"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Pavone S, Veronesi F, Genchi C, Fioretti DP, Brianti E, Mandara MT.In this study, pathological changes caused by Anoplocephala perfoliata in the ileocecal junction were investigated in 31 regularly slaughtered mixed-breed horses of both sexes. Our results showed a significant relationship between parasite burden and grading of histopathological lesions in the mucosa and submucosa. Hypertrophy of the circular muscle layer was found in infected horses. Moreover, enteric nervous system evaluation showed a significant injury of intestinal nervous elements in the horses with moderate to high parasitism expressed as an increase of degenerative-regressive changes in...
Nagy A, Dyson S, Barr A.The transrectal ultrasonographic appearance of the lumbosacral joint was assessed in 43 horses with no history or clinical evidence of back pain or hindlimb lameness. In the majority of horses (34/43, 79.1%) the lumbosacral disc had uniform or mildly heterogeneous echogenicity. However, variation in the ultrasonographic appearance of the lumbosacral joint was also identified, including hyperechogenic regions within the lumbosacral disc with or without an acoustic shadow, and mild or moderate irregularity of the opposing surfaces of the last lumbar and the first sacral vertebral bodies. Marked ...
Holowinski M, Judy C, Saveraid T, Maranda L.Magnetic resonance (MR) imaging is important in diagnosing musculoskeletal injuries in horses. However, there is still much to learn regarding the significance of lesions identified in equine MR images. Of particular importance is the clinical significance of signal change as a function of pulse sequence. We hypothesized that a resolution of tendon, ligament, and bone marrow lesions on short-tau inversion recovery (STIR) images would be associated with a return to soundness, and that a persistence of tendon and ligament lesions on only T1-weighted (T1w) gradient recalled echo (GRE) images woul...
Garrett KS, Woodie JB, Cook JL, Williams NM.A foal was examined for abnormal upper airway noise. Endoscopically, there were narrowed nasal passages and an extralumenal mass of the cranial trachea. Using ultrasonography and magnetic resonance (MR) imaging of the larynx and cranial cervical trachea, irregular margins of the laryngeal cartilages and first tracheal ring containing areas consistent with fluid were identified. In MR images, a widened nasal septum was seen that contained material consistent with fluid. Postmortem examination confirmed the diagnosis of nasal septal, laryngeal, and cranial cervical tracheal cyst-like lesions. Th...
Bugno-Poniewierska M, Dardzińska A, Pawlina K, Słota E.A normal course of meiosis and the associated course of spermatogenesis in males are very significant from the viewpoint of animal breeding, in particular animal reproduction. This takes on special significance when studying late-maturing animals such as horses. The aim of the study was to analyse meiotic cells, with particular consideration of synaptonemal complexes obtained from the testes of young stallions and cryptorchids, based on observations of the X-Y bivalent. The analysis was performed in successive stages of meiotic division using the FISH technique. The greatest diversity and most...
Spriet M, Wisner ER, Anthenill LA, Buonocore MH.Seven isolated equine front limbs were used to establish the normal T1 relaxation time of equine superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and suspensory ligament (SL) using magic angle magnetic resonance (MR) imaging. MR imaging of the metacarpi was performed with the limbs positioned at 55° (the magic angle) relative to the main magnetic field. Transverse spin-echo proton density and inversion recovery images were acquired. T1 relaxation time was calculated based on ratios of signal intensity determined from the different pulse sequences. T1 relaxation tim...
Nuñez CM, Adelman JS, Rubenstein DI.Although the physiological effects of immunocontraceptive treatment with porcine zona pellucida (PZP) have been well studied, little is known about PZP's effects on the scheduling of reproductive cycling. Recent behavioral research has suggested that recipients of PZP extend the receptive breeding period into what is normally the non-breeding season. Results: To determine if this is the case, we compiled foaling data from wild horses (Equus caballus) living on Shackleford Banks, North Carolina for 4 years pre- and 8 years post-contraception management with PZP (pre-contraception, n = 65 births...
