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.
Ramsay L, Eberhardt C, Schoster A.Reports of leptospirosis in horses are limited. Objective: To describe the clinical and diagnostic findings of acute systemic leptospirosis in horses. Methods: Eleven client-owned horses presented to an equine hospital because of acute onset of disease between 2015 and 2023. Methods: Retrospective case series. Horses diagnosed with leptospirosis by 1 or more of urine PCR, serologic microscopic agglutination test (MAT), and histopathology. Results: Common clinical signs included lethargy (10), anorexia (10), fever (9), tachypnea (9), abnormal lung sounds (9), and epistaxis (6). Acute kidney inj...
Wang Z, Zeng S, Wang Y, Wang T, Qu H, Zhu Y, Li J.Reproductive disorders in donkeys present a significant challenge to their health and welfare, impacting their roles in agriculture, conservation, and companionship. With the development of large-scale donkey farming in recent years, reproductive disorders have become a limiting factor for the expansion of the donkey population. In general, donkeys suffer from a similar array of diseases like horses, but little is known about the specificities of donkey reproductive disorders. This review synthesizes current knowledge on the pathogenesis, distribution, presentation, diagnosis, treatment, and p...
Kasem S, Yu MHH, Alkhalefa N, Ata EB, Nayel M, Abdo W, Abdel-Moneim AS, Fukushi H.Equine herpesvirus 1 (EHV-1) causes respiratory illness, fetal loss, perinatal mortality, and myeloencephalopathy. This study investigated ORF15's impact on virus infectivity and neurovirulence. The Ab4p neurovirulent strain of EHV1 was used as a backbone to create Ab4p attB, Ab4p∆ORF15, and Ab4p∆ORF15R chimeras via BAC DNA transfection into RK-13 cells. Viral growth kinetics, plaque size, transcription, and growth were assessed in MDBK cells, mouse neurons, and fetal equine brain cells. Neurovirulence was evaluated post-intranasal inoculation into male CBA/N1 SPF mice, measuring signs, vi...
Al Mheiri FG, Joseph M, Joseph S, Alqassim M, Kinne J, Wernery U.This article describes the development of the pathogenic dimorphic fungus Histoplasma capsulatum var. farciminosum (HCF), which is the causative agent of Equine epizootic lymphangitis (EEL), from the mycelial form in the soil to the yeast form in the horse. In this study, the stages and morphology of HCF were identified through histopathological analysis and culture with various samples collected in Ethiopia from 15 horses showing clinical signs of EEL. In equids, especially cart horses in Ethiopia, poor-quality harnesses cause cutaneous wounds, which often attract flies facilitating the trans...
Batista LAS, de Alencar Santos Júnior D, Rodrigues AS, Menezes AA, do Nascimento MJR, de Galiza GJN, de Medeiros Dantas AF, Frade MTS.The present study describes the morphological and immunohistochemical characteristics of a case of diffuse seminoma in a 16-year-old male mixed-breed horse. According to the owner, the animal's left testicle had been gradually increasing in size over a period of 2 months. On palpation, the testicle had a firm consistency, with no sensitivity to digital pressure, was adhered to the scrotum and measuring 16 cm × 8 cm. In the ultrasound examination, it presented a heterogeneous texture and areas of hypoechogenic echogenicity without visualization of the mediastinum. Therefore, the bila...
Tan Yi Shean L, Milne EM, Shaw DJ, Maxwell S, Del-Pozo J.Lipofuscin is a complex mixture of highly oxidized, cross-linked macromolecules that accumulates in neurons with age and some neurodegenerative diseases. Equine dysautonomia (ED) is a polyneuropathy that mainly affects autonomic and enteric nervous systems, resulting in alimentary tract dysfunction. Our main aim was to determine whether neuronal lipofuscin increased with increasing duration of ED. We investigated the prevalence of lipofuscin in cranial cervical ganglia of horses with acute (AED), subacute (SED), and chronic ED (CED), young controls (of similar age to ED cases), and aged contro...
