Histopathology in horses involves the microscopic examination of tissue samples to study the manifestations of disease. This field provides insights into the structural and cellular changes that occur in equine tissues as a result of various pathological conditions. Common applications of histopathology in equine medicine include the diagnosis of neoplastic, inflammatory, and degenerative diseases. Techniques such as tissue staining and immunohistochemistry are employed to identify specific cellular components and pathological markers. This page aggregates peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of histopathological investigations in equine health.
Kondratjeva J, Julien F, Coutelier C, Humeau L, Moog F, Combarros D, Fourquaux I, Pressanti C, Delverdier M, Moore PF, Cadiergues MC.Cutaneous epitheliotropic T-cell lymphoma is a malignant tumour of the skin already reported in humans, dogs, cats, horses, and other species, but not previously in donkeys. The standard diagnosis is based on clinical, morphological and immunophenotypic data. Differentiation of malignant versus benign proliferation of lymphocytes is crucial; in ambiguous cases T-cell receptor gamma (TRG) molecular clonality should be tested. In the present paper, we report a case of mycosis fungoides diagnosed in a donkey whose diagnosis was based on clinical, histological and immunohistochemical aspects and a...
Sponseller BT, Wong DM, Ruby R, Ware WA, Wilson S, Haynes JS.A 9-year-old Quarter Horse gelding was presented for lethargy, decreased appetite, polyuria and polydipsia (PU/PD), and severe muscle wasting suggestive of immune-mediated myositis. Results: The horse displayed lethargy, fever, tachyarrhythmia, inappetence, PU/PD, and severe epaxial and gluteal muscle wasting. Clinicopathologic findings were consistent with previously reported cases of systemic calcinosis in horses, including increased muscle enzyme activity, hyperphosphatemia, increased calcium-phosphorus product, hypoproteinemia, and an inflammatory leukogram. A diagnosis of systemic calcino...
Ali HHM, Al-Bayati LH. is one of the most important pathogens, which causes a marked economic loss in small ruminants, in particular sheep, worldwide. This study aimed to detect the prevalence of in the sera of aborted ewes in Wasit province, Iraq, using the enzyme-linked immunosorbent assay (ELISA), followed by the investigation of the main histopathological alterations that occurred in some organs of the dead newborns. Out of 180 tested samples by ELISA, 32.22% of the evaluated animals showed positive reactions to IgG antibodies toward . Concerning the titers of the infection of seropositive ewes, there were sig...
Ochi A, Nishioka T, Kurimoto S, Kishi D, Ueno T, Nukada T.A 2-year-old male Thoroughbred horse presented with a mass in the maxilla. The focally ulcerated mass, approximately 8 cm in diameter, covered the upper left intermediate and corner incisor teeth (nos. 602 and 603 according to the modified Triadan system) and radiographic examination revealed displacement and lysis of the incisors. Histologically, the tumour was composed of a dense proliferation of spindle-shaped cells and neoplastic odontogenic epithelial cells arranged in island, follicular, plexiform or sheetlike patterns. The spindle-shaped cells were immunopositive for cytokeratins AE1/A...
Badenhorst M, Saalmüller A, Daly JM, Ertl R, Stadler M, Puff C, de le Roi M, Baumgärtner W, Engelmann M, Brandner S, Junge HK, Pratscher B, Volz A....Equine hepacivirus (EqHV) is the closest known genetic homologue of hepatitis C virus. An effective prophylactic vaccine is currently not available for either of these hepaciviruses. The equine as potential surrogate model for hepacivirus vaccine studies was investigated, while equine host responses following vaccination with EqHV E2 recombinant protein and subsequent EqHV inoculation were elucidated. Four ponies received prime and booster vaccinations (recombinant protein, adjuvant) four weeks apart (day -55 and -27). Two control ponies received adjuvant only. Ponies were inoculated with EqHV...
Yamada ALM, do Prado Vendruscolo C, Marsiglia MF, Sotelo EDP, Agreste FR, Seidel SRT, Fülber J, Baccarin RYA, da Silva LCLC.Combined chondroitin sulfate (CS) and glucosamine (GlcN) has been widely used in oral formulations to prevent and treat osteoarthritis. CS is effective for controlling pain in osteoarthritic patients, whereas GlcN can stimulate glycosaminoglycan synthesis, thus reducing extracellular matrix degradation. Although several studies have been published on this topic, the effectiveness of treatment with oral CS and GlcN remains uncertain. The objective of this study was to analyze the progression of experimentally induced osteoarthritis in horses and verify the effectiveness of an oral compound base...
