Morphology in horses refers to the study of the form and structure of the equine body, including the skeletal, muscular, and integumentary systems. This field encompasses the examination of physical characteristics such as body conformation, limb structure, and cranial features, which can influence a horse's performance, health, and suitability for various activities or disciplines. Morphological assessments are often used in breeding programs to select for desirable traits and in veterinary evaluations to identify potential anatomical issues. This page aggregates peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of morphological studies in equine science.
Vincelette AR, Renders E, Scott KM, Falkingham PL, Janis CM.The traditional story of the evolution of the horse (family Equidae) has been in large part about the evolution of their feet. How did modern horses come to have a single toe (digit III), with the hoof bearing a characteristic V-shaped keratinous frog on the sole, and what happened to the other digits? While it has long been known that the proximal portions of digits II and IV are retained as the splint bones, a recent hypothesis suggested that the distal portion of these digits have also been retained as part of the frog, drawing upon the famous Laetoli footprints of the tridactyl (three-toed...
Erasha AM, Nazih M, Ali S, Alsafy M, El-Gendy S, Sayed RKA.A significant extent of researches in veterinary study have been focused on dental structure; however, there are scanty ones on the orientation and identification of their cusps. Therefore, the present article aimed to spot a light on arrangement pattern of dental cusps in the camel as a folivorous and graminivorous animal. This study was conducted on eight heads of adult, healthy camel of both sexes, collected from slaughter houses. To perform exact orientation of cusps of molar teeth, additional radiological and CT scans were performed on the mandible as a landmark that should facilitate the...
Zhou M, Lu Y, Han L, Lu M, Guan C, Yu J, Liu H, Chen D, Li H, Yang Y, Zhang L, Tian L, Liu Q, Hou Z.The roundworms, Parascaris spp., are important nematode parasites of foals and were historically model organisms in the field of cell biology, leading to many important discoveries. According to karyotype, ascarids in Equus are commonly divided into Parascaris univalens (2n = 2) and Parascaris equorum (2n = 4). Methods: Here, we performed morphological identification, karyotyping and sequencing of roundworms from three different hosts (horses, zebras and donkeys). Phylogenetic analysis was performed to study the divergence of these ascarids based on cytochrome c oxidase subunit I (COI)...
Malacarne BD, Martins RR, Paz CFR, Alves JVA, Dias LA, Cavalcante MA, Santos AM, Silva AGM, Leise BS, Carvalho AM, Faleiros RR.Although the external conformation of wild horse hooves has been proposed as an ideal model for domesticated modern horses, histological signs of laminitis have been reported among them. With the hypothesis that the lamellar tissue of horses of Iberian origin raised in semi-feral is healthier than those raised in an intensive management system (stall confinement and high-calorie diet intake), the objective was to compare their lamellar tissues. Lamellar tissue samples were taken from the forelimb hoof of eight domesticated Mangalarga Marchador (MM) horses and from six semi-feral Marajoara (MJ)...
May-Davis S, Hunter R, White R.In this study, we examined the ventral process of C6 in extinct and extant (sister taxa to only) with the purpose of describing normal morphology and identifying anomalous variations relevant to recent studies describing a congenital malformation in . Overall, 83 specimens from 9 museums and 3 research/educational facilities were examined, totalling 71 extinct specimens from 12 species and 12 extant specimens from 5 species. The lateral view revealed that a large convexity exists in the ventral process between the cranial ventral tubercle (CrVT) and the caudal ventral tubercle (CVT) in the e...
Bastos MS, Solar Diaz IDP, Alves JS, de Oliveira LSM, de Araújo de Oliveira CA, de Godói FN, de Camargo GMF, Costa RB.The measurement of morphometric traits in horses is important for determining breed qualification and is one of the main selection criteria for the species. The development of an index (HPC) that consists of principal components weighted by additive genetic values allows to explore the most relevant relationships using a reduced number of variables that explain the greatest amount of variation in the data. Genome-wide association studies (GWAS) using HPC are a relatively new approach that permits to identify regions related to a set of traits. The aim of this study was to perform GWAS using HP...
Kalmykov NP.Morphological features of the teeth were studied in the three-toed horse Hipparion tchicoicum from the Pliocene of Western Transbaikalia (Russia). Several diagnostic signs of the Chicoi hipparion were described for the first time to provide criteria for distinguishing the taxon among other fossils of three-toed horses and estimating their real diversity at the final stage of their distribution in Inner Asia.