Woo PCY, Mheiri FA, Cavalleri J, Joseph S, Tang JYM, Joseph M, Tsang CC, Lau SKP, Wernery U.Epizootic lymphangitis (EL) is a highly prevalent and contagious infectious disease affecting horses in many parts of Ethiopia caused by Histoplasma capsulatum sensu lato ('var. farciminosum'). In this study, 12 suspected isolates of H. capsulatum sensu lato or yeasts unidentified by conventional biochemical tests isolated from Ethiopian horses with EL were characterised by ITS sequencing. Six of the 12 isolates were identified to be members of H. capsulatum sensu lato and the other six were Pichia kudriavzevii (synonym: Candida krusei) (n = 3), Trichosporon asahii (n = 1), Geotrichum silv...
Korim F, Revajová V, Koľvek F, Bujňák L, Hreus S, Všianský D.The parotid duct has been reported to be the most common site of sialoliths in horses. In this case report, we described the first confirmed case of the equine sialolithiasis in Slovakia. The work was aimed to describe the transcutaneous approach to removing the sialolith, which manifested as a hard painless mass in the area of the maxillary cheek teeth, in a 14-year-old Slovakian warmblood mare. Pathological-anatomical and histological examination after extirpation confirmed the presence of parotid duct ectasia resulting from calculus. The mineral composition of the sialolith was determined w...
Portaels J, Van Crombrugge E, Van Den Broeck W, Lagrou K, Laval K, Nauwynck H.Numerous Aspergillus fumigatus (Af) airborne spores are inhaled daily by humans and animals due to their ubiquitous presence. The interaction between the spores and the respiratory epithelium, as well as its impact on the epithelial barrier function, remains largely unknown. The epithelial barrier protects the respiratory epithelium against viral infections. However, it can be compromised by environmental contaminants such as pollen, thereby increasing susceptibility to respiratory viral infections, including alphaherpesvirus equine herpesvirus type 1 (EHV-1). To determine whether Af spores di...
Usimaki A, Ciamillo SA, Barot D, Linardi RL, Engiles JB, Ortved KF.Autologous protein solution (APS) has been shown to decrease lameness in horses with osteoarthritis (OA). Synovitis is an early driver of OA, providing an opportunity to intervene in the progression of disease via intra-articular (IA) therapeutics. Objective: The objective of this study was to investigate the effects of a single IA APS injection in horses with interleukin-1β (IL-1β)-induced synovitis. We hypothesised that APS would decrease joint swelling and lameness, improve synovial fluid parameters and improve joint pathology scores in horses compared with untreated controls. Methods: Ra...
Bertuglia A, Pallante M, Pagliara E, Valle D, Bergamini L, Bollo E, Bullone M, Riccio B.Tarsocrural osteochondrosis (OCD) is a developmental orthopedic disease commonly affecting young Standardbreds, with different fragment localization and size. Clinically, it is characterized by variable synovial effusion in the absence of lameness, whose determinants are ill-defined. We hypothesized that localization and physical characteristics of the osteochondral fragments like dimensions, multifragmentation, and instability influence joint effusion and correlate with synovial markers of cartilage degradation and inflammation. Clinical data, synovial fluid and intact osteochondral fragments...
Rar V, Marchenko V, Suntsova O, Epikhina T, Tikunov A, Meltsov I, Fedorets V, Igolkina Y, Kozlova I, Tikunova N.Equine piroplasmosis (EP) is a global worldwide infection, which can lead to the death of animals. Despite the causative agents of EP being well studied, there are no data on the distribution and genetic characteristics of EP agents in any region of Russia. In this study, blood samples from 750 horses from Novosibirsk province, Irkutsk province, and Altai region of Russian Siberia were examined for the presence of EP agents. Theileria equi and Babesia caballi were detected in all examined regions, with mean prevalence rates of 60.4% and 7.2%, respectively. The identified pathogens were genetic...