El-Gameel SM, Al-Mokaddem AK, Salaeh NMK, Attia MM.Equine gastrointestinal tract is infected with () which is highly pathogenic parasite for its harmful effect on cranial mesenteric artery during its migration. So, this study was applied for identification of in donkeys ultramorphologically and molecularly. In addition to, detection of the pathological effect of larval stage of on the mesenteric arterial system using histopathology and immunohistochemistry. During the period from September to December; 2019, 60 male and 20 female donkeys at the Giza Zoo was postmortem examined. adults and larvae were collected from the large intestine and ...
Gazzonis AL, Morganti G, Porcellato I, Roccabianca P, Avallone G, Gavaudan S, Canonico C, Rigamonti G, Brachelente C, Veronesi F. is a protozoan causing human zoonotic visceral leishmaniasis (ZVL) and visceral-cutaneous canine leishmaniosis (CanL) in the Mediterranean Basin. is able to infect a large number of wild and domestic species, including cats, dogs, and horses. Since the 1990s, clinical cases of equine leishmaniasis (EL), typically characterized by cutaneous forms, have been increasingly diagnosed worldwide. The aim of the present study was to evaluate the presence of clinical forms of EL in CanL-endemic areas in Italy, where exposure of equine populations was ascertained from recent serological surveys. For t...
Spoormakers TJP, Bergmann W, Veraa S, van Weeren PR, Brommer H.To verify the existence of intertransverse joints (ITJs) in young foals. 11 warmblood foals. Postmortem examination of the lumbar area in foals < 200 days old using CT, MRI, dissection, and histomorphology. Data were analyzed with descriptive statistics. Age of foals varied between 1 and 200 days (median, 11 days). Ten foals had 6 lumbar (L) vertebrae, and 1 foal had 5. All 11 foals, irrespective of age, had ITJs between the first sacral and last lumbar vertebrae and between the last and second-to-last lumbar vertebrae. In 6 foals (all with 6 L vertebrae), ITJs also existed between the four...
Asakawa MG, Jamieson CA, David F, Johnson JP, Mehmood W, Oikawa MA.A 5-year-old Arabian broodmare with acute colic was diagnosed with lymphocytic ganglioneuritis of the coeliac-mesenteric ganglia and lymphocytic‒plasmacytic enterocolitis resembling inflammatory bowel disease. No significant pathogens were identified by aerobic culture or histopathological examination. The ganglia were multifocally infiltrated with small lymphocytes that were immunopositive for CD3 and negative for CD20 and CD79a antigens, indicating CD3+ T-lymphocyte-mediated coeliac-mesenteric ganglioneuritis. The findings suggest immune-mediated inflammatory bowel disease resulting in dis...
Nagel H, Lang H, Sole Guitart A, Lean N, Allavena R, Sprohnle-Barrera C, Young A.This case series presents a 20-year-old Quarter horse gelding and a 10-year-old Thoroughbred gelding with a histologic diagnosis of aggressive submural neoplasia, including an anaplastic sarcoma and a squamous cell carcinoma respectively. The current case series describes these neoplasias with radiography, computed tomography, magnetic resonance imaging and histopathology with immunohistochemistry. The purpose of this case series is to identify the clinical pattern of chronic reoccurring lameness in these cases and highlight the appearance of expansile osteolytic pathology of the distal phalan...
Valberg SJ, Henry ML, Herrick KL, Velez-Irizarry D, Finno CJ, Petersen JL.Genetic tests for variants in MYOT (P2; rs1138656462), FLNC (P3a; rs1139799323 or P3b; rs1142918816) and MYOZ3 (P4; rs1142544043) genes are offered commercially to diagnose myofibrillar myopathy (MFM) and type 2 polysaccharide storage myopathy (PSSM2) in Quarter Horses (QH). Objective: To determine if PSSM2-QH has histopathological features of MFM. To compare genotype and allele frequencies of variants P2, P3, P4 between control-QH and PSSM2-QH diagnosed by histopathology. Methods: Retrospective cross-sectional. Methods: The study includes a total of 229 healthy control-QH, 163 PSSM2-QH GYS1 ...
Hostetter JM, Uzal FA.Evaluation of gastrointestinal (GI) biopsies is a multistep process that includes reviewing an appropriate history, determining sample quality, and evaluating histologic sections. Selected diagnostic parameters that, in combination with intestinal histopathology, can be useful to localize disease to the intestinal tract in the horse include hypoproteinemia and hypoalbuminemia, ultrasound evidence of increased thickness of the small intestinal wall, and alterations in glucose or D-xylose absorption tests. Biopsies may be acquired either endoscopically, or via laparoscopy or standing flank incis...