Kawahisa-Piquini G, Bass L, Pezzanite LM, Moorman VJ.The role of hoof morphology is increasingly recognized as a factor associated with lameness incidence in performance horses. The primary objective was to evaluate effect of training initiation on hoof unevenness in Quarter Horses (n = 42; 29 2-year-olds, 13 3-year-olds) over 6-months (m) in training (m0, m2, m4, and m6). Horses were objectively assessed for lameness (inertial sensor system) and photographs and radiographs of feet were taken. Hoof measurements were taken (palmar/plantar angles, frog base width/length, toe length/angle, heel length/angle, heel/foot width, wall height/angle), a...
Salamanca-Carreño A, Parés-Casanova PM, Crosby-Granados RA, Vélez-Terranova M, Bentez-Molano J.The skull is divided into neurocranium and splanchnocranium, and its variation allows ecomorphological studies to learn about possible evolutionary and adaptive characteristics. The basicranial organization of the neurocranium and splanchnocranium modules was studied in a sample of 31 skulls from adult Araucanian horses by means of 2D geometric morphometric techniques. The neurocranium and splanchnocranium modules on the ventral aspect were analyzed separately using a set of 31 landmarks. The RV coefficient (the multivariate analog of a correlation) was estimated to analyze the independence of...
Pompermayer E, Hoey S, Ryan J, David F, Johnson JP.The objective of this study was to compare the skull morphology of the Straight Egyptian Arabian (SEAR) to the Thoroughbred (TB), using computed tomography (CT) in the context of surgical procedures commonly performed on the equine head. Methods: Measurements relating to surgical considerations of the equine head were taken from 29 clinically normal adult horses (15 SEAR, 14 TB). Methods: A clinical prospective study. Standing skull CTs were performed. Fourteen gross and 10 CT measurements were taken. Results: Several variables showed a significant difference between groups, in all cases great...
Hernández-Avilés C, Ramírez-Agámez L, Pearson M, Beckham AMN, Varner DD, Love CC.Analysis of sperm morphology is an important part of the stallion breeding soundness evaluation since it provides an objective measure of a stallion's sperm quality and is one of many factors that estimate a stallion's fertility potential. To describe the effect of sperm quality level on the technique (Differential Interference Contrast - DIC; Phase-contrast - PH; Dip-Quick staining - DQ; and eosin-nigrosin staining - EN; semen samples fixed in buffered-formal saline) and evaluator (three evaluators; using only DIC), stallions were categorized based on sperm quality into three categories: High...
Poth MKM, McKemie DS, Traynham M, Kass PH, Knych HK.The metabolism and pharmacokinetics of intravenous (i.v.) morphine in the horse have been described; however, administration of therapeutic doses has also been associated with neuroexcitation and adverse gastrointestinal effects. In this study, we hypothesized that oral administration would lead to comparable concentrations of morphine and its presumed active metabolite, morphine 6-glucuronide (M6G) without the adverse effects associated with i.v. administration. Eight horses were administered a single i.v. dose of 0.2 mg/kg morphine and oral doses of 0.2, 0.6, and 0.8 mg/kg of morphine in a...
Clauss M, Codron D, Hummel J.Like other members of the odd-toed ungulates (the perissodactyls), equids once had a higher species diversity in the fossil record than they have today. This is generally explained in comparison to the enormous diversity of bovid ruminants. Theories on putative competitive disadvantages of equids include the use of a single toe as opposed to two toes per leg, the lack of a specific brain cooling (and hence water-saving) mechanism, longer gestation periods that delay reproductive output, and in particular digestive physiology. To date, there is no empirical support for the theory that equids fa...
Klecel W, Drobik-Czwarno W, Martyniuk E.Arabian show horses are well known for their exceptional beauty and elegance. The breed type, body conformation and movement are assessed during horse shows by licensed judges. The 5 judging categories are type, head and neck, body and topline, legs and movement, which are scored on a 20 point scale. It can be hypothesized that the scores in different categories are related to each other, and that the score for the most subjective type category depends on the scores for conformation categories. We analyzed 762 sets of average scores obtained by 583 unique horses at the World Championships. Cor...
