Neoplasms in horses refer to abnormal tissue growths that can be benign or malignant, affecting various body systems. These growths arise from uncontrolled cellular proliferation and can occur in different forms, including tumors and cancerous lesions. Equine neoplasms can impact the skin, gastrointestinal tract, reproductive organs, and other areas, with common types including melanomas, sarcoids, and squamous cell carcinomas. Diagnosis often involves clinical examination, imaging, and histopathological analysis. Treatment and prognosis vary depending on the type, location, and stage of the neoplasm. This page compiles peer-reviewed research studies and scholarly articles that explore the etiology, diagnosis, treatment options, and outcomes associated with neoplasms in equine patients.
Jarry J, De Raeve Y, Dugdale A, Simon V, Vandeweerd JM.Severe ophthalmic conditions such as trauma, uveitis, corneal damage, or neoplasia can lead to eye removal surgery. Poor cosmetic appearance resulting from the sunken orbit ensues. The aim of this study was to demonstrate the feasibility of manufacturing a custom-made 3D-printed orbital implant made of biocompatible material for the enucleated horse and usable in conjunction to a corneoscleral shell. Blender, a 3D-image software, was used for prototype design. Twelve cadaver heads of adult Warmbloods were collected from the slaughterhouse. On each head, one eye was removed via a modified trans...
Barton CK, Hughes KL, Cowan C, Nout-Lomas YS, Nelson BB.A 21-year-old Quarter Horse mare presented with a chronic, progressively worsening left pelvic limb lameness of 3 weeks duration. The initial examination identified a consistent lameness at a walk. Neurological examination showed sensory and gait abnormalities consistent with left femoral nerve dysfunction. The horse minimally advanced the leg cranially and had a shortened stride length at the walk. During the stance phase, the heels of the left hind foot did not contact the ground and the horse quickly took weight off of the limb. Diagnostic imaging (ultrasound and nuclear scintigraphy) exami...
Gysens L, Martens A, Haspeslagh M.Bovine papillomavirus (BPV) types 1 and 2 are causally associated with equine sarcoid, the most common mesenchymal neoplasm of horses, but the viral load (VL) differs between lesions. Sensitive and accurate BPV detection and quantification is essential for clinicians to confirm clinical suspicion, as well as in research settings for stratifying these skin lesions. Due to the limitations of histopathology in sarcoid diagnosis, PCR screening of superficial swabs constitutes the principal sampling method for BPV detection. This study aimed to investigate the ability of superficial swabs and fine-...
Kumbhani TR, Raval SH, Parmar RS, Patel JG, Bechara VJ, Sindhi PI, Modh SP.A 6-year-old Marwari mare presented with recurrent vulvar growth. The growth was surgically excised, fixed and processed routinely. Microscopically, neoplasm showed proliferation of epithelial and myoepithelial cells with tubulopapillary pattern. On immunohistochemistry, myoepithelial cells showed strong immunoreactivity with smooth muscle actin alpha and p63. On basis of histopathology and immunohistochemistry, tumour was diagnosed as complex apocrine carcinoma. This case report describes first confirm vulvar complex apocrine carcinoma in equines.
Rissi DR, Avery AC, Burnett RC.T-cell-rich, large B-cell lymphoma (TCRLBCL) is the most commonly diagnosed type of lymphoma in horses. Here we describe the clinical signs, neuropathology, immunohistochemistry (IHC), and PCR for antigen receptor rearrangement (PARR) analysis results of a TCRLBCL in the brain of an 8-y-old male Quarter Horse that was euthanized after acute anorexia, tremors, head pressing, falling, blindness, incoordination, and seizures. Autopsy revealed a firm, smooth, pale-yellow mass that expanded both lateral ventricles and the adjacent subcortical white matter. Histologically, the mass consisted of a de...
Offer KS, Dixon CE, Sutton DGM.The sarcoid is the most common equine cutaneous neoplasm. Evidence-based treatment of this condition is often lacking, and selection of treatment modality based on clinical experience or anecdotal evidence. Objective: To assess the quality of the currently available best evidence regarding the treatment of the equine sarcoid. Methods: Systematic review. Methods: In compliance with PRISMA guidelines, literature searches were performed in PUBMED, Web of Science, CAB Abstracts, EMBASE (Ovid) and Scopus in April 2021. Included papers were required to describe an interventional study examining sarc...
