"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.
Jarvis GE, Evans RJ, Heath MF.We have shown previously that endotoxin induces platelet aggregation in equine heparinised whole blood in a platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) dependent manner. ADP is an agonist of platelets and is present in platelet dense granules with ATP in high concentrations. An investigation was carried out to establish whether endotoxin-induced platelet activation was associated with release of platelet ATP and ADP. ADP-scavenging enzyme systems significantly inhibited endotoxin-induced aggregation. Plasma levels of adenine nucleotides were measured using ...
Klohnen A, Vachon AM, Fischer AT.To evaluate the use of abdominal ultrasonography as a diagnostic tool in horses with signs of colic. Methods: Prospective study. Methods: 226 horses with signs of acute abdominal pain were compared to 20 clinical normal horses. Methods: The following were performed in horses with signs of colic: physical examination, CBC, abdominal fluid analysis, placement of a nasogastric tube to obtain gastric reflux, abdominal palpation per rectum, and ultrasonography of the abdomen. Results of ultrasonography were compared with the surgical, necropsy, or medical findings. Results: Ultrasonography of horse...
Gupta AK, Singh BK, Yadav MP.Fifty aborted foetus samples were diagnosed for the presence of equine herpes virus-1 (EHV-1) by polymerase chain reaction (PCR) technique. Specific primer pair for amplification of a particular segment of EHV-1 DNA in gc region having 3 Hae III restriction endonuclease sites was used. A 409 base pair segment obtained as PCR amplification product in 9 samples was digested with Hae III to confirm the presence of EHV-1 as the infectious agent in aborted tissues. It was observed that PCR technique was more sensitive, specific and rapid than the conventional virological diagnostic methods.
de Lemos ER, Machado RD, Coura JR, Guimarães MA, Chagas N.In order to obtain information on Brazilian spotted fever, a study in domestic animals was performed in the County of Pedreira, State of São Paulo, Brazil, where 17 human cases had been notified. Serum samples obtained from animals were tested by indirect immunofluorescence for detectable antibodies to spotted fever-group rickettsiae. Seropositivity was revealed in 12 (36.4%) of 33 dogs and seven (77.8%) of nine horses from the endemic area. For comparison, blood samples from dogs and horses from non endemic area were tested and four (12.9%) of 31 dogs and three (27.3%) of 11 horses were posi...
Gastal MO, Gastal EL, Kot K, Ginther OJ.The temporal relationships among day of conceptus fixation (cessation of mobility), conceptus diameter, uterine tone, uterine contractility, and myometrial and endometrial thickness of the middle and caudal segments of the uterine horns were assessed in 13 pony mares with fixation in the caudal segment of a uterine horn. The mean day of fixation (14.9 +/- 0.3) was established by 2-h mobility trials. Uterine tone increased (P < 0.0001) gradually over Days 11 to 21, whereas uterine contractility decreased (P < 0.0001) between Days 14 and 18. The diameter of the spherical embryonic vesicle ...
Caron JP, Kaneene JB, Miller R.To determine the patterns of use and perceived efficacy of polysulfated glycosaminoglycan (PSGAG) for the treatment of degenerative joint disease in horses. Methods: Cross-sectional mail survey. Methods: 1,522 equine practitioners. Methods: Information was obtained on frequency and route of administration of PSGAG for the treatment of each of 4 forms of degenerative joint disease, the efficacy of PSGAG, and its efficacy compared with that of sodium hyaluronate. Data were analyzed by nonparametric and multivariate regression methods. Results: Response rate was 40.5%. Of practitioners responding...
Murray MJ, Eichorn ES, Dubovi EJ, Ley WB, Cavey DM.Whole blood and serum were collected from foals to determine the prevalence of Equine herpesvirus type 2 (EHV 2) infection in foals, age at which infection can first be identified and serological responses to infection. Equine herpesvirus type 2 was isolated from peripheral blood mononuclear cells (PBMC) from 68 of 69 foals, 1-8-months-old, sampled once. Virus isolation was performed twice at intervals of 2-7 months on PBMCs from 33 foals and EHV2 was isolated on both occasions in all but one foal (negative, then positive). Regression analysis of log2-transformed reciprocal serum EHV2 virus ne...
