"Geldings" refers to castrated male horses, while intact males are called stallions. The process of gelding involves the surgical removal of the testicles, which is performed to manage behavior and facilitate handling. Geldings often exhibit more predictable and manageable temperaments compared to stallions, which can be beneficial in various equestrian disciplines and settings. This topic encompasses studies and articles that explore the physiological and behavioral differences between geldings and intact male horses, including aspects of growth, performance, and social interactions. Research in this area provides insights into the impact of castration on equine health and behavior, contributing to informed management practices in equine care and training.
O'Reilly K, Aldworth-Yang S, Catalano DN.There are many different concentrate feeders available to horse owners, but little data exists on feeder effect of equine intake rate. Rapid consumption ("bolting") is associated with issues such as esophageal obstruction. Objective: The objective of this study was to evaluate three common concentrate feeders on intake rate. We hypothesized horses would have the slowest intake rate when fed from the trough. Methods: Four geldings were fed 0.454 kg of concentrate from a pan on the ground (P), shallow trough (T), or hanging feeder (H). Horses were randomly assigned a first feeder and then rotate...
Toddy T, Ledbetter EC, Knickelbein KE.To describe the demographics and treatment outcomes of horses definitively diagnosed with epithelial or stromal immune-mediated keratitis (IMMK) by use of in vivo confocal microscopy (IVCM) and/or histopathology. Unassigned: Medical records of horses presented to the Cornell University Equine Hospital definitively diagnosed with epithelial or stromal IMMK with IVCM and/or histopathology between 2020 and 2024 were reviewed. Patient signalment, affected eye(s), diagnostics, treatments, and outcomes were assessed. Unassigned: 22 horses met the inclusion criteria. The mean age was 16.9 years (SD, ...
Hein M, Volkmann N, Probst J, Kemper N, Venner M.This retrospective report investigated whether starting racehorses' training and racing early is associated with a less successful and a shorter racing career. The data of 600 Thoroughbred racehorses from the German Racehorse Association's archiving programme were evaluated. The horses were classified into three groups regarding their different ages when starting training and racing: early training (16-24 months old)/early racing (two years old); early training/late racing (>two years old); and late training (25-30 months). Statistical models investigated effects on the horses' length of caree...
Naito M, Nishihata S, Amano T.To investigate the factors affecting the utilization of retired Thoroughbred racehorses in equestrian disciplines, Bayesian linear mixed models were separately fitted using rank, round time, and obstacle faults from show-jumping competitions restricted to retired Thoroughbred racehorses as dependent variables, with the interaction between horse sex and the interval from race retirement to competition (as a proxy for transition training to show-jumping) as a fixed effect. When the interval was short (≤1 year), the estimated marginal mean of rank was statistically significantly lower in stalli...
Journal of biomechanicsJanuary 16, 2026
Volume 197 113169 doi: 10.1016/j.jbiomech.2026.113169
Collins AE, Wayne JS, Ferrando CA, De Vita R.This experimental study characterizes the elastic behavior of male and female equine genital tissues using uniaxial tensile testing, with strain measurements obtained via digital image correlation. Dog-bone-shaped tissue specimens were excised from mares and geldings (n=23 from female specimens and n=42 from male specimens) with all specimens aligned along the circumferential direction (CD) of the vagina, penis, and scrotum. The results include load-displacement data, stress-strain data, and tangent moduli for the penile sheath, vaginal canal, and scrotum, with strain measured in both the CD a...
Rönnow E, Roth LSV.Compared to other companion animals, our understanding of the human-horse relationship is limited, particularly from the horse's perspective. This pilot study examined whether horses (N = 30) show a bias towards their owner in a reunion in the presence of both the owner and a stranger. Afterwards, the horses were also presented with the odor of the owner and a stranger. Both tests were video recorded for behavioral analyzation. No significant owner-directed bias was observed at the group level in either the reunion test or the odor test. Nonetheless, in the reunion test, owner bias in physical...
Domańska-Kruppa N, Benoit P, Żukiewicz-Benoit K, Domino M, Kliczkowska K, Szubart M, Stefanik E.Limited data is available on the diagnostic and therapeutic methods for pathologies caused by scarring after castration. It is well recognized that specific behaviors or untypical hindlimb lameness may be observed in geldings with gelding scars and adhesions caused by spermatic cord remnants after castration OBJECTIVES: To describe how to diagnose movement disorders associated with excessive adhesions caused by spermatic cord remnant after castration and to present a successful surgical treatment method. Methods: To assess the impact of gelding scars on horses' movement and behavior, medical r...