Nath LC, Saljic A, Buhl R, Elliott A, La Gerche A, Ye C, Schmidt Royal H, Lundgren Virklund K, Agbaedeng TA, Stent A, Franklin S.Approximately 1-2 per 100,000 young athletes die from sudden cardiac death (SCD) and extreme exercise may be associated with myocardial scar and arrhythmias. Racehorses have a high prevalence of atrial fibrillation (AF) and SCD but the presence of myocardial scar and inflammation has not been evaluated. Cardiac tissues from the left (LAA) and right (RAA) atrial appendages, left ventricular anterior (LVAPM) and posterior (LVPPM) papillary muscles, and right side of the interventricular septum (IVS-R) were harvested from racehorses with sudden cardiac death (SCD, n = 16) or other fatal injur...
Cho PW, Park SA, Sledge D, Gruenwald R, Townsend WM.The aim of this report was to provide a clinical description and clinical, ultrasonographic, and histologic images of a foal with microphthalmia and multiple ocular abnormalities. Methods: A 12-h old Friesian-American Paint Horse crossbred filly presented for blindness, microphthalmia and marked ventral strabismus in both eyes. Methods: A complete ophthalmic examination was performed. Ultrasound biomicroscopy and B-mode ultrasonography were performed. The globes were submitted for histopathology. Results: Ultrasound biomicroscopy demonstrated a hyperechoic cornea void of the typical epithelium...
Kuwano A, Ueno T, Katsurashima Y, Tateno O, Saitoh S.From summer 2018 to summer 2019, several Thoroughbred racehorses held at the Miho Training Centre of the Japan Racing Association inadvertently ingested excessive amounts of sodium selenite, resulting in typical chronic selenium (Se) poisoning - the so-called alkali disease. The typical abnormality was a hoof wall disorder with a circumferentially deep ring and/or transverse hoof wall cracks parallel to the coronet on all feet and appearing after excessive ingestion. One affected Thoroughbred male was unique in that all the hooves had a rough surface with a very fragile hoof wall, but no wall ...
Bernick A, Demattio LS, Wehrend A.Uroperitoneum is a typical disease of the newborn foal, which occurs rarely but regularly. Ultrasonography is considered the most important imaging method for diagnosing this disease. Thus far, only one older case series comprising 31 foals suffering from uroperitoneum has systematically listed results of ultrasound examinations. Objective: This paper presents the findings of an ultrasonographic examination of 34 foals with uroperitoneum in order to inform future interpretation of ultrasonographic data in suspected uroperitoneum cases. Methods: Ultrasonographic data of 34 neonatal foals up to ...
Gaitan HM, Mudge MC, Litsky AS, Arruda AG, Gardner AK.To compare strength of left paramedian colopexies using various techniques in equine ex vivo models. Methods: Experimental study. Methods: Equine cadavers euthanized for nongastrointestinal pathology (36 specimens derived from 9 horses). Methods: Colopexies were performed after euthanasia. Suture pattern (horizontal mattress vs. cruciate) and incorporation of dorsal sheath of the rectus abdominis (partial-thickness) versus incorporation of dorsal and ventral sheath of the rectus abdominis (full-thickness) were evaluated. Single cycle load to failure, work to peak load, stiffness, and mode of f...
Pereira LO, DE Souza AF, Spagnolo JD, Yamada ALM, Salgado DMRA, DE Zoppa ALDV.Osteoarthritis (OA) is a prevalent condition in horses, leading to changes in trabecular bone structure and radiographic texture. Although fractal dimension (FD) and lacunarity have been applied to quantify these changes in humans, their application in horses remains nascent. This study evaluated the use of FD, bone area fraction (BA/TA), and lacunarity in quantifying trabecular bone differences in the proximal phalanx (P1) in 50 radiographic examinations of equine metacarpophalangeal joints with varying OA degrees. In the dorsopalmar view, regions of interest were defined in the trabecular bo...