McCoy AM, Secor EJ, Roady PJ, Gray SM, Klein J, Gutierrez-Nibeyro SD.Plantar osteochondral fragments (POF) are common but their effect on joint health of young Standardbreds in race training is largely unknown. Objective: Evaluate the inflammatory effects of POF in metatarsophalangeal joints of young Standardbreds as a step towards developing evidence-based recommendations for surgical removal. Methods: Cohort study. Methods: Forty-nine Standardbred horses (age 11-33 months) presented for surgical removal of POF from 56 metatarsophalangeal joints. Synovial tissue collected at arthroscopy was subjected to histopathology. IL-1β, TNF-α, and PGE-2 were measured ...
Siwinska N, Janus I, Zak-Bochenek A, Noszczyk-Nowak A.It has been well established that obesity in horses can have a negative impact on their health, including endocrine disturbances. In humans, it is well known that obesity leads to structural and functional changes of the cardiovascular system. The aim of the study was to assess the impact of obesity on the histological structure of the myocardial tissue, as well as great and peripheral arteries in horses. The heart, arteries (aorta, pulmonary artery and palmar arteries) specimens from 7 horses with normal BCS (4-5/9) and 12 extremely obese (BCS 9/9) draft slaughter horses were obtained for his...
Storms N, Medina Torres C, Franck T, Sole Guitart A, de la Rebière G, Serteyn D.Laminitis is a pathology of the equine digit leading to a failure of the dermo-epidermal interface. Neutrophil activation is recognized as a major factor in SIRS-associated laminitis. Less is known about the role of neutrophil activation in laminitis associated with metabolic disorders. The aim of this descriptive study was to observe whether myeloperoxidase is increased in the laminae during early stage laminitis in three horses subjected to a prolonged euglycemic hyperinsulinemic clamp (pEHC). After 48 h of pEHC-treatment, horses were subjected to euthanasia. Two healthy horses are used as c...
Klein CE, Engiles JB, Roessner HA, Hopster K, Hurcombe SD.To compare the application and healing of the zip skin closure system (ZSCS) with sutured closure by use of a split-scar model of ventral midline incisions in horses in a prospective, randomized experimental study. Methods: 8 adult horses. Methods: All horses underwent an exploratory ventral midline celiotomy with a standardized 30-cm skin incision. Each horse was randomized to have either the cranial 15 cm closed with suture and caudal 15 cm with the ZSCS or vice versa (split-scar model). Skin closure time was recorded and compared. Photography and skin biopsies were taken preoperatively and ...
Westendorf J, Wobeser B, Epp T.Inter- and intra-rater variability negatively affects the reliability of various histopathology grading scales used as prognostic aids in human and veterinary medicine. The Kenney-Doig categorization (grading) scale, which is used to associate equine endometrial histologic lesions with prognostic estimation of a broodmare's reproductive potential, has not been evaluated for inter- or intra-rater variability, to our knowledge. To assess whether the Kenney-Doig system produces reliable results among observers, 8 pathologists, all with American College of Veterinary Pathologists certification, we...
Pye J, Spriet M, Dow P, Katzman S, Murphy BG.To describe clinical, imaging, gross, and histopathological abnormalities associated with osteochondral necrosis of the femoral condyles in foals and identify features suggestive of a common pathogenesis. 8 Thoroughbred foals euthanized with a presumptive diagnosis of necrosis of the femoral condyles. Postmortem CT was performed on all distal femoral epiphyseal samples. The articular epiphyseal cartilage complex (AECC) of affected distal femurs was examined grossly and histologically, focusing on lesions of interest identified on CT images. 7 foals were between 9 and 23 days old at the time of...
Carneiro FP, Alonso MA, Redoan MA, Henriques DA, Lima FM, Oliveira RM, Cogliati B, Canisso IF, Fernandes CB.Nocardioform placentitis is a pathologically unique form of placental disease first diagnosed in central Kentucky in the mid-80s. Since then, the occurrence of nocardioform placentitis in the region has varied over the years, from sporadic cases to outbreaks. The disease has been sporadically detected in other countries and has not been confirmed in South America. A 13-year-old multiparous Mangalarga delivered a healthy filly at 340d gestation. The mare passed the fetal membranes 33 minute after foaling. Gross examination of the fetal membranes identified two focal lesions on the chorionic sur...
Story MR, Nout-Lomas YS, Aboellail TA, Selberg KT, Barrett MF, Mcllwraith CW, Haussler KK. Dangerous behavior is considered an undesired trait, often attributed to poor training or bad-tempered horses. Unfortunately, horses with progressive signs of dangerous behavior are often euthanized due to concerns for rider safety and limitations in performance. However, this dangerous behavior may actually originate from chronic axial skeleton pain. This case series describes the medical histories and clinical presentations of horses presented for performance limitations and dangerous behavior judged to be related to intractable axial skeleton pain. Fourteen horses that developed severe pe...