Curnow B, Rich AF, Ireland J, Correa DC, Dunn J, Jenkins D, Carslake H, Ressel L.Although the equine sarcoid is the most common skin neoplasm in domesticated horses, histopathological characteristics have not previously been evaluated for association with recurrence. The aim of this retrospective cohort study was to investigate clinical and histopathological features of excised equine sarcoids and to evaluate their association with recurrence at the original surgical site and at new sites. Clinical records and excisional biopsies from 106 equine sarcoids from 64 horses referred to Leahurst Equine Hospital, University of Liverpool, between March 2010 and February 2015 were ...
Roxon C, Slack J, Bender S, Burns H, Turner R.A 12-year-old Standardbred stallion presented with a 5-month history of a growing mass in the left testis as well as an overall decrease in left testicular size. Palpation and ultrasonography of the left testis revealed a firm, hypoechoic, clearly delineated soft tissue mass in the craniolateral portion of the testis that measured 2.5 × 2.3 × 1.9 cm. Two smaller, hypoechoic regions also were visible ultrasonographically in the left testis, suggesting the presence of multifocal/multicentric neoplasia. The affected testis was very small (testicular volume of 40.3 cm). The right testis was ...
Drozdzewska K, Gehlen H.The diagnosis of internal neoplasia in horses is challenging. Increased production of hormones physiologic for adult animals (e.g., adrenocorticotropin, norepinephrine, and erythropoietin) or typical for the foetal phase (alpha-fetoprotein, anti-Müllerian hormone, and parathyroid-hormone-related protein) might aid in tumour diagnostics. Thymidine kinase-1 and alkaline phosphatase are examples of intracellular enzymes, whose activity in the blood may increase in some neoplasia cases. Furthermore, inappropriate production of abnormal monoclonal or autologous antibodies can accompany lymphoma an...
Daraban Bocaneti F, Altamura G, Corteggio A, Tanase OI, Dascalu MA, Pasca SA, Hritcu O, Mares M, Borzacchiello G.Bovine papillomaviruses -1/-2 (BPVs) are small non-enveloped double-stranded DNA viruses able to infect the skin of bovids and equids, causing development of neoplastic lesions such as bovine cutaneous fibropapillomas and equine sarcoid. Matrix metalloproteinases (MMPs) are a group of zinc-dependent endopeptidases that degrade basal membrane and extracellular matrix, whose function is essential in physiological processes such as tissue remodeling and wound healing. MMPs activity is finely regulated by a balancing with expression of tissue inhibitors of MMPs (TIMPs), a process that is impaired ...
Palmisano M, Bender S, Johnson AL.We describe the unique clinical presentation of a central nervous system neoplasm in a 6-month-old draft horse cross gelding. Based on the neurologic examination at admission, neurolocalization was most consistent with a mildly asymmetric cervical, multifocal, or diffuse myelopathy. Mild vestibular involvement also was considered, but no cranial nerve deficits were observed. The gelding was negative for Sarcocystis neurona or Neospora hughesi based on paired serum and cerebrospinal fluid (CSF) samples analyzed, with no evidence of cervical compression based on contrast myelography. The horse w...
Stefanik E, Górski K, Turek B, Drewnowska-Szczepakowska O, Kliczkowska-Klarowicz K, Stefanik A.Melanomas in horses are most often associated with gray, older horses with an average age of over 16 years. Anaplastic malignant melanoma, however, can very rarely affect non-gray horses. Herein, we report a case of a 16-year-old Wielkopolski gelding with a chronic lameness caused by a mass in the hoof. The first resection of the lesion and histopathological examination confirmed the presence of a keratoma. The regrown mass and persistent lameness resulted in another mass resection. The second histopathological examination result suggested a neoplastic growth of melanocytic origin with a low h...
Hollis AR.Sarcoids are the most common cutaneous neoplasm of the horse, arising as a result of a neoplastic proliferation of fibroblasts associated with infection with bovine papillomavirus, most notably types 1 and 2. Although they do not metastasise, they are locally invasive and aggressive, and can lead to important welfare concerns, interfere with tack and therefore impede athleticism, and undoubtedly lead to a reduction in the value of affected horses. This review discusses the evidence behind the most commonly used treatments for equine sarcoids. The most commonly used treatments are discussed. No...
