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.
Colombo S, Keen JA, Brownstein DG, Rhind SM, McGorum BC, Hill PB.A 13-year-old, thoroughbred mare was presented with an 8-year history of multifocal, generalized, noninflammatory alopecia and a 3-month history of alopecia, erythema and scaling of the white star on the forehead and muzzle. Histopathological examination of biopsy samples from multiple sites on the body (mane, neck, shoulder, flank and gluteal region) showed a subtle lymphocytic inflammatory infiltrate affecting and surrounding the anagen hair bulbs, consistent with a diagnosis of alopecia areata. The biopsy sample from the star on the forehead showed atrophic hair follicles with perifollicula...
Paglia DT, Miller PE, Dubielzig RR.James Wardrop should be remembered not only as one of the founders of ocular pathology but also for his contributions to the field of comparative ophthalmology. He described a "specific inflammation" that veterinarians today know as equine recurrent uveitis. As described by Wardrop in the 19th century, this condition is known today to eventually lead to blindness.
Fintl C, Pearson GT, Ricketts SW, Mayhew IG, Hudson NP.This study set out to determine the pattern of development and distribution of the interstitial cells of Cajal (ICC) in the intestinal tract of the equine fetus and neonate. Intestinal tissue samples from 12 naturally aborted equine fetuses and three euthanized neonates were collected and fixed in formalin prior to applying standard immunohistochemical labelling techniques targeting the c-Kit protein of the ICC. At 6 months of gestation, a network of ICC was present in the myenteric plexus region of both the small and the large intestine. ICC were also present within the circular muscle layer....
Faleiros RR, Stokes AM, Eades SC, Kim DY, Paulsen DB, Moore RM.To determine and compare the number, type, location, and distribution of apoptotic epidermal cells in the laminae of clinically normal horses and horses with laminitis. Methods: Formalin-fixed samples of digital lamellar tissue from 47 horses (including clinically normal horses [controls; n = 7], horses with acute [4] and chronic [7] naturally acquired laminitis, and horses with black walnut extract-induced [11] or carbohydrate overload-induced [18] laminitis). Methods: Blocks of paraffin-embedded lamellar tissues were stained for DNA fragmentation with the terminal deoxynucleotidyl transferas...
Walker JE, Lewis CW, MacLeay JM, Kawcak CE, Wheeler DL.Functional relationships between articular cartilage and underlying subchondral bone have been shown to be associated with the progression of osteoarthritis (OA). However, quantifiable factors substantiating this relationship do not exist. Therefore, the study objective involved quantifying subchondral bone mineral density (BMD) of the equine metacarpophalangeal (MCP) and stifle joints as a step in determining if regional subchondral BMD may be associated with OA changes. BMD was bilaterally quantified using dual energy xray absorptiometry (DEXA) for four subchondral regions: palmer and dorsal...
Harmel JL, Lewis CW, Sah RL, Kawcak CE, Wheeler DL.Millions of Americans suffer from osteoarthritis, a joint disease characterized by cartilage degradation and subchondral bone sclerosis. However, little is known about its pathology. It remains to be discovered which comes first in the progression of osteoarthritis: subchondral bone remodeling or cartilage degeneration. This study assessed equine cartilage degeneration, based upon measurements of cartilage thickness and Indian ink stain uptake. By gaining a greater understanding of the determining factors in cartilage degeneration, we may be able to better understand the pathomechanics of oste...
Axon JE, Robinson P, Lucas J.A 6-year-old gelding was referred with a 3-month history of recurrent fever, inappetance, lethargy and weight loss. On clinical examination major findings were depression, thin condition, thrombophlebitis, nodules on the scrotal skin, leukocytosis, hyperfibrinogenaemia and hyperglobulinaemia. Pleural fluid and areas of lung consolidation were seen on ultrasonographic examination of the thorax. A diagnosis of chronic respiratory disease was made. Initially there was a response to antibiotic therapy but the horse was presented 3 months later with continued weight loss, recurrent fever and multif...
