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.
Martano M, Montagnaro S, Power K, Cuccaro B, Cutarelli A, Maiolino P, Restucci B.This study investigated the presence of δ bovine papillomaviruses (BPV-1, BPV-2, BPV-13, BPV-14) in equine skin lesions from Southern Italy, focusing on equine sarcoids and their histopathological correlations. 63 equine skin samples were analysed using PCR and sequencing for BPV detection, and their histopathological features were assessed. BPV DNA was detected in 69.84% of the samples, with BPV-1 and BPV-2 being the most prevalent genotype, followed by BPV-13, while BPV-14 was not detected. BPV DNA was also found in non-sarcoid tumours and non-neoplastic conditions. Histopathological analys...
Hellige M, Geburek F.Diagnostic imaging is an important part of the diagnostic approach in equine spinal ataxia especially with the cervical spine being commonly involved. The spinal cord may be affected by a variety of conditions including cervical vertebral malformations, osteoarthritis of the articular process joints or less commonly neoplasia. Advanced imaging techniques such as myelography are more accurate in diagnosing spinal cord compression and may be performed under general anesthesia in neutral, flexed and extended positions of the cervical spine. The use of ultrasound is non-invasive and allows ultraso...
Schollmeyer M, Liebler-Tenorio EM, Felton C, Kohl S, Ulrich R.A 34-year-old Haflinger gelding presented with a unilateral, expansile, intranasal mass that regrew after partial excision. After euthanasia, a large pedunculated mass that originated from the left caudal maxillary sinus and obliterated the left nasal cavity was seen by radiological and macroscopic examination. Histopathology revealed a poorly cellular, expansile, well-vascularized neoplasm composed of a loosely arranged meshwork of spindle cells and collagen fibres. Spindle cells were immunopositive for alpha-smooth muscle actin and occasionally for vimentin, whereas endothelial cells immunol...
Reinthaler B, Gabner S, Apprich V, Jehle M, Licka T.Equine hoof canker is a chronic proliferative condition of the hoof tissues that is often time-consuming and frustrating to treat. After surgical debridement, topical application of cisplatin (cis-Diamindichlorplatin II) has been reported, requiring repeatedly handling this hazardous substance during bandage changes. Alternatively, intraarterial application of cisplatin could be used, similar to the treatment of some human neoplastic diseases. As the side effects of such a treatment are currently unknown, evaluation of associated risks is necessary before treating live horses. Thus, forelimbs ...
Labens R, Saba C, Williams J, Hollis A, Ensink J, José-Cunilleras ELV, Jordana-Garcia M, Bergvall K, Ruppin M, Condon F, Spelta C, Elce Y....Intralesional chemotherapeutic administration represents an important treatment option for equine cutaneous neoplasia. Tigilanol-tiglate (TT), a novel molecule extracted from Fontainea picrosperma, an Australian rainforest plant, is registered for intratumoural treatment of canine MCT, leading to rapid oncosis and tumour slough. Evidence from horses is limited but suggests that efficacy may be similar. Objective: To evaluate the response to intratumoural TT treatment in horses with sarcoids (fibroblastic/nodular) and cutaneous melanomas. Methods: Two noncontrolled prospective multicentre clini...
Azari O, Ghamsari SM, Roustaei A, Golchin D, Baharloo F, Javaheri M, Valizadeh N.This report describes a case of massive renal cell carcinoma (RCC) causing mild chronic colic in a 20-day-postpartum Arabian mare. The mare presented with deteriorating abdominal pain following normal parturition. Clinical examination revealed tachycardia, tachypnoea, weak intestinal motility and pale mucosal membranes. Rectal examination identified a very large mass in the caudal part of the abdominal cavity, and abdominal ultrasound examination revealed a huge space-occupying mass with renal architecture. During midline exploratory laparotomy, a massive tumour was observed in the anatomical ...
Quatember H, Nell B, Richter B, Rigler D, Dolezal M, Sykora S, Wallner B.A missense mutation in damage-specific DNA binding protein 2 (DDB2 c.1013 C>T; p.Thr338Met) has been described as a risk factor for ocular squamous cell carcinoma (OSCC) in the Haflinger breed. Here, we examined the impact of DDB2 C>T allele status on the development of OSCC, squamous cell carcinoma (SCC) at other localisations, or equine sarcoid (ES) in Haflingers and other breeds with a high incidence of these tumour types. We genotyped affected Haflinger, Noriker, Warmblood, and Icelandic horses. Results based on 56 Haflingers confirmed the significantly higher risk for OSCC in DDB2-TT Hafl...