Bessonnat A, Hélie P, Grimes C, Lavoie JP.There is a remodeling of the central airways in horses with severe asthma but whether a similar process occurs in horses with the mild or moderate asthma (MMA) is unknown. Objective: To evaluate lesions affecting the central airways of horses with MMA. Methods: Twelve horses with MMA and 8 control horses. Methods: Case-control retrospective study of horses classified as MMA affected or controls based on history and bronchoalveolar lavage fluid cytology. Endobronchial biopsies were analyzed using histomorphometry and a semiquantitative histologic scoring system. Results: Histomorphometry identi...
Zetterström SM, Matz BM, Neto RLALT, Lindley SES, Cole RC, Wilhite R, Boone LH.To describe the surgical findings, histopathological features, and long-term outcome for a horse with parotid salivary carcinoma. Methods: Case report ANIMALS: Twelve year old American Quarter Horse gelding. Methods: The gelding was presented for a 10 × 10 cm swelling below the base of the right ear. Ultrasonographic examination revealed a mass involving the right parotid salivary gland. Incisional biopsy was consistent with parotid carcinoma. The tumor was marginally excised. The lateral wall of the guttural pouch was excised with the mass and was reconstructed with a porcine small int...
Carvalho JRG, Conde G, Antonioli ML, Santana CH, Littiere TO, Dias PP, Chinelatto MA, Canola PA, Zara FJ, Ferraz GC.In horses, there is an increasing interest in developing long-lasting drug formulations, with biopolymers as viable carrier alternatives in addition to their use as scaffolds, suture threads, screws, pins, and plates for orthopedic surgeries. This communication focuses on the prolonged biocompatibility and biodegradation of PLA, prepared by hot pressing at 180 °C. Six samples were implanted subcutaneously on the lateral surface of the neck of one horse. The polymers remained implanted for 24 to 57 weeks. Physical examination, plasma fibrinogen, and the mechanical nociceptive threshold (MNT) w...
Westendorf J, Wobeser B, Epp T.The Kenney-Doig scale is a histopathology categorization (grading) system often used as the standard for assessing endometrial disease and communicating prognostic fertility information for equine breeding prospects. We investigated how Kenney-Doig categories compared within the same institution and across different institutions to determine if observer variability may contribute to category frequencies. We conducted a retrospective analysis of all equine endometrial submission records between 1998 and 2018 at the Western College of Veterinary Medicine (WCVM) and Prairie Diagnostic Services (P...
Vercruysse E, Naranjo C, Sauvage A, Vandersmissen M, Grauwels M, Monclin S.To describe the clinical, diagnostic imaging, and histopathological findings of two visually impaired closely related horses and to identify a possible cause. Methods: Two warmblood horses, with a common dam and sire, were presented to the ophthalmology department of Liège for investigation of impaired vision. Information collected included physical and ophthalmic examination findings, results of ocular ultrasound, electroretinogram, magnetic resonance imaging (MRI), and histopathology. Ophthalmic examination, ocular ultrasound and MRI revealed a complete retinal detachment (RD) in the left e...
Sakurai M, Isshiki S, Sasaki N, Sakai Y, Yamada Y, Morimoto M.A 7-year-old male Thoroughbred horse exhibited recurrent falls followed by convulsive seizures. The horse was clinically diagnosed with epilepsy and phenobarbital treatment was initiated. However, as seizure control was unsuccessful, the animal was euthanized. At necropsy, yellow-brown linear lesions were found extensively at the U-fibres and cingulate gyrus within the cerebral white matter. Histopathologically, linear demyelination and occasional cavitation were observed. Glial cells with yellow-brown pigment granules, which were autofluorescent, positive to the periodic acid-Schiff reaction ...
Tucker R, Parker RA, Meredith LE, Hughes TK, Foote AK.To describe the surgical removal of intra-articular loose bodies (LBs) from the cervical articular process joints (APJs) in five horses and to describe the outcome of the surgery. Methods: Short case series. Methods: Five client-owned horses with naturally occurring LBs within the cervical APJs. Methods: Medical records were reviewed of horses that were diagnosed with LBs of the cervical APJs on computed tomography (CT), where the LBs were subsequently removed surgically. Details of case selection and surgical technique were reviewed along with postoperative complications and clinical outcome....
Jasiński T, Zdrojkowski Ł, Kautz E, Juszczuk-Kubiak E, Ferreira-Dias G, Domino M.Endometrosis is an important mares' disease which considerably decreases their fertility. As classic endometrial classification methods might be insufficient for tissue pathological evaluation, further categorization into active/inactive and destructive/non-destructive types was developed by Hoffmann and others. This study aimed to compare NF-κB pathway genes transcription among histopathological types of endometrosis, following Hoffmann and co-authors' classification. Endometrial samples, collected postmortem from cyclic mares ( = 100) in estrus or diestrus, were classified histologically an...