Munday JS, Knight CG, Luff JA.Papillomaviruses (PVs) are well recognized to cause pre-neoplastic and neoplastic diseases in humans. Similarly, there is increasing evidence that PVs play a significant role in the development of pre-neoplastic and neoplastic diseases of the haired skin of dogs and cats, and the mucosa of horses. As the mechanisms by which PVs cause neoplasia are well studied in humans, it is valuable to compare the PV-induced neoplasms of humans with similar PV-associated neoplasms in the companion animal species. In the second part of this comparative review, the pre-neoplastic and neoplastic diseases thoug...
Nelissen S, Miller AD.Granulosa cell tumors (GCTs) are common ovarian neoplasms in the mare and bitch that can be challenging to diagnose on histopathology. Inhibin has long been the standard immunohistochemical (IHC) marker for GCTs; however, anti-Müllerian hormone (AMH) has not been evaluated widely as an IHC marker in the bitch and mare. We compared the efficacy of AMH and inhibin as IHC markers in canine and equine GCTs. We selected retrospectively 18 equine and 15 canine cases. All equine tumors were dominated by a cystic pattern; canine tumors often had solid patterns. Both inhibin and AMH had similar puncta...
Biegel U, Mevissen M, Schuller S, Ruess K, Christen O, Ayrle H, Koch C, Walkenhorst M.Cancer is a common disease in humans and in companion animals and treatment is challenging. The aim of this systematic review was to identify and assess the potential use of Viscum album L. extracts (VAE) for treatment of neoplastic diseases in companion animals. Peer-reviewed animal, in vivo and in vitro studies were included, considering the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and A Measurement Tool to Assess Systematic Reviews (AMSTAR). Overall, 6,148 references were identified. Following a predefined protocol, 114 full-text references were ...
Maggi R, Mudimba D, Marruchella G.A 11-year-old, Haflinger breed mare developed a slowly growing mass, protruding on the ventral aspect of the mandible. On palpation, the lesion was pedunculated, very firm, cold and not painful. Radiographic examinations showed a radiopaque, multi-lobular, "mushroom-like" lesion, which arose from the mandibular cortex without involving the bone marrow cavity. Thereafter, the mass was excised for cosmetic purposes. Microscopically, the lesion mainly consisted of bone trabeculae, covered by a thick layer of connective tissue resembling the periosteum. History and clinical findings allowed the te...
Pawlina-Tyszko K, Semik-Gurgul E, Ząbek T, Witkowski M.Horses are of great importance in recreation, livestock production, as working animals in poorly developed countries, and for equine-assisted therapy. Equine sarcoids belong to the most commonly diagnosed tumors in this species. They may cause discomfort, pain, and can lead to the permanent impairment of motor function. The molecular bases of their formation are still under investigation. Our previous studies revealed altered microRNA (miRNA) expression and DNA methylation levels in sarcoid tumors. Abnormal patterns of methylation may be responsible for changes in gene expression levels, inclu...
Podstawski P, Ropka-Molik K, Semik-Gurgul E, Samiec M, Skrzyszowska M, Podstawski Z, Szmatoła T, Witkowski M, Pawlina-Tyszko K.An important component of tissues is the extracellular matrix (ECM), which not only forms a tissue scaffold, but also provides the environment for numerous biochemical reactions. Its composition is strictly regulated, and any irregularities can result in the development of many diseases, including cancer. Sarcoid is the most common skin cancer in equids. Its formation results from the presence of the genetic material of the bovine papillomavirus (BPV). In addition, it is assumed that sarcoid-dependent oncogenic transformation arises from a disturbed wound healing process, which may be due to t...
Malek G, Leclere M, Masseau I, Zur Linden A, Beauchamp G, Finck C.Published studies describing the effects of bilateral radiographic projections on the detection of equine pulmonary lesions are currently lacking. The objectives of this retrospective, single center, observational study were to compare unilateral and bilateral thoracic radiographic projections for the detection of pulmonary lesions in a group of horses. Based on their clinical diagnosis, 167 adults and foals with bilateral thoracic radiographs were classified as having pneumonia (n = 88), inflammatory or diffuse pulmonary disease (n = 72), and pulmonary masses (n = 7). After an initial i...
