Disease etiology in horses refers to the study of the causes and development of diseases within equine populations. It encompasses various factors, including genetic predisposition, environmental influences, infectious agents, and nutritional imbalances, that contribute to the onset and progression of diseases in horses. Understanding disease etiology is essential for identifying risk factors and implementing preventative measures in equine health management. This topic includes research on pathogen-host interactions, the impact of management practices on disease incidence, and the role of genetic and environmental factors in disease susceptibility. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, contributing factors, and implications of disease etiology in horses.
Parlevliet JM, Bleumink-Pluym NM, Houwers DJ, Remmen JL, Sluijter FJ, Colenbrander B.Contagious equine metritis (CEM) is a sexually transmissible disease in mares. Although the disease is commonly diagnosed by culturing the causative bacterium Taylorella equigenitalis (T. equigenitalis) . false negative results do occur. A recently developed Polymerase Chain Reaction (PCR) assay, however, appeared to be much more sensitive, with initial results indicating an unexpected high incidence of the agent in selected horses. In this study, samples from 107 randomly selected mares with no clinical signs of CEM submitted for conventional culture were all negative for T. equigenitalis . b...
Uhlinger C.Leukoencephalomalacia in horses is caused by fumonisins. These mycotoxins are produced by Fusarium spp. that contaminate corn and corn byproducts while in the field. The most common clinical presentation is a multifocal neurologic disease that affects multiple horses in a herd. Although the majority of affected horses die, treatment directed at decreasing inflammation and edema in the CNS may result in recovery in some animals.
Wilson WD.Myeloencephalopathy is an uncommon manifestation of equine herpesvirus 1 (EHV-1), but it can cause devastating losses during outbreaks on individual farms. Clinical signs of neurologic disease reflect a diffuse multifocal hemorrhagic myeloencephalopathy secondary to vasculitis and thrombosis. Sudden onset and early stabilization of signs, including ataxia, paresis, and urinary incontinence; involvement of multiple horses on the premises; and recent history of fever, abortion, or viral respiratory disease in the affected horse or herdmates are typical features, although there is considerable va...
Beech J.This article presents a brief description of what is known about the cause and pathogenesis of chronic intermittent rhabdomyolysis in horses. Clinically applicable diagnostic tests and published results in affected horses, prophylaxis, and treatment of the acute case are discussed.
Löfstedt J.White muscle disease (nutritional myodegeneration) of foals is a peracute to subacute myodegenerative disease affecting skeletal and cardiac muscle. It is caused by a dietary deficiency of selenium and vitamin E, usually in association with predisposing factors such as a high intake of dietary unsaturated fats or unaccustomed exercise. White muscle disease has been observed in foals from birth to 1 year of age, particularly those foals born to dams fed selenium-deficient diets, during gestation. The disease in foals may present as an acute, fulminant syndrome, which is rapidly fatal, or a suba...
Trim CM.Hemorrhagic myelopathy or myelomalacia is an uncommon cause of failure to stand after general anesthesia. Affected horses are usually young and have been anesthetized for relatively short times in dorsal recumbency. Clinical signs involve the hind limbs and include loss of deep pain perception. Etiology of this condition is not known. Differentiation from other forms of neuropathy and myopathy is important to the prognosis.
Zheng YH, Nakaya T, Sentsui H, Kameoka M, Kishi M, Hagiwara K, Takahashi H, Kono Y, Ikuta K.We have studied a horse which exhibited typical clinical signs of disease when experimentally infected with a non-adapted virulent strain of equine infectious anaemia virus (EIAV), designated V70. Five viruses (F1V, F2V, F3V, F4V and F5V) were recovered during periodic febrile episodes. Cross-neutralization tests revealed that all of these variants and the parental V70 were antigenically distinct. Sequencing of their full-length env gp90 genes and gp45 5' sequences revealed novel mutations at a limited number of nucleotide positions, consisting of insertions and duplications in the gp90 princi...