Sharma AK, Kathikeyan S, Kaur P, Singh TP, Yadav MP.Lactoferrin is an iron-binding glycoprotein with a molecular weight of 80 kDa. The protein has two iron binding sites. It has two structural lobes, each housing one Fe(3+) and the synergistic CO(3)(2-) ion. The protein was isolated from the colostrum/milk of mares maintained at National Research Centre on Equines, Hisar, India. The purified samples of the protein were crystallized using a microdialysis method. The protein was dialysed against low ionic strength buffer solution. Several crystal forms were obtained, out of which three were characterized which have cell dimensions as follows. For...
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 ...
Lyons ET, Tolliver SC, Drudge JH, Stamper S, Swerczek TW, Granstrom DE.Several compounds (n = 13 single or combinations; most at therapeutic dosages) were evaluated between 1977 and 1992 in critical tests (n = 91) against benzimidazole (BZ) resistant small strongyles (Population S) and several other species of internal parasites in Shetland ponies, mostly under 1 year old. The closed breeding herd, from which the test ponies were selected, had been treated every 8 weeks with cambendazole (CBZ) for 4 years (1974-1978) and oxibendazole (OBZ) for 14 years (1978-1992). Published field test data (1974-1992) on older ponies in the herd showed BZ resistance of small str...
Rasch K, Schoon HA, Sieme H, Klug E.The aim of this field study was to examine the influence of the uterotonic substance oxytocin in 2 different therapeutic dosages of 15 and 25 i.u., respectively on the uterine drainage of oestrous mares and on their fertility. In addition endometrial biopsies of mares with and without intrauterine fluid accumulations around the time of ovulation were evaluated histomorphologically regarding the aetiology of susceptibility to uterine infection. A population of 59 Hanoverian Warmblood mares was used in this study. The mares were divided into Group A (mares with intrauterine fluid accumulations [...
Watson ED, Thomson SR.Aromatase P-450 (P-450arom) is a crucial regulatory enzyme that is necessary for conversion of androgens to oestrogens. Corpora lutea and follicles were obtained from the ovaries of cyclic mares and from mares at day 20 and days 40-70 of pregnancy. The presence of P-450arom within specific cell types was investigated by immunostaining to determine potential sites of oestrogen synthesis. Immunoreactivity for P-450arom was confined to the granulosa layer of non-atretic follicles > 5 mm in diameter and to corpora lutea at all stages of the oestrous cycle and during pregnancy. These findings co...
Snow WF, Wacher TJ, Rawlings P.The prevalence of trypanosome infections in Djallonké sheep and West African Dwarf goats at different sites in The Gambia showed a significant, positive correlation with contemporary assessments of tsetse challenge. A similar correlation was observed in village N'Dama cattle which showed comparable prevalence values in the same areas. Trypanosome prevalences also tended to be higher in horses and donkeys in areas with high tsetse challenge compared with sites with relatively few flies. A ranking of the numbers of tsetse blood-meals from cattle, small ruminants and equines (1:0.06: > 0.03) ...
Hancke J, Burgos R, Cáceres D, Brunetti F, Durigon A, Wikman G.Sport horses with long lasting high levels of gamma Glutamiltransferase (gGT) and Glutamic Oxalacetic Transaminase (GOT) and Creatinine Phosphokinase (CPK) and poor performance were administered during 14 days 3 g of Caval D'Or®, a standardized dried extract of Schizandra chinensis (fructus) orally. At day "0" the horses were divided into two groups: group 1 received a placebo and group 2 received Caval D'Or®. The results showed that Caval D'Or® is able to reduce significantly the levels of gGT and GOT in the serum at day 7 and 14 after administration. The CPK levels were also reduced by da...
Tute AS, Wilkins PA, Gleed RD, Credille KM, Murphy DJ, Ducharme NG.An 8-year-old Trakehner mare developed fulminant pulmonary edema following suspected upper airway obstruction 50 minutes into an otherwise unremarkable anesthetic recovery after surgery for left cricoarytenoideus dorsalis muscle reinnervation and ventriculocordectomy. Establishing a patent airway by orotracheal reintubation and cardiopulmonary resuscitation attempts were unsuccessful. Gross, histological, and electron microscopic postmortem examination showed severe hemorrhagic pulmonary edema. Laryngeal swelling or hemorrhage were not evident, suggesting laryngospasm or functional airway coll...