Selecky ME, Louie EW, Donnelly C, Finno CJ, Morgan JM.Echocardiographic reference intervals for Quarter Horses are infrequently reported. Objective: To provide standard echocardiographic measurements for sedentary Quarter Horses and evaluate the relationship between physical characteristics (body weight, age, sex) and echocardiographic measurements. Methods: Forty-one sedentary Quarter Horses, free of cardiac disease, from a university research herd. Methods: A cross-sectional study evaluating standardized echocardiograms performed on sedentary Quarter Horses (41) between 2020 and 2022. Reference intervals were calculated for raw and weight-corre...
Viljanto M, Cutler C, Habershon-Butcher J, Hincks P, Scarth J.The use of testosterone in racehorses is predominantly monitored using international urine and plasma concentration-based thresholds and complementary steroid ratios. To date, there has been no published pharmacokinetic study on transdermally applied testosterone products in horses and whether their use could result in adverse analytical findings. Therefore, quantitative analysis of testosterone and epitestosterone in urine and testosterone in plasma samples was performed following a pilot multi-dose transdermal Testogel administration (1 mg/kg once a day for 7 days on clipped skin) to one...
Janczarek I, Gazda I, Barłowska J, Kurnik J, Łuszczyński J.It is assumed that horses have a strong herd instinct that cannot be suppressed by any form of social support from humans. The aim of this study was to assess the behaviour and heart rate parameters of horses that received various forms of human support during short-term social isolation. The research material consisted of 12 clinically healthy recreational warmblood mares and geldings. The test was carried out four times. The research test consisted of two parts, which began in the presence of accompanying horses and under conditions of social isolation, with and without support provided by a...
Granella MCS, Mendes RP, da Silva Casa M, Ribeiro GSN, Sangioni LA, Vogel FSF, Braünig P, Ferian PE, Salbego FZ, Schwarz DGG, Fonteque JH.Protozoan Neospora spp. is known to negatively affect horses reared in rural and urban environments, being studied for causing abortion, neonatal mortality and central nervous system disorders in horses. This study aimed to verify the occurrence of anti-Neospora spp. antibodies in horses bred in rural and urban areas from southern Brazil and the risk factors associated with infection. The study consisted of 400 horses, which 241 were bred in rural areas and 159 in urban areas. The detection of serum anti-Neospora spp. antibodies was determined using Immunofluorescence Antibody Test (IFAT). The...
Käfer-Karrer MJ, de Preux M, Van der Vekens E, Mattei LI, Kuhlmann J, Klopfenstein Bregger MD, Easley JT, Koch C.To describe the repair of a fractured cranial articular process (AP) of the sixth cervical vertebra (C6) with cortex screws placed in lag fashion using computer-assisted surgery. Methods: A 12-year-old Swiss Warmblood gelding. Methods: Case report. Methods: The gelding was presented with neck pain and ataxia after a fall. A fracture of the right cranial AP of C6 was identified on radiographs. The fracture was repaired by internal fixation with two 4.5 mm cortex screws of 58 and 48 mm length placed in lag fashion using computer-assisted surgery. Results: During general anesthesia, it was su...
da Fé VCS, Dos Santos VMO, de Lima ACB, Hernandes MSP, Caldara FR, Gomes MNB.This study aimed to evaluate the effect of auditory stimuli on mares and geldings during social isolation and movement restriction, and their ability to promote the reduction of stress responses. The research was conducted with eight Pantaneiro horses, divided into Experiment I (4 mares) and Experiment II (4 geldings), both experiments were executed equally using a 4x4 Latin square design with experimental (classical, country and new age) and control (no music) treatments. Physiological parameters (heart rate, heart rate variability, respiratory rate, ocular temperature by infrared thermograph...
Ho HSM, Mizzi JX, Ho ENM, Wong WT.Ranitidine is a histamine H-receptor antagonist commonly used to treat gastric ulceration in horses. The author's laboratory conducted a study some years ago in the early 2000s on its metabolism as well as its urinary elimination profile in two geldings. With the technology advancement as well as popularity of blood for doping control testing, the laboratory has recently conducted another administration trials of the substance in six horses to study the in vivo metabolism of ranitidine, aiming to identify and reinvestigate the appropriate target(s) for controlling misuse of ranitidine in hors...