Sutton GA, Viel L, Carman PS, Boag BL.The purpose of this experiment was to study the duration and distribution of equine influenza virus in actively infected ponies over a 3 wk period. Pony foals (6-8 mo old) were infected experimentally by nebulizing equine influenza subtype-2 virus ultrasonically through a face mask. Successful infection was clinically apparent as each of the foals (n = 6) had a febrile response, a deep hacking cough and mucopurulent nasal discharge for 7 to 10 d. The virus was isolated from nasopharyngeal swabs of all the ponies 3 and 5 d after infection and all the ponies seroconverted to the virus. Samples w...
Kaneene JB, Miller R, Ross WA, Gallagher K, Marteniuk J, Rook J.A population-based prospective epidemiological study was conducted to assess risk factors for equine colic. A stratified sample of 3925 equids in 138 randomly selected equine farms in the state of Michigan was monitored in two 12-month rounds of data collection. Incidence densities were used to describe the rate of development of colic in the study population. Mortality rates, case fatality rates and survival rates were used to describe the severity of colic on the study population. Multivariable logistic regressions with random effects (grouped according to farm) were used to identify risk fa...
Charan S, Palmer K, Chester P, Mire-Sluis AR, Meager A, Edington N.Up to 21 days after exposure to live or ultraviolet-inactivated equid herpesvirus type-1 (EHV-1) autologous serum from ponies caused an immunosuppressive effect if incorporated into T-cell proliferation assays to EHV-1. The suppressive factor in the sera of ponies also inhibited T-cell response to phytohaemagglutinin. Increased levels of circulating activated transforming growth factor-beta 1 (TGF-beta 1) were detected, and the suppressive activity of the serum could be reversed by antibody to TGF-beta 1. In a challenge experiment the ponies which exhibited circulating TGF-beta 1 activity succ...
Blythe LL.Otitis media/interna in the equine most commonly is a chronic, insidious infection with the unique sequella of temporohyoid osteoarthropathy in some horses. Head shaking may be the only clinical sign of the early stages of this disease. The arthritic condition often leads to fusion of the temporohyoid joint with resultant stress fractures of the petrous temporal bone. When this occurs, the horse presents as an acute neurologic case with clinical signs of vestibular and facial nerve dysfunction. Diagnosis, treatment, and prognosis are discussed. Recognition of this syndrome is important because...
Li F, Drummer HE, Ficorilli N, Studdert MJ, Crabb BS.Equine rhinovirus 1 (ERhV1) is a recognized cause of acute febrile respiratory disease in horse, although the virus is rarely isolated from such animals, despite seroprevalence rates as high as 50% in some horse populations. Recently, ERhV1 has been shown to be most closely related to foot-and-mouth disease virus, raising questions as to its disease associations in horses. We report that ERhV1 infection was the likely cause of two separate outbreaks of severe febrile respiratory disease which involved more than 20 horses. Attempts to isolate ErhV1 from nasopharyngeal swabs by conventional cell...
Griffiths NJ, Walton JR, Edwards GB.Equine anterior enteritis is an acute syndrome with unknown aetiology, although salmonellosis and infection with Clostridium perfringens have both been suggested as potential causes. The main aim of this preliminary study was to compare the prevalence of toxigenic types of C. perfringens in clinically healthy horses and in horses with anterior enteritis. From horses admitted with colic at Phillip Leverhulme Large Animal Hospital in 1995-1996, samples of gastric reflux, small intestinal contents and faeces were taken for isolation of C. perfringens. Five of those horses were admitted as anterio...
Schusser GE, White NA.To determine the number of myenteric plexuses and neurons in the large colon of clinically normal horses and whether the number was decreased in the large colon of horses with colon disease. Methods: Prospective study. Methods: Colon samples from 15 clinically normal horses and 31 horses with colon disease. Methods: Samples were obtained, fixed, and stained with H&E. The number of myenteric plexuses and neurons and longitudinal muscle thickness were determined in each segment of colon for clinically normal horses. Counts for segments were compared with each other and with counts in the sam...