Bach BC, Leal DB, Ruchel JB, Souza Vdo C, Maboni G, Dal Pozzo M, Schlemmer KB, Alves SH, Santurio JM.NTPDase (EC 3.6.1.5) occurs in lymphocytes and plays an important role in immune function, in that hydrolyzes extracellular nucleoside tri- and/or diphosphates to form AMP. Pythium insidiosum causes the disease pythiosis, a pyogranulomatous disease of horses, dogs, cattle, cats and humans. Most antifungal drugs are ineffective against this pathogen, and immunotherapy, a treatment approach that relies on the injection of P. insidiosum antigen, has been successfully used in humans and horses to manage this disease. In this study, we investigated NTPDase activity in lymphocytes from rabbits inocu...
Meghoufel A, Cloutier G, Crevier-Denoix N, de Guise JA.The fiber bundle density (FBD) calculated from ultrasound B-scan images of the equine superficial digital flexor tendon (SDFT) can serve as an objective measurement to characterize the three metacarpal sites of normal SDFTs, and also to discriminate a healthy SDFT from an injured one. In this paper, we propose a shock filter algorithm for the thinning of hyper-echoic structures observed in B-scan images of the SDFT. This algorithm is further enhanced by applying closing morphological operations on filtered images to facilitate extraction and quantification of fiber bundle fascicles. The mean F...
Selvaggi M, Pesce Delfino AR, Dario C.The aim of this study was to assess genetic polymorphism at two loci in the exon 1 of the CSN3 gene in Murgese horse breed by PCR-RFLP analysis. The overall frequencies of alleles A and G at c.-66A > G locus were 0.80 and 0.20, respectively, and no GG animals were found in the population. At the c.-36C > A locus allelic frequencies were 0.74 and 0.26 for allele C and A, respectively, and no AA animals were detected. Population genetic indexes, namely gene heterozygosity, gene homozygosity, effective allele numbers, fixation index, and polymorphism information index were calculated. C...
Simhofer H, Niederl M, Anen C, Rijkenhuizen A, Peham C.The objective of this study was to compare masticatory movements before and after dental treatment using kinematic analysis. The masticatory movements of 15 adult Warmblood horses with mild dental pathology chewing standardised hay were recorded on three consecutive days before and three times after (days 7, 21, 28) dental correction. The results of the leading mandibular tracking marker, located at the caudal edge of the inter-mandibular suture, were compared statistically. Reproducibility of measurements prior to dental treatment was excellent (P<0.05). Rostrocaudal mandibular motion was ...
Figueredo LA, Cafarchia C, Otranto D.Fungi of the genus Geotrichum are commonly found in the environment and, in some circumstances, they may cause diseases in humans and animals. Although these fungi have been isolated from skin lesions of some animal species, their pathogenic role in horses remains uncertain. With the aim to investigate the role of Geotrichum candidum as etiological agent of dermatomycoses, a retrospective study of 64 horses presenting skin lesions and suspected to have fungal infections was carried out. For each animal, anamnestic data were recorded and fungal culture were performed using hair. Out of 64 cases...
Hobo S, Niwa H, Anzai T, Jones JH.In this study, to evaluate the influence of strangles vaccination on serological test results, we investigated the changes in strangles serum antibody levels in horses after vaccination and subsequent intranasal challenge with S. equi. The horses were vaccinated for strangles with either a component vaccine (Group C) or a live vaccine (Group L). We measured changes in strangles serum antibody levels weekly for 20 weeks after vaccinating horses twice for strangles over a 3-week interval, and for 7 weeks after intranasal challenge with S. equi in the same horses. Serum antibody responses to the ...
Scarth JP, Teale P, Kuuranne T.A detailed understanding of equine drug metabolism is important for detection of drug abuse in horseracing and also in veterinary drug development and practice. To date, however, no comprehensive review of equine drug metabolism has been published. The majority of literature regarding equine drug metabolite profiles is derived from sports drug detection research and is generally targeted at detecting marker metabolites of drug abuse. However, the bulk of the literature on equine drug metabolism enzymology is derived from veterinary studies aimed at determining the molecular basis of metabolism...