Lewis N, Canesin H, Choi YH, Foss R, Felix M, Rader K, Hinrichs K.Information on factors associated with developmental competence of equine in vitro -produced (IVP) blastocysts is lacking. Objective: To determine the relationships of stage, grade, day of development, and specific morphological parameters of equine IVP blastocysts, to pregnancy and foaling rates. Methods: Photomicrographs of 316 IVP embryos with known pregnancy outcomes were scrutinised individually by four observers. Inter-observer variation was assessed, and pregnancy outcome evaluated in relation to day of blastocyst development and assigned grade and stage. Individual component analysis w...
Smith S, Yohe LR, Solounias N.It has been recognized as early as the Victorian era that the apex of the distal phalanx has a distinct embryological development from the main shaft of the distal phalanx. Recent studies in regenerative medicine have placed an emphasis on the role of the apex of the distal phalanx in bone regrowth. Despite knowledge about the unique aspects of the distal phalanx, all phalanges are often treated as equivalent. Our morphological study reiterates and highlights the special anatomical and embryological properties of the apex of the distal phalanx, and names the apex "the bony cap" to distinguish ...
Kawahisa-Piquini G, Bass LD, Pezzanite LM, Moorman VJ.Lameness, discipline, training intensity, environmental variability, and shoeing are all factors demonstrated to affect hoof loading and therefore act as adaptive stimuli to alter hoof morphology. Objective: To evaluate the effect of age at training initiation on hoof morphology and lameness incidence and determine if specific hoof morphology measurements correlate with lameness in juvenile American Quarter Horses. Methods: Prospective cohort study. Methods: American Quarter Horses (n = 42; 29 two-year-olds, 13 three-year-olds) entering training were monitored for hoof morphology and lamenes...
Poradowski D, Chrószcz A.The study consisted of the immunohistochemical analysis of fundic and pyloric mucosa in the equine stomach between the 4th and 11th month of gestation. The accessible material was classified into three age groups using the CRL method. The adult reference group was used to define potential differences between foetal and adult populations of gastric APUD cells. The samples were preserved, prepared, and stained according to the standard protocols. The immunohistochemical reaction was assessed using the semi-quantitative IRS method. The results were documented and statistically analysed. The most ...
Ibrahim M.Rhinoestrus species larvae are considered obligatory parasites of the nasal cavities of equine. This type of myiasis is characterised by sneezing, coughing, olfactory nerve damage and encephalomyelitis. Also, it has a zoonotic importance as the larvae might cause ophthalmomyiasis and conjunctivitis in human. While few studies describing R. purpureus adult fly antennal sensillae are available, the R. usbekistanicus antennal sensillae have never been described. Also, scanty data are available on the adult flies of Rhinoestrus species morphology. For this reason, the current study aimed at identi...
Maney JK, Dzikiti BT, Escobar A, Knych HK, Bennett RC.Morphine is the prototypical μ-opioid receptor agonist used to provide analgesia in veterinary species. Its effects are well-described in horses but not donkeys. Objective: To determine the antinociceptive effects of two doses of morphine in donkeys. To describe preliminary pharmacokinetic parameters of morphine in donkeys. Methods: In vivo experiment. Methods: Eight adult castrated male donkeys were given intravenous (IV) 0.9% saline, morphine 0.1 mg/kg bwt (LDM), or morphine 0.5 mg/kg bwt (HDM) in a randomised order with a minimum 1-week washout period. Mechanical nociceptive thresholds (...
Belyaev RI, Kuznetsov AN, Prilepskaya NE.The vertebral column is a hallmark of vertebrates; it is the structural basis of their body and the locomotor apparatus in particular. Locomotion of any vertebrate animal in its typical habitat is directly associated with functional adaptations of its vertebrae. This study is the first large-scale analysis of mobility throughout the presacral region of the vertebral column covering a majority of extant odd-toed ungulates from 6 genera and 15 species. In this study, we used a previously developed osteometry-based method to calculate available range of motion. We quantified all three directions ...
Strootmann T, Spitzbarth I, Della Tommasa S, Brehm W, Köller G, Troillet A.Research and provision of data on macrophages by cytological synovial fluid analysis and light microscopy in horses with septic arthritis MATERIAL AND METHODS: Records of 167 synovial fluid samples were evaluated and subdivided into different groups: (1) non-septic, (2) haematogenous septic arthritis in foals and (3) traumatic/iatrogenic septic arthritis. The effect of joint lavage on synovial fluid cytology and on the occurrence of macrophage phenotypes was investigated. Results: Regardless of aetiology and age of the horse, macrophage concentrations in synovial sepsis are decreased to a medi...