Yamaya Y, Kubo K, Amada A, Sato K.The atrioventricular (AV) conductive functions were investigated before and after the pharmacological autonomic nervous blockade (PAB) through the electrophysiological study on six horses (AV block group) in which the dropped beats occurred more frequently (over 200 beats/24 hr) and on five horses (control group) in which the dropped beats occurred sporadically (under 200 beats/24 hr) or in which the arrhythmias were not recognized at all on the long-term electrocardiogram. As a result, AV conductivity, conduction time and refractoriness in the AV block group were lower, longer and higher, res...
Birch HL, Rutter GA, Goodship AE.Hypoxia has been suggested as a possible cause of tissue degeneration and subsequent rupture in equine tendons. To determine whether low oxygen tension is likely to be detrimental to tendon cell function, experiments were designed to investigate oxidative energy metabolism in freshly isolated and cultured equine tendon cells. Freshly isolated tenocytes and cultured fibroblasts possessed activities of the mitochondrial enzyme citrate synthase similar to those of other mammalian cells, with well defined oxidative metabolism. D-[6(-14)C]-glucose oxidation was measurable in both freshly isolated a...
Hilbe M, Meier D, Feige K.This article describes an eleven year old mare with apathy, fever, enlarged mandibular lymph nodes, skin lesions on the upper lip and edematous, grey-red mucous membranes in the nose, mouth and vulva. Histopathology revealed infiltrates with atypical lymphocytes forming Pautrier's microabscesses. The neoplastic cells had large, often indented nuclei. Immunohistology showed that some cells were CD3-positive (Pan T-cell-marker). The diagnosis of cutaneous epitheliotropic malignant lymphoma (Mycosis fungoides) was made. The etiology in the horse is unknown.
Basher AW, Severin GA, Chavkin MJ, Frank AA.Three horses were examined because of exophthalmos and others signs indicative of a space-occupying orbital mass. In 2 horses, exenteration was used to remove the orbital mass. In a third horse, an orbital tumor and lung metastases were found at necropsy. Routine histologic and Grimelius' histochemical staining were used on fixed tissues; immunohistochemical staining for chromogranin and electron microscopy also were performed. Masses were orbital neuroendocrine tumors. Horses that underwent exenteration were alive 19 and 24 months after surgery. Hypotension was encountered at surgery in both ...
Frazer GS, Perkins NR, Blanchard TL, Orsini J, Threlfall WR.A retrospective investigation was performed to determine the population characteristics of horses presented for dystocia at 2 equine referral hospitals and the types of fetal maldispositions among these horses. The study population consisted of a similar number of Thoroughbreds (25%), Standardbreds (24%) and draft horses (22%). Most of the current literature pertaining to equine obstetrics is based on a predominately draft horse population (63%). The latter population appeared to have more transverse presentations (P = 0.06), possibly because of the higher number of draft mares. In our study, ...
Collinder E, Lindholm A, Rasmuson M.The equine rhabdomyolysis syndrome (RHA) is believed to be multifactorial in origin; and could be caused by an interaction between genetic and environmental factors. In order to analyse its genetic background an association study was undertaken. Two sample groups of Standardbreds (Stb) which had suffered from RHA were compared to the total population of Swedish Standardbred trotters using recorded polymorphic genetic markers. The results showed that gene frequencies for several markers in the RHA groups differed significantly from those estimated for the total population. A rhabdomyolysis risk...
Paweska JT.Eight sexually mature horse stallions were inoculated intranasally with a South African asinine strain of EAV, a strain that was isolated from the semen of a donkey carrier. All horses developed fever, with maximum rectal temperatures of 38.9-39.9 degrees C recorded 3-6 d post challenge. Six horses showed very mild clinical signs of equine viral arteritis and two were asymptomatic. The virus was recovered from the nasopharynxes of six horses 2-7 d after inoculation, and from buffy-coat samples of all horses, 2-11 d after inoculation. Seroconversion to EAV was detected on days 8 and 10 and peak...