McGowan TW, Pinchbeck G, Phillips CJ, Perkins N, Hodgson DR, McGowan CM.To describe management practices and routine preventive care of aged horses in Queensland, Australia, including effects of owner characteristics, affiliation to an equestrian group and retirement of the horse. Methods: Owners of horses were contacted via Equestrian Australia (EA) and asked to complete a questionnaire about their aged horses (e.g. age, breed, sex and colour); their use and management, including preventive health care; and use of equine healthcare providers. Results: Horses aged 15 years or greater represented one-third of the total horses owned in the population sample. The med...
Quinteros DD, García-López JM, Provost PJ.To report the clinical outcome in seven horses following use of a newly described surgical technique for treating caecal impaction. Methods: The medical records of seven horses with caecal impaction treated surgically using a stapling technique to create a complete caecal bypass without ileal transection were reviewed. Data were obtained from the records and through telephone interviews with case-associated personnel. Results: The mean age was 10 years (range 2-22 years) and duration of colic ranged from 24 h to 2 weeks. Five horses had type II motility dysfunction and the remaining two had ty...
Collins NM, Palmer L, Marr CM.The aim of this study was to establish reference values for a series of conventional two-dimensional (2-D) and M-mode echocardiographic variables in Thoroughbred foals at increasing age intervals. Methods: Nineteen healthy Thoroughbred foals (11 males, 8 females) were examined at 1, 2, 4, 8, 12 and 16 weeks of life. Auscultatory findings were recorded and echocardiographic examinations (2-D and M-mode) were performed. Descriptive statistical analyses, including mean, standard deviation and 95% confidence interval for the means, were used to summarise the data. The relationships between selecte...
Gildea S, Arkins S, Cullinane A.In Ireland, horses may be protected against equine influenza virus (EIV) as a result of natural exposure or vaccination. Current mandatory vaccination programmes are targeted at highly mobile horses. A correlation between antibody levels as measured by single radial haemolysis (SRH) and protective immunity against EIV has been established. Objective: The objective of this study was to determine the susceptibility of selected populations of horses by quantifying their antibodies to EIV. Methods: Blood samples were collected from Thoroughbred weanlings, yearlings, racehorses and broodmares, teas...
Yoon MJ, Roser JF.Leydig cells located in the interstitial space of the testicular parenchyma produce testosterone which plays a critical role in the maintenance and restoration of spermatogenesis in many species, including horses. For normal spermatogenesis, maintaining Leydig cells is critical to provide an optimal and constant level of testosterone. Recently, an anti-apoptotic effect of IGF-I in testicular cells in rats has been reported, but a similar effect of IGF-I on equine Leydig cells remains to be elucidated. If IGF-I also protects stallion testicular cells from undergoing apoptosis, then IGF-I may ha...
Podadera JM, Bell RJ, Dart AJ.Two horses presented with a history of severe lameness that was localised to the area around the second phalanx (P2) of one forelimb. Radiographs of the second phalanx of both horses were unremarkable, apart from some smooth periosteal new bone production on the dorsum of P2. Magnetic resonance imaging revealed a non-displaced fracture of P2 in both horses. One horse was euthanased because of a poor prognosis for racing, but the second horse was treated conservatively and salvaged for breeding. Magnetic resonance imaging is a newer imaging modality in horses and may be useful in diagnosing cas...
Georges KC, Ezeokoli CD, Sparagano O, Pargass I, Campbell M, D'Abadie R, Yabsley MJ.Equine piroplasmosis due to Theileria equi and Babesia caballi is endemic in Trinidad. A case of equine piroplasmosis due to T. equi was diagnosed in a thoroughbred foal at 10h post-partum. A high parasitaemia (63%) of piroplasms was observed in a Wright-Giemsa(®) stained thin blood smear from the foal. In addition, the 18S rRNA gene for Babesia/Theileria was amplified from DNA extracted from the blood of the foal and the mare. Amplified products were subjected to a reverse line blot hybridization assay (RLB), which confirmed the presence of T. equi DNA in the foal. The mare was negative by R...