Amer MM, Desouky AY, Helmy NM, Abdou AM, Sorour SS.Strongylid and non-strongylid nematodes are one of the most important parasites infecting equines. The traditional method to identify these nematodes is through coproscopy and fecal culture. Because of the scarcity of data published in Egypt discussing the morphometric features of infective 3 larvae of these nematodes, this study aims to provide a morphometric key for L3 of common strongylid and non-strongylid nematodes infecting Egyptian equines. For this reason, we cultured fecal samples containing GINs eggs and 3 larval stages were identified based on their morphology (i.e., shape and numbe...
Salamanca-Carreño A, Parés-Casanova PM, Monroy-Ochoa NI, Vélez-Terranova M.This study examined paedomorphosis in PAH and F1 crossbreds. A sample of 99 horses was selected from 40 different breeders and consisted of three groups: stallions ( = 16), mares ( = 53), and geldings ( = 30), ranging from 10 months to 27 years in age. All horses presented a concave celloid lateral left head profile in the acquired photographic images. The hypothesis proposed in this study suggested the lateral profile of the head in juveniles was representational in the adult form due to the neonate's facial bones (part of the splanchnocranium) developing at a different rate to those of the s...
Cotuțiu VD, Ionică AM, Lefkaditis M, Cazan CD, Hașaș AD, Mihalca AD.Equine thelaziosis is a neglected vector-borne parasitic disease in modern veterinary medicine, lacking recent reports. It is transmitted by Musca autumnalis, and potentially other Muscidae species, by ingesting the lachrymal secretions of its equine host. The distribution of both Thelazia lacrymalis and its intermediate hosts remains largely unknown throughout Europe, with most studies dating back 20 years. The aim of this study was to assess the presence, prevalence and distribution of T. lacrymalis in horses from Romania. Methods: The eyes of 273 horses, slaughtered at two abattoirs from t...
Hobbs SJ, Curtis S, Martin J, Sinclair J, Clayton HM.Conformation of the hooves and distal limbs of foals and factors influencing their morphological development have not been reported in detail for the Thoroughbred breed. In this paper we explore morphogenesis of the equine distal limb in Thoroughbred foals with emphasis on adaptations in response to weight bearing early in life that prepare the foal for an athletic career. Novel data from four studies are presented chronologically during key time periods to illustrate specific aspects of distal limb growth and adaptation. Dorsal epidermal thickness increased from 2.84 ± 0.41 mm in utero to 4....
Poradowski D, Chrószcz A.Histological and morphometrical analysis of the stomach wall was performed during the foetal period divided into three age groups (4th-11th month of gestation). The material was taken from non-glandular (the blind ventricular sac) and glandular parts (the plicated edge margin/cardiac part, the body of stomach and the pyloric part) of the stomach. It was preserved and prepared according to the standard protocol. The histological slides were stained (H-E, Masson-Goldner and PAS). The analyses were performed using the light microscope. All measurements were statistically elaborated. The crown-rum...
Ammann L, Ohlerth S, Fürst AE, Jackson MA.To determine morphological characteristics of subchondral cystic lesions (SCLs) in the proximal phalanx (PP) of adult horses. Methods: Radiographs and/or CT scans of PP from 46 horses. Methods: There were horses with a SCL in PP, which was diagnosed by radiography and/or computed tomography, included. Additional data (signalment, history, orthopedic examination) were collected retrospectively for each case. Results: Forty-six horses met the required inclusion criteria, with a total of 62 SCLs. Forty-three SCLs (70.5%) were located in the proximal PP (group A). Forty-four percent of these were ...
Roßgardt J, Heilen LB, Büttner K, Dern-Wieloch J, Vogelsberg J, Staszyk C.In the crown pulp of brachydont teeth, a cell-free and a cell-rich zone are established beneath the odontoblastic layer, indicating a mature status. For the equine dental pulp, there are no descriptions which allow for a comparative analysis with regard to functional requirements in terms of lifelong secondary dentin production to compensate for occlusal wear. For histomorphological and immunohistological investigations, ten incisors and ten check teeth were used from seven adult horses and five foals. In the periphery of the equine dental pulp, a constant predentin and odontoblastic cell laye...