Escande F, Vallee E, Aubart F.The isolation of Pasteurella caballi from an horse-bite wound in a 56-year-old man is reported. Biochemical characteristics are described and compared with the other species representing the genus Pasteurella. This strain probably represents the first human isolate of P. caballi in France.
Holmes JR.The paper describes the spatial vector changes during ventricular depolarisation in 190 horses using a semi-orthogonal ECG lead system. The replacement of planar vector loops by a plot of 3 parameters to depict the changing spatial vector, with a time base on the X axis, is described and illustrated. Some horses with diastolic murmurs and some with a history of respiratory problems formed 2 distinct groups. As a result of these findings a possible relationship between the vector changes and the anatomical siting of the ventricles is suggested and discussed. Attention is drawn to certain measur...
Moreno-Millan M, Delgado Bermejo JV, Lopez Castillo G.An X-trisomy has been detected in an intersexuality Spanish-bred horse by using G- and C-banding methods. The external characteristics and the behavioural and physiological irregularities of the horse are described. This is the first time that an association between an X-trisomy and a case of intersexuality has been reported in any domestic animal.
Sleeper MM.Heart disease can be defined as any abnormality of the heart whether it is a cardiac dysrhythmia or structural heart disease, either congenital or acquired. Heart failure occurs when a cardiac abnormality results in the inability of the heart to pump enough blood to meet the body's needs. Heart disease can be present without leading to heart failure. Heart failure, however, is a consequence of heart disease. There are 4 main areas where the clinician can intervene to improve cardiac output with heart failure: preload, afterload, myocardial contractility, and heart rate.
Ryan CA, Sanchez LC.Neonates can have a variety of gastrointestinal disorders, primary and secondary in nature. Important primary disorders include con-genital abnormalities and meconium retention. One of the most important secondary lesions is generalized ileus. Gastric ulceration can occur as a primary or secondary event. This article addresses the pathophysiology, diagnosis, and treatment of gastrointestinal problems commonly observed in neonatal foals.
Mair T, Sherlock C.Most recurrent episodes of non-specific colic are self-limiting, and the results of clinical examinations are unremarkable. Differentiating these cases from serious diseases can be difficult, but repeated evaluations are warranted. Horses presenting with very frequent bouts of colic are more likely to have serious diseases and a higher mortality rate compared to horses presenting with less frequent bouts of transient colic. Horses with recurrent bouts of prolonged colic are more likely to have motility issues or partial intestinal obstruction. Non-gastrointestinal diseases can also cause recur...
Dennis DA, Pinard CL, Kenney DG, Salcedo RJ, Trout DR.The standard placement of a subpalpebral lavage system may not be feasible in some horses with eyelid disease. We describe placement of a commercially available, indwelling nasolacrimal lavage system that circumvents eyelid perforation. This novel approach provided for effective delivery of drugs to 1 horse with periocular and corneal disease. . Le placement standard d’un système de lavage subpalpébral peut ne pas être réalisable chez certains chevaux atteints de maladies oculaires. Nous décrivons le placement d’un système de lavage nasolacrymal à demeure qui évite la perforation d...
Owen R, Fullerton JN, Tizard IR, Lumsden JH, Barnum DA.Clinical, bacteriological, serological and haematological observations were made on 13 adult ponies orally inoculated with Salmonella typhimurium. The results were compared to two control ponies and four others infected by accidental transmission. The clinical responses in inoculated ponies included pyrexia lasting four days and neutropaenia during the first five days after inoculation followed by a neutrophilia. Pyrexia and neutropaenia was associated with maximal shedding of organisms in the rectal faeces. Changes in the character of the faeces occurred between one and two days after inocula...