Brunso L, Segura D, Monreal L, Escolar G, White JG, Diaz-Ricart M.Studies in animal models are useful to understand the basic mechanisms involved in hemostasis and the functional differences among species. Ultrastructural observations led us to predict differences in the activation and secretion mechanisms between equine and human platelets. The potential mechanisms involved have been comparatively explored in the present study. Equine and human platelets were activated with thrombin (0.5 U/ml) and collagen (20 µg/ml), for 90 seconds, and samples processed to evaluate: i) ultrastructural changes, by electron microscopy, ii) actin polymerization and cy...
Gürellı G, Göçmen B.Hemiprorodon gymnoposthium was investigated in the intestine of horses, found in Cyprus. It was found in four of fifth horses examined and thus had a frequency of appearence of 80%. This study reports for the first time the presence of Hemiprorodon gymnoposthium in the intestine of Equids in Cyprus. In addition, it is the second report from the world. Specimens were found to be similar to the original description on the basis of morphological characters and biometric data.
Elfenbein JR, Giguère S, Meyer SK, Javsicas LH, Farina LL, Zimmel DN, Sanchez LC.Hepatic failure is one of the more common complications in foals requiring blood transfusion to treat neonatal isoerythrolysis. Iron intoxication is likely the cause of hepatic injury. Objective: To determine the effects of deferoxamine on iron elimination in normal foals. Methods: Thirteen neonatal foals. Methods: Randomized-controlled trial. At 1-3 days of age, foals received either 3 L of washed packed dam's red blood cells (RBC) or 3 L of saline IV once. Foals were treated with deferoxamine (1 g) or saline (5 mL) SC twice daily for 14 days. Foals were randomly assigned to 1 of 3 gr...
Pacheco RC, Moraes-Filho J, Guedes E, Silveira I, Richtzenhain LJ, Leite RC, Labruna MB.The present study was performed in an area endemic for Brazilian spotted fever (BSF) in Juiz de Fora, state of Minas Gerais, Brazil, during the years 2007 and 2008, when fatal cases of BSF (caused by Rickettsia rickettsii) were reported. Adult ticks (Acari: Ixodidae) identified as Rhipicephalus sanguineus (Latreille) and Amblyomma cajennense (Fabricius) were collected from dogs and horses, respectively, and tested by polymerase chain reaction (PCR). Overall, 13.1% of the Rh. sanguineus ticks and none of the A. cajennense were found to be infected with R. rickettsii. Two isolates of R. ricketts...
Fidel JL.Although the diagnosis of cancer is relatively uncommon in horses, tumors do occur in this species. Surgery, radiation, and chemotherapy are traditional cancer treatments in all species. In equine patients, surgery has often been the only treatment offered; however, not all tumors can be controlled with surgery alone. In small animal oncology, newer and better therapies are in demand and available. Radiation therapy is often used to control or palliate tumors locally, especially to satisfy clients who demand sophisticated treatments. The large size of equine patients can make radiation therapy...
Gehring R, Beard L, Wright A, Coetzee J, Havel J, Apley M.Pituitary pars intermedia dysfunction (PPID) is probably the most common disease of geriatric horses. Affected horses show a variety of clinical signs, including hirsutism, polyuria/polydipsia, immunosuppression, muscle wasting, and laminitis. The most common treatment for PPID is pergolide, a dopamine agonist; however, there are no pharmacokinetic data about the use of this drug in horses. This article describes a study designed to address this complete lack of pharmacokinetic information. The pharmacokinetics of pergolide are described in a small group of relatively young, healthy mares (n =...
Trope GD, Steel CM, Bowers JR, Bradbury LA, Hodge PJ, Maggs DJ.2 horses were examined because of vascular masses involving the lower eyelid. Results: Both horses had a unilateral, fluctuant mass involving the lower eyelid. For horse 1, the mass had been present since birth and had slowly increased in size over time. The mass also changed in size in response to various environmental stimuli, alterations in the position of the horse's head, and digital obstruction of superficial vessels adjacent to the mass. Horse 2 was brought to the hospital for euthanasia, and no historical or antemor-tem data were available. A combination of contrast angiography, Dopple...