Podstawski P, Ropka-Molik K, Semik-Gurgul E, Samiec M, Skrzyszowska M, Podstawski Z, Szmatoła T, Witkowski M, Pawlina-Tyszko K.Matrix metalloproteinases (s) represent a family of enzymes capable of biocatalytically breaking down the structural and functional proteins responsible for extracellular matrix (ECM) integrity. This capability is widely used in physiological processes; however, imbalanced MMP activity can trigger the onset and progression of various pathological changes, including the neoplasmic transformation of different cell types. We sought to uncover molecular mechanisms underlying alterations in transcriptional profiles of genes coding for s, which were comprehensively identified in equine adult dermal ...
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...
Tesena P, Kingkaw A, Phaonakrop N, Roytrakul S, Limudomporn P, Vongsangnak W, Kovitvadhi A.Equine melanocytic neoplasm (EMN) is a common disease in older grey horses. The purpose of this study was to examine the potential proteins throughout EMN stages from faecal proteomic outlining using functional analysis. Faecal samples were collected from the rectum of 25 grey horses divided into three groups; normal group without EMN ( = 10), mild EMN ( = 6) and severe EMN ( = 9). Based on the results, 5910 annotated proteins out of 8509 total proteins were assessed from proteomic profiling. We observed differentially expressed proteins (DEPs) between the normal group and the EMN group, and 1...
Podstawski P, Samiec M, Skrzyszowska M, Szmatoła T, Semik-Gurgul E, Ropka-Molik K.The equine sarcoid is one of the most common neoplasias in the family. Despite the association of this tumor with the presence of bovine papillomavirus (BPV), the molecular mechanism of this lesion has not been fully understood. The transgenization of equine adult cutaneous fibroblast cells (ACFCs) was accomplished by nucleofection, followed by detection of molecular modifications using high-throughput NGS transcriptome sequencing. The results of the present study confirm that - and -mediated nucleofection strategy significantly affected the transcriptomic alterations, leading to sarcoid-like...
Schreeg ME, Radkin M, Haugland J, Murphy BG, Rushton S, Linder KE.Ameloblastic carcinoma is a malignant odontogenic neoplasm that has been reported only rarely in veterinary species. A 16-y-old Arabian crossbred mare was presented for evaluation of a hard mass on the body of the mandible, with evidence of osteolysis on radiographs. Incisional biopsies revealed an invasive neoplasm comprised of spindloid epithelial cells with a high mitotic count and partial dual cytokeratin-vimentin immunoreactivity. The horse was euthanized because of rapid tumor progression 3 mo after presentation. Postmortem evaluation revealed partial obliteration of the mandible by a ...
Martano M, Altamura G, Power K, Liguori P, Restucci B, Borzacchiello G, Maiolino P.It is well known that δ-bovine papillomaviruses (BPV-1, BPV-2 and BPV-13) are one of the major causative agents of equine sarcoids, the most common equine skin tumors. Different viruses, including papillomaviruses, evolved ingenious strategies to modulate autophagy, a complex process involved in degradation and recycling of old and damaged material. Methods: The aim of this study was to evaluate, by immunohistochemistry (IHC) and Western blot (WB) analysis, the expression of the main related autophagy proteins (Beclin 1, protein light chain 3 (LC3) and P62), in 35 BPV1/2 positive equine sarco...
Munday JS, Orbell G, Fairley RA, Hardcastle M, Vaatstra B.Equine sarcoids are common mesenchymal neoplasms of horses that are caused by cross-species infection by . While bovine papillomavirus (BPV) 1 and 2 are the most common causes, there are differences between countries regarding which of these BPV types cause the majority of sarcoids. Additionally, no causative PV can be detected in a subset of sarcoids, suggesting that other PV types could be rarer causes of these neoplasms. In the present study, consensus PCR primers and PCR primers specific for the five types currently known to cause mesenchymal neoplasia (BPV1, BPV2, BPV13, BPV14, and Ovis ...
Munday JS, Gedye K, Daudt C, Chaves Da Silva F.Bovine papillomavirus (BPV) types 1 and 2 are recognized as the main cause of equine sarcoids. However, some studies report that up to a quarter of these tumors do not contain detectible BPV1 or BPV2 DNA. The absence of detectible BPV1 or BPV2 in these sarcoids suggests the possible involvement of other papillomavirus types. Currently, five are recognized to cause mesenchymal neoplasia after cross-species infection. In addition to BPV1 and BPV2, BPV13 has been associated with equine sarcoids in Brazil, BPV14 has been associated with feline sarcoids, and Ovis aries papillomavirus 2 caused a sa...