Ho HSM, Farrington AF, Ho ENM, Wong WT.2-Hydroxyethyl salicylate (2HES), a nonsteroidal anti-inflammatory drug (NSAID), is a medication to treat musculoskeletal injuries and inflammation swelling of humans and horses. Its misuse could affect the performance of horses and mask injuries, which could pose significant health risks. In horseracing, it is reported as an adverse finding once detected in competition. The metabolism of 2HES in either human or horse has not been reported, and therefore, little is known about its metabolic fate. This paper describes the in vivo metabolism of 2HES in horse with an objective to identify the mo...
de la Cuesta-Torrado M, Velloso Alvarez A, Santiago-Llorente I, Armengou L, Nieto F, Ríos J, Cruz-López F, Jose-Cunilleras E.Equine herpesvirus myeloencephalopathy (EHM) is a persistent threat to horses, with unclear risk factors and disease severity. Objective: To evaluate risk factors, effective reproduction rate (Rt), and long-term athletic outcomes of an EHM outbreak. Methods: Retrospective study of the 2021 EHM outbreak in Valencia, Spain, examining associations between risk factors (sex, age, breed, country of origin, and vaccination status) and case fatality rate, EHM development, and odds of returning to competition using odds ratios [95% CI] and Rt via the Robert Kochs Institute method. Results: Among 191 h...
Giannetto C, Aragona F, Fazio F, Piccione G, Giudice E, Arfuso F, Zumbo A.This study aimed to examine the impact of climatic conditions on feed intake, body weight, and rectal temperature in horses residing in the hot Summer Mediterranean climate zone. Eight gelding Italian Saddle horses, with an average body weight of 427.78 ± 54.55 kg and aged between 10 and 13 years, participated in the research. All horses were individually housed in a paddock (800 m/horse), and fed ad libitum. Food intake, body weight, and rectal temperature were recorded every 10 days at four 30-day collection periods in the year: January, April, July, and October. The formula adapted fr...
Solbach V, Grabatin M, Zablotski Y, Fux R, Zerbe H, Witte TS.Contagious Equine Metritis (CEM) caused by the bacterium Taylorella equigenitalis (T. equigenitalis), is a venereal infection of equids which is of international concern to the equine breeding industry. A recent study showed a high prevalence of T. equigenitalis in Icelandic stallions when compared to stallions of other breeds also using for natural breeding. Consequently, the objectives of the present study were to investigate the prevalence of T. equigenitalis in Icelandic mares and geldings and to determine factors associated with a T. equigenitalis-positive qPCR result. In total, 361 Icela...
Herbst AC, Coleman MC, Macon EL, Harris PA, Adams AA.A proportion of senior horses (≥15 years of age) are still used for competition. Information about this particular group of horses is currently sparse. Objective: To provide an overview of the demographics, management and health of competing U.S. senior horses (≥15 years of age). Methods: Online survey. Methods: Descriptive and inferential (Kruskal-Wallis test) analysis of 246 surveys from owners of U.S.-resident senior horses used for competition. Confidence intervals were calculated for prevalence estimates of clinical signs and medical conditions. Results: Competing senior horses we...
Delvescovo B, McOnie R, Pearson G, Pugliese B, Hackett ES.Persistent hemorrhage of testicular vessels is a potentially life-threatening complication of equine castration. Frequently, general anesthesia is required to retrieve and ligate the bleeding vasculature when standing wound packing and retrieval of the spermatic cord are unsuccessful. We propose standing laparoscopic ligation of the testicular arteries via the paralumbar fossa as a rapid, effective means of halting hemorrhage while avoiding castration site trauma as well as the cardiovascular and recovery risks of general anesthesia. Methods: Two geldings, 6 and 9 months old, presented for eme...
Heaton CP, Cavinder CA, McClure EN, Smith T, Smith WB, Liburt N, Krotky A, Harris P.Insulin dysregulation (ID), core to equine metabolic syndrome, may present without obesity. Testing for ID risk is commonly based on breed and obese phenotype but might be valuable for non-obese stock-type horses. This study aimed to determine the prevalence of ID in non-obese stock-type horses and evaluate if morphometric neck measurements (MNM) correlate with ID. Sixty-two, non-obese (BCS 5, range 2.5-6/9) stock-type horses were assessed for MNM: neck circumference at 25%, 50% (NC50), and 75% (NC75) length, and crest height. An oral sugar test (OST; 0.15 mL/kg BW corn syrup) was performed wi...
Renaud B, Kruse CJ, François AC, Cesarini C, van Loon G, Palmers K, Boemer F, Luis G, Gustin P, Votion DM.Equine atypical myopathy (AM) is a severe rhabdomyolysis syndrome primarily caused by hypoglycin A (HGA) and methylenecyclopropylglycine protoxins. This study aimed to refine diagnostic and prognostic criteria for AM while exploring apparently healthy cograzers. Blood samples from 263 horses, including AM cases (n= 95), cograzers (n= 73), colic horses (n= 19), and controls (n= 76), were analyzed for HGA, its toxic metabolite, and acylcarnitines profile. Diseased horses exhibited alterations in acylcarnitines that strongly distinguished them from controls and colic horses. Regression analyses i...