Buzzell GR, Tariq S, Traversa D, Schuster R.The infective larva of the spirurid nematode Habronema muscae, a parasite of houseflies, was measured and specimens fixed in Karnovsky's fluid were examined by scanning electron microscopy. The oral opening contains six teeth and is surrounded by large bilobed dorsal and ventral lips and smaller lateral lips. A pair of amphids lie behind the lateral lips. There are two rows of four cephalic papillae. The body is deeply ridged, both transversely and longitudinally. The caudal end of the worm is studded by small papillae. The position of the anal opening is somewhat ambiguous. These larval morph...
Pauvolid-Corrêa A, Tavares FN, Costa EV, Burlandy FM, Murta M, Pellegrin AO, Nogueira MF, Silva EE.As in humans, sub-clinical infection by arboviruses in domestic animals is common; however, its detection only occurs during epizootics and the silent circulation of some arboviruses may remain undetected. The objective of the present paper was to assess the current circulation of arboviruses in the Nhecolândia sub-region of South Pantanal, Brazil. Sera from a total of 135 horses, of which 75 were immunized with bivalent vaccine composed of inactive Eastern equine encephalitis virus (EEEV) and Western equine encephalitis virus(WEEV) and 60 were unvaccinated, were submitted to thorough viral i...
Schryver HF.Bending properties of samples of cortical bone taken from the cranial, caudal, medial, and lateral quadrants of the midshaft of the radius, femur, and metacarpus of 12 ponies, 18 months old, were determined by 4-point loading at a rate of 10 mm/minute. The elastic modulus for all samples was between 16.2 and 20.2 GN/m2, and the ultimate breaking strength, between 204 and 255 MN/m2. There was greater variation in these properties between bone quadrants than between bones. Samples from the cranial and medial quadrants of both femur and radius were stiffer and had greater ultimate breaking streng...
Sarradell JE, Alvarez J, Biscia M, Zumarraga M, Wunschmann A, Armien AG, Perez AM.A 2-year-old dappled Percheron horse had a wasting condition that did not respond to antibiotic treatments and ultimately resulted in death. Thickening of the wall of the large colon and enlargement of the mesenteric lymph nodes were observed at postmortem examination, along with the presence of pinpoint whitish foci in the liver. Microscopic examination of affected tissues revealed diffuse chronic granulomatous enterocolitis, granulomatous mesenteric lymphadenitis, and multifocal granulomatous hepatitis. The DNA extracted from paraffin-embedded intestinal and lymph node samples was analyzed u...
Louro LF, Robson K, Hughes J, Loomes K, Senior M.In equine anaesthesia, the recovery period is critical, accounting for most anaesthesia-related fatalities reported. Horses may recover unassisted or may be assisted, for example, using a head and tail rope recovery method. Objective: To compare the impact of head and tail rope and unassisted recovery method on quality of recovery in horses undergoing colic surgery under general anaesthesia (GA). Methods: Single centre retrospective cross-sectional study, with prospective model performance analysis. Methods: Clinical data were obtained from horses undergoing emergency exploratory laparotomy ov...
Payne RC, Sukanto IP, Graydon R, Saroso H, Jusuf SH.During an outbreak of trypanosomiasis in cattle, buffalo and horses on the island of Madura, a survey was conducted to determine the prevalence of Trypanosoma evansi in the region. Blood samples were collected from 130 cattle and 147 buffalo in 5 villages, whole blood was examined for trypanosomes by the microhaematocrit (MHCT) method and serum samples were subjected to an enzyme linked immuno absorbent assay to detect T. evansi antibodies. T. evansi was detected by MHCT in 50% of the buffalo examined and 13% of the cattle, while antibodies were detected in 47% of the buffalo and 30% of the ca...