Ing ST, Pinard CL, James-Jenks EM, Leis ML.Our objective was to investigate the demographics and prevalence of ocular disease in a large referral population of horses in Ontario over a 10-year period. Unassigned: A retrospective analysis of medical records for 283 horses evaluated by Board-certified veterinary ophthalmologists at the Ontario Veterinary College (Guelph, Ontario) was conducted. Signalment and ocular disease were recorded. Unassigned: The 3 most common ocular abnormalities identified were uveitis (43.7%, 123 horses), ulcerative keratitis (42.0%, 119 horses), and cataract (25.1%, 71 horses). Uveitis was most often secondar...
Holz N, Suárez J, Hetzel U, Rampazzo A, Stoppini R.A 15-year-old Swiss Warmblood gelding was presented to the ophthalmology service of Zurich University due to severe visual impairment. Ophthalmic and neurologic examinations were performed, raising suspicion of post-retinal blindness. Standing contrast computed tomography (CT) of the head revealed a partially calcified, soft tissue attenuating mass in the sphenopalatine sinus with concurrent compression of the optic nerves and chiasm. Differential diagnosis included neoplasia and granulomatous disease. The horse was euthanized, and the head was subsequently examined by magnetic resonance imagi...
de Moura Alonso J, Apolonio EVP, Teng FS, Perandré PI, Amorim RL, Mazaro RD, Watanabe MJ, Alves ALG, Hussni CA.In horses, basal cell neoplasms are uncommon benign tumors with slow growth mostly reported in the skin and eyelid. Malignant presentation is even more uncommon. This report describes a basal cell carcinoma (BCC) in the periocular region of a 10-year-old donkey. The animal presented good body condition and a neoformation in the right eye, noted 3 months prior to hospital admission. At the ophthalmological examination, the mass was identified above and adhered to the cornea, measuring 3.0 × 2.5 × 1.5 cm. Cytology revealed a suspicion of a malignant epithelial neoplasm, characterized ...
Jacob O, Hause B, Peters-Smith K, Adam EN, Page AE, Floyd C, Tucker C, Eertink LG, Wang D, Li F.Equine sarcoids are the most identified skin tumors of horses, which are highly associated with bovine papillomavirus infection. Sarcoids can impair the use of the horse and are difficult to treat, resulting in significant economic losses and a welfare concern. There is no vaccine available to protect global equines from sarcoids. We aimed to determine the safety and protective antibody response in horses immunized with a recombinant baculovirus vector vaccine expressing the L1 protein of bovine papillomavirus type 1 (BPV1). A group of 10 clinically healthy, sarcoid-free horses were immunized ...
Johnson JP, Cardenas FA, Asakawa MG, Oikawa MA.Myofibroblastic fibrosarcoma (MFS) is a malignant soft tissue tumour that is rare in domestic animals. Here we report a case of congenital MFS in an Arabian foal at birth. A large solitary subcutaneous mass arising in the left temporal region was found in the foal. On cut section, an unencapsulated hemispheric, white-yellowish, elastic fibrous mass was attached to the temporal bone. Histologically, the mass was composed of a neoplastic proliferation of spindle-shaped fibroblasts arranged in fasciculate or interwoven streams and bundles, with low nuclear atypia and mitotic rate, local invasion ...
Resetic N, Comino F, Wilmink J, Gorvy DA.To report the management and outcomes of five horses with ear skin defects treated with the use of full-thickness mesh grafts and full-thickness Meek micrografts. Methods: Five horses with acute or granulating pinna skin wounds. Methods: Short case series. Methods: A full-thickness graft was harvested from the pectoral region under general anesthesia. The sheet graft was stretched on a sterile plastic board with the epidermal side facing down. The subcutaneous fat and fascia were removed by sharp dissection. The skin graft was then meshed by hand or using a block mesher, or manually cut into m...
Vinijkumthorn R, Kingkaw A, Yanyongsirikarn P, Phaonakrop N, Roytrakul S, Vongsangnak W, Tesena P.Equine melanocytic neoplasm (EMN) represents a form of skin tumor observed predominantly in grey horses aged over 15 years. Despite its prevalence, current therapeutic and preventive strategies for EMN have been subject to limited investigation. This study endeavors to shed light on potential phosphoproteins present in equine serum and fecal samples, potentially linked to EMN, with a specific focus on functional interactions in EMN pathogenesis. We examined 50 samples (25 serum, 25 feces), divided into three groups based on EMN severity: normal (n = 16), mild (n = 18), and severe EMN (...
