The study of diseases in horses encompasses a wide range of conditions affecting equine health, including infectious diseases, metabolic disorders, and genetic abnormalities. These diseases can impact various systems within the horse, such as respiratory, gastrointestinal, and musculoskeletal systems, and can lead to significant health challenges. Research in this area focuses on understanding the pathophysiology, diagnosis, prevention, and treatment of equine diseases. Common diseases studied include equine influenza, equine herpesvirus, and laminitis. This page provides access to peer-reviewed research studies and scholarly articles that explore the etiology, clinical presentation, and management strategies of diseases in horses, contributing to the advancement of equine veterinary medicine.
Horsington J, Lynch SE, Gilkerson JR, Studdert MJ, Hartley CA.Of the many members that comprise the family Picornaviridae, only two species are known to infect horses: equine rhinitis A virus (ERAV) and equine rhinitis B virus (ERBV). Each species now occupies a distinct phylogenetic branch within the family, with the single serotype of ERAV grouping with the aphthoviruses, such as foot-and-mouth disease virus (FMDV), and the three serotypes of ERBV as the sole members of the genus Erbovirus. The high seroprevalence of equine picornaviruses in horse populations worldwide contrasts with the relatively few reports of detection of these viruses and poor und...
Miao Q, Wang X, She LN, Fan YT, Yuan FZ, Yang JF, Zhu XQ, Zou FC.Toxoplasma gondii is an intracellular protozoan parasite that infects almost all warm-blooded animals, including humans, with a worldwide distribution. There have been limited reports about the seroprevalence of T. gondii infection in equids around the world and little is known about the seroprevalence of T. gondii in equids in southwestern China, in particular in Yunnan Province. The objective of the present investigation was to estimate the seroprevalence of T. gondii infection in equids in this area. Methods: A total of 399 serum samples (266 from horses and 133 from donkeys) were collected...
Welsh CE, Lewis TW, Blott SC, Mellor DJ, Lam KH, Stewart BD, Parkin TD.A retrospective cohort study of important musculoskeletal conditions of Thoroughbred racehorses was conducted using health records generated over a 15 year period (n=5062, 1296 sires). The prevalence of each condition in the study population was: fracture, 13%; osteoarthritis, 10%; suspensory ligament injury, 10%; and tendon injury, 19%. Linear and logistic sire and animal regression models were built to describe the binary occurrence of these musculoskeletal conditions, and to evaluate the significance of possible environmental risk factors. The heritability of each condition was estimated us...
Cao X, Vidyashankar AN, Nielsen MK.Decades of intensive anthelmintic treatment has caused equine large strongyles to become quite rare, while the cyathostomins have developed resistance to several drug classes. The larval culture has been associated with low to moderate negative predictive values for detecting Strongylus vulgaris infection. It is unknown whether detection of other large strongyle species can be statistically associated with presence of S. vulgaris. This remains a statistical challenge because of the rare occurrence of large strongyle species. This study used a modified Poisson regression to analyse a dataset fo...
Xie J, Liu G, Tian Z, Luo J.Several approaches have been developed for diagnosis of Theileria equi infection in horses and donkeys but all of them have limitations in practice. Due to numerous strengths including easy operation, cheapness and high sensitivity and specificity, LAMP has been already extensively used for surveillance of a number of diseases. We here set up a LAMP assay based on 18S rRNA gene for T. equi diagnosis. The approach was specific enough to differentiate T. equi from other evolutionary-related protozoa. Moreover, it was sensitive enough that LAMP was capable of detecting as much low as 10 copy targ...
Gordon S, Bolwell C, Rogers C, Guthrie A, Magunda F, Hove P.A study of the prevalence of African horse sickness in horses was conducted, using records from two private equine practices in Harare for the period 1998-2004. Results indicated a higher prevalence of the disease in horses in Zimbabwe in the late rainy season (March - May). Age of the horse was found to be a significant risk factor, with foals or yearlings appearing to be 1.80 times more likely to contract the disease compared with horses older than two years. The case fatality rate in foals or yearlings was also higher than in older age groups, but this difference was not significant. The va...