Poradowski D, Chrószcz A.Studies of equine stomach prenatal development are very rare, and descriptions usually focus on the processes taking place in the embryonic period. Only general information about gastric organogenesis in the fetal period is available in embryology textbooks on domestic mammals. The material for our study included twenty half-breed horse fetuses divided into three age groups on the basis of known fetal age (verified using the CRL method). Our study consists of the topographical, morphological, and morphometrical description of stomach development between the 4th and 11th months of gestation. Ev...
Todhunter PG, Kincaid SA, Todhunter RJ, Kammermann JR, Johnstone B, Baird AN, Hanson RR, Wright JM, Lin HC, Purohit RC.To use lipopolysaccharide (LPS) to create synovitis in the midcarpal joint of ponies, and to assess the morphologic, histochemical, and immunohistochemical effects of synovitis on articular cartilage of the third carpal bone. Methods: 2- to 3-year-old ponies, 6 control (group 1) and 6 treated (group 2). Methods: Synovitis was induced in 1 midcarpal joint of group-2 ponies by intra-articular injections of LPS (0.02 micrograms/kg of body weight), morphine (0.1 mg/kg), and saline solution (group 2a) and a morphine and saline solution alone in the contralateral midcarpal joint (group 2b). Articula...
Dall'Olio S, Fontanesi L, Nanni Costa L, Tassinari M, Minieri L, Falaschini A.Myostatin (MSTN) is a negative modulator of muscle mass. We characterized the horse (Equus caballus) MSTN gene and identified and analysed single nucleotide polymorphisms (SNPs) in breeds of different morphological types. Sequencing of coding, untranslated, intronic, and regulatory regions of MSTN gene in 12 horses from 10 breeds revealed seven SNPs: two in the promoter, four in intron 1, and one in intron 2. The SNPs of the promoter (GQ183900:g.26T>C and GQ183900:g.156T>C, the latter located within a conserved TATA-box like motif) were screened in 396 horses from 16 breeds. The g.26C an...
Kaiser TM, Fortelius M.A new approach of reconstructing ungulate diet, the mesowear method, was recently introduced by Fortelius and Solounias ([2000] Am Mus Novitat 3301:1-36). Mesowear is based on facet development on the occlusal surfaces of the teeth. Restricting mesowear investigation to maxillary cheek teeth would allow mesowear investigation only in assemblages of large numbers of individuals and therefore would generally restrict this method to relatively few assemblages of recent and fossil ungulates. Most of the fossil, subfossil, and recent ungulate osteological assemblages that may be assigned to a singl...
Hung GC, Chilton NB, Beveridge I, Gasser RB.In this study, molecular data sets were used to address the controversies relating to the systematics of strongyloid nematodes of equids utilising morphological data sets. DNA sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of ribosomal DNA were determined for 30 species of equine strongyles and the systematic relationships reconstructed using phenetic and phylogenetic tree-building methods. The molecular data provided support for the hypothesis that the genera with large subglobular buccal capsules are ancestral to those with small cylindrical buccal capsules,...
Williams IF, McCullagh KG, Goodship AE, Silver IA.The histological and morphological characteristics of the scar tissue formed during healing after traumatic equine tendon injury have been compared with those of scar tissue produced in response to an enzyme-induced pony tendon injury. Several techniques are currently in use in the treatment of equine tendon sprain and this work formed part of a study of their respective efficacy. It was concluded that the enzyme-induced lesion is resolved by a reparative process very similar in its prognosis and extent to that following a naturally occurring tendon sprain. It may therefore justifiably be used...
Chaichanasiriwithaya W, Rikihisa Y, Yamamoto S, Reed S, Crawford TB, Perryman LE, Palmer GH.Ehrlichia risticii causes an acute infectious disease in horses called Potomac horse fever. To investigate the biological diversity of E. risticii organisms, nine E. risticii isolates derived from the peripheral blood monocytes of clinically sick horses in Ohio and Kentucky during the summers of 1991 and 1993 were compared with Illinois and Virginia isolates originally obtained from horses in Maryland in 1984. Seven of the nine isolates (081, 606, 380, 679, As, Co, and Ov) formed large morulae (tightly packed inclusions of ehrlichial organisms). The remaining isolates, including 1984 isolates,...
Morrell JM, Johannisson A, Dalin AM, Rodriguez-Martinez H.The objective was to investigate whether it is possible to improve the quality of stallion semen, with respect to sperm morphology and chromatin integrity, both of which have been linked to fertility, using either density gradient centrifugation (DGC) or a new method, hereby named single layer centrifugation (SLC). The two methods of colloidal centrifugation were evaluated using 38 ejaculates from 10 stallions. Sperm morphology, subjective motility and sperm chromatin integrity were compared in uncentrifuged samples and in centrifuged sperm preparations. The proportion of morphologically norma...
