Disease diagnosis in horses involves the identification and characterization of illnesses through various diagnostic methods and tools. This process is essential for effective veterinary care and management of equine health. Techniques used in diagnosing diseases in horses include clinical examinations, laboratory tests, imaging modalities such as ultrasonography and radiography, and molecular diagnostics. Blood tests are frequently utilized to assess parameters such as complete blood count and biochemical profiles, which can indicate underlying health issues. Additionally, advancements in genetic testing and biomarker identification have enhanced the ability to detect specific diseases early. This page aggregates peer-reviewed research studies and scholarly articles that explore diagnostic methodologies, their applications, and their impact on equine health management.
Crijns CP, Martens A, Bergman HJ, van der Veen H, Duchateau L, van Bree HJ, Gielen IM.Computed tomography (CT) is increasingly accessible in equine referral hospitals. Objective: To document the level of agreement within and between radiography and CT in characterising equine distal limb fractures. Methods: Retrospective descriptive study. Methods: Images from horses that underwent radiographic and CT evaluation for suspected distal limb fractures were reviewed, including 27 horses and 3 negative controls. Using Cohen's kappa and weighted kappa analysis, the level of agreement among 4 observers for a predefined set of diagnostic characteristics for radiography and CT separately...
Hjertner B, Olofsson KM, Lindberg R, Fuxler L, Fossum C.There is accumulating evidence for the involvement of pro-inflammatory cytokines associated with a T helper 17 response in intestinal disorders such as inflammatory bowel disease (IBD) in humans. The involvement of interleukin (IL)-17 or IL-23 in equine IBD has not been studied and most gene expression studies in the equine intestine have been limited to the use of a single non-validated reference gene. In this study, expression of the reference gene candidates β2 microglobulin (β2M), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), histone H2A type 1, hypoxanthine-guanine phosphoribosyltra...
Menzies R.The oral examination is performed in equids to assess and monitor oral health status, provide diagnoses, and determine efficacy of treatments. While there is currently insufficient scientific material of adequate quality to enable evidence-based medicine in equine dentistry, this by no means negates the clinician's responsibility to provide oral health care in a scientific and ethical manner. To do so requires that the clinician be knowledgable and skilled in dentistry and general medicine, that each case upholds the principles of scientific method, and that data is gathered and appraised in a...
Na W, Kang B, Kim HI, Hong M, Park SJ, Jeoung HY, An DJ, Moon H, Kim JK, Song D.Equine influenza virus (EIV) causes a highly contagious respiratory disease in equids, with confirmed outbreaks in Europe, America, North Africa, and Asia. Although China, Mongolia, and Japan have reported equine influenza outbreaks, Korea has not. Since 2011, we have conducted a routine surveillance programme to detect EIV at domestic stud farms, and isolated H3N8 EIV from horses showing respiratory disease symptoms. Here, we characterized the genetic and biological properties of this novel Korean H3N8 EIV isolate. This H3N8 EIV isolate belongs to the Florida sublineage clade 1 of the America...
Hellander-Edman A, Makdoumi K, Mortensen J, Ekesten B.Corneal ulcers are one of the most common eye problems in the horse and can cause varying degrees of visual impairment. Secondary infection and protease activity causing melting of the corneal stroma are always concerns in patients with corneal ulcers. Corneal collagen cross-linking (CXL), induced by illumination of the corneal stroma with ultraviolet light (UVA) after instillation of riboflavin (vitamin B2) eye drops, introduces crosslinks which stabilize melting corneas, and has been used to successfully treat infectious ulcerative keratitis in human patients. Therefore we decided to study i...
Abutarbush SM.The objective of this observational study is to describe clinical, haematological and serum biochemical findings of horses affected with alfalfa dodder (Cuscuta campestris) toxicity. Twenty horses naturally exposed to alfalfa dodder toxicity were examined and information was collected on history and clinical signs. Physical examination was done on horses in the premises (n=20), and venous blood samples of 12 horses were submitted for haematology and serum biochemical examination for each horse. Abnormal clinical signs started around 36 hours after horses were fed the contaminated alfalfa. Abno...