Terio KA, Stalis IH, Allen JL, Stott JL, Worley MB.Coccidioidomycosis is a rare, often subclinical infection in domestic animals caused by the fungus Coccidioides immitis. Because of an apparent high incidence of coccidioidomycosis in Przewalski's horses (Equus przewalskii) housed at a single facility, necropsy records and biomaterials from animals that died between 1984 and 2000 were reviewed (n = 30, 15 males, 15 females). Coccidioidomycosis was the leading cause of death (33%) in this population with lesions in the lungs and tracheobronchial lymph nodes of all animals and variable involvement of the skeletal muscle, heart, kidney, liver, sk...
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...
McGlothlin JA, Lester GD, Hansen PJ, Thomas M, Pablo L, Hawkins DL, LeBlanc MM.An experimental model of ascending placentitis was developed in the mare to characterize the uterine myoelectrical pattern in late gestation and determine how ascending placentitis altered this pattern. In experiment 1, myometrial electrical activity was analyzed during the early morning, late morning and evening hours in four mares in the last 15 days of gestation to identify patterns of activity. In experiment 2, nine mares received intra-cervical inoculations of Streptococcus equi subspecies zooepidemicus. Myoelectrical activity in the early morning and evening hours in these mares was comp...
Scotty NC, Ford M, Williams F, Loiacono C, Johnson PJ, Messer NT, Turnquist SE, Essman S.An 11-year-old Quarterhorse mare developed a paranasal sinus osteoma that extended into the right orbit and led to ipsilateral exophthalmia. Although the tumor was radiographically evident in the paranasal sinuses, ultrasonography was used to demonstrate extension of the tumor into the retrobulbar space, and endoscopy was used to identify its extension into the nasopharynx. Biopsies were obtained using both fine-needle aspiration and paranasal sinus trephination. Despite numerous antemortem diagnostic tests, only postmortem histologic analysis of the mass afforded the diagnosis of osteoma.
Ruohoniemi M, Mäkelä O, Eskonen T.Research on the clinical significance of ossification of the cartilages of the foot has been limited, despite the common nature of the condition and conflicting reports in previous literature. Objective: Some radiographic features in the ossification of the cartilages, such as incomplete fusion lines between separate centres of ossification and the ossified base, are of clinical significance. Methods: The relationships between radiopharmaceutical uptake in bone phase nuclear scintigraphy at the heels (palmar processes of the distal phalanx, including ossification of the cartilages of the foot)...
Ryu SH, Kim JG, Bak UB, Lee CW, Lee YL.A 7-year-old Thoroughbred gelding was admitted to Equine Hospital, Korea Racing Association for evaluation and treatment of colic. Based on the size and duration of the large colonic and cecal impaction, a routine ventral midline celiotomy and large colon enterotomy were performed to relieve the impaction. Six days following surgery the gelding exhibited signs of lethargy, fever, inappetence and diarrhea. Eleven days following surgery, the jugular veins showed a marked thrombophlebitis. On the sixteenth day of hospitalization the gelding died suddenly. Upon physical examination, the horse was ...
Billinghurst RC, Brama PA, van Weeren PR, Knowlton MS, McIlwraith CW.To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. Methods: 43 Dutch Warmblood foals with varying severity of osteochondrosis. Methods: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined...
Jolly RD, Palmer DN, Dalefield RR.Analytical studies of three lipopigments show that much can be achieved. Lipopigment from ovine ceroid-lipofuscinosis is composed of discrete protein and lipid molecules in orderly arrays and lipid peroxidation is not involved in its formation. Subunit c of mitochondrial ATP synthase accounts for approximately 50% of accumulated material and is specific to the disease process in this and other forms of the disease. Lipofuscin from bovine heart was mostly soluble and also contained discrete proteins, lipids and metals. Equine thyroid lipofuscin was less soluble but also had a relatively high pr...
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...