Ekman S, Carlson CS.Osteochondrosis is a disorder of epiphyseal cartilage about which there is considerable confusion in the literature. We believe that this is due to the fact that osteochondrosis has been studied in the chronic stage when the lesions are morphologically complicated and the initial causative insult is impossible to determine. The etiology of osteochondrosis appears to be multifactorial, with trauma, hereditary factors and rapid growth, nutritional factors, and ischemia all having a role in its pathogenesis. Although predilection sites are variable among species, the morphology of the early lesio...
Okely M, Anan R, Gad-Allah S, Samy AM.Ticks are important vectors of emerging health problems in humans and animals. We conducted several field surveillances to investigate the fauna of hard ticks on domestic animals in seven governorates of Egypt during 2018-2019. A total of 3265 individual tick specimens were collected and identified to the species level; the specimens belong to 11 species within three genera (Amblyomma, Hyalomma, and Rhipicephalus). Tick infestation was highest in dromedary camels (70%), followed by dogs (52.5%), cattle (50%), buffaloes (38%), and horses (12%). Ten species were collected from dromedary camels, ...
Reznik GK.The anatomical characteristics of the upper respiratory tract of various experimental animals and man are described. There are a number of differences and similarities macroscopically and microscopically between the species. Perhaps one of the most obvious examples of anatomical differences is in the structure of the turbinates. Some of the differences could affect deposition and clearance of particles in the nasal cavities. Effects of compounds in the nasal cavity, larynx, and trachea can differ depending on the cellular composition of the mucosa.
Patterson-Kane JC, Parry DA, Birch HL, Goodship AE, Firth EC.The superficial digital flexor tendon is the most commonly injured tendon in the racing Thoroughbred. Despite the clinical significance of this structure, only limited data exist regarding normal age-related morphology of the tensile units, the collagen fibrils. The age at which these collagen fibrils become mature in composition and structure may be of importance. Consequently, the association of age and collagen fibril crosslink composition, diameter distribution and crimp morphology in the superficial and deep digital flexor tendons of Thoroughbreds up to and including three years of age ha...
Fureix C, Hausberger M, Seneque E, Morisset S, Baylac M, Cornette R, Biquand V, Deleporte P.Describing postures has always been a central concern when studying behaviour. However, attempts to compare postures objectively at phylogenetical, populational, inter- or intra-individual levels generally either rely upon a few key elements or remain highly subjective. Here, we propose a novel approach, based on well-established geometric morphometrics, to describe and to analyse postures globally (i.e. considering the animal's body posture in its entirety rather than focusing only on a few salient elements, such as head or tail position). Geometric morphometrics is concerned with describing ...
Smith JE, Mohandas N, Shohet SB.Deformability is an important aspect of erythrocyte physiology and has been extensively studied using human red cells. We have studied erythrocytes from 25 different animals using a viscometric technique. Erythrocyte diameters ranged from 3.3 microns in the goat to 11.4 microns for the elephant seal. Erythrocytes from most species deformed readily when a fluid shear stress was applied. A deformability index of the stressed cell defined as (length - width)/(length + width) correlated with cell size. The erythrocytes of four animals (pygmy goat, goat, Batanga horse, and miniature horse) deformed...
Wilsman NJ, Farnum CE, Reed-Aksamit DK.The incidence and structure of equine and murine chondrocytic cilia were studied using serial sections and transmission electron microscopy. Overall, 96% of all equine chondrocytes and 100% of all murine chondrocytes had one cilium. The structure of these cilia included rootlets, basal feet, alar sheets, and an axoneme of nine peripheral doublets which progressively bent and terminated as they coursed towards the tip of the ciliary shaft. Together with the previous studies on neonatal and adult canine chondrocytic cilia, we conclude that the structure and incidence of chondrocytic cilia does n...
Rizzo M, Ducheyne KD, Deelen C, Beitsma M, Cristarella S, Quartuccio M, Stout TAE, de Ruijter-Villani M.Advanced mare age is associated with declining fertility and an increased risk of early pregnancy loss. Compromised oocyte quality is probably the primary reason for reduced fertility, but the defects predisposing to embryonic death are unknown. In women, advanced age predisposes to chromosome segregation errors during meiosis, which lead to embryonic aneuploidy and a heightened risk of miscarriage. Objective: To evaluate the effect of advanced mare age on chromosome alignment and meiotic spindle morphology in in vitro-matured (IVM) oocytes. Methods: Morphometric and morphological analysis. M...