Pacyńska JA.Horses are characterized by a very high incidence of mycoses in comparison with most livestock and companion animals. They are highly susceptible to asymptomatic infections caused by yeast-like fungi, but the carrier state may be disrupted under the influence of autogenic and allogenic factors. The above leads to severe organ mycoses, often with an acute form of infection. "Carrier horses" may also act as vectors which transmit potential pathogens between individuals and species. The aim of this study was to identify yeast-like fungi and yeast colonizing the ontocenoses of healthy horses and t...
Harlow BE, Lawrence LM, Flythe MD.Antibiotics are important to equine medicine, but antibiotic-associated diarrhea (AAD) can lead to poor performance and even mortality. AAD is attributed to disruption of the hindgut microbiota, which permits proliferation of pathogenic microbes. The goal of this study was to evaluate the effects of common antibiotics on cellulolytic bacteria, lactobacilli, and AAD-associated pathogens in the feces of healthy horses. Fifteen horses were assigned to three treatment groups (blocked by age and sex): control (no antibiotics), trimethoprim-sulfadiazine (PO), or ceftiofur (IM). Fecal samples (n=8 pe...
Fontaine P, Blond L, Alexander K, Beauchamp G, Richard H, Laverty S.Osteochondrosis dissecans (OCD) is a focal failure of endochondral ossification of the epiphysis characterized by the presence of cartilage flaps and osteochondral fragments. The objective of this study was to image epiphyseal development in the equine pelvic limb to determine whether there was a variation in site maturation that could be a predisposing factor for OCD. Pelvic limbs (fetuses and foals) were studied post-mortem. The epiphyses of the distal femur, tibia and talus were scanned with computed tomography (CT) and 1.5T magnetic resonance imaging (MRI) to investigate the degree and pat...
Wagnerová P, Sak B, Květoňová D, Maršálek M, Langrová I, Kváč M.A total of 9 (8 stallions and 1 mare) 1 year old ponies were used for the experimental infection caused by Encephalitozoon cuniculi genotype II (10(7) spores per animal). Subsequently, individual horses were slaughtered 7, 14, 21, 28, 35, 42, 49, 56, and 63 days post infection. Immediately after slaughter, tissues samples of stomach, duodenum, jejunum, ileum, caecum, colon, spleen, liver, kidney, bladder, heart, lungs, and brain were sampled. In addition, urine, feces and blood specimens were collected. Enzyme-linked immunosorbent assay was used for determination of humoral immune response and...
Trachsel DS, Schwarzwald CC, Bitschnau C, Grenacher B, Weishaupt MA.Atrial natriuretic peptide (ANP) and cardiac troponin I (cTnI) serve as biomarkers for increased cardiac pressure/volume loading and for myocardial stress or damage. The objective was to describe the time course of plasma ANP concentrations (CpANP) and plasma cTnI concentrations (CpcTnI) in horses with mitral regurgitation (MR) compared to healthy horses at rest and after exercise, and to describe the relationship of CpANP with cardiac dimensions and intracardiac pressures. Methods: 15 healthy Warmblood horses and 7 Warmblood horses with MR. Methods: Cardiac dimensions at rest were measured us...
Qablan MA, Oborník M, Petrželková KJ, Sloboda M, Shudiefat MF, Hořín P, Lukeš J, Modrý D.Microscopic diagnosis of equine piroplasmoses, caused by Theileria equi and Babesia caballi, is hindered by low parasitaemia during the latent phase of the infections. However, this constraint can be overcome by the application of PCR followed by sequencing. Out of 288 animals examined, the piroplasmid DNA was detected in 78 (27·1%). Multiplex PCR indicated that T. equi (18·8%) was more prevalent than B. caballi (7·3%), while mixed infections were conspicuously absent. Sequences of 69 PCR amplicons obtained by the 'catch-all' PCR were in concordance with those amplified by the multiplex str...
Sipma KD, Cornillie P, Saulez MN, Stout TA, Voorhout G, Back W.Hydrocephalus is uncommon in horses. However, in recent years, it has become clear that the prevalence of hydrocephalus is greater in Friesian horses than in other breeds probably due to their limited gene pool. Before identification of candidate genes that predispose to the development of hydrocephalus in Friesian horses can be pursued, an in-depth, phenotypic, pathological description of the condition in Friesians would be of great benefit. Our study aimed to characterize the morphology of hydrocephalus in Friesian horses, to support further investigation of the genetic background of this co...