Michishita M, Shibata R, Machida Y, Matsumoto M, Ochiai K, Azakami D.A 20-year-old Dutch Warmblood gelding was referred with clinical signs of anorexia, weight loss, intermittent fever, cough, subcutaneous oedema and exercise intolerance. Haematological examination revealed the presence of blast cells, decreased lymphocytes, mild thrombocytopenia and anaemia but no leucocytosis. Serum analyses detected elevated aspartate aminotransferase and gamma-glutamyl transferase activities and triglyceride concentrations. Twenty-two days after the initial visit, the horse died after showing clinical signs of decreased appetite, increased body temperature, tachypnoea and t...
Zehetner V, Cavalleri JV, Klang A, Hofer M, Preining I, Steinborn R, Ramsauer AS.There is strong evidence that equine parvovirus-hepatitis (EqPV-H) is associated with the onset of Theiler's disease, an acute hepatic necrosis, in horses. However, the impact of this virus on other hepatopathies remains unknown. The objective of this retrospective study was to evaluate the prevalence and quantify the viral loads of EqPV-H in formalin-fixed, paraffin-embedded equine and donkey livers with various histopathologic abnormalities. The pathologies included cirrhosis, circulatory disorders of the liver, toxic and metabolic hepatic diseases as well as neoplastic and inflammatory dise...
Traver DS, Moore JN, Thornburg LP, Johnson JH, Coffman JR.An aged gray stallion was examined because of fullminating posterior paresis, bladder paralysis, and perineal anesthesia. Lower motor neuron dysfunction was detected at the lumbosacral level of the spinal cord, and cerebrospinal fluid was yellow. After brief supportive treatment, the horse died. Necropsy revealed a single epidural melanoma at L5-6. The absence of cutaneous melanotic growth, absence of organ involvement, and extensive vertebral remodeling indicated the neoplasm to have been primary and to have been present for an extended period. Neurologic dysfunction was acute and progressive...
Bacci B, Stent AW, Walmsley EA.Lymphoma is the most common intestinal neoplasm in horses, but its clinical-pathological features are poorly characterized. Primary intestinal lymphoma was diagnosed in 20 horses on biopsy samples and further confirmed by postmortem examination in 16 cases. Lymphoma was found in the small intestine in 12 of 20 (60%), in the colon in 5 of 20 (25%), and in both small and large intestines in 3 of 20 (15%) cases. Gross findings included thickening of the intestinal wall (45%), mural nodules or masses (30%), and both thickening and nodules (10%). Cases were classified according to the human World H...
Johns I, Stephen JO, Del Piero F, Richardson DW, Wilkins PA.Hemangiosarcoma is a rare neoplasm of horses and hemangiosarcoma in young horses might behave differently than in mature horses. The purpose of this study was to identify the characteristics of hemangiosarcoma occurring in horses < or = 3 years of age. Medical records from 1982 to 2004 were searched for horses < or = 3 years of age with a histopathologic diagnosis of hemangiosarcoma. Eleven records were identified. Thoroughbred and Thoroughbred crosses predominated. Age ranged from 9 days to 3 years. All horses presented with cutaneous or leg swellings or joint effusion. Physical examina...
Miller CA, Durham AC, Schaffer PA, Ehrhart EJ, Powers BE, Duncan CG.Equine cutaneous lymphoma is an uncommon disease that can present with variable clinical signs, immunosuppression, and rapid systemic disease progression. Various subtypes of equine lymphoma have been described and classified according to a veterinary adaptation of the World Health Organization classification system, but little data is available regarding the association between lymphoma subtypes and epidemiological criteria and/or clinical outcome. The objective of the current study was to classify previously diagnosed cases of equine cutaneous lymphoma and correlate subtypes with clinical da...
Luethy D, Habecker P, Murphy B, Nolen-Walston R.Pheochromocytoma is the most common adrenal medullary neoplasm of domestic animals, but it is rare in horses. Antemortem diagnosis in horses is difficult, with clinical signs often being vague or non-specific. Objective: The objective of this study was to describe the clinical, laboratory, and pathologic findings of pheochromocytoma in horses. Methods: Thirty-seven horses diagnosed with pheochromocytoma based on postmortem examination from 2007 to 2014. Methods: Retrospective case series. Results: Pheochromocytoma was identified in 37/4094 horses during postmortem examination. Clinical signs c...