Veraa S, Bergmann W, van den Belt AJ, Wijnberg I, Back W.Diagnostic imaging is one of the pillars in the clinical workup of horses with clinical signs of cervical spinal disease. An improved awareness of morphologic variations in equine cervical vertebrae would be helpful for interpreting findings. The aim of this anatomic study was to describe CT variations in left-right symmetry and morphology of the cervical and cervicothoracic vertebrae in a sample of horses. Postmortem CT examinations of the cervical spine for horses without congenital growth disorders were prospectively and retrospectively recruited. A total of 78 horses (27 foals, 51 mature h...
van Heel MC, van Dierendonck MC, Kroekenstoel AM, Back W.Foot stance in grazing significantly influences hoof conformation and development from foal to yearling age. Objective: To conduct a longitudinal study to establish if the relationship between motor laterality and uneven front feet persisted in 3-year-old horses at the time of studbook selection and to investigate if such laterality and unevenness might influence the horses' ability to perform symmetrically while trotting, cantering and free jumping. Methods: Seventeen clinically sound but untrained (with only minimal experience of handling) and sound Warmblood horses that had participated in ...
Young LE, Rogers K, Wood JL.Cardiac morphology in human athletes is known to differ, depending on the sports-specific endurance component of their events, whereas anecdotes abound about superlative athletes with large hearts. As the heart determines stroke volume and maximum O(2) uptake in mammals, we undertook a study to test the hypothesis that the morphology of the equine heart would differ between trained horses, depending on race type, and that left ventricular size would be greatest in elite performers. Echocardiography was performed in 482 race-fit Thoroughbreds engaged in either flat (1,000-2,500 m) or jump racin...
Tzelos T, Barbeito JS, Nielsen MK, Morgan ER, Hodgkinson JE, Matthews JB.Parasitic nematodes, particularly cyathostomins, are ubiquitous in grazing horses world-wide. Considerable burdens of cyathostomin larvae can encyst in the large intestinal wall. The most recommended treatment against these pathogenic stages is moxidectin. Information is required on how effective moxidectin is against cyathostomin populations in different regions. The objectives here were to determine the efficacy of moxidectin treatment and estimate the strongyle egg reappearance period (ERP) after treatment in several equine populations, to confirm the type of strongyle nematodes present and...
Nyman G, Funkquist B, Kvart C, Frostell C, Tokics L, Strandberg A, Lundquist H, Lundh B, Brismar B, Hedenstierna G.The anatomical basis of gas exchange impairment in the anaesthetised horse was studied by computerised tomography (CT; three shetland ponies) and morphological analysis (one pony and three horses). By means of CT, densities were seen in dependent lung regions early during anaesthesia, both with spontaneous breathing and with mechanical ventilation. The densities remained for some time where they had initially been created when the animal was turned from dorsal to sternal recumbency. Deep insufflation of the lungs reduced the dense area. Gas exchange was impaired roughly in proportion to the de...
Johannisson A, Morrell JM, Thorén J, Jönsson M, Dalin AM, Rodriguez-Martinez H.The objective was to investigate the changes in stallion sperm quality (sperm motility, viability, membrane integrity and chromatin integrity) occurring during cool storage, and to study the effect of sperm selection by single layer colloidal centrifugation on these parameters of sperm quality. Spermatozoa from 3 stallions (10 ejaculates, 3-4 per stallion) were selected by centrifugation through a single layer of colloid (SLC). The resulting sperm preparations and the control samples (extended but unselected semen samples) were stored at 5 degrees C for 48h. Assessments of sperm quality, such ...
Sánchez-Guerrero MJ, Cervantes I, Molina A, Gutiérrez JP, Valera M.Making a morphological pre-selection of Pura Raza Español horses (PRE) for dressage is a challenging task within its current breeding program. The aim of our research was to design an early genetic selection morphological linear traits index to improve dressage performance, using 26 morphological linear traits and six dressage traits (walk, trot, canter, submission, general impression - partial scores - and total score) as selection criteria. The data set included morphological linear traits of 10 127 PRE (4159 males and 5968 females) collected between 2008 and 2013 (one record per horse) and...