Ho HSM, Farrington AF, Bond AJ, Ho ENM, Wong WT.Estra-4,9-diene-3,17-dione (dienedione) is an anabolic-androgenic steroid (AAS) available on the market as a dietary supplement for bodybuilding. It is prohibited in both human and equine sports due to its potential performance-enhancing effect. With the rare presence of the 4,9-diene configuration in endogenous steroids, dienedione has been considered as a synthetic AAS. Nevertheless, the reoccurring detection of dienedione in entire male horse urine samples led to the investigation of its possible endogenous nature in horses, and its endogenous nature in entire male horses has been recently ...
Brooks J, Maeda T, Ringhofer M, Yamamoto S.The oxytocinergic system has been suggested to make up an important part of the endocrine basis of group cohesion. However, controlled studies in open-group settings have not been performed. We here investigated the impact of exogenous intranasal oxytocin on the group-level social organization of 5 groups of horses ( = 58; 12 mares and 46 geldings) through GPS tracking and social network analysis. We find oxytocin flattened social differentiation across levels. Most strikingly, oxytocin did not simply reinforce existing bonds but selectively shifted social preferences toward homogenization -...
Luick ML, Khouzam NA, Pérez-Nogués M.To establish racing prognosis in Thoroughbred yearlings with proximal sagittal ridge osteochondral lesions and compare them to dorsoproximal and palmar/plantar first phalanx osteochondral lesions. Methods: A total of 47 horses had proximal sagittal ridge lesions, 34 had palmar/plantar first phalanx lesions, and 115 had dorsoproximal first phalanx lesions. Methods: Retrospective case series. Methods: Medical records of Thoroughbred yearling racing prospects treated arthroscopically for fetlock osteochondral lesions were reviewed. Data were collected from a public database, including the ability...
Omyla K, Conley A, Varner D, Dini P.Persistent stallion-like behavior is a common sign of cryptorchidism in supposed geldings. The presence of testicular tissue can be evaluated by analyzing hormones such as testosterone and anti-Müllerian hormone (AMH). Here, we used hormonal analysis to investigate relationships between the likely presence of testicular tissue and stallion-like behavior in samples submitted from presumptive geldings (n = 1,202), retrospectively. Most geldings with stallion-like behaviors had serum concentrations of testosterone (851/1,056; 80.6 %) and AMH (682/877; 77.8 %) below the laboratory reference range...
Karasu GK, Rogers CW.The aim of this study was to estimate the potential for nutrient leaching based on current feeding practices of horses in the Netherlands. An online survey of horse owners collected data on the demographics of the horses (n = 274) and feeding practices. The median age was 8 years, the majority being warmblood and geldings with a mean bodyweight of 542.4 ± 101.9 kg. Most horses (85 %) had access to a limited area of pasture (<200m2 per horse), with a median grazing time of 10 hours. Grass hay was the predominant conserved forage offered (77 %) within diets. Concentrate feeds were provided to m...
Artman JL, Wesolowski LT, Semanchik PL, Isles JK, Norton SA, White-Springer SH.We aimed to test the hypothesis that repeated muscle collections would impact mitochondrial function, antioxidant status, and markers of inflammation and muscle damage. Twenty-six horses (8 geldings, 18 mares; mean±SD 9.5±3.5 y) had gluteus medius muscle biopsy samples collected at: 0 and 24h (n=7); 0 and 6h (n=6); 0, 6, and 12h (n=7); or 0, 6, 12, and 24h (n=6). Blood was collected from all horses every 6h for 72h, starting 24h prior to the 0h muscle collection. Data were analyzed using mixed linear models. Muscle integrative (per mg tissue) electron transfer capacity of complex II decrease...
Rankins EM, McKeever KH, Malinowski K.Little literature exists on horses in adaptive horsemanship (AH) despite concerns about their well-being. The study objective was to evaluate behavioral and physiological responses of horses to ground-based AH lessons for veterans with post-traumatic stress disorder (PTSD). Lessons were expected to alter horses' hormone concentrations, behavior, and muscle activity. Geldings were assigned to AH (n=6; 20.3 ± 1.9 yrs., mean ± SE) or control (CON; stall in arena, n=6; 13.8 ± 1.7 yrs.) conditions for 8-week sessions based on current occupation (AH = equine-assisted services; CON = recreational ...
Bell T, Kyriazopoulou P, Mowbray C, Murphy BA.Equine headshaking syndrome is a poorly understood neuropathic pain condition presenting as uncontrollable shaking, flicking, or striking of the head. Therapeutic options are limited, and treatments are only partially successful. Currently, epidemiological information on headshaking in the Southern Hemisphere is lacking. An online survey was circulated to Australian owners of headshaking horses to collect information on triggers, symptoms, seasonality, treatments, and perceived treatment efficacy. The responses (n = 216) showed the mean age at symptom onset as 9.6 (±4.7) years. More geldings ...