Larsen MME, Eriksson A, Impellizeri JA.To describe the procedure and outcome of electrochemotherapy (ECT) with bleomycin as a first-line treatment for bilateral ocular surface squamous neoplasia (OSSN) in the eye of a horse. Methods: A client-owned 5-year-old Haflinger gelding with limbal-conjunctival squamous cell carcinoma. Methods: During general and local anesthesia, injection of bleomycin in the ocular tumor was followed by electroporation, applied with a 15 mm needle electrode, needles held parallel to the ocular surface. Results: Treatment with ECT resulted in therapeutic electric pulses and complete tumor response with no...
Brunner S, Fürst AE, Jackson MA.Dermal melanoma is a common neoplastic disease in horses, which occurs particularly in gray horses. There are various local and systemic therapeutic approaches to treat this skin tumor. Vaccination with human tyrosinase, ONCEPT ® vaccine, is a newer type of systemic melanoma therapy. In this study, the effectiveness of this ONCEPT ® vaccine was retrospectively examined in eight treated horses. In half of the horses (4) a positive change in tumor growth in the sense of retardation, stagnation and, in one of these horses, even reduction in the size of the melanomas was observed. Of the rem...
Mau A, Keller SM, Kol A.Basophils are the rarest blood leukocyte in most healthy domestic mammals and the clinical significance of basophilia is poorly understood. Objective: To empirically determine magnitude thresholds for basophilia, identify its hematologic correlates, and identify associations between breeds, specific diseases, disease categories, organ systems, and basophilia in dogs, cats, and horses. Methods: CBCs and clinical information from dogs, cats, and horses were collected from the University of California-Davis School of Veterinary Medicine between 2000 and 2020. Relationships between basophil concen...
Robert MP, Buyck C, Tricaud C, Cousty M, Pujol R.To report a radical surgical technique for perianal melanomas involving the anal margin in standing horses. Methods: Observational retrospective study. Methods: Twenty client-owned horses presented for surgical excision of extensive (≥4 cm) perianal melanomas. Methods: Demographic data, surgical technique, intraoperative, immediate- and late-postoperative complications were reviewed. Results: All horses (median age 15, Q1-Q3 12 to 17.3 years) were operated under standing sedation and epidural anesthesia. Median hospitalization period was 6.5 days (Q1-Q3 5 to 8.3 days). The anal margi...
Apolonio EVP, Gobbo LL, Woiblet NG, Dinau FC, Pyles MS, Ferrari LC, de Moura Alonso J, Alves ALG.Vascular hamartoma is an abnormal development of endothelial tissue that rarely affects horses. Histopathological examination remains the gold standard for definitive diagnosis, yet the presence of abnormal vascular structures must be carefully differentiated from other vascular anomalies and neoplasms. This report describes two cases of vascular proliferation affecting the skin on the lateral side over the left tarsus and the dorsolateral region over the fetlock joint of two fillies. The clinical history, presentation, and radiographic and sonographic findings in both patients suggested a neo...
Labelle AL, Gemensky Metzler AM, McMullen RJ, Wiggans KT, Labelle P, Hamor RE.To describe the clinical appearance, histopathology, and treatment of equine intraocular melanocytic neoplasia in adult horses. Unassigned: A retrospective review of medical records was conducted. Data recorded included signalment, ocular examination findings, physical examination findings, therapeutic interventions, and case outcomes. Histopathologic characteristics of enucleated globes were evaluated. A Student's -test was used to evaluate differences in the interval from diagnosis to last known outcome between horses receiving therapeutic interventions and horses undergoing monitoring alone...
Martano M, Power K, Cuccaro B, Razzuoli E, Maiolino P, Restucci B.The equine sarcoid is the most common skin neoplasia of fibroblastic origin in horses, characterized by an excessive accumulation of extracellular matrix produced by sarcoid fibroblasts under hypoxic condition. Neoplastic cells can adapt to hypoxia by using alternative energy sources, particularly those that arise from fatty acid oxidation (FAO). The Carnitine Palmitoyl Transferase 1A (CPT1A) belongs to Carnitine System (CS) and promotes the entrance of fatty acids into the mitochondria for β-oxidation. In this study, CPT1A expression was comparatively addressed in 25 equine sarcoids and 5 no...
