Pathology in horses involves the study of diseases and abnormalities affecting equine health, encompassing a range of conditions that can impact various systems within the horse's body. This field examines the causes, mechanisms, and effects of diseases, as well as the structural and functional changes they induce in equine tissues and organs. Common pathological conditions in horses include laminitis, colic, equine infectious anemia, and respiratory disorders. Understanding these diseases involves evaluating clinical signs, diagnostic methods, and treatment options. This page compiles peer-reviewed research studies and scholarly articles that explore the etiology, pathogenesis, and clinical implications of pathological conditions in horses.
Cercone M, Brown BN, Stahl EC, Mitchell LM, Fortier LA, Mohammed HO, Ducharme NG.Respiratory function in the horse can be severely compromised by arytenoid chondritis, or arytenoid chondropathy, a pathologic condition leading to deformity and dysfunction of the affected cartilage. Current treatment in cases unresponsive to medical management is removal of the cartilage, which can improve the airway obstruction, but predisposes the patient to other complications like tracheal penetration of oropharyngeal content and dynamic collapse of the now unsupported soft tissue lateral to the cartilage. A tissue engineering approach to reconstructing the arytenoid cartilage would repr...
Shaffer SK, To C, Garcia TC, Fyhrie DP, Uzal FA, Stover SM.Proximal sesamoid bone (PSB) fracture is the most common fatal injury in Thoroughbred (TB) racehorses in the United States. Epidemiological and pathological evidence indicates PSB fracture is likely the acute culmination of a chronic stress-related process. However, the aetiopathogenesis of PSB fracture is poorly understood. Objective: To characterise bone abnormalities that precede PSB fracture. Methods: Two retrospective case-control groups of PSBs from TB racehorses with, and without, unilateral biaxial PSB fracture. Methods: Proximal sesamoid bones were harvested post-mortem from TB raceho...
Veronesi F, Di Palma S, Gabrielli S, Morganti G, Milardi GL, Middleton B, Lepri E.The only species currently known to inhabit the fibers of skeletal and cardiac muscles in horses are , and . We describe herein the invasion of myofibers in a horse by , a sheep-specific species with low virulence in the original host. A hunter gelding was referred to a veterinary surgeon in Newmarket (UK). The anamnestic data reported that the horse had an initial history of swelling of the right forelimb with fluid on the front of the carpus and edema spreading up the forearm. Subsequently, 2 firm lumps were found on the left pectoral muscle adjacent to the axilla of the left forelimb. Hist...
Galantino-Homer H, Brooks SA.Laminitis is a devastating disease with diverse etiologies and few, if any, effective treatments. Gene expression and hypothesis-generating genomic studies have provided a fresh look at the key molecular players at crucial timepoints in diverse experimental and naturally affected tissues. We summarize findings to date, and propose a unifying model of the laminitis disease process that includes several pathogenesis concepts shared with other diseases of epidermal and epithelial tissues. The value of these new pathways as potential therapeutic targets is exciting but will require careful future ...
Rieger J, Kaessmeyer S, Al Masri S, Hünigen H, Plendl J.The cardiovascular system is the first functional organ in the embryo, and its blood vessels form a widespread conductive network within the organism. Blood vessels develop de novo, by the differentiation of endothelial progenitor cells (vasculogenesis) or by angiogenesis, which is the formation of new blood vessels from existing ones. This review presents an overview of the current knowledge on physiological and pathological angiogenesis in the horse including studies on equine endothelial cells. Principal study fields in equine angiogenesis research were identified: equine endothelial progen...
Keen JA.Pathological bradyarrhythmia is rare in horses but should be especially considered when presented with a horse that has signs consistent with episodic weakness or collapse. This paper reviews the literature describing our current knowledge of, and possible mechanisms causing, clinically significant bradyarrhythmia in horses.
Tartor YH, Hamad MH, Abouzeid NZ, El-Belkemy FA.Equine pythiosis is an emerging, devastating disease that is hard to treat. The tumour-like nodular skin masses grow rapidly and the outcome is generally fatal, and thus early diagnosis and intervention are important. Objective: (i) To highlight the clinical, histological and haematological findings in pythiosis, and (ii) to evaluate the efficacy of direct sample multiplex-PCR targeting the single nucleotide polymorphisms within the ribosomal DNA region for detection and genotyping of Pythium insidiosum. Methods: Two hundred and twenty horses including 204 Arabian and 16 draft horses were surv...