Byrne CA, Voute LC, Marshall JF.Agreement between experienced observers for assessment of pathology and assessment confidence are poorly documented for magnetic resonance imaging (MRI) of the equine foot. Objective: To report interobserver agreement for pathology assessment and observer confidence for key anatomical structures of the equine foot during MRI. Methods: Exploratory clinical study. Methods: Ten experienced observers (diploma or associate level) assessed 15 equine foot MRI studies acquired from clinical databases of 3 MRI systems. Observers graded pathology in seven key anatomical structures (Grade 1: no pathology...
Lin ST, Foote AK, Bolas NM, Sargan DR, Murray RC.Information regarding the histopathology of the proximal phalanx (P1) sagittal groove in racehorses is limited. Twenty-nine cadaver limbs from nine Thoroughbred racehorses in racing/race-training underwent histological examination. Histological specimens of the third metacarpal/metatarsal (MC3/MT3) parasagittal grooves and P1 sagittal grooves were graded for histopathological findings in hyaline cartilage (HC), calcified cartilage (CC), and subchondral plate and trabecular bone (SCB/TB) regions. Histopathological grades were compared between (1) fissure and non-fissure locations observed in a ...
Pimenta J, Prada J, Pires I, Cotovio M.Sarcoids and squamous cell carcinomas (SCCs) are the most concerning equine oncological diseases. Both tumors are challenging to manage due to their invasive behavior and high prevalence of recurrences. Furthermore, SCCs have a propensity to metastasize. Programed cell-death ligand 1 (PD-L1) has been one of the main therapeutic targets for immunotherapy in various human tumors. PD-L1 research in equine tumors is scarce and more efforts are necessary to understand the potential of this biomarker as a therapeutical target. Unassigned: Evaluate the immunohistochemical expression of PD-L1 in equin...
Medina B AL, Faleiros RR, Martínez A JR.Equine Gastric Ulcer Syndrome (EGUS) occurs with variable prevalence in horses, donkeys, and mules. Due to the particularities of the mucous membranes, the syndrome is made up of Squamous Gastric Disease (ESGD) and Glandular Gastric Disease (EGGD). Given the multifactorial nature and multiple classification systems of the syndrome, significant differences have been reported between prevalence studies performed ante mortem, which are even more remarkable when compared with postmortem evaluations. This study aimed to determine the presence and grade of squamous gastric disease in horses, donkeys...
Höglund N, Rossi H, Javela HM, Oikari S, Nieminen P, Mustonen AM, Airas N, Kärjä V, Mykkänen A.Equine asthma (EA) is a chronic lower airway inflammation that leads to structural and functional changes. Hyaluronic acid (HA) has crucial functions in the extracellular matrix homeostasis and inflammatory mediator activity. HA concentration in the lungs increases in several human airway diseases. However, its associations with naturally occurring EA and airway remodelling have not been previously studied. Our aim was to investigate the association of equine neutrophilic airway inflammation (NAI) severity, airway remodelling, and HA concentration in horses with naturally occurring EA. We hypo...
Scharf A, Cheng TY, Urion R, Hostnik E.The objective of this study was to optimize an MRI-based diffusion tensor imaging (DTI) protocol for imaging the plantar nerves at the level of the tarsus in normal equine limbs. Methods: 12 pelvic cadaver limbs from horses without evidence of proximal suspensory pathology were imaged with a 3T MRI system. Methods: For diffusion-weighted imaging, b values of 600, 800, and 1,000 s/mm2 were tested. Data were processed with DSI Studio. Cross-sectional areas of the medial and lateral plantar nerve along the plantar tarsus were recorded. The length and number of fiber tracts, signal-to-noise ratio,...
Gudea A, Stan FG, Irimie A, Mârza S, Martonos CO, Gal A.The reconstruction of past life based on archaeozoology is a challenging domain that offers a range of valuable details concerning former human and animal populations. Additionally, the ancient era is a source of information for human and veterinary medicine, as well as for other biological sciences. This report highlights a pathological lesion identified during the investigation of a horse skeleton from a pit dated La Tène in Alba County (Romania). The left scapula with lesions was collected from the skeleton of a buried 7-8-year-old male horse. The aforementioned bone underwent gross, radio...