Navas de Solis C, Slack J, Boston RC, Reef VB.To describe the prognosis and clinical, echocardiographic, and pathological features of hypertensive cardiomyopathy in horses. Methods: Retrospective case series. Methods: 5 horses with cardiac hypertrophy and systemic hypertension. Methods: Demographics, history, physical and cardiological examination findings, diagnosis, clinical progression, prognosis, and pathological findings were obtained from medical records. Results: The primary diagnosis was chronic laminitis in 3 horses and chronic renal failure in 2. Persistent tachycardia, hypertension, chronic laminitis, or a combination of these ...
Schuster RK, Sivakumar S.Equine habronematidosis has a global distribution and is caused by three spirurid species, Habronema muscae, Habronema microstoma and Draschia megastoma. A case of cutaneous habronematidosis in a stallion in a stable in Dubai, UAE gave occasion to investigate the parasite situation on the farm. Patent H. muscae infections were diagnosed in 18 out of 49 horses in a stable in Dubai, UAE with a xenodiagnostic test using houseflies as indicator host. All horses in the stable were treated with a single dose of moxidectin administered orally as 2% gel in a dosage of 0.4 mg/kg body weight and the eff...
Belgrave RL, Dickey MM, Arheart KL, Cray C.To compare serum amyloid A (SAA) concentration, plasma fibrinogen concentration, total WBC count, and serum albumin-to-globulin concentration ratio (A:G ratio) in clinically normal (CN) and clinically abnormal (CA) horses. Methods: Prospective cohort study. Methods: 111 CN horses and 101 CA horses hospitalized at a specialty clinical practice. Methods: Shortly after admission, a blood sample (20 mL) was collected from each horse for a CBC, serum protein electrophoresis, and determination of plasma fibrinogen concentration; SAA concentration was assessed with a previously validated immunoturbid...
Clarke L, Simon A, Ehrhart EJ, Mulick J, Charles B, Powers B, Duncan C.Mast cell tumors are uncommon in horses and typically have a benign clinical course, but there are occasional reports of more aggressive behavior. The objective of this study was to review histologic features and KIT expression patterns of 72 previously diagnosed equine cutaneous mast cell tumors to determine if either is associated with clinical outcomes. Biopsy specimens were reviewed using histologic criteria derived from grading schemes, and KIT antibody expression patterns used in canine tumors and surveys were sent to referring veterinarians for follow-up clinical data. Arabians were ove...
Spelta CW, Axon JE, Begg A, Diallo IS, Carrick JB, Russell CM, Collins NM.Equine multinodular pulmonary fibrosis (EMPF) is a recently described form of interstitial pneumonia associated with the presence of equine herpesvirus type 5 (EHV-5). Since 2007, several case reports from America, Europe and the United Kingdom have further characterised the clinical presentation and laboratory findings of this disease. Methods: Three Thoroughbred broodmares were diagnosed with EMPF. Diagnosis was based on lung histopathology and positive identification of EHV-5 using PCR DNA amplification. There was multiple organ involvement in all three cases, including identification of EH...
Pelkonen S, Lindahl SB, Suomala P, Karhukorpi J, Vuorinen S, Koivula I, Väisänen T, Pentikäinen J, Autio T, Tuuminen T.Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a zoonotic pathogen for persons in contact with horses. In horses, S. zooepidemicus is an opportunistic pathogen, but human infections associated with S. zooepidemicus are often severe. Within 6 months in 2011, 3 unrelated cases of severe, disseminated S. zooepidemicus infection occurred in men working with horses in eastern Finland. To clarify the pathogen's epidemiology, we describe the clinical features of the infection in 3 patients and compare the S. zooepidemicus isolates from the human cases with S. zooepidemicus isolates...
Knight CG, Dunowska M, Munday JS, Peters-Kennedy J, Rosa BV.Equus caballus papillomavirus type 2 (EcPV-2) infection has been associated with equine genital squamous cell carcinomas (SCCs). However, quantitative PCR (qPCR) has not been performed to determine viral copy numbers within these lesions. Additionally, the frequency with which EcPV-2 can be detected in other common sites of equine SCC development remains uncertain. The aim of this study was to develop a qPCR assay to estimate the viral load in a variety of equine tissue samples. These included 40 SCC lesions, 19 penile non-SCC or precursor disease lesions, and 222 tissues without observable le...