Ethell MT, Hodgson DR, Hills BA.This study was undertaken to determine the hydrophobicity of the luminal surface of the equine stomach and to elucidate the ultrastructure of the lining imparting that property. Gastric and duodenal mucosal samples from 5 horses were collected immediately after euthanasia and subjected to surface contact angle measurement using a goniometer. Gastric mucosal samples from 4 horses and a foal were examined by electron microscopy following a fixation procedure known to preserve phospholipids and oligolamellar structures. Contact angles for the equine gastric glandular mucosal surface (mean +/- s.e...
Van Heerden J, Reyers F.The clinical signs, response to treatment and features of the spirochaete, Borrelia theileri as was found in a horse with suspected borreliasis are described.
Frederico LM, Gerard MP, Pinto CR, Gradil CM.An Arabian mare was referred for right granulosa-theca cell tumor (GTCT) evaluation. The mare was presented 4.5 years later for a left GTCT, after successfully conceiving and delivering a normal foal in the interim. The concurrent or nonconcurrent occurrence of bilateral GTCT in mares appears to be rare. Une jument Arabe a été référée pour l’évaluation d’une tumeur de la granulosa et de la thèque du côté droit (TGT). La jument avait été présentée 4,5 ans plus tôt pour une TGT du côté gauche, ayant entre temps conçu et mis au monde un poulain normal. La présence, simultan...
Curling A.Equine recurrent uveitis has traditionally been treated with medical management to reduce ocular inflammation and control pain during a single episode. Newer management methods include surgical options such as cyclosporine implantation and vitrectomy. These methods were developed not only to control inflammation but also to eliminate the underlying cause of uveitis in order to prevent recurrence.
Giancola F, Gentilini F, Romagnoli N, Spadari A, Turba ME, Giunta M, Sadeghinezhad J, Sorteni C, Chiocchetti R.Equine ileocolonic aganglionosis, which is also called lethal white foal syndrome (LWFS), is a severe congenital condition characterized by the unsuccessful colonization of neural crest progenitors in the caudal part of the small intestine and the entire large intestine. LWFS, which is attributable to a mutation in the endothelin receptor B gene, is the horse equivalent of Hirschsprung's disease in humans. Affected foals suffer from aganglionosis or hypoganglionosis of the enteric ganglia resulting in intestinal akinesia and colic. In other species with aganglionosis, fibers of extrinsic origi...
Weiss DJ, Trent AM, Johnston G.Prothrombotic changes occurring in the prodromal stages of carbohydrate-induced laminitis were investigated. Hemostatic alterations were evaluated by determining platelet counts, platelet survival, activated partial thromboplastin time, one-stage prothrombin time, and monocyte procoagulant activity. Thrombosis of vessels in the hoof wall was evaluated by contrast arteriography and histologic examination. Of 5 horses, 4 became lame between 28 and 52 hours after carbohydrate administration. Mean platelet count in laminitis-affected horses was lower throughout the prodromal stages of laminitis, c...
de Linde Henriksen M, Andersen PH, Mietelka K, Farina L, Thomsen PD, Plummer CE, Mangan BG, Heegaard S, Coleman JK, Toft N, Brooks DE.To investigate histopathologic and immunohistochemical aspects of equine deep stromal abscesses (DSA) with a focus on the histopathologic diagnosis, presumptive etiology, and the immunohistochemical expression of three angiogenesis-related factors: vascular endothelial growth factor-A (VEGF-A), pigment epithelium-derived factor (PEDF), and interleukin-1 receptor antagonist (IL-1ra). Methods: Paraffin-embedded biopsy samples from 51 DSA. The biopsies were collected from full-thickness penetrating keratoplasty or split-thickness lamellar keratoplasty surgeries at the University of Florida Veteri...