Hoffman RM, Boston RC, Stefanovski D, Kronfeld DS, Harris PA.Insulin resistance is considered a risk factor in obesity, laminitis, exertional rhabdomyolysis, and osteochondrosis. The objective was to use the minimal model to estimate glucose effectiveness (Sg) and insulin sensitivity (Si) in nonobese to obese horses initially adapted to forage only, then adapted to forage plus supplements rich in starch and sugar (SS) or fiber and fat (FF). Ten Thoroughbred geldings, with BCS of 5 (nonobese), 6 (moderately obese), and 7 to 8 (obese), were adapted to pasture and hay, allocated to two groups, and fed SS or FF in a switch-back design with 8 wk of adaptatio...
Wagnerová P, Sak B, Květoňová D, Buňatová Z, Civišová H, Maršálek M, Kváč M.Faecal samples were collected from 377 horses on 23 farms with varying management systems in the Czech Republic. Microsporidia were found on 16 farms and the overall prevalence of Enterocytozoon bieneusi and Encephalitozoon cuniculi was 17.3% (66/377) and 6.9% (26/377), respectively. The prevalence of E. cuniculi in horses over 3 years of age was significantly higher (10.0%) compared to younger horses (4.0%). No significant differences in prevalence were observed among stallions, geldings, and mares for both microsporidia. Significantly higher infection rates of E. bieneusi and E. cuniculi wer...
Rüegg SR, Torgerson P, Deplazes P, Mathis A.Epidemiological factors of tick-borne equine piroplasmoses, caused by Theileria equi and Babesia caballi, were investigated using logistic regression (GLM) and general additive models (GAM) based on the prevalences determined in 510 domestic horses and in ticks in S.W. Mongolia by indirect immunofluorescence antibody test (IFAT) and/or multiplex PCR. Prevalences of T. equi and B. caballi in horses were 66.5% (95% CI: 62.1-70.7) and 19.1% (15.6-22.9), respectively by PCR and 78.8% (74.9-82.3) and 65.7% (61.3-69.9) by IFAT. Of 166 ticks analysed from PCR- and IFAT-negative horses 1 was PCR posit...
Jensen RB, Danielsen SH, Tauson AH.Obesity is related to the development of several diseases like insulin resistance and laminitis in horses. The prevalence of obesity among mature Icelandic horses in Denmark has not been investigated previously. This study aimed to find the prevalence of obesity, to compare body condition score (BCS) based on owner perception with that of an experienced person and to correlate the BCS to body weight (BW) and morphometric measures in a group of mature Icelandic horses in Denmark. A total of 254 Icelandic horses (≥4 years; 140 geldings, 105 mares, 9 stallions) from 46 different farms were inc...
Carter RA, McCutcheon LJ, Valle E, Meilahn EN, Geor RJ.To determine effects of exercise training without dietary restriction on adiposity, basal hormone and lipid concentrations and glucose and insulin dynamics in overweight or obese, insulin-resistant horses. Methods: 12 overweight or obese (body condition score > or = 7), insulin-resistant (insulin sensitivity < or = 1.2 x 10(-4) L/min/mU) geldings. Methods: 4 horses remained sedentary, and 8 horses were exercised for 4 weeks at low intensity and 4 weeks at higher intensity, followed by 2 weeks of detraining. Prior to and after each training period, frequently sampled IV glucose tolerance ...
Kornaś S, Cabaret J, Skalska M, Nowosad B.A 11-year survey on helminth intestinal infection of horses was done in seven provinces of southern Poland. 21,641 faecal samples were collected from horses of different age, sex, breed and management system originating from 84 farms. Age was the major factor influencing the cyathostome egg excretion, the maximum being observed in yearlings and second year horses. Parascaris was found mostly in foals and yearlings. The main factor for Anoplocephala was the access to pasture. The level of cyathostome egg shedding (EPG) could be related to sex (geldings had higher values of EPG), breed (Thorough...
Murray MJ, Eichorn ES.To determine the effect of decreasing gastric acidity in a feed-deprivation protocol on induction of gastric ulcers, and to determine whether stall confinement may be a factor contributing to gastric ulceration in horses. Methods: 8 adult horses, 4 geldings and 4 mares, 3 to 8 years old, and 7 adult horses, 5 geldings and 2 mares, 4 to 11 years old. Methods: Gastric ulceration was induced in horses by alternating 24-hour periods of feed deprivation and ad libitum access to hay, for a total of 96 hours' feed deprivation. This protocol was repeated with the horses receiving the histamine type-2 ...