Capik I, Ledecky V, Mihály M.Abnormalities of dental development such as hypoplasia of cementum, oligodontia, polydontia, enamel hypoplasia, brachygnathia, and prognathia are quite common in the horse. Abnormalities of eruption are less common and often associated with trauma. This case report describes the diagnosis and therapy for pre-eruption displacement of the maxillary left third and fourth premolar teeth resulting from previous facial trauma in a 1.5-year-old filly.
Murray RC, Dyson SJ, Schramme MC, Branch M, Woods S.Chronic laminitis is a severe disease affecting the equine digit. It was hypothesized that magnetic resonance (MR) imaging would improve visualization of structures within the foot and pathology associated with chronic laminitis. This study aimed to describe the MR imaging findings in chronic laminitis, compare different pulse sequences for visualization of pathology, and to compare MR imaging with standard radiography. Twenty (10 forelimb, 10 hindlimb) cadaver limbs from 10 horses clinically diagnosed with chronic laminitis (group L) and 10 limbs without laminitis (group N) were used. Laterom...
Cavani F, Fini M, de Terlizzi F, Cadossi M, Ciminelli L, Ortolani S, Cherubini R, De Aloysio D, Giavaresi G, Cadossi R, Canè V.Osteoporosis involves alterations, not only in density, but also in the architectural organisation of the bone; in particular, trabecular orientation, following the skeletal load directions, lends a high degree of stiffness to the whole bone. We investigated the relationship between trabecular orientation, density, stiffness and ultrasound (US) propagation in two orthogonal directions (par. = parallel to, and ort. = orthogonal to the main orientation of the trabeculae) in cylindrical equine bone specimens (thoracic vertebrae) where a preferential orientation is present. A total of 15 cylinders...
Walter I, Helmreich M, Handler J, Aurich C.Chronic degenerative disease of the mare's endometrium is characterised by changes in the uterine glands, including cystic dilation, hyperplasia and periglandular fibrosis. Endometrial biopsies were taken from 23 mares with different grades of endometrial degeneration. Solid structures were identified within the lumina of the uterine glands and shown to be calcified by histochemical staining. Most of them were not homogenous but composed of a mixture of mineral and organic substances. Further examinations of these mineralised structures by immunohistochemical methods revealed the presence of t...
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...
Bedenice D, Heuwieser W, Brawer R, Solano M, Rand W, Paradis MR.A total of 207 thoracic radiographs obtained from 128 foals were evaluated to assess the impact of pulmonary radiographic pattern, distribution, and severity of pulmonary changes on short-term survival of neonatal foals. The association between selected clinical variables and the radiographic manifestation of neonatal respiratory disease was also investigated. The evaluation of interstitial and alveolar-interstitial radiographic patterns within the caudodorsal, caudoventral, and cranioventral lung regions proved to be highly reliable between viewers in the study. A diagnosis of systemic inflam...
Szeredi L, Hornyák A, Dénes B, Rusvai M.A 4-days-old foal died after a short course of respiratory syndrome and fever. Large areas of the alveoli, bronchioles and bronchi were partly or completely filled by hyaline membranes. Pronounced oedema and mild interstitial pneumonia were present and, in the small muscular arteries, fibrinoid necrosis and vasculitis or perivasculitis could be seen. Vasculitis was found in several other organs, and it was most severe in the thymus. The virus was detected in the lung, kidney and spleen using virus isolation and in the lung and spleen using polymerase chain reaction. The virus was also detected...
Anastasiou A, Skioldebrand E, Ekman S, Hall LD.The distal row of carpal bones (C2, C3, and C4) from eight left intercarpal joints--four from Standardbred Trotters and four from Swedish Warmblood horses--were used to assess the potential of magnetic resonance (MR) imaging to detect cartilage and bone lesions. The joints used in the study were classified by macroscopic and radiographic examinations as having normal, mild, moderate, or severe articular cartilage lesions and bone sclerosis. Those classifications correlated well with the appearance of the MR images. Bone sclerosis in the MR images was observed as regions of decreased signal int...