Bacci B, Stent AW, Walmsley EA.Lymphoma is the most common intestinal neoplasm in horses, but its clinical-pathological features are poorly characterized. Primary intestinal lymphoma was diagnosed in 20 horses on biopsy samples and further confirmed by postmortem examination in 16 cases. Lymphoma was found in the small intestine in 12 of 20 (60%), in the colon in 5 of 20 (25%), and in both small and large intestines in 3 of 20 (15%) cases. Gross findings included thickening of the intestinal wall (45%), mural nodules or masses (30%), and both thickening and nodules (10%). Cases were classified according to the human World H...
Steuer AE, Stewart JC, Barker VD, Adams AA, Nielsen MK.The role of the immune response to cyathostomin infections in horses remains unknown. Intestinal goblet cell hyperplasia has previously been noted as a component in cyathostomin infection; however, the function is unclear. The goal of this study was to evaluate the local and systemic gene expression to cyathostomin infections following larvicidal treatment and explore their relation to goblet cells. Thirty-six ponies with naturally acquired cyathostomin infections were randomly allocated into three groups: fenbendazole-treated (10 mg/kg PO 5 days), moxidectin-treated (0.4 mg/kg PO once) and...
Guzmán C, Calderón A, Oviedo T, Mattar S, Castañeda J, Rodriguez V, Moraes Figueiredo LT.Venezuelan equine encephalitis virus (VEEV) is an alphavirus that causes encephalitis with a high impact on public health in Latin America. However, only in Guatemala, Trinidad and Tobago, and Mexico have found antibodies in VEEV in bats, using immunohistochemistry, the sensitivity and specificity are improved; thus, it is better for demonstrating natural infection in bats as potential hosts. This study aimed to determine the presence of VEEV in tissues of frugivorous bats. Methods: A prospective descriptive cross-sectional study with a non-probabilistic sampling was carried out in 12 localiti...
Pye J, Kilcoyne I, Roy M, Vaughan B, Ormond C, Spriet M.A 20-year-old Quarter horse gelding was referred for evaluation of an acute onset non-weight-bearing right forelimb lameness. Marked soft tissue swelling was apparent over the right scapula and shoulder region; no crepitus was palpable. A complete transverse fracture of the scapular neck was suspected based on ultrasonography and radiographs were obtained to confirm the presumptive diagnosis. A complete, oblique fracture of the right scapular neck with mild cranial and proximal displacement of the distal fragment was detected. Computed tomography of the upper right forelimb was performed post-...
Barton MH, Hart KA.The dynamic physiologic changes and unique diet during the neonatal period contribute to key differences in clinicopathologic test results of healthy foals relative to healthy adult horses. When reporting results, most diagnostic laboratories only provide reference intervals for mature horses. Thus, failure to recognize the unique differences that occur in foals relative to adult horses can lead to erroneous interpretation of neonatal clinical pathologic values. Thus, the main objective of this article was to review distinct features of common clinicopathologic tests in foals, relative to matu...
Wernery U, Joseph S, Raghavan R, Dyer B, Spendrup S.Our investigation has shown that multiple vaccinations with inactivated African horse sickness (AHS) vaccines containing all 9 serotypes and produced at the Central Veterinary Research Laboratory in Dubai, UAE, protect horses from AHS. However, the immunization did not prevent African horse sickness fever (AHSF) in approximately 10% of the vaccinated horses despite high enzyme-linked immunosorbent assay and virus neutralizing antibodies. African horse sickness fever is a very mild form of AHS with similar clinical signs. From all 6 horses which had developed AHSF, no virus was isolated from ED...
Kinoshita Y, Niwa H, Uchida-Fujii E, Nukada T.Mycoplasma felis causes conjunctivitis in cats and respiratory diseases in horses. We report here the complete genome assembly of equine Mycoplasma felis strain Myco-2, which was isolated from an ill horse in Japan.