Lv S, Zhang Y, Zhang Z, Meng S, Pu Y, Liu X, Liu L, Ma Y, Liu W, Jiang L.The gut microbiomes of equine are plentiful and intricate, which plays an important part in the growth. However, there is a relative lack of information on the microbial diversity in the pony's gut. Unassigned: In this article, 118 fecal samples from DeBa pony, NiQi pony and GuZh horse were studied by 16S rRNA amplicon sequencing. Unassigned: Diversity analysis was used to determine the difference of gut microbiota composition among different breeds. Alpha diversity analysis showed that the gut microbiota of NiQi ponies were abundant and various. Beta diversity analysis showed that the microor...
Kersten AA, Edinger J.Little information exists about the normal ultrasonographic appearance of the equine sacroiliac region, but knowledge of the ultrasonographic anatomy is necessary to understand the possible pathological changes in sacroiliac diseases. Objective: The normal ultrasonographic appearance of soft tissues and bony structures of the sacroiliac region in horses was studied in order to establish clinically relevant reference parameters. Methods: Thirteen cadaver specimens were examined using a transcutaneous approach above the tubera sacrale to image the dorsal sacroiliac ligament and the tendon of the...
Muñoz A, Riber C, Trigo P, Castejón FM, Lucas RG, Palacio J.This study investigated the effect of hypertonic dehydration on exercise in horses. Valencian draft horses (n=43) with hypertonic dehydration following water and food deprivation and competing in pulling events (COM), were compared to euhydrated horses (n=11) during a pulling exercise test (PET). Both groups were divided into bodyweight (BW) categories A (≤350 kg), B (351-450 kg), and C (≥451 kg), and pulled 2, 2.25, and 2.5 times BW, respectively. Exercise duration (ED) was 1.3±0.8 min. Heart rate, respiratory rate, rectal temperature and blood samples were taken at rest, after exercise,...
Bell C, Tatarniuk D, Carmalt J.To describe and evaluate an endoscope-guided balloon sinuplasty technique for dilation of the equine nasomaxillary opening (NMO). Methods: Experimental study. Methods: Equine cadaver heads (n=5); Quarter Horses (n=4). Methods: A custom rigid balloon introducer was passed into position within the NMO at the caudal recess of the middle meatus. Under endoscopic guidance, a balloon catheter was passed via the introducer into the NMO and inflated to 6 atmospheres, for 30 seconds 3 times, to dilate the NMO. Drainage rates after sinuplasty were evaluated for the caudal maxillary sinus in 5 cadaver he...
Barton MH, Sharma P, LeRoy BE, Howerth EW.A 13-year-old gelding was examined because of weight loss, hyperglobulinemia, and hypercalcemia. Possible causes of hypercalcemia that were considered included renal failure, primary hyperparathyroidism, vitamin D toxicosis, and malignancy. There was no history of vitamin D ingestion, and serum creatinine and parathyroid hormone concentrations were normal, making renal failure and primary hyperparathyroidism unlikely. The hypercalcemia was suspected to be a result of malignancy, but thorough testing did not reveal any neoplastic disease. Eight months later, serum parathyroid hormone-related pr...
Robertson SA.Several ocular procedures, including examination, removal of corneal foreign bodies, nictitans surgery, eyelid repair, and tumor excision,can be successfully performed in the appropriately restrained and sedated standing horse. Sedation is best achieved with xylazine,with or without the addition of acepromazine. Additional analgesia can be provided with appropriate local anesthetic blocks. Surgical conditions are greatly improved by using an auriculopalpebral and supraorbital block and topical anesthetics. More elaborate standing sedation involving continuous rate infusions of lidocaine or det...
Craig DR, Pankowski RL, Car BD, Hackett RP, Erb HN.Several surgical alternatives have been described for the management of cecal impaction in the horse, but none has met with consistently successful results. This study was done to evaluate a surgical bypass of the cecum by anastomosis of the ileum to the right ventral colon (ileocolostomy). A ventral midline celiotomy was performed on nine adult ponies (155-350 kg) and a mechanically stapled 10 cm side-to-side ileocolostomy was created. In five ponies a complete cecal bypass (CCB) was created by transecting the ileum distal to the anastomosis. In the other four, an incomplete cecal bypass (ICB...