Dubuc J, Schneider MJ, Dubuc V, Richard H, Pinsard M, Bancelin S, Legare F, Girard C, Laverty S.Investigate meniscal extracellular matrix degradation. Equine menisci ( = 34 from 17 horses) were studied. Site-matched sections were cut and scored from three regions (ROIs; = 102) and stained for histology, proteoglycan (safranin O and fast green), aggrecan, and collagen cleavage (NITEGE, DIPEN, and C1,2C antibodies, respectively). Picrosirius red and second harmonic generation microscopy were performed to investigate collagen ultrastructure. A total of 42 ROIs met the inclusion criteria and were included in the final analysis. The median (range) ROI histological score was 3 (0-9), providin...
Marsella R.Allergy to insects is the most common skin allergy in horses. Pruritus in affected patients can be extreme. Face, ears, mane, and tail area are commonly affected areas. Diagnosis of insect bite hypersensitivity (IBH) is clinical and is based on history, clinical signs, and response to repellents. Allergy tests are not to be used for diagnostic purposes. Currently, there is no specific treatment for IBH other than insect avoidance, treatment of secondary infections, and symptomatic relief of pruritus. Many allergic horses become also sensitized to pollens. For these patients, allergen specific ...
Veiga IB, Affolter VK, Moore PF, Maia-Nussbaumer PJ, Gerber V, Unger L, Dettwiler M.This report describes a multicentric intermediate-size B-cell lymphoma with epitheliotropism in a Freiberger mare affecting multiple mucous membranes, skin and internal organs. The clonal neoplastic B-cell population was accompanied by numerous reactive polyclonal small T cells. Differential diagnoses for these unusual findings are discussed. 本报告描述了一种多中心性中等大小B细胞淋巴瘤, 其在弗雷伯格母马中具有驱上皮性, 影响多处粘膜、皮肤和内脏。克隆性肿瘤B细胞群伴有大量反应性多克隆小T细胞。就这些异常发现对鉴别诊...
Ochala J, Finno CJ, Valberg SJ.Myosinopathies are defined as a group of muscle disorders characterized by mutations in genes encoding myosin heavy chains. Their exact molecular and cellular mechanisms remain unclear. In the present study, we have focused our attention on a -related E321G amino acid substitution within the head region of the type IIx skeletal myosin heavy chain, associated with clinical signs of atrophy, inflammation and/or profound rhabdomyolysis, known as equine myosin heavy chain myopathy. We performed Mant-ATP chase experiments together with force measurements on isolated IIx myofibres from control horse...
Dixon PM, Tremaine WH, Pickles K, Kuhns L, Hawe C, McCann J, McGorum BC, Railton DI, Brammer S.Of 400 referred horses with dental disorders, 349 cases suffered from primary disorders of their cheek teeth, ninety of these from disorders of development or eruption, or displacements. These included 20 cases with rostral maxillary and caudal mandibular cheek teeth overgrowths, 16 with diastemata, 15 with grossly enlarged mandibular 'eruption cysts', 4 with grossly enlarged maxillary cheek teeth 'eruption cysts', 10 cases with supernumerary cheek teeth and 23 cases with displaced cheek teeth. These displacements were believed to be developmental in 16 cases and acquired in the remaining 7 ca...
Lazary S, Gerber H, Glatt PA, Straub R.The distribution of equine leucocyte antigens (ELA) in horses affected by equine sarcoid tumours was determined and compared with unaffected controls. ELA-haplotype W3,B1 occurred more frequently in affected riding horses of Irish, Swiss and French background. The combined data for the three breeds resulted in a chi 2 value of 20.35 (P less than 0.0005 after correction). Simultaneously, ELA-specificity W11 was more frequently found in horses of Irish background, while W5 was found in Swiss and French horses with sarcoids. The combined data for haplotype W3,B1 and/or W5 specificity demonstrated...
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...