J Rgensen E, Hjerpe FB, Hougen HP, Bjarnsholt T, Berg LC, Jacobsen S.To evaluate histologic changes and gene expression patterns in body and limb wounds in horses in response to bacterial inoculation. Methods: Wound biopsy specimens from 6 horses collected on days 7, 14, 21, and 27 after excisional wounds (20 wounds/horse) were created over the metacarpal and metatarsal region and lateral thoracic region (body) and then inoculated or not inoculated on day 4 with Staphylococcus aureus and Pseudomonas aeruginosa. Methods: Specimens were histologically scored for the amount of inflammation, edema, angiogenesis, fibrosis organization, and epithelialization. Quantit...
Lloyd KA, Ayodele BA, Hitchens PL, Beck C, Mackie EJ, Whitton RC.Abnormalities in vascular channel appearance within the proximal sesamoid bone (PSB) are the most common findings in Thoroughbred yearling presale radiographs and are often evaluated on radiographs of adult racehorses. Despite this, their pathogenesis and clinical significance are poorly understood, and associations with racing performance are inconsistent. Objective: To determine microstructural characteristics of the PSBs associated with the radiographic appearance of vascular channels using microcomputed tomography (µCT) and to determine associations with past racing performance in mature ...
Taylor BM, Chaffin MK, Hoffmann AR, Edwards JF, Arenas-Gamboa AM.Prolonged exposure to water, known as immersion foot syndrome in humans, is a phenomenon first described in soldiers during World War I and characterized by dermal ischemic necrosis. In this report, we describe the pathologic findings of a condition resembling immersion foot syndrome in 5 horses and 1 donkey with prolonged floodwater exposure during Hurricane Harvey. At necropsy, all animals had dermal defects ventral to a sharply demarcated "water line" along the lateral trunk. In 5 animals, histologic examination revealed moderate to severe perivascular dermatitis with vasculitis and coagula...
Nagel C, Aurich J, Aurich C.Economic losses due to dystocia or neonatal death as well as animal welfare and ethical concerns demand a reliable prediction of parturition with the aim to improve survival of the dam and her offspring. In this review, estimation of gestational age by ultrasound and prediction of parturition based on clinical signs, behaviour changes and changes in body temperature, composition of mammary gland secretions as well as hormonal changes are discussed in comparison between horses and cattle. Based on the physiological changes associated with the end of gestation and onset of labor, several systems...
El-Sheikh Ali H, Boakari YL, Loux SC, Dini P, Scoggin KE, Esteller-Vico A, Kalbfleisch T, Ball BA.The key event in placentitis-induced preterm labor is myometrial activation with the subsequent initiation of labor. However, the molecular mechanisms underlying myometrial activation are not fully understood in the mares. Therefore, the equine myometrial transcriptome was characterized during placentitis (290.0 ± 1.52 days of GA, n = 5) and the prepartum period (330 days of GA, n = 3) in comparison to normal pregnant mares (289.8 ± 2.18 days of GA, n = 4). Transcriptome analysis identified 596 and 290 DEGs in the myometrium during placentitis and the prepartum period, respectively...
Olomski F, Fettelschoss V, Jonsdottir S, Birkmann K, Thoms F, Marti E, Bachmann MF, Kündig TM, Fettelschoss-Gabriel A.Insect bite hypersensitivity (IBH) is the most common seasonal pruritic allergic dermatitis of horses occurring upon insect bites. In recent years, a major role for IL-31 in allergic pruritus of humans, monkeys, dogs, and mice was acknowledged. Here, we investigate the role of IL-31 in IBH of horses and developed a therapeutic vaccine against equine IL-31 (eIL-31). IL-31 levels were quantified in allergen-stimulated peripheral blood mononuclear cells (PBMCs) and skin punch biopsies of IBH lesions and healthy skin from IBH-affected and healthy horses. The vaccine consisted of eIL-31 covalently ...
Schott HC, Esser MM.Clinicopathologic evaluation of renal function and renal disease in sick adult horses remains grounded in detection of azotemia, assessment of serum and urine electrolyte concentrations, and evaluation of urinalysis findings, including specific gravity, reagent strip analysis, and sediment examination. Because increases in serum or plasma urea nitrogen and creatinine concentrations are insensitive indicators of a decreased glomerular filtration rate, there is considerable interest in identifying novel biomarkers of renal function or injury in blood and urine, with serum symmetric dimethylargin...