Schneiders FI, Noble GK, Boston RC, Dunstan AJ, Sillence MN, McKinney AR.Acepromazine (ACP) is a useful therapeutic drug, but is a prohibited substance in competition horses. The illicit use of ACP is difficult to detect due to its rapid metabolism, so this study investigated the ACP metabolite 2-(1-hydroxyethyl)promazine sulphoxide (HEPS) as a potential forensic marker. Acepromazine maleate, equivalent to 30mg of ACP, was given IV to 12 racing-bred geldings. Blood and urine were collected for 7days post-administration and analysed for ACP and HEPS by liquid chromatography-mass spectrometry (LC-MS). Acepromazine was quantifiable in plasma for up to 3h with little r...
Hanot P, Bayarsaikhan J, Guintard C, Haruda A, Mijiddorj E, Schafberg R, Taylor W.The potential of artificial selection to dramatically impact phenotypic diversity is well known. Large-scale morphological changes in domestic species, emerging over short timescales, offer an accelerated perspective on evolutionary processes. The domestic horse (Equus caballus) provides a striking example of rapid evolution, with major changes in morphology and size likely stemming from artificial selection. However, the microevolutionary mechanisms allowing to generate this variation in a short time interval remain little known. Here, we use 3D geometric morphometrics to quantify skull morph...
Sorrell MS, Fish RE, Taylor KH.Horses and ponies are used infrequently in research but may be valuable animal models for studying both equine-specific diseases and biomedical applications. We report here 2 cases of pediculosis in random-source ponies. Infestation and clinical signs were not present during a 4-wk quarantine period or for 3 to 9 mo thereafter but became apparent coincident with the ponies' movement from pasture to indoor housing. These 2 geldings presented with pruritus associated with excoriating lesions on the neck, and infestation with Bovicola (Werneckiella) equi Denny, 1842 was diagnosed. Ponies were tre...
Dixon PM, Kennedy R, Reardon RJM.Background: Limited objective information is available on the prevalence of non-traumatic equine cheek teeth fractures, the signalment of affected horses, and the clinical features and treatment of these fractures. Objectives: This study aims to document patterns of idiopathic and infundibular caries-related cheek teeth fractures in a referral population and evaluate associations between fracture patterns and horse age, Triadan position of affected teeth, clinical signs, and deemed necessity for treatment. Study Design: A retrospective case review. Methods: The clinical records at Edinburgh Un...
Cole FL, Mellor DJ, Hodgson DR, Reid SW.The proportion of the horses, of both sexes and of different ages, breeds and levels of activity, owned by a stratified random sample of Australian owners, which had suffered one or more episodes of exertional rhabdomyolysis during the previous 12 months was determined. The proportion in the general population was 1.9 per cent, and horses which exercised were significantly more likely to have experienced the condition than horses which did not. There were significant differences between the sexes and between certain breeds and activity groups in the proportions of horses affected.
Nixon AJ, Schachter BL, Pool RR.To determine the clinical, radiographic, ultrasonographic, and arthroscopic findings associated with tenosynovitis of the carpal synovial sheath induced by exostoses that originate from the caudal surface of the physeal scar of the distal radius and determine the results of surgical removal of those exostoses in horses. Methods: Retrospective study. Methods: 10 horses. Methods: Medical records of horses with effusion in the carpal synovial sheath and lameness evaluated from 1999 to 2003 were examined. Results: All horses had a history of intermittent mild to moderate effusion of the carpal syn...
Fowlie JG, Arnoczky SP, Lavagnino M, Stick JA.To identify potential functional-anatomical characteristics of the cranial horn attachment of the medial meniscus (MM) that may help explain the pathogenesis of the common tear patterns that have been reported. Objective: Full extension of the stifle generates a significant increase in tensile forces within the cranial meniscotibial ligament (CrMTL) of the MM, which may predispose this structure to injury. Methods: The effect of femorotibial angle (160°, 150°, 140° and 130°) on tensile forces in the axial and abaxial components of the CrMTL was examined in 6 mature cadaver stifles using an...