Boyen F, Smet A, Hermans K, Butaye P, Martens A, Martel A, Haesebrouck F.The use of β-lactam antibiotics results in the selection of bacteria showing resistance toward this class of antibiotics. The review focuses on the increasing importance of methicillin resistant staphylococci and broad-spectrum β-lactamase-producing Enterobacteriaceae in horses. Diagnostic protocols that optimize accurate identification of these bacteria from both clinical samples and samples obtained from putative carrier animals are described. In addition, the opportunities and pitfalls for preventive and curative measures are discussed.
Ribeiro IB, Câmara AC, Bittencourt MV, Marçola TG, Paludo GR, Soto-Blanco B.This study aimed to determine whether asymptomatic horses naturally infected with Theileria equi retain infected erythrocytes in the spleen and whether the presence of the hemoparasite in this organ is associated with parasitemia. We collected samples from 25 adult horses without clinical signs of any disease. From each animal, we collected whole blood samples from the jugular vein and a splenic puncture blood sample. All samples were submited to blood cell counts and detection of Theileria or Babesia. DNA extraction and PCR were performed in all samples for identification of piroplasm infecti...
Tozer SJ, Lambert SB, Strong CL, Field HE, Sloots TP, Nissen MD.Q fever is a vaccine-preventable disease; despite this, high annual notification numbers are still recorded in Australia. We have previously shown seroprevalence in Queensland metropolitan regions is approaching that of rural areas. This study investigated the presence of nucleic acid from Coxiella burnetii, the agent responsible for Q fever, in a number of animal and environmental samples collected throughout Queensland, to identify potential sources of human infection. Samples were collected from 129 geographical locations and included urine, faeces and whole blood from 22 different animal s...
Laatamna AE, Wagnerová P, Sak B, Květoňová D, Aissi M, Rost M, Kváč M.Faecal samples from two horse farms in Algeria keeping Arabian, Thoroughbred, and Barb horses were examined for the presence of Cryptosporidium in 2010-2011. A total of 138 faecal samples (16 from a farm keeping 50 animals and 122 from a farm with 267 horses) were screened for Cryptosporidium spp. infection using molecular tools. DNA was extracted from all samples. Nested PCR was performed to amplify fragments of the SSU rDNA and gp60 genes to determine the presence of Cryptosporidium species and genotypes. Sequence analyses of SSU and gp60 genes revealed four animals positive for the presence...
Cordeiro Rde A, Bittencourt PV, Brilhante RS, Teixeira CE, Castelo-Branco Dde S, Silva ST, De Alencar LP, Souza ER, Bandeira Tde J, Monteiro AJ....Respiratory infections are a common problem among equines and occur with variable rates of morbidity and mortality. Although some fungal species are considered primary agents of respiratory tract infections in several mammals, their relevance in respiratory diseases of equines is frequently neglected. In the present study, we performed an active search for Candida spp. in the nasal cavity of horses. The presence of Candida spp. was investigated through the use of nasal swabs that were streaked on culture media. These yeasts were identified through physiological testing and their in vitro antif...
Schwab U, Caldwell S, Matychak MB, Felippe J.We developed a 3-D equine bronchial epithelial cell (BEC) culture that fully differentiates into ciliary beating and mucus producing cells. Using this system, we evaluated how mucus affects the phagocytic activity of macrophages. Adult horse monocyte-derived macrophages were incubated with Rhodococcus equi for 4h either in the mucus layer of in vitro generated airway epithelium or on collagen coated membranes. Using light and electron microscopy, we noted that the number of macrophages with intracellular bacteria, and the number of intracellular bacteria per macrophage were lower in the presen...
Cushing TL.A 4-year-old crossbred Quarterhorse mare was submitted to the Clemson Veterinary Diagnostic Center for necropsy examination with a chronic history of inappetence, weight loss and lethargy. Prior to death the horse had developed mild diarrhoea and began showing evidence of colic. Necropsy examination revealed a markedly enlarged heart due predominantly to marked dilation of the right atrium, tortuous congested mesenteric blood vessels, marked ascites, pleural effusion and pulmonary oedema. Further examination of the heart showed the endocardium of the left side of the heart, including the mitra...
