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.
Parente EJ, Richardson DW, Spencer P.Medical records of 57 horses admitted between 1980 and 1991 because of basal sesamoidean fractures were evaluated. Radiographic measurements of fragment size and fracture characteristics were recorded to determine their relationship to outcome. A successful outcome was assessed on the basis of the ability to return to racing, ability to race more than one time, and ability to finish first, second, or third. Any change in racing class also was assessed. There was a significant (P < 0.001) overrepresentation of Thoroughbreds, compared with other breeds in the hospital population. Fractures of...
Bernard WV, Bolin C, Riddle T, Durando M, Smith BJ, Tramontin RR.Leptospirosis was documented as the cause of abortion in a 5-year-old mare. Leptospires were detected in tissue specimens from fetal kidneys and from placenta by histologic evaluation of silver-stained sections. Antibodies against Leptospira interrogans serovar pomona were detected in fetal serum at a titer of 1,600 by use of a microscopic agglutination test. The mare had serum titers of 6,400; 0; 400; 800; 3,200; and 6,400 to L interrogans serovars bratislava, canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona, respectively. A serologic survey identified titers of at least 6,400...
Handy LH, Peyton LC, Calderwood-Mays MB, Ackerman N.A diagnosis of gingival hyperplasia in a 22-year-old Quarter Horse gelding was confirmed by histologic examination. Clinical signs included difficulty eating hay, and a large, intraoral soft tissue mass measuring 13 x 8 x 4.5 cm. The mass was located in the mucosa on the lingual aspect of the caudal left portion of the mandible, ventral to the base of the tongue, and covered the second and third lower molars, extending rostrally along the buccal mucosa to the premolars. The left maxillary second and third molars were overgrown with sharp edges. Lateral radiography of the mandible revealed abse...
Tözsér J, Friedman D, Weber IT, Bláha I, Oroszlan S.The proteinase of the equine infectious anemia virus (EIAV), a lentivirus closely related to human immunodeficiency virus (HIV), was purified from concentrated virus. The specificity of the enzyme was characterized using oligopeptides representing naturally occurring cleavage sites in the Gag and Gag-Pol polyproteins. The length of the substrate binding pocket was found to be 1-2 residues longer than that of HIV proteinases. Although the EIAV and HIV proteinases cleaved most of the peptides at the same bond, some were hydrolyzed by only the EIAV enzyme. Oligopeptides representing cleavage site...
Park RD.Radiographic examinations of the equine head can be performed with portable x-ray machines. The views comprising the examination depend on the area of the head being examined. With a knowledge of radiographic anatomy and radiographic signs of disease, valuable diagnostic information can be obtained from the radiographic examination. In addition, the radiographic information can also be used to develop a prognosis and determine the most appropriate therapy.
Gardner SY, Sweeney RW, Divers TJ.Serum concentrations of cefotaxime and desacetylcefotaxime were measured in 1-week-old pony foals after IV administration of a single dose of cefotaxime. The cefotaxime disposition data conformed to a two-compartment model with elimination half-life of 0.60 hour. The combined cefotaxime and desacetylcefotaxime data was best described by a four-compartment model. The apparent half-life describing the disappearance of desacetylcefotaxime was 1.69 hours. Dosage of 40 mg/kg of body weight given IV every 4 to 6 hours for neonatal foals with gram-negative septicemia and every 2 hours for foals with ...
Yvorchuk-St Jean KE, Debowes RM, Gift LJ, Kraft SL, Sinha AK, Kennedy GA.A 5-week-old belgian colt was examined for colic of 12 hours duration after several episodes of diarrhea. Physical examination revealed signs of abdominal pain, mild dehydration and normal auscultable borborygmi in all abdominal quadrants. Distention of the cecum, large colon and small intestinal was evident on abdominal radiographs. The foal was treated medically as the owners declined surgery. The colt was euthanized because of continued deterioration and failure to respond to medical therapy. Post-mortem exam revealed the presence of a trichophytobezoar obstructing the distal part of the tr...