Fogarty U, Perl D, Good P, Ensley S, Seawright A, Noonan J.A cluster of 6 cases of equine granulomatous enteritis is described. Aluminium was demonstrated in the tissues and lesions of these horses and in the intimal bodies of intestinal vessels. The relationship between granulomatous lesions, aluminium, acidity and invading microorganisms, particularly parasites, is presented and discussed.
Grosås S, Østevik L, Revold T, Ottesen N, Ropstad EO.A uveal leiomyosarcoma of a horse is reported. There are few published reports of intraocular tumors in horses. Intraocular tumors challenge animal welfare by causing uveitis, glaucoma, and loss of vision. Knowledge regarding treatment of intraocular tumors with globe preservation is sparse, and further investigations on this topic are required.
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...
Cavalcante AL, Dias LM, Alves JT, Veras AA, Guimarães LC, Rocha FS, Gala-García A, Retamal P, Ramos RT, Azevedo V, Silva A, Carneiro AR.Corynebacterium pseudotuberculosis is related to several diseases infecting horses and small ruminants, causing economic losses to agribusiness. Here, we present the genome sequence of C. pseudotuberculosis strain E19. The genome includes one circular chromosome 2,367,956 bp (52.1% G+C content), with 2,112 genes predicted, 12 rRNAs, and 48 tRNAs.
Miller MA, Kottler SJ, Ramos-Vara JA, Johnson PJ, Ganjam VK, Evans TJ.Response to 3-methylindole (3MI) varies among species. Mice recover from 3MI-induced bronchiolar epithelial injury but sustain persistent olfactory mucosal injury with scarring and epithelial metaplasia. In contrast, 3MI induces obliterative bronchiolitis in horses and ponies, but olfactory mucosal injury has not been reported. To evaluate the effect of 3MI on equine olfactory mucosa, ponies were dosed orally with 100 mg 3MI/kg (n = 9) or corn oil vehicle (n = 6). All ponies treated with 3MI developed obliterative bronchiolitis with mild olfactory injury. By 3 days after 3MI dosing, olfactory ...
Arnold CE, Chaffin MK, Rush BR.Cystic hematomas were diagnosed in 3 neonatal foals. In all 3 foals, cystic hematomas resulted from umbilical trauma or thrombocytopenia. Findings in these foals suggest that cystic hematoma should be included in the differential diagnosis of hematuria in neonatal foals. Management of cystic hematomas includes both medical and surgical options.
Menzies-Gow NJ, Bailey SR, Berhane Y, Brooks AC, Elliott J.To determine the effect of endotoxin (lipopolysaccharide [LPS]) on vasoactive mediator production by cultured equine digital vein endothelial cells (EDVECs). Methods: EDVECs obtained from forelimb digital veins of 7 healthy adult horses. Methods: EDVECs were incubated with or without LPS (1 microg/mL) for 0, 2, 4, 6, 22, and 24 hours. The EDVECs were incubated for 18 hours with LPS (10 pg/mL to 1 microg/mL) with or without ibuprofen, cycloheximide, or L-nitroarginine methyl ester. Medium concentrations of prostacyclin, cyclic guanosine monophosphate, endothelin-1, and thromboxane A(2) were det...
Duckett WM, Matthews HK.Paraneoplastic eosinophilia is reported in dogs, cats, and humans. Hypereosinophilia (an eosinophil count greater than 1.5 x 10(9) L) is often associated with metastasis and a poor prognosis. This report describes a case of paraneoplastic hypereosinophilia in a pony. Neoplasia should be included in the differential diagnoses in a horse with eosinophilia.
Reef VB.Cardiac disease in the equine neonate occurs infrequently. Murmurs are often heard in foals and are not considered significant unless they persist beyond 4 days of age. Congenital cardiac defects are the most common form of primary cardiac disease in the foal, with ventricular septal defects occurring most frequently. Other neonatal foal diseases such as ruptured bladders, white muscle disease, neonatal respiratory distress syndrome, and septicemia have secondary cardiac involvement.