Merritt AM, Burrow JA, Horbal MJ, Madison JB, Tran T.To better characterize the source of the large nonparietal secretory response to pentagastrin (PG) expressed in gastric contents of cannulated horses. Methods: Adult cross-bred horses: 4 geldings and 1 mare. Methods: Horses were prepared by surgical insertion of a silastic gastric cannula from which gastric contents after feed was withheld could be continuously collected by gravity drainage. During experiments, the horses were lightly restrained in stocks, the gastric cannula was opened, and a catheter was inserted into a jugular vein. Over the next 5 hours, gastric contents were collected in ...
Chaffin MK, Matthews NS, Cohen ND, Carter GK.A commercially available pulse oximeter was evaluated in anaesthetised foals to determine its accuracy for estimating arterial haemoglobin saturation (SaO2). Five different transducer/transducer attachment site (TTAS) combinations were evaluated; 1-3) a fingertip transmission transducer attached to the foal's ear, lip and tongue, 4) an adhesive transmission transducer positioned on the foal's ear and 5) a forehead reflectance transducer placed on the ventral aspect of the foal's tail-base. Eight normal, Quarter Horse foals (age 5-10 days) were studied while under general anaesthesia. Alteratio...
Ramos-Vara JA, Ortiz-Santiago B, Segalès J, Dunstan RW.This report contains the clinical, histologic, immunohistochemical, and electron microscopic findings in two cases of equine cutaneous leishmaniasis. Nodular, sometimes crusty or ulcerated lesions were confined to the pinna and adjacent neck in both animals. The dermal inflammatory infiltrate was lymphohistiocytic in horse No. 1 and pyogranulomatous with formation of tuberculoid granulomas in horse No. 2. Numerous Leishmania organisms were found within macrophages in both animals. There was moderate to intense and specific reaction by immunoperoxidase using a polyclonal antiserum against Leish...
Schmidt A.Superficial mycoses caused by dermatophytes, as well as asymptomatic carriership of dermatophytes, have a high prevalence among domestic animals and pets. We examined 606 clinical specimens from skin lesions of animals with a significant tendency towards superficial mycosis due to their clinical features. Samples were obtained from horses, dogs, cats, small rodents, birds, and rabbits. The specimens were examined by microscopic and cultural techniques. Microscopically, there was no significant difference in the prevalence of structures which may develop fungal elements between the groups cultu...
England GC, Clarke KW.In recent years the usefulness of the alpha 2 adrenoceptor agonist drugs has been recognized in equine practice. Several agents have become available and are now licensed for use in a number of countries. The principle actions of all alpha 2 adrenoceptor agonists are similar, in that they produce a reduction in heart rate and alteration of heart rhythm, an initial hypertension followed by a prolonged hypotension, a decrease in the cardiac output and respiratory depression. For clinical purposes, these agents produce sedation and analgesia, they are useful for premedication and markedly potenti...
Bahmani MK, Nowrouzian I, Nakaya T, Nakamura Y, Hagiwara K, Takahashi H, Rad MA, Ikuta K.Borna disease virus (BDV) naturally infects horses and sheep and induces progressive poliomeningoencephalomyelitis. Here, BDV recombinant proteins of the first open reading frame (ORF-I; coding for p40 nucleoprotein) and the second ORF-II (coding for p24 polymerase cofactor) were immunoblotted with plasma derived from 72 healthy (28 Arabic, 17 thoroughbred and 27 cross-bred) race horses at Tehran in Iran to detect anti-BDV antibodies. In addition, their peripheral blood mononuclear cells (PBMCs) were also examined for BDV RNA by a nested reverse transcriptase-polymerase chain reaction (RT-PCR)...