Denoix JM, Jacquet S, Lepeule J, Crevier-Denoix N, Valette JP, Robert C.Radiographic examination in young horses is commonly used to detect juvenile osteochondral conditions (JOCC). The aim of this study is to present the radiographic findings (RF) detected at the age of 6months in the joints of 392 foals from three breeds: French Trotter Standardbreds (FT), Selle-Français Warmbloods (SF) and Thoroughbreds (TB). Radiographic examination included lateromedial views of the fore and hind digits, tarsi and stifles, and dorsopalmar projections of both carpi. In all areas RF indicative of JOCC were classified according to a four-grade severity scoring system. Distribut...
Rushton JO, Lecollinet S, Hubálek Z, Svobodová P, Lussy H, Nowotny N.An unexpectedly high infection rate (26.1%) of tick-borne encephalitis virus (TBEV) was identified in a herd of 257 horses of the same breed distributed among 3 federal states in Austria. Young age (p<0.001) and male sex (p=0.001) were positively associated with infection.
Perrucci S, Buggiani C, Sgorbini M, Cerchiai I, Otranto D, Traversa D.Cryptosporidium infection was molecularly investigated in mares and in their neonatal foals for which the occurrence of foal heat diarrhoea was also assessed. Thirty-seven mare/foal pairs were included in the study. All foals were born in the same stud farm during 2006-2008 breeding seasons. Two faecal samples, one prior to and one after delivery were collected from each mare, whereas three faecal samples were taken from each foal, i.e. at 8, 10 and 12 days of age. All samples (74 from mares and 111 from foals) were divided into two aliquots, one of which was examined for the presence of Crypt...
Oliveira T, Santos A, Silva J, Trindade P, Yamada A, Jaramillo F, Silva L, Baccarin R.In humans, hospitalisation, disease type, and environmental factors evidently affect the quality of sleep, further influencing patient recovery. The objective of the present study was to report the resting and lying behaviour of hospitalised horses, and whether lying behaviours differ depending on the physiological severity of joint damage. We hypothesised that the resting and lying behaviour can change during the hospitalisation and physiological severity of joint damage affect the time of rest in horses. A descriptive observational study was performed to evaluate the effect of hospitalisatio...
Bedenice D, Heuwieser W, Brawer R, Solano M, Rand W, Paradis MR.A total of 207 thoracic radiographs obtained from 128 foals were evaluated to assess the impact of pulmonary radiographic pattern, distribution, and severity of pulmonary changes on short-term survival of neonatal foals. The association between selected clinical variables and the radiographic manifestation of neonatal respiratory disease was also investigated. The evaluation of interstitial and alveolar-interstitial radiographic patterns within the caudodorsal, caudoventral, and cranioventral lung regions proved to be highly reliable between viewers in the study. A diagnosis of systemic inflam...
Malan FS, Reinecke RK, Scialdo RC.The entire gastro-intestinal tract and viscera of the abdomen and thorax, including the heart, aorta and its branches to the viscera, are removed from the carcass. All the branches of the aorta, with the exception of the A. gastrica sinistra, are dissected from the intestinal tract, and subsequently each branch is isolated from the mesentery, fat, pancreas, kidneys, etc. Usually, the A. ileocolica is grossly enlarged due to chronic arteritis with thrombus formation caused by 4th stage larvae, 4th moult and 5th stage Strongylus vulgaris. Descriptions of methods to examine the subperitoneal tiss...
Ladds PW, Thomas AD, Pott B.A case of acute meningoencephalomyelitis caused by infection with Pseudomonas pseudomallei is described. Clinically there was inability to stand, opisthotonus, facial paralysis and nystagmus, rapidly progressing to violent struggling. Gross examination revealed malacia and haemorrhage in the medulla oblongata and adjacent spinal cord. Microscopically there were disseminated focal neutrophilic accumulations in affected areas, perivascular cuffing with mononuclear cells and lymphocytes and marked oedema. Intracellular bacteria were identified in sections stained by the Giemsa method.
Anwer MS, Engelking LR, Gronwall R, Klentz RD.Plasma bile acid concentration was determined in normal dogs,sheep, calves and ponies for three days before and six days after liver damage, induced by carbon tetrachloride. In all species, a significant increase in plasma bile acid concentration was associated with a concomitant significant increase in plasma sorbitol dehydrogenase and transferase activity. Plasma bilirubin also significantly increased in all animals except the dogs. Results suggested that plasma bile acid levels could be used to test liver function in domestic animals.