Domino M, Jasinski T, Kautz E, Juszczuk-Kubiak E, Ferreira-Dias G, Zabielski R, Sady M, Gajewski Z.Equine endometrosis is a multifactorial chronic degenerative condition, considered to be one of a major causes of equine infertility. The formation of periglandular fibrosis seems to be linked to chronic inflammation of the mare endometrium in a paracrine way and in a response to numerous forms of inflammatory stimuli elicit the net deposition of extracellular matrix (ECM) around the endometrial glands and stroma. We hypothesized some of these stimuli, such as monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), and hyaluronan synthases (HASs), may share the nuclear factor-κB (NF...
van Zadelhoff C, Schwarz T, Smith S, Engerand A, Taylor S. To describe detectable and non-detectable naturally occurring cartilage damage of the equine distal interphalangeal (DIP) joint using plain magnetic resonance (MR) imaging and gadolinium and saline MR arthrography. The second objective was to quantify the sensitivity, specificity and accuracy in detection of cartilage damage. In a pilot study, the distal limbs of two horses with confirmed osteoarthritis of the DIP joint were imaged with low-field MR. Magnetic resonance images were assessed in consensus by three observers and compared to gross pathological findings. Subsequently, a prospectiv...
Sallé G, Guillot J, Tapprest J, Foucher N, Sevin C, Laugier C.Horses are infected by a wide range of parasite species that form complex communities. Parasite control imposes significant constraints on parasite communities whose monitoring remains, however, difficult to track through time. Postmortem examination is a reliable method to quantify parasite communities. Here, we compiled 1,673 necropsy reports accumulated over 29 years, in the reference necropsy centre from Normandy (France). The burden of non-strongylid species was quantified and the presence of strongylid species was noted. Details of horse deworming history and the cause of death were reg...
Ehmann R, Brandes K, Antwerpen M, Walter M, V Schlippenbach K, Stegmaier E, Essbauer S, Bugert J, Teifke JP, Meyer H.Cases of pox-like lesions in horses and donkeys have been associated with poxviruses belonging to different genera of the family . These include the orthopoxviruses vaccinia virus (VACV), horsepoxvirus (HPXV) and cowpoxvirus (CPXV), as well as a potentially novel parapoxvirus and molluscum contagiosum virus (MOCV). However, with the exception of VACV, HPXV and CPXV, the genomic characterization of the causative agents remains largely elusive with only single short genome fragments available. Here we present the first full-length genome sequence of an equine molluscum contagiosum-like virus (EM...
Frazer LL, Santschi EM, Ring SJ, Hewitt RE, Fischer KJ.Equine subchondral bone cysts (SBCs) develop most often in the medial femoral condyle (MFC) of yearlings intended for performance. SBCs often cause lameness and can cause secondary injuries to the meniscus and tibial cartilage. A novel surgical technique using a transcondylar lag screw (TLS) across an MFC SBC has shown success in lameness resolution and radiographic healing of MFC SBC. In a previous study using finite element analysis, our lab showed that a TLS stimulated bone formation on the inner surface of the SBC and altered third principal stress vectors to change the direction of surfac...
Recent advances in tendinopathy research have focused on tendon vascularization detected with Color Doppler (CD) ultrasound. The use of CD has also been described in horses in a study on chronic lesions of superficial digital flexor tendon and suspensory ligament. The aim of this study was to investigate the occurrence and distribution of power Doppler (PD) signal in horses with superficial digital flexor tendinopathy. Twenty-five horses with tendinopathy were included and 10 healthy horses with no lameness and no ultrasonographic abnormalities were used for comparison. In all horses with tend...
Fingerhut L, Ohnesorge B, von Borstel M, Schumski A, Strutzberg-Minder K, Mörgelin M, Deeg CA, Haagsman HP, Beineke A, von Köckritz-Blickwede M....Equine recurrent uveitis (ERU) is considered one of the most important eye diseases in horses and typically appears with relapsing inflammatory episodes without systemic effects. Various disorders have been described as an initial trigger, including infections. Independent of the initiating cause, there are numerous indications that ERU is an immune-mediated disease. We investigated whether neutrophil extracellular traps (NETs) are part of the ERU pathogenesis. Therefore, vitreous body fluids (VBF), sera, and histological sections of the eye from ERU-diseased horses were analyzed for the prese...