Jaeschke G, Lange W.In this paper three outbreaks of equine influenza in Berlin (Germany) in the years of 1988, 1989 and 1991 are discussed, reporting mainly clinical, hematological, virological and some epizootiological aspects. We have detected variations from the traditional pattern of equine influenza, whereby the main clinical symptoms like cough or fever were absent in several cases. If cough was found, it was moist. Furthermore a mucous nasal discharge was present in a number of cases for a period of 4-5 days. Extreme neutropenia, lymphocytosis and predominantly an unchanged level of monocytes were observe...
Gaughan EM, DeBowes RM.Many questions concerning heritability arise when a veterinarian is asked to supervise and treat disease of congenital origin. Genetic counseling, ethics, and legality are often confronted in discussions between animal health professionals and laymen in animal industry. Guidelines have been offered as in the 1984 statement of the Judicial Council of the American Veterinary Medical Association: "Performance of surgical procedures in all species for the purpose of concealing genetic defects in animals to be shown, raced, bred, or sold as breeding animals is unethical. However, should the health ...
Driesang I, Böhm D.Both hock joints were examined clinically, radiologically and scintigraphically in 80 horses with special regard to bone spavin. The positive x-ray and bone scan results corresponded in most cases. It was evident that there was no correlation between degree of lameness and/or extent of radiological findings and increased radioactive uptake in the joint. Scintigraphic evaluation may demonstrate early changes at the onset of bone spavin as well as the frequent bilateral nature of the condition.
Troedsson MH, deMoraes MJ, Liu IK.The relationship between histologic lesions in endometrial biopsy specimens and susceptibility to chronic uterine infection (CUI) in mares was investigated. Mares were allotted to 4 groups on the basis of degree of endometrial lesions. Mares in group 1 (n = 6) had no pathologic changes, mares in group 2 (n = 5) had only mild pathologic changes, group-3 mares (n = 7) had moderate changes, and group-4 mares (n = 7) had severe inflammatory and fibrotic endometrial changes. Susceptibility to CUI was determined by the inflammatory response to intrauterine inoculation of 5 x 10(6) Streptococcus zooe...
Moore BR, Reed SM, Kowalski JJ, Bertone JJ.A National Show Horse with a mediastinal granuloma was presented with clinical signs which included fever, nasal discharge and cough. The mediastinal mass was identified radiographically and ultrasonographically. A presumptive diagnosis of aspergillosis was made following isolation of Aspergillus spp. from both transtracheal aspirate and bronchoalveolar lavage fluid samples and agar gel immunodiffusion (AGID) identification of serum antibody to Aspergillus spp. The diagnosis was confirmed by histopathologic examination of the mediastinal mass obtained at necropsy examination.
Bertone JJ, Biller DS, Ruggles A.Physical examination of the paranasal sinuses is often insufficient to confidently reach a conclusion concerning suspected pathology in these cavities. Often, other evaluation techniques are necessary. This article describes physical examination, rhinoscopy, sinus centesis, radiology, and sinus endoscopy of the equine paranasal sinuses. These techniques can be used to diagnosis and determine the cause of most sinus disorders.
Kainer RA.This topical presentation emphasizes the structures most likely to be encountered in the diagnosis and treatment of diseases of the equine head. Most of the approaches are from superficial to deep. Anatomic variations associated with aging are described. The larynx and guttural pouches are not included in this article.
Watney GC, Norman WM, Schumacher JP, Beck E.The accuracy of a reflectance pulse oximeter was determined in 22 anesthetized horses. Oximetric blood oxygen saturation was measured with the pulse oximeter probe attached to the mucosa of the mandible. Arterial blood oxygen saturation (SaO2) was calculated from arterial blood gas values and the equine blood oxygen dissociation curve. The mean +/- SD difference between oximetric blood oxygen saturation and SaO2 was -1.3 +/- 3.1% for values of SaO2 ranging from 80 to 100%. The difference between oximetric blood oxygen saturation and SaO2 was influenced by SaO2, the mean arterial blood pressure...