Soares IR, Silva SO, Moreira FM, Prado LG, Fantini P, Maranhão Rde P, da Silva Filho JM, Melo MN, Palhares MS.This study reports the first evidence of infection by Leishmania infantum in Equus caballus in Americas and the first mixed infection of L. infantum/Leishmania braziliensis on this mammalian species in the world. The diagnoses was based on presence of parasites in lesions and bone marrow aspirates, their identification by using specific primers for L. infantum and L. braziliensis complexes and also serological methods IFAT and ELISA. The analysis of the PCR products suggested mixed infection in three animals. Further studies involving equine leishmaniasis are carrying out in order to clarify t...
Dzięgiel B, Adaszek L, Winiarczyk M, García-Bocanegra I, Carbonero A, Dębiak P, Winiarczyk S.The aim of this study was to conduct a comparative analysis of the 16S rRNA gene fragment nucleotide sequences for Anaplasma phagocytophilum strains detected in the blood of horses from various parts of Europe. The study comprised 234 horses that had had contact with ticks. Using PCR, the genetic material of A. phagocytophilum was identified in the blood of 42 animals. The sequences of the 16S RNA gene amplicons that were obtained from our A. phagocytophilum isolates had 100 % similarity with each other and 96.4-100 % similarity with Anaplasma spp. sequences selected from those available i...
Hartley CA, Dynon KJ, Mekuria ZH, El-Hage CM, Holloway SA, Gilkerson JR.The evolutionary success of the equine gammaherpesviruses (GHVs) is demonstrated by their consistent and widespread presence in horse populations worldwide. Equine GHVs establish infection in young foals and can be continually detected over the lifetime of the host either by recrudescence of latent infections or by re-infection. A definitive diagnosis of clinical disease in horses due to GHV infection remains challenging given the ubiquitous nature of the GHVs in horses without clinical signs, as well as in horses with clinical signs ranging from mild respiratory disease to severe equine multi...
Barrett EJ, Munsterman AS, Hanson RR.To determine the effect of gastric distension on intraabdominal pressures (IAP) measured directly from the intraperitoneal space. Methods: Prospective, experimental study. Methods: A university-based equine research facility. Methods: Ten healthy adult horses, 5 males and 5 females. Methods: Intraabdominal pressures were measured through an intraperitoneal cannula zeroed at a height midway between the height of the tuber ishii and point of the shoulder at 6 time points: at rest, after placement of a nasogastric tube, and after instillation of each 5 L increment up to a total of 20 L of water. ...
Herbach N, Nagel L, Zwick T, Hermanns W.Pancreatic neuroendocrine tumors of glucagon-producing cells are extremely rare in domestic animals. In this report, we describe for the first time, to our knowledge, the incidental finding of multiple glucagon-producing neuroendocrine tumors of the pancreas of a horse. The animal was euthanized due to severe local infection after tooth extraction. On postmortem examination, multiple white nodules of up to 4 cm in diameter were observed in the pancreas. Histologically, pancreatic nodules had the appearance of neuroendocrine neoplasms with positive immunoreactivity for glucagon, synaptophysin, ...
Hildebrandt L, Jäger K, Snyder A, Sobiraj A.The case report describes a narrowing of the spinal canal in the lumbar and sacroiliac regions with entailing acute recumbency in a nearterm 17-year-old Welsh B Pony mare. The reason for recumbency was metastases of a malignant melanoma in the spinal canal of the lumbo-sacral region, where the tumour had invaded the dura mater and applied severe pression on the spinal cord over a length of 10 cm. Clinical findings, laboratory diagnostics, pathological-anatomical and histopathological findings are presented.
Lassaline-Utter M, Miller C, Wotman KL.To review the signalment, clinical characteristics, treatment, and outcome of equine EK cases in the Mid-Atlantic United States; to evaluate the effects of topical or systemic corticosteroid treatment, oral cetirizine treatment and secondary corneal infection on disease duration; and to evaluate the association between corticosteroid and cetirizine treatment and likelihood of recurrence. Methods: Twenty-seven horses (47 eyes) diagnosed with EK from 2008 to 2012. Methods: Retrospective medical record review followed by phone interview to obtain recurrence data. Results: Average age of affected ...