Nielsen IL, Jacobs KA, Huntington PJ, Chapman CB, Lloyd KC.Adverse reactions to intramuscular injections of procaine penicillin G are reported in 11 horses, five of which died. The clinical findings are presented and suggest central nervous involvement in most cases. Post mortem findings in one horse were consistent with anaphylaxis whereas in other cases the clinical findings, duration of treatment, speed of onset and subsequent completion of treatment supports diagnosis of an acute procaine toxicity syndrome.
Alwan WH, Carter SD, Dixon JB, Bennett D, May SA, Edwards GB.Synovial fluid samples of horses with osteoarthritis were investigated to detect interleukin-1 (IL-1) activity which could contribute to the disease pathogenesis. Of the 32 samples tested, 12 (37.5 per cent) showed an augmented phytohaemagglutinin induced proliferation of C3H/HeJ mouse thymocytes. Positive results were also seen in horses with infected arthritis, osteochondritis, traumatic arthritis and undefined synovial effusions. Normal synovial fluid and sera from all groups failed to show any detectable IL-1 activity. Fractionation of synovial fluid showed that the IL-1 activity was in th...
Stadler P, van den Berg SS, Tustin RC.A Hansen type I cervical intervertebral disc prolapse was diagnosed in a 16-year-old American Saddler showing clinical signs of paresis and ataxia. An ante-mortem diagnosis was made by means of plain radiographs and a myelogram. The horse was euthanased and the diagnosis confirmed on a post-mortem examination.
Thomsen LN, Thomsen PD, Downing A, Talbot R, Berg LC.The synovial membrane lines the luminal side of the joint capsule in synovial joints. It maintains joint homeostasis and plays a crucial role in equine joint pathology. When trauma or inflammation is induced in a joint, the synovial membrane influences progression of joint damage. Equine synovial membrane research is hampered by a lack of markers of fibroblast-like synoviocytes (FLS) to distinguish FLS from other fibroblast-like cells in musculoskeletal connective tissues. The aim of this study is to identify potential FLS markers of the equine synovial membrane using microarray to compare bet...
Williamson LH, Farrell RL.A case of intracranial schwannoma is described in a young horse. Clinical signs developed slowly and were suggestive of a lesion involving the left cerebrum. The filly exhibited a change in mentation, and circled to the left. Visual impairment and decreased facial sensation were noted on the right side. A solitary schwannoma which compressed the left cerebrum was found at necropsy.
Schlocker N, Gerber-Bretscher R, von Fellenberg R.In a search of viral agents in pulmonary macrophages of horses with chronic pulmonary disease, equine herpesvirus 2 was found to be unique. In 8 of 9 horses with chronic pulmonary disease, antigens of equine herpesvirus 2 were detected by indirect immunofluorescence staining of scattered foamy macrophages immediately after harvesting by bronchoalveolar lavage and fractionation on metrizamide gradients. In a healthy horse, antigens were not found. After 1 week of cultivation of bronchoalveolar lavage cells from a second group of 9 horses with chronic pulmonary disease, viral antigens were detec...
Fjordbakk CT, Kenney DG, Rodriguez-Palacios A, Keller S, Stalker M.An inflammatory aural polyp was identified in a 1-year-old standardbred filly, which presented with otorrhea and head rubbing. The polyp was removed by traction-avulsion, and the filly showed no subsequent signs of otorrhea. Aural polyps have not been reported in horses, but they are commonly seen in companion animals and humans. Un polype auditif inflammatoire a été identifié chez une pouliche Standardbred d’un an présentée pour otorrhée et frottage de tête. Le polype a été retiré par traction-avulsion et la pouliche n’a pas manifesté de signes subséquents d’otorrhée. Les ...
Paciello O, Passantino G, Costagliola A, Papparella S, Perillo A.Histiocytic diseases in veterinary medicine have been revised in the last few decades, but these are considered relatively rare in horses. This report describes a 9-year-old female horse, Dutch Warmblood, presented for investigation of severe nasal bleeding. A multinodular bilateral mass of 5 cm, reddish to white in color, that invaded and destroyed the surrounding tissues, was observed during a clinical examination of the nostril The morphological features of the tumor cells were represented by cytologically bizarre, highly phagocytic, multinucleated giant cells. These findings, together with...