Salas-Romero J, Gómez-Cabrera KA, Salas JE, Vázquez R, Arenal A, Nielsen MK.Anthelmintic resistance in equine cyathostomins has been described worldwide, with resistance to the benzimidazole class being particularly widespread. The status of anthelmintic efficacy in Cuba has been virtually unknown due to the lack of equine labelled products. One recent report documented suboptimal efficacy levels of extra-label albendazole products against cyathostomins, but it remains unknown to which extent benzimidazole resistance exists in the population. The aim of the present study was to evaluate the anthelmintic efficacy of two benzimidazole products labelled for equines, fenb...
Tongu EAO, Segabinazzi LGTM, Alvarenga ML, Monteiro A, Papa FO, Alvarenga MA.This study aimed to evaluate the effects of mesenchymal stem cell-conditioned medium (MSC-CM) on sperm parameters, intrauterine polymorphonuclear neutrophils (PMN), intrauterine fluid accumulation (IUF), and fertility in mares. In experiment 1, two ejaculates from ten stallions were extended to 50 million sperm/mL using a milk-based extender. Thereafter, 20 mL of extended semen was added of MSC-CM as follows: 0, 5, 10, 15, and 20 mL. Sperm kinetics and plasma membrane integrity were evaluated immediately after dilution (T0) and 2 h post-incubation at 37 °C (T2). In experiment 2, mares cha...
Amitrano FN, Gutierrez-Nibeyro SD, Schaeffer DJ.OBJECTIVE To determine and compare the effect of hoof boots (HBs) and shoes with a toe extension on stance duration, ground reaction force, and sole length in contact with the ground in nonlame horses during walking. ANIMALS 6 nonlame Standardbreds. PROCEDURES Force plate gait analyses of the forelimbs were performed while the horses were walking barefoot before manipulation of feet (baseline), while the horses were walking fitted with HBs, while the horses were walking shod with toe-extension shoes, and while the horses were walking barefoot after shoe removal. Horses underwent radiography of...
Boys Smith SJ, Clegg PD, Hughes I, Singer ER.There are no data on the frequency of post operative complications following keratoma removal, such as recurrence, hoof wall instability and excessive granulation tissue formation, or their relation to the method of surgical removal. Objective: To identify important factors in the outcome for horses undergoing surgical removal of a keratoma and compare the post operative complications encountered following keratoma removal by complete hoof wall resection (CR) and partial hoof wall resection (PR). Objective: Horses undergoing PR would have fewer post operative complications and would return to ...
Hobbs SJ, Richards J, Matuszewski B, Brigden C.To develop and evaluate a marker cluster set for measuring sagittal and extrasagittal movement of joints in the distal portion of the forelimb in ponies. Methods: 4 ponies. Methods: 5 infrared cameras were positioned on a concrete walkway in a frontal-sagittal arc and calibrated. Four segments were defined: hoof, middle phalanx, proximal phalanx, and metacarpus. Rigid clusters with 4 retroreflective markers were placed on each segment. A static trial was recorded with additional anatomic markers on the medial and lateral joint lines. Those anatomic markers were removed, and kinematic data were...
Beisser A, McClure S, Rezabek G, Soring KH, Wang C.To determine the incidence and anatomic location of and potential risk factors for catastrophic musculoskeletal injuries (CMIs) in racing Quarter Horses. Methods: Retrospective matched case-control study. Methods: 67 racing Quarter Horse racehorses euthanized because of CMIs and 134 matched controls. Methods: Data for Quarter Horses that sustained CMIs and the total number of race starts for each year were obtained from 2 Midwestern racing jurisdictions from 2000 through 2011. Information for each horse with a CMI and for 2 randomly selected control horses that ran in the same race but did not...
Ramzan PH, Marr CM, Meehan J, Thompson A.A novel radiographic projection is described for assessing part of the temporomandibular articulation of horses. It minimises the superimposition of osseous structures of the cranium that limit the usefulness of conventional projections and permits improved imaging in cases of suspected disease.