Hurtado C, Torres R, Pérez-Macchi S, Sagredo K, Uberti B, de Souza Zanatto DC, Machado RZ, André MR, Bittencourt P, Müller A.Anaplasma phagocytophilum is the causative agent of equine granulocytic anaplasmosis (EGA). This study aimed to perform serological and molecular surveys of A. phagocytophilum in thoroughbred horses from racecourses in Chile. Additionally, hematological findings related to A. phagocytophilum molecular positivity were addressed, and phylogenetic analysis of selected positive samples was performed. Complete blood count and msp2 gene real-time PCR were performed in 457 thoroughbred horses from three racecourses located in three different cities of Chile (Santiago, Viña del Mar and Concepción). ...
Zink MC, Johnson JA.Bronchoalveolar lavage was performed 5 times, sequentially, on 3 healthy foals when each was between 2 and 63 days of age. Total and differential counts were performed on recovered cells. The lungs of foals less than 19 days of age contained few alveolar macrophages recoverable by bronchoalveolar lavage. This number increased sharply during the first 2 to 3 weeks of life, but remained relatively constant subsequently. Approximately 86% of the alveolar cells in the lungs of foals up to 3 weeks of age were alveolar macrophages. During the first 2 months of life, this number decreased to approxim...
Teifke JP, Weiss E.Unfixed and formalin-fixed frozen sections and paraffin-sections of histopathologically confirmed sarcoids of 20 horses were studied in the PCR. The used set of primers was located in the E5 open reading frame fitting both to bovine papillomavirus 1 (BPV-1) and BPV-2. Independent of the quality of the used tissues BPV-DNA was detected in all 20 sarcoids. By cleaving with restriction endonuclease Bst XI it was shown that the DNA-sequences amplified by PCR were identical with that of BPV-1. The results support the general view that BPV play an important role in equine sarcoids.
Paslaru AI, Torgerson PR, Veronesi E.Biting midges (Diptera: Ceratopogonidae) are arthropods of veterinary importance since they can transmit pathogens and cause severe allergic dermatitis in horses. Very little is known about the species at higher altitudes and their seasonal dynamics. In this work, adult Culicoides were collected with Onderstepoort UV-light suction traps (OVI) from June to September 2016 at two areas situated at around 1600 m asl (pre-alpine area I, 2 farms) and 2030 m asl (pre-alpine area II, 1 farm) in the Canton of Grisons (south-east Switzerland). Overall, 17 049 Culicoides were collected, including 8...
Parks A, O'Grady SE.Laminitis is divided into four different phases: developmental, acute, subacute, and chronic. The focus of this article is on treating the laminitic horse after the cessation of therapy for the acute phase, that is, usually 2 to 4 weeks after the onset of clinical signs.
de Holanda AGB, da Silva Leite J, Consalter A, da Silva KVGC, Dos Santos Batista BP, Fonseca ABM, Brandão FZ, Ferreira AMR.Endometritis consists of an acute or chronic inflammatory process involving the endometrium and together with endometrosis constitute the main causes of infertility in mares. The aim of this study was to associate the histopathological findings with the immunohistochemical markers interleukins 6 (IL-6) and 10 (IL-10) to evaluate the inflammatory changes and progression of uterine tissue lesions of mares in the diestrus phase and their diagnostic implications. Twelve crossbred cyclic mares were used for endometrial biopsy collection. Samples were collected in the diestrus period (6 ± 1 da...
Lankveld DP, Ensink JM, van Dijk P, Klein WR.Thrombophlebitis is a well-known complication of the use of long-term in-dwelling catheters. In humans, catheter material has been shown to strongly influence the occurrence of thrombophlebitis. In the horse, the influence of catheter material has been studied in healthy experimental animals, but information on the relative importance of this factor is lacking. To investigate which factors have most impact on the frequency of jugular vein thrombosis in post-surgical colic horses, a clinical study was performed on 38 animals. Horses were randomly divided into two groups. In one group a polytetr...
Patteson MW, Cripps PJ.Auscultation was used to examine 545 horses for cardiac murmurs and some arrhythmias. The most significant finding was the high prevalence of right-sided holosystolic or pansystolic plateau-type murmurs compatible with a diagnosis of tricuspid regurgitation in National Hunt racing Thoroughbreds of all ages (16.4%). This condition was found in 4.7% of flat-racing Thoroughbreds, 3.7% of non-racing Thoroughbreds and Thoroughbred crosses, and in none of the ponies examined. High prevalences of left-sided early systolic murmurs (53%), left-sided early diastolic murmurs (23%), right-sided early dias...