Villagrán CC, Vogt D, Gupta A, Fernández EA.A 3-year-old Quarter Horse gelding was evaluated for chronic weight loss, diarrhea, and pruritus. Physical examination revealed several ulcerative lesions on the skin and mucosal membranes. Diagnostic imaging findings were consistent with enteritis, typhlitis, and colitis. Multisystemic eosinophilic epitheliotropic disease (MEED) was diagnosed upon necropsy. This disease may be considered a form of equine inflammatory bowel disease complex which can be challenging to diagnose, requiring histological assessment, and in some cases, the use of immunohistochemical markers. Key clinical message: Mu...
Kaikkonen R, Niinistö K, Sykes B, Anttila M, Sankari S, Raekallio M.Recurrent colic and unexplained weight loss despite good appetite and adequate feeding and management practices are common conditions in the horse. However, little information has been published on the systematic diagnostic evaluation, response to treatment, prognostic factors or outcome of either presentation. The aims of this study were to 1) identify possible prognostic indicators and 2) report the short- and long-term response to treatment with corticosteroid therapy of a variety of horses with a presumptive diagnosis of inflammatory bowel disease (IBD). Thirty-six horses with a history of...
Horses affected by chronic piroplasmosis may develop poor performance and muscle atrophy. Here we investigate the pathological and immunopathological aspects of myopathy occurring in chronic equine piroplasmosis. The study included 16 horses serologically positive for equine piroplasms presenting with clinical signs and supporting serum biochemical evidence of a myopathy. Skeletal muscle was evaluated by histopathology, immunohistochemistry, indirect immunofluorescence, and molecular detection of piroplasms and inflammatory cytokines in skeletal muscle. Histologic lesions included muscle fiber...
Stanley RL, McCue ME, Valberg SJ, Mickelson JR, Mayhew IG, McGowan C, Hahn CN, Patterson-Kane JC, Piercy RJ.A glycogen synthase (GYS1) mutation has been described in horses with histopathological evidence of polysaccharide storage myopathy (PSSM) in the USA. It is unknown whether the same mutation is present in horses from the UK. Objective: To determine whether the GYS1 mutation occurs in UK horses with histopathological evidence of PSSM and exertional rhabdomyolysis. Objective: The R309H GYS1 mutation is present in a variety of UK horse breeds and that the mutation is commonly associated with exertional rhabdomyolysis. Methods: DNA was extracted from 47 muscle or blood samples from UK horses with ...
White SD, Affolter VK, Bannasch DL, Schultheiss PC, Hamar DW, Chapman PL, Naydan D, Spier SJ, Rosychuk RA, Rees C, Veneklasen GO, Martin A, Bevier D....Data on fifty horses with hereditary equine regional dermal asthenia (HERDA; "hyperelastosis cutis") were collected on clinical, histopathological, ultrastructural and immunohistological findings. All horses were Quarter horses or of Quarter horse ancestry. Pedigree evaluation strongly supported an autosomal recessive mode of inheritance. The most common lesions were seromas/haematomas, open wounds, sloughing skin, and loose, easily tented skin that did not return to its initial position. Definitive diagnosis could not be made via histopathology, although the presence of tightly grouped thin a...
Ceriotti S, Bullone M, Leclere M, Ferrucci F, Lavoie JP.Pulmonary hypertension and cor pulmonale are complications of severe equine asthma, as a consequence of pulmonary hypoxic vasoconstriction. However, as pulmonary hypertension is only partially reversible by oxygen administration, other etiological factors are likely involved. In human chronic obstructive pulmonary disease, pulmonary artery remodeling contributes to the development of pulmonary hypertension. In rodent models, pulmonary vascular remodeling is present as a consequence of allergic airway inflammation. The present study investigated the presence of remodeling of the pulmonary arter...
Cox A, Dixon P, Smith S.Equine periodontal disease (EPD) is a common and painful condition, the aetiology and pathology of which are poorly understood. To characterise the histopathological lesions associated with EPD, the skulls of 22 horses were assessed grossly for the presence of periodontal disease, and a standard set of interdental tissues taken from each for histopathological examination. Histological features of EPD included ulceration and neutrophilic inflammation of the gingival epithelium. Mononuclear and eosinophilic inflammation of the gingival lamina propria and submucosa was commonly present irrespecti...
Wang L, Luo DK, Pan ZY.The aim of the present study was to investigate the association between glucocorticoid receptors and steroid‑induced avascular necrosis of the femoral head (SANFH). Healthy New Zealand rabbits were randomly divided into 3 groups (n=16/group); the normal (no treatment), control (horse serum injections) and treatment (horse serum and methylprednisolone injections) groups. Methylprednisolone and horse serum injections were used to establish a SANFH model in rabbits; magnetic resonance imaging (MRI) and histopathological analysis were used to evaluate the SANFH rabbit model. Total cholesterol an...