Cordes DO, Perry BD, Rikihisa Y, Chickering WR.Potomac horse fever was reproduced in 15 ponies by transfusion of whole blood originally from two natural cases and subsequently from ponies infected by the transfusions. Incubation periods varied from 9 to 15 days. Affected ponies developed varying degrees of fever, diarrhea, anorexia, depression, and leukopenia. Eleven affected ponies were killed, three died in the acute phase of the disease, and one did not show clinical signs. The most consistent post-mortem findings were fluid contents in the cecum and large colon, and areas of hyperemia (of inconstant degree and distribution) in mucosae ...
Choi YK, Kang MS, Yoo HS, Lee DY, Lee HC, Kim DY.Acute hemorrhagic myonecrosis accompanied by severe inter- and intrafascicular edema and hemorrhage of the right gluteal area was diagnosed in a 13-year-old male thoroughbred horse. Once the muscular and fascicular changes were subsided, the horse then developed acute respiratory problem. Histologically, the lung had diffuse severe hemorrhage with mild neutrophilic infiltration. The cause of death was acute respiratory failure that is believed to occur secondary to toxaemic event. Alpha and beta2 toxin secreting Clostiridum perfringens type A was isolated from the muscle and lung. The diagnosi...
Dowdall SM, Proudman CJ, Klei TR, Mair T, Matthews JB.Cyathostomins are the most common parasitic nematodes of horses. Larval stages, which inhabit the intestinal wall, are particularly pathogenic and can cause severe colitis and colic. Despite their clinical importance, diagnostic techniques for the prepatent stages do not exist. A method that could estimate mucosal infection intensity would have a major impact on the control and diagnosis of cyathostominosis. Here, serum IgG(T) responses to two larval antigen complexes of 25 and 20 kDa were quantified in horses with experimental infections, natural infections and in horses that presented with c...
Valberg SJ, Mickelson JR, Gallant EM, MacLeay JM, Lentz L, de la Corte F.The purpose of this study was to determine if chronic exertional rhabdomyolysis (ER) in Quarter Horses and Thoroughbreds represents one or several distinct myopathies. Eighteen Quarter Horses and 18 Thoroughbreds with ER were selected from cases presented to the Veterinary Hospital on the basis of a history of ER, assessment of muscle histopathology, and serum CK activity before and 4 h post exercise. In addition, 2 of 3 of the following parameters were evaluated: muscle glycogen concentrations, thyroid hormones (T3, T4), fractional excretion (FE) of sodium, potassium and chloride. The CK resp...
Draper ACE, Piercy RJ.Recurrent Laryngeal Neuropathy (RLN) is a highly prevalent and predominantly left-sided, degenerative disorder of the recurrent laryngeal nerves (RLn) of tall horses, that causes inspiratory stridor at exercise because of intrinsic laryngeal muscle paresis. The associated laryngeal dysfunction and exercise intolerance in athletic horses commonly leads to surgical intervention, retirement or euthanasia with associated financial and welfare implications. Despite speculation, there is a lack of consensus and conflicting evidence supporting the primary classification of RLN, as either a distal ("d...
Martineau D, Bowser PR, Wooster G, Forney JL.Sixty-seven adult walleye fish were examined by light and transmission electron microscopy. The fish were affected by a mesenchymal tumor previously termed Walleye Dermal Sarcoma that commonly affects up to 27% of the population seasonally. Biopsies from 24 fish were collected, and complete postmortem examinations were performed on 43 fish. Grossly, the tumors had the appearance of randomly distributed, often clustered, spherical nodules, 2-5 mm in diameter with a smooth and often ulcerated surface. The tumors arose from the superficial surface of scales and consisted of fibroblast-like cells ...
Da Silva AS, Garcia Perez HA, Costa MM, França RT, De Gasperi D, Zanette RA, Amado JA, Lopes ST, Teixeira MM, Monteiro SG.In this study, we reported the first outbreak of the infection by Trypanosoma vivax in horses in southern Brazil, a non-endemic region where bovines have only recently been found infected by this trypanosome species. We evaluated 12 horses from a farm in southern Brazil, where four horses displayed pale mucous membranes, fever, weight loss, and swelling of abdomen, prepuce, or vulva. The diagnosis of T. vivax was confirmed in four horses by morphological parameters of trypomastigotes in blood smears and species-specific PCR. All T. vivax-infected animals showed anemia, and most showed increase...
van Eps AW.Acute laminitis is a serious complication of many primary conditions in the horse. This article summarizes the most appropriate approach to management of the horse with acute laminitis, based on current information.