Dalefield RR, Palmer DN.Thyroid tumours have been described as "moderately common" in horses, but diseases associated with them are rare and the actual incidence has not been reported. A survey of thyroids from 29 horses aged 12 to 32 years revealed gross lesions in 11 animals, all older than 17. Most lesions were microfollicular adenomas. There was no evidence that the horses suffered from long-standing iodine deficiency or diffuse hyperplasia. Adenomas were more common than hyperplastic nodules and it is unlikely that the former arose from the latter. One thyroid adenocarcinoma was discovered. Progression from thyr...
James KE, Smith WA, Conrad PA, Packham AE, Guerrero L, Ng M, Pusterla N.OBJECTIVE To describe the general seroprevalence of anti-Sarcocystis neurona and anti-Neospora hughesi antibodies among healthy equids by use of indirect fluorescent antibody tests and determine potential risk factors for seropositivity. DESIGN Cross-sectional study. SAMPLE Whole blood samples collected from 5,250 equids (1 sample/animal) across 18 states in the United States during October 2013. PROCEDURES Information regarding potential risk factors (geographic region, breed, primary use, sex, and age) was collected along with the blood samples. For each equid, an indirect fluorescent antibo...
Underwood C, van Eps AW, Ross MW, Laverman P, van Bloois L, Storm G, Schaer TP.Liposomes are phospholipid nanoparticles that extravasate at sites of increased vascular permeability. They have potential in equine medicine for targeted drug delivery and diagnostic imaging of infectious, inflammatory and neoplastic lesions. Objective: This study evaluates the safety and biodistribution of i.v. polyethyleneglycol(PEG) liposomes in normal horses. Methods: PEG-liposomes were prepared by the film hydration method and labelled using (99m) Tc-hexamethyl-propylene-amine-oxime. A single dose of 0.24 µmol/kg bwt (99m) Tc-PEG-liposomes and 2.4 µmol/kg bwt unlabelled PEG-liposomes...
Tesena P, Kingkaw A, Vongsangnak W, Pitikarn S, Phaonakrop N, Roytrakul S, Kovitvadhi A.Equine melanocytic neoplasm (EMN) is a cutaneous neoplasm and is mostly observed in aged grey horses. This preliminary study aimed to identify potential proteins to differentiate normal, mild and severe EMN from serum proteomic profiling. Serum samples were collected from 25 grey horses assigned to three groups: normal (free of EMN; = 10), mild ( = 6) and severe EMN ( = 9). To explore the differences in proteins between groups, proteomic profiling and analysis were employed. Accordingly, 8241 annotated proteins out of 8725 total proteins were compared between normal and EMN groups and inspect...
Dobromylskyj MJ, Copas V, Durham A, Hughes TK, Patterson-Kane JC.A 9-year-old Haflinger mare presented to the Liphook Equine Hospital with a history of weight loss, azotemia, and repeated episodes of ascites over a period of 10 days. The horse was euthanized after exploratory laparotomy revealed large numbers of variably sized masses distributed throughout the peritoneal cavity. Macroscopically, some masses were papillary, while others were nodular. Histologically, the masses were comprised of large to giant, variably shaped, and occasionally multinucleated neoplastic cells with marked anisokaryosis and anisocytosis and a high mitotic rate. Small to moderat...
Pawlina-Tyszko K, Gurgul A, Szmatoła T, Ropka-Molik K, Semik-Gurgul E, Klukowska-Rötzler J, Koch C, Mählmann K, Bugno-Poniewierska M.Although they are the most common neoplasms in equids, sarcoids are not fully characterized at the molecular level. Therefore, the objective of this study was to characterize the landscape of structural rearrangements, such as copy number variation (CNV) and copy neutral loss of heterozygosity (cnLOH), in the genomes of sarcoid tumor cells. This information will not only broaden our understanding of the characteristics of this genome but will also improve the general knowledge of this tumor and the mechanisms involved in its generation. To this end, Equine SNP64K Illumina microarrays were appl...