Hilla D, Distl O.In this study, the prevalences of osteochondral fragments in the distal (DUI) and proximal interphalangeal joints (PIJ) as well as in the fetlock, hock and stifle joints, of palmar/plantar osteochondral fragments in the fetlock joints (POFs) and of osteochondrosis dissecans (OCD) in fetlock, hock and stifle joints were estimated in a large sample of Hanoverian Warmblood horses. For this purpose, radiographic findings of 9478 Hanoverian Warmblood horses collected from 2005 to 2011 were analyzed. Overall 31.9% of the horses showed one or more osteochondral fragments in at least one joint. The fe...
Shon W, Folpe AL.Cartilaginous tumors of soft tissue are uncommon, with benign chondromas of soft parts greatly outnumbering rare soft-tissue chondrosarcomas. Over the past several years, we have seen in consultation a distinctive, benign-appearing chondroid soft-tissue lesion of the plantar foot that differs in a number of respects from chondroma of soft parts. Herein we report our experience with this distinctive lesion. A retrospective review of all cases from the foot in our soft-tissue consultation and institutional surgical pathology archives identified 9 similar cases, most often previously coded as 'fi...
Ireland JL, Wylie CE, Collins SN, Verheyen KL, Newton JR.This study aimed to describe the provision of preventive health care and owner-reported disease prevalence in horses and ponies within Great Britain (GB), and to assess geographical variations in health care provision. A cross-sectional survey was conducted, using a postal questionnaire administered to a random sample of veterinary-registered owners of horses and ponies in GB (n=797). The majority of animals received regular preventive health care: 95.6% had regular hoof care; 71.3% were vaccinated for both influenza and tetanus and median time since last anthelmintic administration was 8.7 we...
Tremaine H.The last decade has seen a number of studies that have illuminated our knowledge of hypsodont dental disease and re-examined some of the traditionally performed practices. In addition there has been a major interest in routine preventative dentistry and non-traumatic treatments. These have highlighted some potential risks of the use of modern tools when applied to traditional techniques. This has also led to a reflective review of equine dentistry with the emphasis on attempting to preserve and salvage dental and periodontal tissues, with minimal trauma. In addition, precise imaging and instru...
Gao X, Jiang CG, Wang XF, Lin YZ, Ma J, Han XE, Zhao LP, Shen RX, Xiang WH, Zhou JH.The contribution of S2 accessory gene of equine infectious anemia virus (EIAV) to the virulence of pathogenic strains was investigated in the present study by reverse mutation of all four consensus S2 mutation sites in an attenuated EIAV proviral strain, FDDV3-8, to the corresponding sequences of a highly pathogenic strain DV117. The S2 reverse-mutated recombinant strain FDDVS2r1-2-3-4 replicated with similar kinetics to FDDV3-8 in cultivated target cells. In contrast to the results of other studies of EIAV with dysfunctional S2, reverse mutation of S2 only transiently and moderately increased...
Wulf M, Wohlsein P, Aurich JE, Nees M, Baumgärtner W, Aurich C.Identification of horses by microchip transponder is mandatory within the European Union with only a few exceptions. In this study, the readability of such microchips in 428 horses with three different scanners (A, B and C) and the histological changes at the implantation site in 16 animals were assessed. Identification of microchips differed between scanners (P<0.001), and with 'side of neck' (P<0.001). Scanners A, B and C identified 93.5%, 89.7% and 100% of microchips, respectively, on the 'chip-bearing' side of the neck. From the contralateral side, scanners A, B a...
Joyce JR, Martin JE, Storts RW, Skow L.The clinical, gross and microscopic ophthalmic lesions of iridial hypoplasia, limbic dermoids and cataracts in a Quarterhorse stallion and a group of its offspring are described. It is proposed that the lesions in the stallion were the result of an independent mutation and that the defects were transmitted to its offspring by an autosomal dominant gene.
McPherson EA, Lawson GH, Murphy JR, Nicholson JM, Fraser JA, Breeze RG, Pirie HM.Mean normal values for PaO, and max A Ppl for horses were determined. Using 2 standard deviations below (Pa0,) and above (max A Ppl) the mean normal values as a guide, horses affected with COPD were satisfactorily distinguished from other horses in a series of 100 animals. The frequency of occurrence of 20 different clinical parameters in affected, not affected and possibly affected horses was examined statistically. Poor work performance and a history of previous febrile illness occurred more often in COPD horses than in others. The presence of a chronic cough, dyspnoea, double expiratory eff...