Wilk I, Wnuk-Pawlak E, Janczarek I, Kaczmarek B, Dybczyńska M, Przetacznik M.It was assumed that a horse with its rider body weight found in the upper limit may negatively impact the horse's welfare. The objective of this paper was to analyze the differences in body temperature and selected heart rate parameters in horses in response to physical exercise accompanied by various rider's body weight loads. The study was carried out on 12 leisure, 10-15-year-old warmblood geldings. The horses were ridden by two equally qualified riders whose body weights were about 20% and 10% of the average body weight (BW) of the animals (about 470 kg). Each rider rode each of the 12 hor...
Kindig CA, McDonough P, Erickson HH, Poole DC.There is evidence that oxidative enzyme inertia plays a major role in limiting/setting the O(2) uptake (VO(2)) response at the transition to higher metabolic rates and also that nitric oxide (NO) competitively inhibits VO(2) within the electron transport chain. To investigate whether NO is important in setting the dynamic response of VO(2) at the onset of high-intensity (heavy-domain) running in horses, five geldings were run on a treadmill across speed transitions from 3 m/s to speeds corresponding to 80% of peak VO(2) with and without nitro-L-arginine methyl ester (L-NAME), an NO synthase in...
Love EJ, Taylor PM, Murrell J, Whay HR.To investigate the antinociceptive effects of buprenorphine administered in combination with acepromazine in horses and to establish an effective dose for use in a clinical environment. Objective: To evaluate the responses to thermal and mechanical stimulation following administration of 3 doses of buprenorphine compared to positive (butorphanol) and negative (glucose) controls. Methods: Observer blinded, randomised, crossover design using 6 Thoroughbred geldings (3-10 years, 500-560 kg). Thermal and mechanical nociceptive thresholds were measured 3 times at 15 min intervals. Horses then rec...
Madigan JE, Bell SA.To determine signalment, history, clinical signs, duration, seasonality, and response to various treatments reported by owners for headshaking in horses. Methods: Owner survey. Methods: 109 horses with headshaking. Methods: Owners of affected horses completed a survey questionnaire. Results: 78 affected horses were geldings, 29 were mares, and 2 were stallions. Mean age of onset was 9 years. Headshaking in 64 horses had a seasonal component, and for most horses, headshaking began in spring and ceased in late summer or fall. The most common clinical signs were shaking the head in a vertical pla...
Marr CM, Love S, Boyd JS, McKellar Q.Ultrasonographic examination was used to define the severity of injuries to the superficial digital flexor tendon in 73 National Hunt or point-to-point racehorses and the factors influencing the outcome of the cases were examined. Thirty-four of the horses (46 per cent) returned to work with an average time out of training of 13.5 months. The rate of recurrence of the injury was 35 per cent. The severity of the lesions was related to the outcome; all the mildly affected horses returned to work, with 63 per cent of them racing and an average time out of training of 10.2 months; 50 per cent of t...
Crowhurst FA, Dickinson G, Burrows R.An outbreak of paresis occurred on a small isolated stud farm in July 1980. Of the 42 horses on the stud, infection was confined to a group of nine in-foal mares and their foals and eight other horses which were either housed together at night or grazed adjacent pastures. Eight mares and two geldings developed ataxia or paresis and one mare died. Equid herpesvirus 1 was isolated from 17 animals and serological studies confirmed that 24 of 26 animals sampled had experienced infection.
Colborn DR, Thompson DL, Roth TL, Capehart JS, White KL.Sexual stimulation induces rapid secretion of cortisol and prolactin (PRL) in stallions. Experiment 1 was designated to determine whether stallions associated location and(or) procedure with previous sexual stimulation in that location. After a control period on d 1, four stallions were exposed to an estrous mare for 5 min on d 2. On d 3, 4, 5, and 6, the same procedure was followed with no mare present. Concentrations of PRL and cortisol increased (P less than .05) after mare exposure on d 2 but did not vary (P greater than .05) on d 1, 3, 4, 5, or 6. In Exp. 2, six stallions were used to det...
Abutarbush SM, Carmalt JL, Shoemaker RW.The medical records of equine gastrointestinal colic cases presented to the Western College of Veterinary Medicine between 1992 and 2002 are reviewed. There was no breed predisposition to colic. Geldings were more prone to colic than females and stallions. Overall, the 3 most common causes of colic were large colon impaction (20.8%), large colon displacement (16.5%), and spasmodic colic (11.7%), after excluding the 13% of cases in which the diagnosis was undetermined. Of the medical cases, large colon impaction (38.4%) and spasmodic colic (22.5%) were the most common. Of the surgical cases, la...