Coffman JR, Colles CM.Sensitivity to insulin was assessed in ponies episodically affected with chronic laminitis by measurement of blood glucose and arterial blood pressure during insulin tolerance tests. In terms of blood glucose values, laminitic ponies were significantly less sensitive to insulin than controls. Conversely, a post-insulin decline in diastolic, systolic and mean blood pressure values was significantly greater in laminitic ponies than in controls.
Hedenström UO, Olsson U, Holm AW, Wattle OS.It has not yet been shown that ossification of ungular cartilages (OUC) is a pathological condition. Beside heredity, factors such as sex, age, repeated concussion, local trauma, hoof and body size have been suggested as contributing factors for OUC development. By comparing radiographs of front hooves from cold-blooded trotters with different age we wanted to evaluate when development of OUC in cold-blooded trotters occurs and if and when it stabilizes in relation to age and workload. Diagnosis and grading of OUC were based on radiological field examinations of 649 Swedish and Norwegian cold-...
Klingeborn B, Dinter Z.The infectivity of equine abortion (herpes) virus (EAV) was inactivated by treatment with reduced dithiothreitol (DTT). According to their susceptibility to DTT, the EAV strains could be divided into three groups. The vaccine strain RAC-H (419) proved to be more resistant to DTT than all of the other 14 strains tested. The hemagglutinin of EAV was also inactivated by DTT; no strain differences were observed in this respect.
Vostry L, Vostra-Vydrova H, Citek J, Gorjanc G, Curik I.Inbreeding depression is the reduction of performance caused by mating of close relatives. In livestock populations, inbreeding depression has been traditionally estimated by regression of phenotypes on pedigree inbreeding coefficients. This estimation can be improved by utilising genomic inbreeding coefficients. Here we estimate inbreeding depression for insect bite hypersensitivity (IBH) prevalence, the most common allergic horse disease worldwide, in Old Kladruber horse. In a deep pedigree with 3214 horses (187 genotyped), we used a generalised linear mixed model with IBH phenotype from 558...
Franklin SH, Usmar SG, Lane JG, Shuttleworth J, Burn JF.It has long been recognised that the production of abnormal respiratory sounds by horses during exercise is frequently associated with upper airway obstructions. Respiratory acoustic measurements have shown promise in investigation of upper airway disorders in man and, more recently, in horses with experimentally-induced obstructions. Objective: To evaluate sounds from exercising horses with naturally occurring dynamic obstructions of the upper respiratory tract and to compare these with those from normal horses in order to determine whether different obstructions produce characteristic spectr...
Riera FL, Hinrichs K, Hunt PR, Kenney RM.Cervical hyperplasia with prolapse through the vulvar lips was documented in a mare. Postmortem examination indicated that the mass originated from the cervical wall. The surface of the prolapsed mass had histologic features of normal cervix. Cervical hyperplasia can be considered in a list of differential diagnoses in cases of prolapse of the internal genitalia in mares.
Bernstock JD, Ostby S, Fox B, Sotoudeh H, Janssen A, Kang YJ, Chen J, Prattipati V, Elsayed G, Chagoya G, Yamashita D, Friedman GK, Nabors B, Huh WK....Leptomeningeal metastasis is extremely rare in patients with ovarian cancer, but should be considered in patients presenting with neurologic deficits such as cauda equine syndrome. Given its poor prognosis and lack of data currently on management, additional studies are needed to optimize treatment regimens and improve outcomes.
MacKay RJ, Urquhart KA.Eight mature horses which had been affected with a moist cough for six weeks were found to have large numbers of eosinophils in tracheal mucus samples taken by transtracheal washing. These horses were kept on irrigated pasture and fed a hay-free diet. A companion yearling donkey was found to be passing Dictyocaulus arnfieldi larvae in its faeces. Two oral treatments with a dose of thiabendazole (440 mg/kg) resulted in the resolution of the clinical signs and the disappearance of eosinophils from transtracheal washings. The eosinophilic bronchitis seen in these horses was presumed to be a manif...