Weiser MG.A multichannel, semiautomated, blood cell counting system (Coulter Counter Model S550) was modified for use in veterinary hematology by increasing both the erythrocyte and leukocyte aperture currents to 225 V and 195 V, respectively, followed by calibration with human blood. It was evaluated by use of 350 samples from dogs, cats, horses, and cows. Values for leukocyte count, erythrocyte count, mean corpuscular volume, and hematocrit generated by the S550 were compared with values generated by an automated multichannel counter with histogram capability and other reference procedures when approp...
Beccati F, Gialletti R, Giontella A, Davanzo S, Di Meo A, Pepe M.The aim of this study was to identify differences in bone shape (height and width) of proximal sesamoid bones (PSB) in 2-year-old Thoroughbred racehorses in training. Dorsal 15° proximal-palmarodistal oblique images of each metacarpophalangeal joint were acquired before the horses started training and at 1 year after the start of exercise and racing. There were no changes in height and width of PSBs induced by training. There was a significant difference of height and width between medial and lateral PSBs. In both forelimbs, the medial PSB was significantly wider and shorter than the lateral...
Muylle S, Simoens P, Lauwers H.The dentinal tubules of 20 permanent equine incisors were investigated by scanning electron microscopy. Occlusal surfaces and longitudinal fracture planes of both etched and undecalcified teeth were examined. Three different types of structure were observed inside the dentinal tubular lumen. Odontoblastic processes could only be visualized in the circumpulpal parts of the tubules. The more peripheral parts were empty or housed cylindrical structures that probably correspond to the laminae limitantes. Collagen fibres were frequently observed in the tubular lumina and were most numerous in the c...
Vickroy TW, Chang SK, Chou CC.The goals of this study were to elucidate the temporal and quantitative relationships between caffeine and its major bioactive metabolites in blood and cerebrospinal fluid (CSF) and to characterize the pharmacokinetic-pharmacodynamic relationship for caffeine-induced changes in spontaneous locomotor activity in the horse. We hypothesized that caffeine and its metabolites distribute efficiently into the CSF to antagonize adenosine A1 and A2a receptors and that spontaneous locomotor activity correlates well with caffeine and/or metabolite concentrations in CSF and blood. A microdialysis system w...
Richer CL, Romagnano A.Both dynamic G-banding and cell synchronization produced by bromodeoxyuridine (BrdU), were applied to equine chromosomes. BrdU incorporated during the first half of the S-phase is taken up into the R-bands that are early replicating. These bands, which have incorporated BrdU, cannot contract as usual and remain elongated; only the other regions of the chromosome, i.e., the G-bands, contract normally and are sharply defined. BrdU also can be used for cell synchronization. The addition of BrdU in a high concentration, 15 hours before harvest, and its removal 11 hours later, has two effects: init...
Sato F, Yamashita S, Kugo T, Hasegawa T, Mitsui I, Kijima-Suda I.To determine the full-length complementary DNA (cDNA) sequence of equine erythropoietin (EPO) and to develop region-specific antibodies to differentiate equine EPO (eEPO) and human EPO (hEPO). Methods: RNA and lysate extracted from renal tissues of an adult Thoroughbred. Methods: Full-length cDNA was determined by use of a reverse transcriptase-polymerase chain reaction assay and a rapid amplification of cDNA ends method. The deduced amino acid sequence was compared with sequences of EPO reported for other species. Furthermore, 4 synthetic peptides were designed in 2 distinctive parts of the e...
Ogilvie GK.The importance of paraneoplastic syndromes is often underestimated in the horse. Clinically, paraneoplastic syndromes can cause greater morbidity than the actual physical presence of the malignant tumor. The appearance may be the first sign of a malignancy and may be so severe that appropriate therapy for the underlying cancer is not initiated. This article reviews some of the most common paraneoplastic syndromes that are likely to occur in the horse.
Hurcombe SD, Klein CE, Roessner HA, Engiles JB, Hopster K.To report the use of nylon cable ties (NCT) for omentectomy in the horse. Methods: Experimental study. Methods: Eight healthy adult horses. Methods: Horses underwent nylon cable tie (NCT) ligation of the greater omentum after ventral midline celiotomy. The time required to complete the omentectomy was recorded. Horses were recovered for 14 days before repeat celiotomy, adhesions assessment, and histological examination of the omentectomy site using a proposed histologic grading scheme. The total time for omentectomy procedure and histologic score was assessed for normality. Data are expresse...