Bulnes F, Argüelles D, Buzón A, García-Álamo K, Rodríguez-Gómez IM, Hernández E, Mozos E.This case report details a long-term follow-up of a hoof melanoma with dermo-epidermal activity (resembling Spreading Superficial Melanoma (SSM)) in a bay horse with a history of a right front hoof keratoma. Melanomas involving the horse's foot are seldom reported and usually diagnosed as anaplastic melanomas based on signalment and post-mortem examination. The clinical-pathological characteristics of the foot melanoma in this bay horse are consistent with SSM-like described in humans, which is considered an intermediate malignant tumour attending their biological behaviour. However, a definit...
Parkinson NJ, Ward A, Malbon AJ, Reardon RJM, Kelly PG.Equine sarcoids are common non-metastasising skin tumours in horses, associated with bovine papillomavirus (BPV) infection. Six subtypes are recognised (occult, verrucose, nodular, fibroblastic, mixed and malevolent lesions), with variable clinical behaviour. The pathophysiology underlying varying tumour phenotype is poorly understood, and previous data on associations with viral load have been conflicting. To better understand this clinical variation, we investigated associations between tumour subtype and viral load, viral early protein gene expression, and expression of 10 host genes by qua...
Carpenter AL, Townsend KS, Johnson PJ, Kim DY.An 8-y-old National Show Horse mare was presented for evaluation of pneumonia and laminitis. Harsh bronchovesicular sounds were auscultated throughout both lung fields, and the mare had signs of moderately painful laminitis. Thoracic ultrasonography revealed lung consolidation throughout the dorsal aspect of both lungs, and radiography revealed an extensive diffuse-to-patchy bronchointerstitial lung pattern. The mare's clinical condition rapidly deteriorated, and euthanasia was elected. On postmortem examination, the lungs, omentum, spleen, liver, adrenal glands, kidneys, and femur contained 0...
Fintl C, Wilkins PA.There are a number of unusual tumors in the horse. Gross tumor characteristics, anatomical location, and signalment may assist with identification. Clinical pathology is often unrewarding with non-specific findings, while fine needle aspirates may not obtain sufficient tissue material to confirm a diagnosis. Although regular staining of biopsy material may be sufficient, immunohistochemistry markers may be required, especially in less differentiated tumors. The prognosis is dependent on the type, location, tumor size as well as on metastatic spread. A selection of unusual and rare tumors that ...
Hollis AR.Melanomas are very common in older gray horses, with 80% of gray horses having at least 1 melanoma by 15 years of age. Historically considered a benign disease, it is now known that up to 66% of lesions will eventually metastasize. Melanomas may also cause local problems due to abscessation, ulceration, and interference with function of the affected areas. Treatment can be limited by size and location, but surgical resection, where possible, is likely to be the treatment of choice.
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.
Samuels A, Burns TA.Lymphoma and myeloproliferative diseases in horses are relatively uncommon. The clinical signs, prognosis, and treatment options depend upon the anatomic location and subtype. Significant gaps in knowledge remain regarding prevalence, pathogenesis of different subtypes, antemortem diagnostic tests, response to treatment, and standardized treatment protocols. However, treatment options are available, accessible on the farm, and could improve quality of life and prolong survival.
Fiske-Jackson A.Equine neoplasia poses challenges in surgical management owing to their diverse locations and potential for aggressive behavior. Surgical interventions aim for complete excision while minimizing cosmetic and functional impairments. Techniques such as laser ablation and electrochemotherapy offer minimally invasive options for accessible tumors. For deeper or larger masses, surgical excision with adequate margins remains the gold standard. Preoperative biopsy and imaging guides surgical planning, ensuring complete tumor removal while preserving vital structures. Close adherence to a strict surgi...
Ivens P, South V.Thoracic neoplasia often presents with generalized and nonspecific clinical signs and should be considered as a differential especially when patients are nonresponsive to therapeutic intervention for more common differential diagnoses of respiratory disease (such as equine asthma) and where there is evidence thoracic and/or abdominal effusion upon examination. Antemortem diagnosis can be challenging and working closely with a pathologist to differentiate the respective neoplasia is helpful. Early recognition and appropriate management of thoracic neoplasia are vital for patient welfare as rap...