Page AE, Slovis NM, Horohov DW.Lawsonia intracellularis is the etiologic agent for equine proliferative enteropathy (EPE), which typically affects weanling and yearling horses. In North America, EPE cases often occur between August and January, although cases outside of this time frame have been reported. Clinical signs of EPE are usually nonspecific and include lethargy, pyrexia, anorexia, peripheral edema, weight loss, colic, and diarrhea. Diagnosis is based on the presence of hypoproteinemia and hypoalbuminemia along with clinical signs and positive commercial serologic and/or molecular testing. Treatment requires the us...
Roberts MC, O'Boyle DA.Over a 3-year period, 1178 faecal samples were cultured from 462 horses admitted to the equine clinic of the University of Queensland; 185 samples were positive for salmonella yielding 213 isolations consisting of 21 serotypes. S. anatum was the predominant serotype isolated (54%) followed by S. ohio (11.27%) and S. typhimurium (9.4%). One hundred and ten horses (23.81%) were positive on one or more occasion, and 42 (9.09%) on more than one occasion. S. anatum was the most common serotype isolated (71.43%) from the main drains in the stable block (33.57% positive samples). The prevalence of sa...
Durando MM.Horses have a high prevalence of resting arrhythmias, cardiac murmurs, and valvular regurgitation, and training can increase the prevalence. This makes it challenging for equine veterinarians who are asked to evaluate horses for poor performance to determine the clinical relevance of some findings. In addition, cardiac disease has the potential to cause collapse or sudden death, putting both the horse and rider at risk. Further diagnostics, such as echocardiograms and resting and exercising ECGs can help to sort out the impact of an abnormality found on resting physical examination. However un...
Walker RL, Runyan CA.To determine whether previously unidentified variations of the SzP protein of Streptococcus equi subsp zooepidemicus were present in horses with various clinical signs of infection and whether any relationship could be identified between SzP protein variants and naturally occurring clinical conditions. Methods: 23 isolates of S equi subsp zooepidemicus were recovered from specimens of horses with various clinical conditions and used as a representative population of isolates for evaluation of different SzP protein variants. Methods: Genetic heterogeneity of the isolates was demonstrated by rep...
MacHarg MA, Adams SB, Lamar CH, Becht JL.Bipolar electrodes, strain gauge force transducers, intraluminal pressure recording catheters, and extraluminal intestinal obstructors were surgically implanted in 4 ponies to record myoelectrical and mechanical activity of the distal portion of the jejunum and ileum. After determining normal intestinal activity and pressures, the distal portion of the jejunum was obstructed with an extraluminal obstructor. Myoelectrical and mechanical activity recorded from jejunal segments proximal to the obstruction increased significantly (P less than 0.01), whereas activity distal to the obstruction remai...
Arencibia A, Vazquez JM, Ramirez JA, Ramirez G, Vilar JM, Rivero MA, Alayon S, Gil F.The purpose of this investigation was to define the magnetic resonance (MR) imaging appearance of the brain and associated structures of the equine head. MR images were acquired in oblique dorsal (T2-weighted), sagittal (T1-weighted), and transverse planes (T2-weighted), using a magnet of 1.5 Tesla and a human body coil. Relevant anatomic structures were identified and labeled at each level. The resulting images provided excellent anatomic detail of the cranioencephalic structures. Annotated MR images from this study are intended as a reference for clinical imaging studies of the equine head, ...
Yovich JV, Horney FD, Hardee GE.Ten cases of pheochromocytoma in horses were obtained from the literature and a computer search of medical records. The clinical, laboratory and pathological features of pheochromocytoma in horses were reviewed. Pheochromocytoma is a catecholamine secreting tumor which tends to occur in older horses without breed or sex predisposition. It is usually unilateral adrenal medullary in location and benign. Malignancy was present in one horse. The most common clinical signs were sweating, tachycardia, tachypnea, muscle tremor and anxiety; however the tumor may be asymptomatic. Clinical signs were no...