Lin ST, Foote AK, Bolas NM, Peter VG, Pokora R, Patrick H, Sargan DR, Murray RC.Fissure in the third metacarpal/tarsal parasagittal groove and proximal phalanx sagittal groove is a potential prodromal pathology of fracture; therefore, early identification and characterisation of fissures using non-invasive imaging could be of clinical value. Thirty-three equine cadaver limbs underwent standing cone-beam (CB) computed tomography (CT), fan-beam (FB) CT, low-field magnetic resonance imaging (MRI), and macro/histo-pathological examination. Imaging diagnoses of fissures were compared to microscopic examination. Imaging features of fissures were described. Histopathological fin...
Estell KE, Dawson DR, Magdesian KG, Swain E, Laing ST, Siso S, Mapes S, Pusterla N.Data associating quantitative viral load with severity, clinical signs and survival in equine herpesvirus-1 myeloencephalopathy (EHM) have not been reported. Objective: To report the clinical signs, treatment, and temporal progression of viral loads in 7 horses with naturally occurring EHM and to examine the association of these factors with survival. Methods: Retrospective case series. Methods: The population included 7 horses with EHM presented to the University of California, Davis William R. Pritchard Veterinary Medical Teaching Hospital from May to September 2011. Horses were graded using...
Bedford HE, Valberg SJ, Firshman AM, Lucio M, Boyce MK, Trumble TN.To characterize clinical findings, outcomes, muscle characteristics, and serum or muscle concentrations of α-tocopherol for horses with vitamin E-responsive signs of muscle atrophy and weakness consistent with signs of equine motor neuron disease (EMND). Methods: Retrospective case-control study. Methods: 8 affected (case) adult horses with acute (n = 3) or chronic (5) gross muscle atrophy that improved with vitamin E treatment and 14 clinically normal (control) adult horses with adequate (within reference range; 8) or low (6) muscle concentrations of α-tocopherol. Methods: Medical records w...
Lee H, Hwang H, Ro Y, Kim JH, Lee K, Choi E, Bae Y, So B, Lee I.This study was performed to examine and clarify the cause of hindlimb ataxia and neuropathy seen in the South Korean horse population. Fifty horses diagnosed with hindlimb ataxia and neuropathy were referred for this study. Neurological examination was performed on 47 horses while necropsy was performed in all 50 animals. The occurrence of neurological diseases increased rapidly in the summer and 47 out of 50 horses were referred after the end of July. The incidence of neurological diseases started from the southern part of Korea in July and proceeded northward in August and September. Althoug...
Hendrix DV, Brooks DE, Smith PJ, Gelatt KN, Miller TR, Whittaker C, Pellicane C, Chmielewski N.The medical records of 24 horses with corneal stromal abscesses were reviewed. Twenty of the horses initially presented with a corneal ulcer, corneal opacity, or evidence of ocular pain. All of the horses were treated with topical antibiotics prior to referral. Most had also been treated with topical atropine sulphate and systemic flunixin meglumine. Ophthalmic examinations revealed focal, yellow-white corneal opacities, corneal vascularisation and evidence of iridocyclitis. Nine of the horses were treated primarily medically as the initial response to topical and systemic medication was rapid...
Vesonder R, Haliburton J, Stubblefield R, Gilmore W, Peterson S.Corn from an Arkansas farm, where three horses died and others became sick, was investigated for causative principles. Necropsy of the three horses revealed what appeared to be severe hepatic necrosis. Histopathological examination indicated a pattern of hepatic lesions that was suggestive of aflatoxin contamination of the feed. Mycological examination of the corn by dilution plating revealed 95% of the colonies as Aspergillus flavus. Chemical analysis of the corn for mycotoxins was positive for aflatoxin B1, B2, and M1 at concentrations of 114, 10, and 6 micrograms/Kg, respectively. Cyclopiaz...
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...
Ricketts SW, Alonso S.Paired endometrial biopsy samples were taken from 530 subfertile mares, before and after treatment (where indicated) and a period of sexual rest. Prognoses were made after each biopsy (Categories 1A-4A before treatment and Categories 1B-4B after treatment), using histopathological criteria similar to those described by Kenney and Doig (1986). Eighty-seven per cent of the mares were assigned to first biopsy prognosis Category 3A. The second biopsy prognosis produced a more even population distribution (10, 47, 40 and 3 per cent respectively for Category 1B, 2B, 3B and 4B mares). First biopsy Ca...