Boswinkel M, Sloet van Oldruitenborgh-Oosterbaan MM.The importance of Anoplocephala perfoliata in horses with colic was studied in 139 horses referred for colic and 139 control horses with no signs of colic for at least three years. The serodiagnostic method of Proudman and Trees, which measures the level of A. perfoliata antibody, was used to detect A. perfoliata infection. Thirty-two horses were examined at necropsy, to determine whether the presence of A. perfoliata in the ileocaecal region was associated with the A. perfoliata antibody level. The mean A. perfoliata antibody level was significantly higher in horses with colic than in horses ...
Waitt LH, Cebra CK.To characterize signalment, clinical signs of disease, and clinical response to insulin in equids with hypertriglyceridemia. Methods: Retrospective case series. Methods: 20 horses, 17 ponies, and 7 donkeys with hypertriglyceridemia. Methods: For analysis of medical record data, horses, donkeys, and ponies with multiple serum or plasma triglycerides measurements were separated into groups. Hypertriglyceridemic equids that were (HT-I; n = 14) or were not (HT-N; 10) treated with insulin consisted of equids with an initial triglycerides concentration > 44 mg/dL but < 500 mg/dL. Equids with an init...
MacKay RJ.Neurologic examination of the neonatal foal is quite different from the process used to examine older foals and adult horses. Abnormal neurologic signs are best appreciated in the context of a detailed knowledge of general neonatal medicine and awareness of nor-mal foal behavior and milestones of development. A systematic approach to neurologic examination is provided. The results of such examination are used to localize a lesion or lesions in the nervous system. Descriptions and treatment strategies are given for most common and important neonatal neurologic diseases.
Stokol T, Erb HN, De Wilde L, Tornquist SJ, Brooks M.Fibrin(ogen) degradation products (FDPs) and D-dimer are sensitive indicators of excessive fibrinolysis due to disseminated intravascular coagulation (DIC) in dogs. To the authors' knowledge, latex-agglutination-based plasma FDP and D-dimer assays have not been validated for use in horses. Objective: To determine: 1) sensitivity and specificity of latex agglutination serum and plasma FDP and D-dimer assays for diagnosis of DIC; and 2) their prognostic value in horses with severe colic. Methods: At hospital admission and 24 hours later, blood was collected from 30 healthy horses and 20 horses w...
Valk N, Doherty TJ, Blackford JT, Abraha TW, Frazier DL.The effect of phenylbutazone on gastric emptying in horses was determined by measuring serum concentrations of acetaminophen. Gastric emptying was determined in normal fasted horses (n = 6), horses given endotoxin intravenously (n = 6), horses given intravenous phenylbutazone (n = 6), and horses given intravenous phenylbutazone plus endotoxin (n = 6). The mean time to reach maximum serum acetaminophen concentration (Tmax), the maximum serum concentration (Cmax), and the area under the serum acetaminophen concentration versus time curve (AUC) were compared among treatment groups. Phenylbutazone...
Schlusselhuber M, Guldbech K, Sevin C, Leippe M, Petry S, Grötzinger J, Giguère S, Cauchard J.The equine antimicrobial peptide eCATH1 previously has been shown to have in vitro activity against antibiotic-susceptible reference strains of Rhodococcus equi and common respiratory bacterial pathogens of foals. Interestingly, eCATH1 was also found to be effective in the treatment of R. equi infection induced in mice. The aim of this study was to assess the in vitro activity of eCATH1 against equine isolates of Gram-negative (Escherichia coli, Salmonella enterica, Klebsiella pneumoniae and Pseudomonas spp.) and Gram-positive (R. equi, Staphylococcus aureus) bacteria resistant to multiple cla...
Fischer AT.A technique for laparoscopically assisted resection of umbilical structures in foals was developed. Eleven foals ranging from 8 to 42 days old underwent this procedure. Results of bacteriologic culture of umbilical structures were positive in 7 foals. Mean duration of anesthesia was 99 minutes, of which the initial 20 to 25 minutes were typically devoted to positioning and preparation of the foal for surgery. Major complications did not develop in any foal. Minor complications, such as slippage of the endoscopic ligating clip or laceration of the bladder during dissection, were dealt with succ...