Westerman TL, Tornquist SJ, Foster CM, Poulsen KP.To evaluate use of serum amyloid A (SAA) and haptoglobin concentrations as prognostic indicators for horses with inflammatory disease in regard to euthanasia, complications, and hospitalization duration and cost. Methods: 20 clinically normal horses and 53 horses with inflammatory disease. Methods: Total WBC count, neutrophil count, and fibrinogen, SAA, and haptoglobin concentrations were determined for clinically normal horses and horses with suspected inflammatory disease. Clinicopathologic values at admission were compared to test the use of SAA and haptoglobin concentrations in predicting ...
Allen GP, Yeargan MR, Turtinen LW, Bryans JT.From restriction endonuclease characterization of the DNA of 317 isolates of equine abortion virus (equine herpesvirus-1; EHV-1) from 176 epizootically unrelated outbreaks of equine virus abortion occurring over 24 years in Kentucky, an epizootic pattern and variation of the virus have emerged. Two electropherotypes of EHV-1 (1P and 1B) accounted for greater than 90% of the nonvaccine-related abortion isolates examined. From 1960 to 1981, EHV-1 1P was the predominant isolate circulating in the central Kentucky area and the cause of greater than 80% of EHV-1-related abortions. In 1981, the occu...
Donoghue EM, Lyons ET, Bellaw JL, Nielsen MK.Parascaris spp. infects foals worldwide and may cause airway inflammation in addition to small intestinal impaction and rupture. It is observed that acquired immunity eliminates ascarid burdens beginning at about 6 months of age, and current evidence suggests that a single parasite generation propagates in each foal crop. The purpose of this study was to monitor natural parasitic infections in untreated mixed breed horse foals over the course of 0-300 days of age. Fecal samples were collected monthly from all foals born in 2014 (n=13), beginning July 2014 through February 2015. Fecal egg count...
Bjorneby JM, Leach DR, Perryman LE.Cryptosporidial infections were established in five young foals with severe combined immunodeficiency following oral administration of 10(8) Cryptosporidium parvum oocysts. All foals shed oocysts (average of 8 x 10(6) to 2 x 10(8)/g of feces) until death. Inflammation and C. parvum organisms were observed in the common bile duct, duodenum, jejunum, and ileum. Since foals with severe combined immunodeficiency lack functional T and B lymphocytes and are incapable of antigen-specific immune responses, they are well suited for evaluating the pathogenesis and treatment of persistent cryptosporidios...
Fielding CL, Magdesian KG.Sepsis and septic shock represent a major cause of morbidity and mortality in equine neonates and in all species. Early recognition of the condition is important, but definitive examination and laboratory variables to predict equine neonatal sepsis are lacking. Early and aggressive treatment should include broad-spectrum antimicrobial coverage, source control, and hemodynamic support. Field practitioners and intensive care clinicians work together in the management of this condition because the recognition and initial treatment should begin as early as possible.
Kemppainen RJ, E Peterson M.Cushing's disease, defined as hyperadrenocorticism resulting from excessive secretion of pituitary ACTH, occurs spontaneously and quite commonly in dogs and horses. In dogs, as in humans, the disease is usually associated with a small tumor of the pituitary pars distalis. However, the disease may arise occasionally (dogs) or exclusively (horses) from tumors or hyperplasia of the pituitary pars intermedia. In dogs, pars intermedia tumors may arise from one of two proopiomelanocortin-containing cell types that are present in normal tissue.
Maher MA, Farghali HAM, Abdelnaby EA, Emam IA.The present study was performed on 12 heads of donkey's cadavers of both sexes for different anatomic techniques and on 20 live adult donkeys for ultrasonographic approaches of local anesthetic techniques. The aim was to achieve safe desensitization of the ear canal and tympanic membrane in addition to measuring different parameters of the structures occupying the infra-auricular parotid region. The internal auricular nerve was divided into two fine branches and constituting, at its origin, a characteristic V-shape with the caudal auricular nerve. The styloid process of auricular cartilage was...
Harrison IW.The average age of 122 horses with ascending colon volvulus was 6.6 +/- 0.4 years. Gastric reflux was a presenting sign in 35% of the cases. Peritoneal fluid protein levels had a mean of 2.54 +/- 0.14 g/dl and 20 horses had grossly normal peritoneal fluid at the time of presentation. Ascending colon volvulus was most commonly found at the level of the cecocolic fold with the initial ventral colon movement in a dorsomedial direction about the ascending mesocolic axis. The overall survival rate was 34.7% with a recurrence rate of only 4.9%.