Shawaf TM.Occurrence of intra-nasal foreign bodies is uncommon in horses. This report describes -for the first time- a case of a 4-year-old Arabian-cross mare with unilateral mucopurulent nasal discharge, epistaxis and exercise intolerance due to intra-nasal foreign body. Clinical signs, radiography and endoscopic examination confirmed the presence of a tooth fragment (foreign body) embedded in the ventral valve of the left nasal cavity. The foreign body was successfully removed using alligator forceps under endoscopic guidance.
Chandra AM, Woodard JC, Merritt AM.A yearling Arabian filly was referred to the Veterinary Medical Teaching Hospital with a history of weight loss, profound anemia, and peritoneal effusion. At necropsy, a large, soft, mottled tan and red neoplastic mass was at the pelvic inlet replacing the left ovary. Additional tumor nodules of various sizes were disseminated throughout the mesentery, diaphragm, and serosal surfaces of the abdominal viscera. Histologically, the neoplasm had sheets of large round to polygonal cells separated into lobules by fibrous connective tissue with multifocal areas of necrosis. Tumor cells stained strong...
Gurel V, Lambert K, Page AE, Loynachan AT, Huges K, Timoney JF, Fettinger M, Horohov DW, McMichael J.The addition of streptolysin-O (SLO) to the standard antibiotics regimen was shown to be superior to antibiotics alone after experimental infection of foals with Rhodoccocus equi (R. equi). The objective of this study is to investigate this response by determining the site-specific expression of extracellular matrix (ECM) and inflammatory response genes in biopsy samples taken from three distinct lung regions of the infected foals. Twenty-four foals were challenged by intrabronchial instillation of R. equi and assigned to four treatment groups: SLO/antibiotics adjunct therapy, antibiotics-only...
Elliott CR, McCowan CI.Nigropallidal encephalomalacia was diagnosed in two horses in northern Victoria that had a history of long-term pasture access to a dense growth of Rhaponticum repens. The region in which the affected horses lived had received well above average rainfall for several months preceding the poisoning. Affected horses had sudden onset of subcutaneous oedema of the head, impaired prehension and mastication, dullness, lethargy and repeated chewing-like jaw movements. Diagnosis was confirmed at necropsy, with characteristic malacic lesions in the substantia nigra and globus pallidus of the brain. This...
Reiners JK, Rossdeutscher W, Hopster K, Kästner SBR.The use of pulse oximetry in horses is limited due to inadequate readings with conventional transmission sensor probes. Objective: The objectives of this study were to 1) develop an improved sensor design for horses to be used at an appropriate anatomical site, and 2) evaluate this design in an experimental study. Methods: In vivo experiment. Methods: A new sensor design for reflectance pulse oximetry at the buccal mucosa was developed. A conventional Nonin 2000SL sensor for transmission pulse oximetry was included into this design. Three different prototypes (N1, N2a, N2b) were constructed an...
Clayton HM, Belock B, Lavagnino M, Kaiser LJ.The objectives of this study were to measure forces and pressure profiles when riding with a conventional saddle compared to bareback riding. An electronic pressure mat was used to compare contact area, mean total force and pressure variables for one rider riding seven horses at sitting trot with a conventional saddle or bareback. The use of a saddle was associated with a larger contact area and higher mean total force compared with the bareback condition. Mass normalized mean total force for bareback riding was lower than expected based on the rider's body mass, suggesting that shear forces e...
Waelchli RO, Winder NC.Endometrial sections from mares with varying degrees of mononuclear cell infiltration were examined for immunoglobulin (Ig)A-, IgM-, IgG(T)- and IgG(Fc)-containing cells, luminal and glandular epithelial cell Ig-staining and free interstitial Ig-staining, using a peroxidase anti-peroxidase technique. Mares with mild to moderate (Group 2) and mares with severe diffuse mononuclear cell infiltration, superimposed by acute endometritis (Group 3), had significantly higher numbers of Ig-containing cells than genitally-normal mares (Group 1). The differences between Groups 1 and 3 were significant fo...