Taylor SD, Haldorson GJ, Vaughan B, Pusterla N.Gastric neoplasia of horses is incompletely described. Objective: Provide history, clinical signs, and clinicopathological and pathological findings associated with gastric neoplasia in horses. Methods: Twenty-four horses with gastric neoplasia. Methods: Retrospective study. History, clinical signs, and clinicopathological and pathologic findings in horses diagnosed histologically with gastric neoplasia were reviewed. Results: Horses ranged in age from 9 to 25 years (median 18 years at presentation). There was no apparent breed or sex predisposition. The most common presenting complaints were ...
Murray DR, Ladds PW, Campbell RS.Lesions encountered in a clinicopathological study of cutaneous lesions resembling 'swamp cancer' from horses in North Queensland included 37 cases of subcutaneous phycomycosis, 5 of which were also infected with Habronema sp larvae. In addition 9 cases of primary cutaneous habronemiasis, 58 sarcoids, 12 fibromas, 8 fibrosarcomas, 10 squamous cell carcinomas, 4 haemangiomas, 3 melanomas, 1 papilloma, 1 palpebral adenocarcinoma and 7 cases of simple granulation were diagnosed. Subcutaneous phycomycosis resulted in the most extensive lesions. These were rapidly growing and provided the poorest p...
Borzacchiello G, Mogavero S, De Vita G, Roperto S, Della Salda L, Roperto F.The equine sarcoid is the most common dermatologic neoplasm reported in horses. Bovine papillomavirus (BPV) types 1 and 2 are associated with sarcoids, in which the expression of the major transforming oncoprotein (E5) is often recorded. The transformation activity of the virus is due to the binding of the E5 to the platelet-derived growth factor beta receptor (PDGFbeta-r). In the present study, we show by Western blot in 4 sarcoid samples and 3 normal equine skin samples that the PDGFbeta-r is more phosphorylated in sarcoid tissue than in normal skin (P < .001). Furthermore, the physical i...
Pitel PH, Romand S, Pronost S, Foucher N, Gargala G, Maillard K, Thulliez P, Collobert-Laugier C, Tainturier D, Fortier G, Ballet JJ.Neospora caninum, an apicomplexan protozoan parasite, is recognized as a major cause of abortion in cattle while limited information is presently available on association between equine Neospora infections and abortions. The aim of the present study was to document prevalence of antibodies against Neospora sp. in aborted mares as a clue to the role of N. caninum in mare reproductive failure in Normandy, France. Using an agglutination test, the number of animals with elevated (>80) anti-Neospora sp. antibody titer was higher in a group of 54 aborted mares than in randomly chosen groups of 45 ma...
Peiffer RL, Wilcock BP, Yin H.Histologic examination was made of 1,419 globes from domestic animals (964 dogs, 374 cats, 41 horses, and 40 cattle) with ocular disease; pre-iridal membranes (rubeosis iridis) were found in 98. The membranes originated as endothelial budding from the anterior iridal stroma and seemed to mature into fibrous or fibrovascular membranes that were often followed by hyphema or, occasionally, glaucoma. Pre-existent disease in the 98 affected globes included chronic endophthalmitis (27/98), chronic glaucoma (24/98), anterior uveal melanoma (15/98), ciliary body adenoma (14/98), neoplasms metastatic t...
Taylor SD, Pusterla N, Vaughan B, Whitcomb MB, Wilson WD.Intestinal neoplasia of horses is inadequately described. Objective: Intestinal neoplasia of horses has characteristic clinicopathologic features. Methods: Thirty-four horses with intestinal neoplasia. Methods: Retrospective study. Results: Anamnesis, clinical signs, clinicopathologic and pathologic findings in 34 adult horses diagnosed histologically with intestinal neoplasia were reviewed. The horses ranged in age from 2 to 30 years (mean 16.6 years at presentation). The Arabian breed was most represented and there was no sex predisposition. The most common presenting complaints were weight ...
Ramos-Vara JA, Frank CB, DuSold D, Miller MA.The immunoreactivity of PNL2, Melan A, and protein gene product (PGP) 9.5 was compared with that of S100 protein in 50 formalin-fixed, paraffin-embedded equine melanocytic neoplasms. PNL2, PGP 9.5, and S100 protein were detected in all 50 neoplasms; none expressed Melan A. PNL2 was not expressed in 62 nonmelanocytic tumors (equine sarcoids, schwannomas, carcinomas, sarcomas, endocrine tumors, sex-cord stromal tumors, germ cell tumors, and leukocytic tumors) or in normal tissues other than epidermis. In summary, antibody PNL2 is a sensitive marker of equine melanocytic neoplasms and is more spe...