Richards AJ, Kelly DF, Knottenbelt DC, Cheeseman MT, Dixon JB.This report summarises clinical and pathological observations on Fell pony foals with a range of signs that included ill thrift, anaemia, respiratory infection, glossal hyperkeratosis and diarrhoea. Some of the foals had normochromic, normocytic anaemia and some had low levels of plasma proteins, including immunoglobulin G. Antibiotic and supportive treatment was ineffective and all affected foals died or were killed on humane grounds. Postmortem examination of 12 foals and tissues from 2 other foals revealed a range of lesions that included glossal hyperkeratosis, typhlocolitis, intestinal cr...
Cardwell JM, Christley RM, Gerber V, Malikides N, Wood JL, Newton JR, Hodgson JL.The term 'inflammatory airway disease' (IAD) is often used to describe the syndrome of lower airway inflammation that frequently affects young racehorses in training around the world. In practice, this inflammation is generally diagnosed using a combination of endoscopic tracheal examination, including grading of amounts of mucus present and tracheal wash sampling. However, a recent consensus statement from the American College of Veterinary Internal Medicine concluded that bronchoalveolar lavage (BAL) sampling, rather than tracheal wash (TW) sampling, is required for cytological diagnosis of ...
Leid RW, Coley SC, Blanchard DP, Perryman LE.The equine alternative complement pathway has been partially characterized and compared to the equine classical activation pathway. A dose-dependent lysis of RbRBC was observed with peak lytic values noted within 10 minutes at 37 degrees C when rabbit red blood cells (RbRBC) were used as an alternative pathway activator. Sheep red blood cells (SRBC) sensitized with rabbit hemolysin or partially purified equine IgM antibodies were equally sensitive to lysis. Dilution of the commercial hemolysin by 1/5 reduced lysis from 90% to 38% in the presence of constant cell numbers. Hemolysis of SRBC peak...
Johns I, Bryan J.The diagnosis of neoplasia in the horse is both simple and extremely challenging, depending on the type of neoplasm and its location. Obtaining an accurate diagnosis of a neoplastic condition is key to formulating an appropriate treatment plan if possible or developing a palliative plan if curative treatment options do not exist. A combination of historical features, clinical examination findings, and diagnostic testing typically allow a working diagnosis of neoplasia to be made, with a definitive diagnosis requiring the identification of neoplastic cells in a sample or tissue.
Taulescu M, Palmieri C, Leach J, Nagy A, Ober C, Cernea M, Catoi C.This case report describes the pathological findings of multiple congenital cardiac defects in a 2-year-old female Shetland pony with clinical signs of chronic respiratory distress. Persistent truncus arteriosus (PTA) type IV, interventricular septal defect, overriding aorta, pulmonary trunk agenesis, pulmonary arteries arising from the descending aorta, and compensatory right ventricular hypertrophy were observed.
Mueller PO, Harmon BG, Hay WP, Amoroso LM.To evaluate the effect of sodium carboxymethylcellulose (SCMC) or a hyaluronate-carboxymethylcellulose membrane (HA membrane) on healing of the small intestine in horses. Methods: 18 healthy adult horses. Methods: Midline celiotomy and 2 jejunal resection-and-anastomosis surgeries were performed. In treated horses, SCMC (n = 6) or a HA membrane (6) was applied to the jejunum to cover the anastomosis. There were 6 untreated control horses. Horses were euthanatized 10 days after surgery. For each horse, 1 anastomosis was used for histologic examination, and the second was used to determine intes...
Romero BF, Iglesis García M, Gil Molino M, Gómez L, Galapero J, Parejo C, Martín Cuervo M.Equine uveitis is a common eye disease that affect horses from different breeds, ages, and genders. Uveitis has been described as inflammation of the uvea secondary immunomediated processes or eye trauma. Renal cell carcinoma (RCC) is the most common tumor that can affect the equine kidneys. The present case describe a horse that was referred to the Veterinary Teaching Hospital of the University of Extremadura with bilateral uveitis. The horse was treated for the primary complain but the horse collapse and die during hospitalization. At necropsy, a tumoral mass in kidney with extensive in othe...