Williams KJ, Derksen FJ, de Feijter-Rupp H, Pannirselvam RR, Steel CM, Robinson NE.Exercise-induced pulmonary hemorrhage (EIPH) is common in horses following intense exertion, occurring in up to 75% of racing Thoroughbreds and Standardbreds. In spite of this, the pathogenesis of EIPH is poorly understood. In 7 racing Thoroughbred horses with EIPH, 6 sections were collected from the left and right lung, representing the cranial, middle, and caudal region of the dorsal and ventral lung (84 sites total). Grossly, both right and left lungs had numerous dark brown to blue-black foci along the caudodorsal visceral pleura. Tissue sections were stained with hematoxylin-eosin, Masson...
Muranaka M, Yamanaka T, Katayama Y, Niwa H, Oku K, Matsumura T, Oyamada T.To investigate the pathology of equine influenza, necropsy of 7 horses experimentally infected with equine influenza A virus (EIV) subtype H3N8 was conducted on post-infection days (PID) 2, 3, 7, and 14. Histopathologically, rhinitis or tracheitis including epithelial degeneration or necrosis with loss of ciliated epithelia and a reduction in goblet cell numbers, was observed in the respiratory tracts on PIDs 2 and 3. Epithelial hyperplasia or squamous metaplasia and suppurative bronchopneumonia with proliferation of type II pneumocytes were observed on PIDs 7 and 14. Viral antigen was detecte...
Cotovio M, Monreal L, Armengou L, Prada J, Almeida JM, Segura D.Septicemia in human neonates frequently is complicated by activation of the coagulation system, disseminated intravascular coagulation (DIC) and multiple organ failure syndrome, which may contribute to high mortality. In adult horses with DIC, the lung has been the organ most frequently affected by fibrin deposits. In addition, in vivo studies suggest that hemostatic mechanisms may be immature in foals < 1-day old. Objective: Newborn foals with severe septicemia have fibrin deposits in their tissues independently of their age, and these fibrin deposits are associated with organ failure. Met...
Schvartz G, Farnoushi Y, Berkowitz A, Edery N, Hahn S, Steinman A, Lublin A, Erster O.In this report we describe the molecular and pathological characteristics of West Nile virus (WNV) infection that occurred during the summer and fall of 2018 in avian species and equines. WNV is reported in Israel since the 1950s, with occasional outbreaks leading to significant morbidity and mortality in birds, high infection in horses and humans, and sporadic fatalities in humans. Methods: Animal and avian carcasses in a suitable condition were examined by post-mortem analysis. Tissue samples were examined for WNV by RT-qPCR and the viral load was quantified. Samples with sufficient material...
Martineau H, Thompson H, Taylor D.Gastric ulceration is now widely recognised as an important disease in high performance horses. Little is known about gastric histopathology in healthy or diseased animals; a comprehensive assessment would enhance interpretation of gross findings through assessment of their accuracy and allow for identification of lesion variety and pathogenesis in different anatomical regions of the stomach. Objective: To investigate the true extent and variety of gastric lesions in a mixed population of mature horses at post mortem. Methods: Stomachs were removed from a mixed population of 21 horses at post ...
Prichard M, Ducharme NG, Wilkins PA, Erb HN, Butt M.We hypothesized that xanthine oxidase plays a role in the postischemic reperfusion injury in the equine small intestine. Under anesthesia, four horses and two ponies underwent ischemic strangulating obstructions of segments of the proximal jejunum, mid-jejunum and ileum. Prior to vascular occlusion, and at 1 h and 2 h of ischemia, full-thickness intestinal biopsies were collected for histopathological evaluation and for determination of combined xanthine dehydrogenase (XDH) plus xanthine oxidase (XO) activity, and XO activity alone. The level of XO activity was expressed in percentage accordin...
Zamos DT, Schumacher J, Loy JK.Nasopharyngeal conidiobolomycosis caused by Conidiobolus coronatus was diagnosed in a horse after endoscopic and histopathologic examinations of a biopsy specimen. The fungal lesions in the nasopharynx were substantially reduced in size after intralesional injection of amphotericin B through the biopsy channel of a videoendoscope in combination with i.v. administration of sodium iodide and oral administration of potassium iodide during a 2-month period. Endoscopy performed 15 months after initial examination revealed regression of the granulomatous masses in the nasopharynx and complete disapp...
Valberg SJ, McKenzie EC, Eyrich LV, Shivers J, Barnes NE, Finno CJ.Although exertional rhabdomyolysis (ER) is common in Arabian horses, there are no dedicated studies describing histopathological characteristics of muscle from Arabian horses with ER. Objective: To prospectively identify distinctive histopathological features of muscle from Arabian endurance horses with a history of ER (pro-ER) and to retrospectively determine their prevalence in archived samples from Arabian horses with exertional myopathies (retro-ER). Methods: Prospective and retrospective histopathological description. Methods: Middle gluteal muscle biopsies obtained from Arabian controls ...