Zicker SC, Wilson WD, Medearis I.The medical records of 25 horses with intra-abdominal neoplasms and 15 horses with intra-abdominal abscesses were reviewed. Common clinical signs of disease observed by owners of horses in both groups included anorexia, weight loss, fever, signs of colic, and depression. Clinical laboratory abnormalities included leukocytosis, hyperfibrinogenemia, hypoalbuminemia, and hypocalcemia. There was considerable overlap of laboratory test results within and between the 2 groups of horses. Peritoneal fluid was classified as an exudate in 12 of 15 horses with intra-abdominal abscesses and in 14 of 25 ho...
Foley GL, Valentine BA, Kincaid AL.In a retrospective study, cutaneous melanocytic tumors from 18 horses, less than 2 years old, were examined histopathologically and clinical follow-up requested. Melanocytomas (benign melanomas) occurred in a variety of breeds and in horses of varied coat color. The age of the horses at the time of biopsy ranged from 3 weeks old to 2 years old. Four melanocytomas were congenital, 11 melanocytomas were acquired by 1 year of age, and three were acquired prior to 2 years of age. Of the 18 horses, five were male, and 13 were female. All tumors were solitary and located on the legs or trunk; none w...
Pettersson CM, Broström H, Humblot P, Bergvall KE.Equine sarcoids are the most prevalent skin neoplasm in horses worldwide. Although several treatments are available, none are consistently effective and recurrence is common. Objective: To evaluate the efficacy and safety of topical imiquimod 5% cream and Sanguinaria canadensis + zinc chloride for treatment of equine sarcoids and investigate possible systemic effects on distant untreated sarcoids. Unassigned: Twenty-five client-owned horses with a total of 164 tumours were included in the study. Fifty-seven tumours were treated and 107 tumours were left untreated. Methods: Skin biopsy sample...
Mair TS, Taylor FG, Pinsent PJ.Fever of unknown origin (FUO) is a syndrome characterised by prolonged, unexplained fever associated with non-specific signs of illness such as lethargy, inappetence and weight loss. This paper reviews the details of 63 horses affected by FUO. The cause was found to be infection in 43 per cent of the cases, neoplasia in 22 per cent, immune-mediated diseases in 6.5 per cent and miscellaneous diseases in 19 per cent; the cause remained undiagnosed in 9.5 per cent.
Nelissen S, Miller AD.Granulosa cell tumors (GCTs) are common ovarian neoplasms in the mare and bitch that can be challenging to diagnose on histopathology. Inhibin has long been the standard immunohistochemical (IHC) marker for GCTs; however, anti-Müllerian hormone (AMH) has not been evaluated widely as an IHC marker in the bitch and mare. We compared the efficacy of AMH and inhibin as IHC markers in canine and equine GCTs. We selected retrospectively 18 equine and 15 canine cases. All equine tumors were dominated by a cystic pattern; canine tumors often had solid patterns. Both inhibin and AMH had similar puncta...
Patrick DJ, Kiupel M, Gerber V, Carr EA.A 2-year-old female Miniature Horse that presented with a history of progressive weight loss, depression, and diarrhea was diagnosed at necropsy with a highly malignant abdominal neoplasm involving the left ovary, kidneys, adrenal glands, intestines, and various abdominal and thoracic lymph nodes. Microscopic examination of these masses revealed large pleomorphic cells that stained positive for vimentin and inhibin and negative for epithelial membrane antigen and placental alkaline phosphatase. Ultrastructural examination of the cells revealed a high nucleocytoplasmic ratio and indented euchro...
Murphy B, Bell C, Koehne A, Dubielzig RR.Odontoameloblastoma (OA) is a mixed odontogenic tumor that is an ameloblastoma with concurrent histologic evidence of odontoma differentiation. As a mixed tumor, OA is a tripartite lesion comprised of neoplastic odontogenic epithelium, induced dental ectomesenchyme (dental pulp), and mineralized dental matrix. Although rare, OA represents a diagnostic conundrum, as it is histologically closely related to 2 other mixed odontogenic tumors: odontoma (complex and compound) and ameloblastic fibro-odontoma. Herein we describe an OA arising from the mandible of a 4-mo-old Fischer 344 rat that had bee...