Gerber V, De Feijter-Rupp H, Wagner J, Venta P, Harkema JR, Robinson NE.Airway mucus accumulation is associated with indoor irritant and allergen exposure in horses with recurrent airway obstruction (RAO). Epidermal growth factor receptor (EGFR) and a chloride channel (calcium activated, family member 1; CLCA1) are key signalling molecules involved in mucin gene expression. Objective: We hypothesised that exposure to irritants and aeroallergens would lead to increased expression of the mucin gene eqMUC5AC and increased stored mucosubstance in the airways of RAO-affected horses, associated with increased neutrophils and CLCA1 and EGFR mRNA levels. Methods: We perfo...
Carvallo FR, Poppenga R, Kinde H, Diab SS, Nyaoke AC, Hill AE, Arthur RM, Uzal FA.Five horses originating from 4 different California race tracks were submitted to the California Animal Health and Food Safety Laboratory for necropsy and diagnostic workup. The 5 horses had a history of sudden collapse and death during exercise. In all of them, massive hemoperitoneum and hemorrhages in other cavities or organs were observed. The liver from these 5 animals and from 27 horses that had been euthanized due to catastrophic leg injuries (controls) were subjected to a rodenticide anticoagulant screen. Traces of brodifacoum, diphacinone, or bromadiolone were detected in the 5 horses ...
Costa LR, Seahorn TL, Moore RM, Oliver JL, Hosgood GL.To determine concentrations of nitric oxide (NO) in plasma and bronchoalveolar lavage fluid (BALF) and localize nitric oxide synthesis in the lungs of horses with summer pasture-associated obstructive pulmonary disease (SPAOPD). Methods: 7 adult horses with SPAOPD and 6 clinically normal adult horses. Methods: Severity of SPAOPD was determined by use of clinical scores, change in intrapleural pressure (APpl) during tidal breathing, cytologic analysis of BALF, and histologic evaluation of lung specimens obtained during necropsy. Nitric oxide concentrations in plasma, BALF and epithelial lining ...
Kisailus EC, Kabat EA.The specificity of Bandeiraea simplicifolia lectin I (BS I) has been studied by competitive-binding assays (CBA) using tritium-labeled human B and hog A substances. Blood-group B substances isolated from horse gastric mucosae and from human ovarian-cyst fluids were much better inhibitors of binding of tritiated blood-group B substance to insoluble BS I-Sepharose 2B than were human blood-group A substances from saliva and ovarian-cyst fluid. A and B active blood-group substances showed the same range of potency in inhibiting binding of tritium-labeled hog A substance to BS I-Sepharose 2B. CBA w...
Fintl C, Pearson GT, Ricketts SW, Mayhew IG, Hudson NP.This study set out to determine the pattern of development and distribution of the interstitial cells of Cajal (ICC) in the intestinal tract of the equine fetus and neonate. Intestinal tissue samples from 12 naturally aborted equine fetuses and three euthanized neonates were collected and fixed in formalin prior to applying standard immunohistochemical labelling techniques targeting the c-Kit protein of the ICC. At 6 months of gestation, a network of ICC was present in the myenteric plexus region of both the small and the large intestine. ICC were also present within the circular muscle layer....
Ostevik L, de Souza GA, Wien TN, Gunnes G, Sørby R.Two horses with chronic uveitis and histological lesions consistent with equine recurrent uveitis (ERU) were examined. Microscopical findings in the ciliary body included deposits of amyloid lining the non-pigmented epithelium, intracytoplasmic, rod-shaped, eosinophilic inclusions and intraepithelial infiltration of T lymphocytes. Ultrastructural examination of the ciliary body of one horse confirmed the presence of abundant extracellular deposits of non-branching fibrils (9-11 nm in diameter) consistent with amyloid. Immunohistochemistry revealed strong positive labelling for AA amyloid and m...