Friday PA, Scarratt WK, Elvinger F, Timoney PJ, Bonda A.An outbreak of neurologic disease associated with serologic evidence of equine herpesvirus type 1 (EHV-1) infection occurred in a herd of 46 riding school horses. Ataxia and paresis were observed in 14 geldings and 5 barren mares. Eight affected horses had distal limb edema, 1 horse had a head tilt, and 3 others had urinary incontinence. Other clinical signs included fever, depression, and inappetance in 30 horses. Seven horses with neurologic signs were treated with acyclovir. Serum neutralizing antibody titers against EHV-1 increased 4-fold between acute and convalescent samples or exceeded ...
Claes A, Ball BA, Almeida J, Corbin CJ, Conley AJ.Anti-Müllerian hormone (AMH), a homodimeric glycoprotein, is secreted early in fetal life when it exerts a crucial function in sexual differentiation. The secretion of AMH in male humans persists after birth and is characterized by high prepubertal concentrations followed by a significant decrease at the onset of puberty. The expression of AMH in the normal and cryptorchid equine testis is well characterized but data regarding circulating AMH concentrations are lacking. The objectives of this study were to determine serum AMH concentrations in neonatal colts and fillies, prepubertal colts, an...
The Journal of heredityFebruary 16, 2016
Volume 107, Issue 3 214-219 doi: 10.1093/jhered/esw007
Jacobs LN, Staiger EA, Albright JD, Brooks SA.Shared signaling pathways utilized by melanocytes and neurons result in pleiotropic traits of coat color and behavior in many mammalian species. For example, in humans polymorphisms at MC1R cause red hair, increased heat sensitivity, and lower pain tolerance. In deer mice, rats, and foxes, ASIP polymorphisms causing black coat color lead to more docile demeanors and reduced activity. Horse (Equus caballus) base coat color is primarily determined by polymorphisms at the Melanocortin-1 Receptor (MC1R) and Agouti Signaling Protein (ASIP) loci, creating a black, bay, or chestnut coat. Our goal was...
Schreiber CM, Stewart AJ, Kwessi E, Behrend EN, Wright JC, Kemppainen RJ, Busch KA.To determine whether seasonal variations exist in endogenous plasma ACTH, plasma α-melanocyte-stimulating hormone (α-MSH), serum cortisol, and serum insulin concentrations and in the results of a dexamethasone suppression test for older, clinically normal geldings in Alabama. Methods: Cohort study. Methods: 15 healthy mixed-breed geldings (median age, 14 years). Methods: Sample collection was repeated monthly for 12 months. Dexamethasone (0.04 mg/kg [0.02 mg/lb], IM) was administered and cortisol concentrations were determined at 15 and 19 hours. Radioimmunoassays were used to measure ACTH, ...
Aune A, Fenner K, Wilson B, Cameron E, McLean A, McGreevy P.Horse trainers and riders may have preconceived ideas of horse temperament based solely on the sex of the horse. A study (n = 1233) of horse enthusiasts (75% of whom had more than 8 years of riding experience) revealed that riders prefer geldings over mares and stallions. While these data may reflect different sex preferences in horses used for sport, they may also reduce the chances of some horses reaching their performance potential. Further, an unfounded sex prejudice is likely to contribute to unconscious bias when perceiving unwanted behaviours, simplistically attributing them to demograp...
Earing JE, Cassill BD, Hayes SH, Vanzant ES, Lawrence LM.The objective of this study was to determine if in vitro methodologies developed for the Ankom Daisy(II) incubator could produce accurate estimates of in vivo equine DM digestibility (DMD) and NDF digestibility (NDFD) when equine feces were used as the inoculum source. Four mature geldings were utilized in a 4 × 4 Latin square design experiment with a 2 × 2 factorial arrangement of dietary treatments (timothy hay, alfalfa hay, timothy hay plus oats, and alfalfa hay plus oats), in which the geldings were individually housed and fed. During each 5-d total fecal collection period, feces were co...
Velie BD, Knight PK, Thomson PC, Wade CM, Hamilton NA.Studies of Thoroughbred racing populations have provided evidence of a positive effect on racing careers for horses that commence racing as 2-year-olds. Currently, research investigating the presence of this effect in the Australian Thoroughbred racing population is limited. Objective: To investigate the association between age at first start and career length in the Australian Thoroughbred population and estimate the risk of racing retirement for horses racing in Australia based on age at first start, career earnings, number of starts as a 2-year-old and distance raced. Methods: Data were col...