Holz CL, Sledge DG, Kiupel M, Nelli RK, Goehring LS, Soboll Hussey G.Histopathological differences in horses infected with equine herpesvirus type 1 (EHV-1) of differing neuropathogenic potential [wild-type (Ab4), polymerase mutant (Ab4 N752), EHV-1/4 gD mutant (Ab4 gD4)] were evaluated to examine the impact of viral factors on clinical disease, tissue tropism and pathology. Three of 8 Ab4 infected horses developed Equine Herpesvirus Myeloencephalopathy (EHM) requiring euthanasia of 2 horses on day 9 post-infection. None of the other horses showed neurologic signs and all remaining animals were sacrificed 10 weeks post-infection. EHM horses had lymphohistiocyti...
Schöniger S, Valentine BA, Fernandez CJ, Summers BA.Schwannomas are uncommonly recognized in horses. This study describes cutaneous schwannomas in 22 horses aged 8 to 25 years: 12 male, 7 female, and 3 of unknown sex. The horses had solitary cutaneous masses: 9 on the head, 3 on the neck, and the others on the shoulder, hip, thorax, abdomen, rump, extremities, or tail. The location of 1 tumor was unknown. The dermal tumors were well demarcated and expansile. Twelve had a multinodular pattern, whereas 10 formed a single nodule. Antoni A areas were observed in all tumors, and 10 tumors contained Antoni B areas. In Antoni A areas, the densely pack...
Rieger J, Kaessmeyer S, Al Masri S, Hünigen H, Plendl J.The cardiovascular system is the first functional organ in the embryo, and its blood vessels form a widespread conductive network within the organism. Blood vessels develop de novo, by the differentiation of endothelial progenitor cells (vasculogenesis) or by angiogenesis, which is the formation of new blood vessels from existing ones. This review presents an overview of the current knowledge on physiological and pathological angiogenesis in the horse including studies on equine endothelial cells. Principal study fields in equine angiogenesis research were identified: equine endothelial progen...
Cahill JI, Goulden BE.This study confirmed that neurogenic muscle pathology exists in intrinsic laryngeal muscles supplied by the recurrent laryngeal nerves in horses subclinically and clinically affected with laryngeal hemiplegia. An important additional observation was the occurrence in three out of four laryngeal hemiplegic horses of neurogenic muscle changes in a hindlimb muscle, the extensor digitorum longus, a muscle supplied by another long peripheral nerve. This finding suggests that a polynenropathy exists in laryngeal hemiplegic horses, and supports the classification of this disease as a distal axonopath...
Kimman TG, Binkhorst GJ, van den Ingh TS, Pol JM, Gielkens AL, Roelvink ME.Aujeszky's disease virus was isolated from the brain of a horse which had shown severe neurological signs, including excessive sweating, muscle tremors and periods of mania. Pathological examination revealed a non-suppurative meningoencephalitis. The virus was propagated in cell culture and inoculated into the conjunctiva and nostrils of two ponies. The ponies developed fever seven days after inoculation and subsequently started to behave abnormally, showing severe neurological signs on the ninth day after inoculation. One pony became excited and the other was depressed. One pony died on the n...
Kim DY, Taylor HW, Moore RM, Paulsen DB, Cho DY.Osteoarthritis (OA) is the most common joint disease in horses. Chondrocyte apoptosis has been implicated as a major pathological OA change in humans and experimental animals but no studies have been performed on equine OA. Articular cartilage was collected from three normal and five OA horses. Histopathological changes were scored by a modified Mankin grading system. A terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay was performed to identify chondrocyte apoptosis. Nitric oxide (NO) production from chondrocytes was indirectly evaluated by immunohistochemistr...
Sponseller ML, Binn LN, Wooding WL, Yager RH.Four field strains of western encephalitis virus were inoculated subcutaneously or intracranially (i/c) into recently weaned ponies. After s/c inoculation, 3 of the 4 strains produced an inapparent infection with a short period of viraemia. The 4th strain produced viraemia, fever, and signs of central nervous system disease. Viraemia occurred after intracranial inoculation with each strain; however, a variation in clinical response occurred, ranging from an inapparent infection to death. The disease pattern was characterized by three successive phases: viraemia, increased body temperature, and...
