and repeated after horses were standing). Methods: Linea alba length was measured in standing position from xiphoid to umbilicus, and transverse ultrasonographic images were obtained at five reference points to measure LA width and thickness. In 30 horses, measurements were ...
Furosemide administration onehour before bone scintigraphy examination in horses does not improve the image quality or reduce the radiation dose rate. This prospective, cross-sectional, pilot study aimed to investigate the effects of furosemide as a diuretic on the image quality of bone scintigraphy performed using Tc-HDP and to investigate the impact of furosemide on the radiation dose rate. Thirty-one horses undergoing bone scintigraphy were included. The horses were divided into the control (n = 14) and furosemide group (n = 17), which received 1 mg/kg furosemide intravenously 1 h post Tc-HDP administration. The image quality was assessed subjectively and semi-quantitatively. The bone-to-soft tissue (B:S) ratio was calculated from...
Evaluation of the effects of medial saphenous venous pressures as an indirect method of measurement of intra-abdominal pressures in the horse. To evaluate the effect of changes in intra-abdominal pressure (IAP) on medial saphenous venous pressure (MSVP) and hemodynamics in normal horses. Methods: Experimental, in-vivo study. Methods: University Teaching Hospital. Methods: Convenience sample of 7 mixed breed horses; 5 geldings, and 2 mares. Methods: Pneumoperitoneum was induced in horses under standing sedation with carbon dioxide gas using a laparoscopic insufflator for a total of 60 minutes to simulate clinical elevation in IAP. Pressure was increased stepwise to 20 mm Hg over 30 minutes, and maintained at that pressure for 30 minu...
Radiographic findings and anatomical variations of the caudal cervical area in horses with neck pain and ataxia: case-control study on 116 horses. Abnormalities of the ventral lamina of the sixth cervical vertebra (AVL-C6) are thought to exert abnormal stress on the articular process joints (APJs) of the cervicothoracic junction. The aim of the study was to investigate the association between AVL-C6 and radiographic findings in the caudal cervical area and between clinical signs of neck pain and ataxia and radiographic findings. Methods: Medical records of horses subjected to cervical radiography were reviewed. Horses were classified into those with neck pain (group C), those with ataxia (group A) and healthy horses (group H). Presence o...
Influence of abdominal elevation on radiographic measurements of the thoracolumbar interspinous spaces in asymptomatic horses. The objective of this study was to determine if abdominal elevation could induce radiographically visible widening of the interspinous spaces in the thoracolumbar region of standing sedated horses and facilitate the surgical approach to the region. Radiographs centered on T13 and T18 were taken while applying different degrees of tension on a wide strap placed under the abdomen of 7 healthy horses. Then, the interspinous spaces between T11 and L2 were measured following a standardized method. The interspinous spaces widen radiographically between T11 to L2, except for T18-L1. Thus, the reporte...
Ultrasonographic measurement of the adrenal gland in neonatal foals: reliability of the technique and assessment of variation in healthy foals during the first five days of life. Adrenal gland ultrasonographic measurements are useful in clinical evaluation of patients with adrenal dysfunction in several species. In human healthy neonates, the ultrasonographic size of the adrenal glands decreases during the first days of life. Ultrasonography of adrenal glands was demonstrated to be feasible in neonatal foals. The aims of this study were to describe a technique for ultrasonographic measurement of adrenal gland size to test its reliability in neonatal foals, and to assess any variation of ultrasonographic measurements during the first five days of life in healthy foals. ...
Integrin alpha-v/beta3 expression in equine lungs and jejunum. Integrin alpha-v/beta3 (αvβ3) recognizes arginine-glycine-aspartic acid (RGD) sequences and has important functions in cell adhesion, signaling, and survival. However, the expression of integrin αvβ3 in the equine lungs and jejunum is not well understood. The objective of this study was to explore the hitherto unknown expression of integrin αvβ3 in the lungs and jejuna of the horse using light and electron immunocytochemistry. Immunohistochemistry showed integrin αvβ3 on the epithelium, the immune cells in Peyer's patches, the smooth muscle, and the endothelium of equine jejuna. In equ...
Macroscopic and Histological Morphology of the Equine Digital Cushion and Its Association with Subcutaneous Fat Thickness. This study evaluated the influence of the Body Condition Score (BCS) and subcutaneous fat thickness on the tissue composition of the digital cushion in horses. Sixty mixed breeds of Criollo horses (21 males and 39 females) were sent for slaughter. All animals were submitted to BCS analysis, through visual antemortem evaluation, and then ultrasound evaluation to estimate the subcutaneous fat thickness. Macroscopic analyses of the thoracic and a pelvic limb (weight, volume, and density of the hooves and digital cushions) were performed. In addition, measurements of the area of internal structure...
Morphological variations of the conduction system in the atrioventricular zone and its clinical relationship in different species. Atrioventricular node is responsible for delaying the passage of the electrical impulse to ventricles in order to protect them from fast depolarizations coming from the atria. The importance of this study is to identify the morphological variations of the components of atrioventricular zone that affect the conduction system and its clinical relationship in different species of mammals. We analyzed ten human hearts, nine from horses, eight from pigs, and five from dogs without a clinical history of cardiac pathologies. Histological section thickness of 5 μm were obtained with a microtome and ...
Functional Electrical Stimulation (FES) and the Effect on Equine Multifidi Asymmetry. Asymmetry of the multifidi has been correlated with scoliosis and back pain in humans and has been investigated as a factor in equine back pain as well. The purpose of this study was to determine if FES would affect the symmetry of equine thoracolumbar multifidi when compared to controls. Twelve horses received 24 FES treatments bilaterally over the thoracolumbar region for 8 weeks. Twelve additional control horses received no FES treatments. Ultrasonographic measurements of the cross-sectional area (CSA) of the multifidi of the treatment horses at seven thoracolumbar levels were compared to ...
Attenuation From Shoes and Pads in Equine Nuclear Scintigraphy, With Relevance to Solar Views. Nuclear scintigraphy can be beneficial in the investigation of equine lameness and poor performance. Images obtained through the sole allow for better identification of a region of increased radionuclide uptake in the foot. The presence of shoes or pads may affect these images. To determine the degree of radioactive attenuation different types of shoes and pads of different thickness and materials were evaluated by placing the material directly on the gamma camera detector acquiring flood images from a point source. The study compared five different types of shoes from 3 different shoeing mate...