Karikoski NP, Patterson-Kane JC, Singer ER, McFarlane D, McGowan CM.Hoof lamellar pathology in horses with pituitary pars intermedia dysfunction (PPID) has not been described previously. Objective: To describe the histomorphometry and pathological lesions in hoof lamellar tissue of animals that had PPID with or without concurrent laminitis, with reference to age-matched controls. We hypothesised that lamellar lesions consistent with laminitis would be associated with PPID, even in animals without current or historical laminitis. Methods: Prospective case-control study. Methods: Mid-dorsal hoof histological sections were obtained post mortem from the forelimbs ...
Townsend HG, Leach DH.The anatomical features of 21 equine thoracolumbar spines, obtained from horses with clinically normal backs, were examined and the results compared with recent data on the mobility of the joint complexes of the horse's spine. The thoracolumbar spine can be divided into four regions based upon the morphology of the joint complexes: the first thoracic intervertebral joint (T1-2), the cranial and mid thoracic region (T2-T16), the caudal thoracic and lumbar region (T16-L6) and the lumbosacral joint. The mobility of the intervertebral joints in each of these regions can be related to their morphol...
Blumer R, Maurer-Gesek B, Gesslbauer B, Blumer M, Pechriggl E, Davis-López de Carrizosa MA, Horn AK, May PJ, Streicher J, de la Cruz RR, Pastor ÁM.To test whether palisade endings are a general feature of mammalian extraocular muscles (EOMs). Methods: Thirteen species, some frontal-eyed (human, monkey, cat, and ferret), and others lateral-eyed (pig, sheep, calf, horse, rabbit, rat, mouse, gerbil, and guinea pig) were analyzed. Palisade endings were labeled by using different combinations of immunofluorescence techniques. Three-dimensional reconstructions of immunolabeled palisade endings were done. Results: In all frontal-eyed species, palisade endings were a consistent feature in the rectus EOMs. Their total number was high and they exh...
Perumal AN, Gunawardene YI, Dassanayake RS.Setaria digitata is a filarial parasite that causes fatal cerebrospinal nematodiasis in goats, sheep and horses, resulting in substantial economic losses in animal husbandry in the tropics. Due to its close resemblance to Wuchereria bancrofti, this nematode is also frequently used as a model organism to study human lymphatic filariasis. This review highlights numerous insights into the morphological, histological, biochemical, immunological and genetic aspects of S. digitata that have broadened our understanding towards the control and eradication of filarial diseases.
Arienti G, Carlini E, De Cosmo AM, Di Profio P, Palmerini CA.Human semen contains membranous vesicles called prostasomes. They are secreted by the prostate gland and contain large amounts of cholesterol, sphingomyelin, and Ca2+. Prostasomes enhance the motility of ejaculated spermatozoa and are involved in a number of additional biological functions. No prostasome-like vesicles have been described in horse semen up to now. We have demonstrated the presence of prostasome-like vesicles in the equine semen and characterized them as to size, morphology, and lipid composition; we have found that they are similar to human prostasomes in many respects. We prop...
Riemersma DJ, Schamhardt HC.The mechanical properties of the deep digital flexor tendon (DDFT), the superficial digital flexor tendon (SDFT) and the suspensory ligament (SL) of the hindlimb of the horse were studied in vitro. The tendons were observed at several morphologically distinct sites. The loaded tendon is homogeneously strained, in spite of large variations in cross-sectional area. Consequently the modulus of elasticity was inversely proportional to the corresponding cross-sectional area and ranged from 738 MPa (megaPascal, N mm-2) to 1398 MPa within the DDFT, from 1000 MPa to 1282 MPa within the SDFT and from 5...
Tremoleda JL, Stout TA, Lagutina I, Lazzari G, Bevers MM, Colenbrander B, Galli C.Blastocyst formation rates during horse embryo in vitro production (IVP) are disappointing, and embryos that blastulate in culture fail to produce the characteristic and vital glycoprotein capsule. The aim of this study was to evaluate the impact of IVP on horse embryo development and capsule formation. IVP embryos were produced by intracytoplasmic sperm injection of in vitro matured oocytes and either culture in synthetic oviduct fluid (SOF) or temporary transfer to the oviduct of a ewe. Control embryos were flushed from the uterus of mares 6-9 days after ovulation. Embryo morphology was eval...