Reinemeyer CR, Herd RP.The large intestines of 6 horses were divided by length into 12 segments, and each segment was washed and weighed. At least 5% by weight of each segment was examined by mural transillumination, and encysted cyathostome larvae were counted. Total numbers of larvae in each segment were calculated. Encysted larvae (98%) were present in the proximal 7 segments of the large intestine (cecum and proximal 75% of the ventral colon), and 2% were present in the distal 25% of the ventral colon and entire dorsal colon. Encysted larvae (6%) were located in the dorsal colon of 1 heavily infected horse. Larv...
May SA, Lees P, Higgins AJ, Sedgwick AD.The cardinal signs of acute inflammation have been recognised for almost 2000 years, but it is only in the last hundred years that significant progress has been made in understanding the underlying cellular response. Our knowledge of the chemical messengers which regulate and in some cases lead to persistence of the inflammatory process is, as yet, incomplete, but it is hoped that further research at this level will lead to the development of more effective therapeutic agents.
Uhlinger CA.This article focuses on what has been established concerning the interaction of equine parasites and their hosts, highlighting those issues for which convincing data are still lacking. There is a compelling need for the participation of the veterinarian in the design of appropriate anthelmintic treatments and prevention strategies.
Frame SR, Harrington DD, Fessler J, Frame PF.Mechanobullous disease was diagnosed in a male Belgian foal that had sloughed hooves at 30 hours and at 6 and 12 days of age. Histologic and electron microscopic studies disclosed that lesions were the result of separation of the basal epithelial cell layer from the lamina densa of the basement membrane zone along the lamina lucida. Results of immunofluorescence on tissue specimens were negative for immunoglobulin deposition. The breeding history of the foal's dam indicated that the foal was produced from breeding of the mare to its full sibling stallion. This same mare had produced a female f...
Meyers PJ, Varner DD.A mummified fetus was aborted at 284 days of gestation from a Quarter Horse mare with a history of consecutive abortions. The abortion occurred 12 days after administration of supplemental progestogen had been discontinued. Results of a breeding soundness evaluation revealed that this mare had a short uterine body. Other abnormalities were not discovered. This condition may have been responsible for repeated abortions in this mare, and may represent a cause of fetal mummification other than twin pregnancy in mares.
Nevard R, Labens R, Stephen CP.Fetal maceration and pyometra were diagnosed in a 16-year-old maiden Welsh pony mare. Due to anatomical and surgical difficulties encountered throughout treatment, previously reported techniques including both per-vaginum removal of fetal remnants and ovariohysterectomy were attempted and resulted in novel complications. Fetal bones were unable to be removed completely transcervically due to failure of cervical dilation despite repeated attempts. Subsequent surgical complications such as inadequate exposure of the uterus and incorporation of fetal bones into the uterine stump following ovarioh...
Griffin LV, Gibeling JC, Gibson VA, Martin RB, Stover SM.Experiments and analyses were performed to determine the cause of a nonlinear force-deflection response observed in four-point flexural fatigue of beams of cortical bone machined from the mid-diaphysis of the equine third metacarpus. Observable grooves which formed on the beam surface at supports and load noses were found to be the primary cause of the nonlinearity. An additional geometric nonlinearity at large deflections revealed by finite element modeling may be minimized by using the smallest diameter supports and load noses recommended in ASTM 790. However, frictional constraint of the be...
Timoney PJ, O'Reilly PJ, McArdle JF, Ward J, Harrington AM, McCormack R.Reproduction of contagious equine metritis 1977 in Pony mares was achieved with cultures of an unclassified Gram-negative coccobacillus. Infected mares developed a vaginal discharge and associated inflammatory changes of the cervix and vagina. There was evidence of variation in pathogenicity between different strains of the organism. Although all infected mares made spontaneous clinical recoveries, the Gram-negative coccobacillus persisted in the genital tracts of a considerable proportion for a variable period after challenge. Recovery of the organism was not associated solely with the occurr...