Tyler CM, Davis RE, Begg AP, Hutchins DR, Hodgson DR.Case records of 450 horses with signs of neurological disease are reviewed. One hundred and nineteen horses with neurological disease due to trauma were examined, of which 60 were due to spinal cord trauma, 47 to brain or cranial nerve trauma and 12 to peripheral nerve trauma. Cervical vertebral fractures/trauma were the most common injury. Basisphenoid/basioccipital bone fractures were the most common form of cranial trauma and facial nerve paralysis the most common cranial nerve injury. Eighty-nine horses with neurological disease due to malformation were examined. Cervical vertebral malform...
Haralambus R, Burgstaller J, Klukowska-Rötzler J, Steinborn R, Buchinger S, Gerber V, Brandt S.Sarcoids are nonmetastasising, yet locally aggressive skin tumours that constitute the most frequent neoplasm in equids. Infection by bovine papillomaviruses types 1 and 2 (BPV-1, BPV-2) has been recognised as major causative factor in sarcoid pathogenesis, but a possible correlation of intralesional virus load with disease severity has not been established thus far. Objective: Given the pathogenic role of BPV-1 and BPV-2 in sarcoid disease, we suggest that intralesional viral DNA concentration may reflect the degree of affection. Methods: Severity of disease was addressed by recording the tum...
van der Kolk JH, Kalsbeek HC, van Garderen E, Wensing T, Breukink HJ.The records of 21 horses with an adenoma of the pars intermedia of the pituitary gland were reviewed. The animals comprised nine Dutch warmblood horses and 12 ponies. They ranged in age from 12 to 30 years (mean +/- sem 21 +/- 1.3 years) for 20 of the horses, and comprised 13 geldings and eight mares. All the animals showed hirsutism. In 1991, nine horses were diagnosed as having the adenoma, equivalent to 0.5 per cent of the horses examined in 1991. The mean +/- sem survival time of four of the horses (from discharge to the development of complications which required euthanasia) was 192 +/- 5...
Mair TS, Walmsley JP, Phillips TJ.The medical records of 45 horses treated for suspected squamous cell carcinoma of the penis and/or prepuce were reviewed. The age of 40 horses was known, and these had a mean age of 17.4 years. The duration of neoplasia was known for only 3 of the 45 horses. The results of histological evaluation of lesions, available for 35 horses, confirmed that the diseased tissue was squamous cell carcinoma. The location of gross neoplastic lesions was recorded for 43 horses; the glans penis was involved in 24 horses, the body of the penis or the inner lamina of the preputial fold in 27 horses, and the ext...
Muñoz A, Riber C, Trigo P, Castejón F.Leukemia, i.e., the neoplasia of one or more cell lines of the bone marrow, although less common than in other species, it is also reported in horses. Leukemia can be classified according to the affected cells (myeloproliferative or lymphoproliferative disorders), evolution of clinical signs (acute or chronic) and the presence or lack of abnormal cells in peripheral blood (leukemic, subleukemic and aleukemic leukemia). The main myeloproliferative disorders in horses are malignant histiocytosis and myeloid leukemia, the latter being classified as monocytic and myelomonocytic, granulocytic, prim...
Strafuss AC.In a review of neoplasm registry records at Kansas State University (1961 through 1971), 58 squamous cell carcinomas were reported in 10 breeds of horses. Mean age of the affected horses was 12.4 years. The head, eye and ocular adnexa accounted for 43.1%, the external male genitalia, 44.8%, and female perineal region, 12.0% of the squamous cell carcinomas, altogether representing 20.2% of 287 neoplasms recorded.
Davidson HJ, Blanchard GL, Wheeler CA, Render JA.Intraocular melanoma was diagnosed in a 13-year-old horse. Secondary clinical findings included keratitis, cataract, and glaucoma. The eye was enucleated. Follow-up information did not give an indication of metastatic disease.
Ciaramella P, Corona M, Cortese L, Piantedosi D, Santoro D, Di Loria A, Rigato R.One hundred and fifty horses from Italy were tested for serum antibodies to Neospora caninum by indirect fluorescence antibody test (IFAT). Antibodies were present in 42 horses (28%). The positive titres were: 1:50 (16/150-10.5%), 1:100 (26/150-17%), 1:200 (8/150-5.3%) and 1:800 (1/150-0.6%). No neurological anomalies were observed in the seropositive horses. This is the first serologic survey for Neospora spp. antibodies performed on horses born and raised in Italy.