Bowling AT, Wictum E.A fourth allele at the horse erythrocyte phosphohexose isomerase (Phi) locus was proposed to account for phenotypes observed after starch gel electrophoresis and enzymatic staining of red cell lysates from American Saddlebred and Tennessee Walking Horse breeds. The gene was rare, having an estimated frequency of 0.009 in 949 Saddlebreds tested.
Kvart C, Carlsten J, Jeffcott LB, Nilsfors L.M-mode echocardiography is a safe and practical means of using ultrasound to evaluate the dynamic movements of cardiac structures. The technique can be refined by using a simple contrast medium in the form of carbon dioxide mixed with heparinised blood to provide a strong echogenic result. This technique was employed in a series of 15 normal conscious standing horses and in three animals with specific cardiac defects. In the clinical cases it was possible to confirm the diagnosis and differentiate between a congenital septal defect and mitral regurgitation. The method was found to be safe and ...
Biscoe EW, Whitcomb MB, Vaughan B, Dechant JE, Magdesian KG.OBJECTIVE To describe clinical features and outcome of horses with severe large intestinal thickening diagnosed with transabdominal ultrasonography. Methods: Retrospective case series. ANIMALS 25 horses. PROCEDURES Medical records of horses that underwent transabdominal ultrasonography between 2003 and 2010 were reviewed. Horses were included if the wall of the large intestine was ≥ 9 mm thick in any of 6 abdominal zones. RESULTS Median age was 13 years (range, 3 to 28 years). Horses were initially examined because of colic, diarrhea, inappetence, weight loss, lethargy, fever, or hematuria. ...
Zweygarth E, Ahmed JS, Rehbein G, Voigt WP.The capacity of equine peripheral blood lymphocytes (PBL) to proliferate in the presence of Babesia equi-transformed lymphoblastoid stimulator cells was tested in an autologous as well as in an allogenic one way mixed lymphocyte reaction (MLR). It was found that both autologous and allogeneic responder lymphocytes incorporated high amounts of 3H-thymidine. The incorporation of 3H-thymidine was lower in MLR using as stimulator cells lymphocytes from which the cell line had previously been established, than when using parasitized culture cells as stimulator. Proliferation of PBL was achieved onl...
Wichtel JJ, Grace ND, Firth EC.To examine the effect of intramuscular barium selenate on the blood selenium concentration of horses with marginal selenium status. Methods: Eighteen mares were assigned to one of six groups. The mares in groups 1-4 received barium selenate at 0.5, 0.75, 1.0 and 1.5 mg Se/kg, respectively, injected into the right pectoral muscle mass. The mares in group 5 received sodium selenate at 0.05 mg Se/kg orally at 8-week intervals. The mares in group 6 were left untreated. Blood samples were collected at 0, 1, 2, 5, 10, 30, 60, 90, 120, 180, 240, 300 and 360 days after the initial treatment for assay ...
Meisler SD, Doherty TJ, Andrews FM, Osborne D, Frazier DL.The effect of yohimbine pretreatment on gastric emptying of a liquid marker in horses was evaluated by measuring serum concentrations of acetaminophen. Gastric emptying was determined in normal, fasted horses, in horses given endotoxin (E. coli 055 B5; 0.2 microg/kg) intravenously, and in horses given yohimbine (0.25 mg/kg, IV, over 30 minutes) plus endotoxin. Acetaminophen (20 mg/kg) was given by stomach tube 15 minutes after the endotoxin infusion. Blood samples for acetaminophen analysis were collected, and time to reach the peak serum concentration (Tmax), the maximum serum concentration (...
Yeruham I, Elad D, Egozi O.A retrospective study of an outbreak of dermatophilosis in a herd of 18 adult horses and 13 foals, in Israel, is presented. To the best of our knowledge this is the first time such an outbreak has been reported from a country in the Mediterranean climatic zone. This outbreak might be associated with exposure of the horses to water and humidity as a result of excessive rainfall in November 1994, as well as intensive washing of the horses and a long period spent by the animals in a marshy manege.