Shkap V, Cohen I, Leibovitz B, Savitsky , Pipano E, Avni G, Shofer S, Giger U, Kappmeyer L, Knowles D.Sera from 361 horses were tested by indirect immunofluorescence antibody test (IFA) and by competitive inhibition ELISA (cELISA), to detect antibodies to Babesia equi. The concordance between the assays was 95.7%. Application of a cutoff based on a calculated percent inhibition of 20% inhibition was used. Approximately one-third of all the horses tested were found serologically positive to B. equi, with more horses testing positive from northern Israel. Among horses raised with access to pasture there was a significant difference in the percentage of seropositive reactors (76.6% in the north ...
van den Top JG, de Heer N, Klein WR, Ensink JM.Preputial and penile tumours are more common in horses than in other domestic animals, but no large surveys of male horses with tumours of the external genitalia are available. Objective: To present a retrospective analysis of male horses with neoplasms of the external genitalia. Methods: The penile and preputial tumours of 114 horses were evaluated. Data recorded included age, gelding or stallion and breed; type and site of lesion; involvement of regional lymph nodes; histopathology (including grading of squamous cell carcinoma); and results of radiographic examination of the thorax. Results:...
Delling U, Lindner K, Ribitsch I, Jülke H, Brehm W.The objective of this study was to compare bone marrow (BM) aspirates from the sternum and the tuber coxae of middle-aged horses. Bone marrow was obtained from the sternum and both tubera coxae of 12 healthy, 13-year-old geldings. Two different puncture techniques were used for the tuber coxae. The 2 syringes used for sternal sampling were evaluated separately. The mononuclear cell (MNC) fraction of the BM was isolated and the mesenchymal stem cells (MSCs) were culture-expanded. At the sternum, BM aspiration was always possible. Bone marrow aspiration at the tuber coxae required straight and d...
McCollum WH, Little TV, Timoney PJ, Swerczek TW.Twelve geldings all became infected when inoculated intranasally with the KY-84 strain of equine arteritis virus (EAV), a strain previously shown to be capable of establishing the carrier state in the stallion. With the exception of one animal that showed no effects other than pyrexia, all of the geldings developed clinical signs characteristic of equine viral arteritis (EVA). The geldings were febrile for varying periods within the range of 2-10 days after inoculation. Viraemia occurred from day 2 onwards, for periods varying from 9 to at least 19 days. Nasal shedding of virus began 2-4 days ...
Dhakal P, Tsunoda N, Nakai R, Kitaura T, Harada T, Ito M, Nagaoka K, Toishi Y, Taniyama H, Gen W, Taya K.Changes in follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, immunoreactive(ir)-inhibin, testosterone, estradiol-17β, and insulin-like growth factor (IGF)-I in Thoroughbred stallions along with changes in prolactin secretion in geldings were studied. The correlations of day-length with changes in the concentrations of these hormones were also studied. Five stallions and thirteen geldings were employed to draw blood samples in monthly basis and radioimmunoassay was performed to measure these hormones. All hormones showed a seasonal pattern, the levels being highest durin...
Spier SJ, Carlson GP, Holliday TA, Cardinet GH, Pickar JG.Eleven horses (3 mares, 7 stallions, 1 gelding) with clinical and biochemical evidence of hyperkalemic periodic paralysis were studied. Each horse had history of episodic weakness, muscular tremors, or collapse, which lasted for periods of a few minutes to hours. Diagnosis was based on hyperkalemia in association with a spontaneous episode of paralysis or by precipitation of an episode by oral administration of potassium chloride. Clinical and biochemical events were documented during spontaneous and induced episodes of muscular weakness. During episodes, electrocardiographic findings were con...
Prinsloo M, Hynd P, Franklin S, Weaver S, van den Boom R.Equine squamous gastric disease (ESGD) is common in horses and many factors, including stress, may play a role in lesion development. Hair cortisol concentration (HCC) provides a measure of medium to long-term stress and therefore, the relationship between HCC and ESGD was examined in this study. Hair samples were collected from 25 horses and gastroscopy was performed to determine the presence and severity of ESGD. Hair cortisol concentrations were lower in horses with ESGD (P = 0.014), and negatively correlated with lesion severity. Mares had lower HCC than geldings (P = 0.031), and a...
Pearce SG, Bouré LP, Taylor JA, Peregrine AS.A 12-year-old Arabian gelding with a granuloma caused by the nematode Halicephalobus gingivalis caudal and dorsal to the left orbit was examined. There was no evidence of dissemination of the nematode to the kidneys or the CNS, and the horse was treated with ivermectin (1.2 mg/kg [0.55 mg/lb] of body weight, p.o., every 2 weeks for 3 treatments). The granuloma was surgically debulked 2 days after the first dose of ivermectin. The granuloma resolved with no evidence of nematode infection after 18 months. Halicephalobus gingivalis is a ubiquitous saprophytic nematode that has been reported to in...