Lehmbecker A, Liebing J, Barthel Y, Habierski A, Cavalleri J, Puff C, Rademacher B, Lumpe S, Beineke A.Neurolymphomatosis is a rare manifestation of lymphoma and is characterized by neoplastic infiltration of the peripheral nervous system. The present report describes neoplastic infiltration of peripheral nerves in three horses with multicentric lymphoma. Immunohistochemistry revealed the presence of CD79a(+) lymphoblastic cells and well-differentiated CD3(+) T cells, characteristic of T-cell-rich B-cell lymphoma in all cases. Nerve infiltration by lymphoma is rare, but should be considered as a differential diagnosis for peripheral neuropathy in horses with lymphoma.
McCauley CT, Hawkins JF, Adams SB, Fessler JF.To determine outcome of horses in which cutaneous masses were removed with a carbon dioxide laser. Methods: Retrospective study. Methods: 32 horses. Methods: Medical records of horses with 1 or more cutaneous masses treated with a carbon dioxide laser were examined. Follow-up information was obtained through telephone interviews with owners and referring veterinarians. Results: Cutaneous masses were classified as sarcoids (15 horses), neoplastic masses other than sarcoids (squamous cell carcinoma [91; fibroma [1]; and melanoma [1]), and nonneoplastic masses (6). Minimum follow-up time was 6 mo...
Takeuchi K, Hagiwara Y, Kanaya K, Wada K, Shiba M, Kato Y.The diagnosis of pituitary carcinoma cannot be made easily histologically, and most cases of pituitary carcinoma are diagnosed only after the clinical detection of metastasis. Distant metastasis of pituitary tumor occurs in 0.1% to 0.2% of cases and has been reported in the liver, bone and central nervous system, with only one case of metastasis to the cauda equine reported. This study describes a rare case of the drop metastasis of adrenocorticotropic hormone-producing pituitary adenocarcinoma to the cauda equina, causing cauda equina syndrome.
Löhr CV, Juan-Sallés C, Rosas-Rosas A, Parás García A, Garner MM, Teifke JP.Sarcoids were diagnosed in two captive zebras from different facilities. Zebra 1 (Equus burchellii boehmi) was a 4.5-yr-old, captive-born male that presented with a 9- by 7-cm inguinal mass. Seven months after surgical excision of the inguinal mass, the zebra presented with a similar lesion in the right upper eyelid that has relapsed repeatedly and has not responded to treatment including local cisplatin injections and cryosurgery. Zebra 2 (of undetermined taxon) was housed at a private wild animal farm. The zebra presented with a single, raised, 2.5- by 2.0- by 2.0-cm, ulcerated mass on the n...
Potocki L, Lewinska A, Klukowska-Rötzler J, Bugno-Poniewierska M, Koch C, Mählmann K, Janda J, Wnuk M.It is widely accepted that equine sarcoid disease, the most common skin associated neoplasm in equids, is induced by bovine papillomavirus (BPV-1). Although BPV-1 DNA has been found in almost all examined sarcoids so far, its detailed impact on the horse's host cell metabolism is largely unknown. We used equine fibroblast cell lines originating from sarcoid biopsies to study BPV-1-associated changes on DNA methylation status and oxidative stress parameters. Sarcoid-derived fibroblasts manifested increased proliferation in vitro, transcriptional rDNA activity (NORs expression) and DNA hypometh...
Baker JR, Leyland A.In a histological survey of 244 tumerous growths from 155 horses, the tumours commonly found were fibromas, squamous cell carcinomas, sarcoids and papillomas, most frequently affecting the skin, external genitalia, eye and orbit. The histological features that differentiate fibroblastic citaneous growths are detailed so that the clinical behaviour of these distinct neoplasms can be studied.
Antonello AM, Pivoto FL, Camillo G, Braunig P, Sangioni LA, Pompermayer E, Vogel FS.Neospora spp. is a intracellular protozoan phylogenetically closely related to Toxoplasma gondii and Sarcocystis neurona, and it can infect horses leading to the development of reproductive or neurological diseases. We determined the presence of antibodies to Neospora sp. in mares at their parturition time and determine the frequency of vertical transmission in healthy foals to verify the importance of transplacental transmission. The samples were analyzed by indirect immunofluorescence antibody test, showing that seroprevalence in mares is higher than in foals and seropositive mares are likel...