Hamir AN, Tornquist SJ, Gerros TC, Topper MJ, Dubey JP.Equine protozoal myeloencephalitis (EPM) was clinically diagnosed in a 20-year-old horse with severe ataxia. The cerebrospinal fluid was positive for Sarcocystis neurona antibodies by western blot. The horse was administered corticosteroids to facilitate in vitro culture of S. neurona from its spinal cord following necropsy. Microscopic lesions of EPM were present in the brain and in the spinal cord, including multifocal inflammatory cellular infiltrates and several large groups of protozoa. Immunohistochemical, and light and electron microscopic examinations revealed that the protozoa were Ne...
Morris DD, Beech J.Disseminated intravascular coagulation (DIC) was diagnosed as a secondary disease in 6 horses. Four horses had localized and/or systemic sepsis, one horse had disseminated neoplasia, and one had idiopathic ulcerative enteropathy. The diagnosis of DIC was based on the finding of at least 3 of 4 abnormalities: thrombocytopenia, prolonged prothrombin time, prolonged activated partial thromboplastin time, and a high concentration of fibrinolytic degradation products. The most common clinical signs other than those attributable to the primary disease process were abnormal hemorrhage (4 hours) and v...
Hollis AR.Sarcoids are the most common cutaneous neoplasm of the horse, arising as a result of a neoplastic proliferation of fibroblasts associated with infection with bovine papillomavirus, most notably types 1 and 2. Although they do not metastasise, they are locally invasive and aggressive, and can lead to important welfare concerns, interfere with tack and therefore impede athleticism, and undoubtedly lead to a reduction in the value of affected horses. This review discusses the evidence behind the most commonly used treatments for equine sarcoids. The most commonly used treatments are discussed. No...
Castleman WL, Toplon DE, Clark CK, Heskett TW, Farina LL, Lynch TM, Bryant UK, Del Piero F, Murphy B, Edwards JF.This multi-institutional report describes 8 cases of rhabdomyosarcoma in horses. Four neoplasms were in the tongue and other areas of the mouth or head, 2 were in the abdominal wall, and 1 each was in right shoulder muscles and heart. Four rhabdomyosarcomas that were less than 10 cm in diameter were treated by surgical excision or radiation with no recurrence. Two neoplasms greater than 10 cm in diameter in the abdominal wall and the right shoulder were considered inoperable and led to decisions to euthanize the horses. Two neoplasms were incidental findings at necropsy. All the neoplasms were...
Eberhardt C, Malbon A, Riond B, Schoster A.CASE DESCRIPTION A 27-year-old Dutch Warmblood mare was evaluated because of a history of lethargy, reluctance to move, weight loss, persistent hyperproteinemia, and recurrent episodes of mild lameness. CLINICAL FINDINGS Hematologic evaluation revealed anemia (RBC concentration, 3.84 × 106 cells/μL), thrombocytopenia (47 × 103 thrombocytes/μL), and hyperproteinemia (total protein concentration, 11.2 g/dL) with hyperglobulinemia and hypoalbuminemia. Results of protein electrophoresis of serum and urine samples indicated a monoclonal gammopathy; the paraprotein was identified as a κ light c...
Szczerba-Turek A, Siemionek J, Ras A, Bancerz-Kisiel A, Platt-Samoraj A, Lipczynska-Ilczuk K, Szweda W.Equine sarcoids are the most common neoplasms in horses. Bovine papilloma- virus type 1 (BPV-1) is the main viral type identified in equine sarcoids in Europe. Objective: The aim of the present study was to genetically evaluate BPV types based on DNA analyses of the CDS of the L1 gene. The presence of BPV DNA was confirmed by Degenerate Oligonucleotide-Primed Polymerase Chain Reaction (DOP PCR) with FAP59/FAP64 consensus primers. Results: The DNA was detected in 21/40 (52.5%) of clinically diagnosed sarcoids. More than half of 14 isolates (66.7%) shared 100% homology with BPV-1 Deltapapillomav...
Kuwamura M, Shirota A, Yamate J, Kotani T, Ohashi F, Sakuma S.A thyroid gland tumor, showing unusual histology, was identified in a 13-year-old male Andalusian horse. Microscopically, the tumor consisted of neoplastic proliferation of C-cell (parafollicular cell) with cytoplasmic fine granules, containing diffusely distributed, variously sized colloid-containing follicles. Immunohistochemically, the neoplastic C-cell were positive for calcitonin and follicleforming epithelial cells showed a positive reaction for thyroglobulin. Ultrastructurally, membrane-bound secretory granules up to 250 nm in diameter were found in the cytoplasm of the parafollicular c...