Ali AA, Refat NA, Algabri NA, Sobh MS.EHV-1 infection is responsible for huge economic losses in equines due to abortion and neonatal mortality. In this study, we describe 4 cases of abortion and neonatal deaths from pregnant mares and a she-donkey from different localities in Egypt during the period from May 2015 to October 2017. Attempts were made to isolate and identify EHV-1, in addition to compare the different pathological lesions in various tissues of the necropsied cases. EHV-1 was successfully isolated from two aborted fetuses and one dead neonatal foal from mares, beside one aborted fetus from a she-donkey. The positive ...
Webbon PM.The results of a survey are presented in which 589 limbs from 206 horses were dissected. In174 of the limbs lesions were found in either the superficial (131) or deep (43) digital flexor tendons. Changes occurring with age were also recorded. The sites of the abnormalities and their macroscopical appearance are described and the value of the results is considered in relation to the diagnosis and the treatment of clinical lesions.
Ramirez S, Lester GD, Roberts GR.The aim of this retrospective study was to determine the clinical usefulness of thoracic ultrasonography compared to thoracic radiography in evaluation of Rhodococcus equi pneumonia. Criteria for patient inclusion in this study were: (1) isolation of R. equi from transtracheal aspirate, (2) radiographic evaluation of the pulmonary parenchyma, and (3) sonographic evaluation of the pulmonary parenchyma. Seventeen foals met this criteria and their medical records were reviewed. Pyogranulomatous pneumonia was identified radiographically in 13 foals. Severe consolidative pneumonia with no detectabl...
Mair TS, Taylor FG, Harbour DA, Pearson GR.Combined immunodeficiency syndrome is an inherited disorder of the Arabian breed of horses. Affected foals usually die of infectious disease within the first few months of life, and the respiratory tract is the commonest site of infection. This report describes the clinical and pathological features of a case which showed signs of alimentary and respiratory infections. Intestinal infection by coronavirus (not previously recorded in cases of the syndrome) and cryptosporidia was identified. Histopathological evidence also suggested the presence of an adenovirus infection.
Martins TB, Kommers GD, Trost ME, Inkelmann MA, Fighera RA, Schild AL.Twenty-one cases of pythiosis in horses (n = 10), dogs (n = 9) and cattle (n = 2) were investigated. The aetiology in all cases was confirmed by immunohistochemistry. Data related to the clinical course and outcome and localization of the lesions were obtained from pathology reports. The equine lesions consisted of fibrotic tissue with multiple, often coalescing, areas of immature granulation tissue encircling eosinophilic cores. Affected dogs had gastrointestinal and/or cutaneous lesions with either or both of a granulomatous/pyogranulomatous or necrotizing eosinophilic inflammatory reaction....
Proudman CJ, Trees AJ.Until recently, the equine tapeworm Anoplocephala perfoliata was difficult to diagnose and considered to be of questionable pathogenicity. Here, Chris Proudman and Sandy Trees describe recent advances in the immunodiagnosis of this parasite that have facilitated epidemiological studies. These studies suggest that A. perfoliata may be an important cause of intestinal disease in the horse and demonstrate a dose-response relationship between infection intensity and risk of disease. If tapeworm infection is a risk factor for ileocaecal colic, the identification and treatment of infected individual...
The Journal of parasitologyApril 25, 2001
Volume 87, Issue 2 345-353 doi: 10.1645/0022-3395(2001)087[0345:COTOIO]2.0.CO;2
Dubey JP, Liddell S, Mattson D, Speert CA, Howe DK, Jenkins MC.Neospora hughesi was isolated in cell cultures inoculated with homogenate of spinal cord from a horse in Oregon. Tachyzoites of this Oregon isolate of N. hughesi were maintained continuously by cell culture passage and tachyzoites were infective to immunosuppressed mice. Gamma interferon gene knockout (KO) mice injected with tachyzoites developed fatal myocarditis and numerous tachyzoites were seen in lesions. Gerbils (Meriones unguiculatus) inoculated with tachyzoites developed antibodies (> or = 1:500) as indicated by the Neospora caninum agglutination test but did not develop clinical si...