Boujon CE, Bestetti GE, Meier HP, Straub R, Junker U, Rossi GL.Clinico-pathological correlations in horses with pituitary adenomas are poorly understood. This paper describes the functional and morphological features of five cases of equine pituitary adenoma and of a case of multinodular pituitary hyperplasia. New findings reported include immunoreactivity for beta-lipotropin (beta-LPH), beta-melanocyte-stimulating hormone (beta-MSH), gamma 3-MSH, prolactin (PRL), and follicle-stimulating hormone (FSH) in neoplastic cells of the pituitary adenoma; and, in the multinodular hyperplasia, beta-LPH, beta-endorphin (beta-END), alpha-MSH, beta-MSH, gamma 3-MSH a...
Howarth S, Lucke VM, Pearson H.A retrospective analysis was performed on 48 cases of suspected neoplasia involving the equine external genitalia. Forty nine squamous cell carcinomata (SCC) and 23 squamous papillomata (SP) were identified. Two cases of epithelial hyperplasia and one case of habronemiasis were also recognised histopathologically. The glans penis was the most common site of tumour development accounting for 53 per cent of cases of SCC and 61 per cent of SP. The urethral diverticulum, urethral process or urethra was involved in 27.6 per cent (8/29) of cases of SCC. Twelve per cent (5/41) of cases of SCC were co...
West HJ.In horses with hepatic necrosis, lipidosis, neoplasia and cirrhosis, progression of the disease was studied by serial measurements of total serum bile acid concentrations and of plasma glutamate dehydrogenase (GD) and gamma glutamyl transferase (gamma GT) and by liver biopsy. Plasma ammonia concentrations were significantly elevated compared to clinically normal horses, but such changes were not always accompanied by a decline in plasma urea concentration. A fall in plasma glucose concentration carried a guarded prognosis. These were all invaluable aids in early diagnosis and throughout the di...
Southwood LL, Schott HC, Henry CJ, Kennedy FA, Hines MT, Geor RJ, Hassel DM.Thirty-five cases of disseminated hemangiosarcoma (21 clinical cases and 14 previously reported cases) were reviewed to describe the disease in horses. Hemangiosarcoma occurred in mature, particularly middle-aged horses, with no apparent sex predilection. Thoroughbreds seemed to be overrepresented (13 cases) but a true breed predilection could not be established. The respiratory and musculoskeletal systems were most commonly affected and presenting complaints included dyspnea (26%), subcutaneous or muscular swelling (24%), epistaxis (17%), and lameness (12%). Heart and respiratory rates were u...
De Cock HE, MacLachlan NJ.Neoplastic and hyperplastic disorders that affect multiple endocrine tissues in a single individual are well described in humans but less so in domestic animals. Multiple endocrine neoplasia (MEN) in humans is a genetically determined syndrome characterized by the appearance of benign or malignant proliferations within two or more endocrine glands. The primary endocrine tumors that are characteristic of MEN arise from cells that share the capacity for amine precursor uptake and decarboxylation. Here we describe the case of a 22-year-old Thoroughbred mare that died during an unattended parturit...
Giuliano EA.Neoplastic adnexal disease represents one of the most frequently encountered and therapeutically challenging ophthalmic problems of horses. This paper reviews current concepts in equine periocular neoplasia. Specifically, a literature-based review of the aetiopathogenesis of the most common tumours to affect the equine eyelid (squamous cell carcinoma, sarcoid, melanoma and lymphosarcoma) is provided. Current and emerging treatment modalities, including photodynamic therapy, are reviewed.
Epperson ED, Castleman WL.Histopathologic differentiation between deep dermal or subcuticular equine sarcoids (ie, nodular sarcoids) and other spindle cell tumors in the dermis and subcutis such as peripheral nerve sheath tumors (PNSTs) can be challenging based on morphologic criteria alone. It has been proposed that polymerase chain reaction (PCR) for bovine papillomavirus (BPV) DNA and S100 immunohistochemistry be used as diagnostic tests to separate equine sarcoids from PNSTs. We reviewed 197 skin-associated spindle cell tumors (ie, soft tissue sarcomas), including PNSTs and sarcoids, received at the University of F...