Mills ML, Rush BR, St Jean G, Gaughan EM, Mosier D, Gibson E, Freeman L.To determine the serum and synovial fluid concentrations of ceftiofur sodium after intraarticular (IA) and intravenous (IV) administration and to evaluate the morphologic changes after intraarticular ceftiofur sodium administration. Methods: Strip plot design for the ceftiofur sodium serum and synovial fluid concentrations and a split plot design for the cytologic and histopathologic evaluation. Methods: Six healthy adult horses without lameness. Methods: Stage 1: Ceftiofur sodium (2.2 mg/kg) was administered IV. Stage 2: 150 mg (3 mL) of ceftiofur sodium (pHavg 6.57) was administered IA into ...
McClure SR, VanSickle D, Evans R, Reinertson EL, Moran L.Extracorporeal shock-wave therapy (ESWT) may stimulate healing of desmitis in multiple species. The objective of this study was to evaluate the ultrasonographic and histologic appearance of collagenase-induced suspensory ligament (SUL) desmitis in untreated ligaments and ligaments treated with ESWT in horses. Four mature horses had SUL desmitis induced in both forelimbs. Beginning 3 weeks after induction of the lesions, one ligament per horse was treated 3 times at 3-week intervals with ESWT. The percent lesion, echogenicity and fiber alignment scores of the SULs were evaluated at 3-week inter...
Ramos-Vara JA, Ortiz-Santiago B, Segalès J, Dunstan RW.This report contains the clinical, histologic, immunohistochemical, and electron microscopic findings in two cases of equine cutaneous leishmaniasis. Nodular, sometimes crusty or ulcerated lesions were confined to the pinna and adjacent neck in both animals. The dermal inflammatory infiltrate was lymphohistiocytic in horse No. 1 and pyogranulomatous with formation of tuberculoid granulomas in horse No. 2. Numerous Leishmania organisms were found within macrophages in both animals. There was moderate to intense and specific reaction by immunoperoxidase using a polyclonal antiserum against Leish...
Miagkoff L, Girard CA, St-Jean G, Richard H, Beauchamp G, Laverty S.Osteoarthritis (OA) is a major cause of equine lameness. Cannabinoid (CB) receptors are now considered to be promising therapeutic targets in human rheumatology for pain and inflammation, however, little is known about the equine endocannabinoid system. Objective: The primary goal was to assess the presence and expression pattern of CB1 and CB2 in the synovium of healthy joints. A secondary goal was to explore the relationship between the CB expression, degree of synovitis and OA pathology. Methods: Ex vivo experimental study. Methods: Metacarpophalangeal joints (n = 25) from a tissue bank w...
Arroyo LG, Costa MC, Guest BB, Plattner BL, Lillie BN, Weese JS.Duodenitis-proximal jejunitis (DPJ) is an acute sporadic gastrointestinal disorder of horses of unknown cause. Objective: We hypothesize that Clostridium difficile toxins are involved in the pathogenesis of DPJ in horses. The objective of this study was to determine whether experimentally delivered C. difficile toxins cause clinical signs and histologic lesions similar to those of naturally occurring DPJ. Methods: Six healthy mature mixed breed horses. Methods: Experimental study: animal model of animal disease. Fasted horses were administered crude C. difficile toxins via gastroscopy and moni...
Valberg SJ, Nicholson AM, Lewis SS, Reardon RA, Finno CJ.To report a novel exertional myopathy, myofibrillar myopathy (MFM) in Warmblood (WB) horses. Objective: To 1) describe the distinctive clinical and myopathic features of MFM in Warmblood horses and 2) investigate the potential inheritance of MFM in a Warmblood family. Methods: Retrospective selection of MFM cases and prospective evaluation of a Warmblood family. Methods: Retrospectively, muscle biopsies were selected from Warmblood horses diagnosed with MFM and clinical histories obtained (n = 10). Prospectively, muscle biopsies were obtained from controls (n = 8) and a three generation WB...
Freitas MS, Pereira AHB, Pereira GO, Menezes IS, Lucena AR, Almeida CRF, Pereira EG, Santos LA, Tozin LRS, Alves FM, Macedo AL, Silva DB, Ubiali DG.Poisoning by avocado (Persea americana) has been confirmed in sheep, goats, dogs, rabbits and ostriches. The clinical signs and lesions are attributed to the acetogenin, persin. Little is known regarding the epidemiology, clinical signs, lesions and therapy caused by acetogenin-induced heart damage. During the two-year study, we investigated a horse farm with six horses that often fed themselves with P. americana leaves or mature fruit pulp and skin on the ground. Two horses died, and one underwent necropsy, histopathology, and immunohistochemistry using the anti-cardiac troponin C (cTnC). Gro...