Veraa S, Voorhout G, Klein WR.Infundibular changes are frequently encountered computed tomographic studies of the equine maxillary cheek teeth but the possible importance of this finding is not known. Infundibular caries is a possible cause for pulpitis and apical infection in some horses. Objective: To study the relationship between the 2 pathologies and the frequency of changes. Methods: The maxillary cheek teeth 108-208, 109-209 and 110-210 of 25 horses were evaluated using computed tomography and both the prevalence of infundibular and apical infection changes as the possible link with apical infection evaluated statis...
Taylor SD, Haldorson GJ, Vaughan B, Pusterla N.Gastric neoplasia of horses is incompletely described. Objective: Provide history, clinical signs, and clinicopathological and pathological findings associated with gastric neoplasia in horses. Methods: Twenty-four horses with gastric neoplasia. Methods: Retrospective study. History, clinical signs, and clinicopathological and pathologic findings in horses diagnosed histologically with gastric neoplasia were reviewed. Results: Horses ranged in age from 9 to 25 years (median 18 years at presentation). There was no apparent breed or sex predisposition. The most common presenting complaints were ...
Yoshikawa H, Yasu T, Ueki H, Oyamada T, Oishi H, Anzai T, Oikawa M, Yoshikawa T.To evaluate the possibility that Streptococcus equi subsp. zooepidemicus (S.z) the causative bacterial agent of equine shipping fever pneumonia (ESFP), as well as to investigate its pathogenesis, 10 horses (seven Thoroughbreds and three Anglo-Arab species, ranging from 2-4 years in age) were experimentally inoculated, via an endoscope, into bronchus of the lung lobe with a dose of 30 ml of 1-7 x 10(8) CFU/ml of S.z. After inoculation, autopsy and pathological examinations were sequentially conducted 30 min, 1, 2, 3, 4, 17, 20 hr and 2 weeks later. Pneumonia induced by the intrapulmonary inocul...
Sleutjens J, Cooley AJ, Sampson SN, Wijnberg ID, Back W, van der Kolk JH, Swiderski CE.The impact of cervical pathology on performance is of great importance to the horse industry. Accurate diagnosis of cervical disease with imaging modalities, including computed tomography (CT) and magnetic resonance imaging (MRI), requires thorough appreciation of normal cervical anatomy. Objective: (1) To describe in detail the anatomy of the equine cervical spine by comparing anatomical sections with corresponding MR and contrast-enhanced CT images in the sagittal, dorsal, and transverse plane. (2) To discuss the ability of MR and contrast-enhanced CT imaging to visualize anatomical structur...
Blunden A, Dyson S, Murray R, Schramme M.Causes of palmar foot pain and the aetiopathogenesis of navicular disease remain poorly understood, despite the high incidence of foot-related lameness. Objective: Abnormalities of the collateral sesamoidean ligaments (CSLs), distal sesamoidean impar ligament (DSIL), deep digital flexor tendon (DDFT), navicular bone, navicular bursa, distal interphalangeal (DIP) joint or collateral ligaments (CLs) of the DIP joint may contribute to palmar foot pain. Methods: Feet were selected from horses with a history of unilateral or bilateral forelimb lameness of at least 2 months' duration that was improv...
Blunden A, Dyson S, Murray R, Schramme M.Causes of palmar foot pain and the aetiopathogenesis of navicular disease remain poorly understood, despite the high incidence of foot-related lameness. Objective: Abnormalities of the deep digital flexor tendon (DDFT) may contribute to palmar foot pain; ageing degenerative changes may be seen in horses free from lameness; and horses with lameness are likely to have a greater severity of abnormalities than age-matched horses with no history of foot pain. Methods: Feet were selected from horses with a history of uni- or bilateral forelimb lameness of at least 2 months' duration. Histology of th...
Edwards RB, Lu Y, Uthamanthil RK, Bogdanske JJ, Muir P, Athanasiou KA, Markel MD.The purpose of this study was to develop a long-term model of cartilage injury that could be used to compare the effects of radiofrequency energy (RFE) and mechanical debridement as a treatment. Methods: Partial thickness fibrillation of patellar cartilage was created in 16 mature ponies. Three months after the initial surgery all injured patellae were randomly selected to receive one of the four treatments (n = 8/treatment): (1) control, (2) mechanical debridement with a motorized shaver, (3) TAC-CII RFE probe, and (4) CoVac 50 RFE probe. The ponies were euthanized 22 months after treatment. ...