Sweeney CR, Freeman DE, Sweeney RW, Rubin JL, Maxson AD.Three horses were determined to have hemorrhage into a guttural pouch unassociated with mycosis, empyema, neoplasia, or foreign body. The source of the hemorrhage appeared to be the rupture of the longus capitis muscle and its associated vascular supply.
MacDonald MH.Examination of the equine head should be a routine part of any complete physical examination. It can be performed rapidly and efficiently while providing important information about the health and function of several major body systems.
Schumacher J, Honnas CM.Anatomy, physiology, and diseases of the teeth are presented. Signs of dental disease and techniques for oral and radiographic examination of the teeth are discussed. Surgical procedures described include extraction, repulsion, and endodontic therapy.
Collins MH.The placenta provides many critical services to the developing foetus. Proper placental implantation, growth and function are necessary for normal foetal growth and development. Placental structure varies widely among species but all mammalian placentas have a convoluted materno-foetal interface that may be quite simple or highly complex; the more complicated interdigitations tend to characterise smaller placentas that have limited areas of contact between the placenta and the endometrium. The intimacy of the contact between maternal and foetal tissue varies from apposition only, as in the equ...
Kollias-Baker CA, Pipers FS, Heard D, Seeherman H.Pulmonary edema associated with transient airway obstruction was detected in 3 horses. The cause of obstruction was different in each horse, but after relief of the obstruction, clinical signs and radiographic abnormalities were indicative of pulmonary edema. In 2 of the 3 horses, pink frothy fluid was evident in the airways. The horses were treated with furosemide, nasal insufflation of O2, anti-inflammatory agents, and anti-biotics. Of the 3 horses examined, 1 horse died acutely, 1 horse recovered fully, and 1 developed pleuritis and was subsequently euthanatized.
Cohen ND.Neurologic evaluation should be performed in horses with diseases of the head. Although neurologic examination should focus on assessing behavior, mental status, and cranial nerve evaluation, evaluation of neurologic function of other body regions should be performed. Neurologic evaluation of the head can be performed expediently by practitioners to provide useful diagnostic and prognostic information. The numerous causes of dysphagia can be classified as obstructive, painful, or neurogenic. Common causes of neurogenic dysphagia are summarized, and methods for initial diagnosis and management ...
van der Kolk JH, van der Wijden MW, Jongejan F.Equine granulocytic ehrlichiosis (EGE) has been observed in the U.S.A., Brazil, Germany, Sweden, Switzerland and possibly in Great Britain. The causative agent is rickettsia Ehrlichia equi, identified for the first time in 1969. The clinical features of the disease are anorexia, fever, depression, (limb) oedema, icterus, ataxia, petechiae and orchitis. Hematologic changes are leukopenia, thrombocytopenia, anemia and cytoplasmic inclusion bodies in the neutrophils and eosinophils. Vasculitis may be observed at autopsy. Following a positive hematological diagnosis (Giemsa stained blood smear) of...
Smyth GB, Young DW, Duran SH.Postprandial insulin and glucose concentrations were measured in 3 Arabian and 3 Thoroughbred foals at 1 day, 1 week, 1 month and 3 months of age. Prefeeding serum insulin concentrations were similar in foals at 1 day (25.9 +/- 5.1 pmol/L), 1 week (32.4 +/- 5.8 pmol/L), and 1 month (38.2 +/- 7.9 pmol/L), but had increased significantly to 131.0 +/- 20.2 pmol/L at 3 months of age (P < 0.05). There was significantly increased serum insulin secretion after a feed in foals at 3 months of age (P < 0.05) when compared with that at younger ages. Prefeeding serum glucose concentrations ranged fr...
Freestone JF, Seahorn TL.Nutritional secondary hyperparathyroidism is associated with horses that are fed diets with an imbalance of calcium and phosphorus or diets containing oxalates. Clinical signs include a shifting lameness, with tenderness of the joints, reluctance to move, or a stiff, stilted gait. Some horses may have broadening of the nasal bones, enlargement of the maxilla and/or the mandible, or a ridge over the nasal bones. Diagnosis may include physical examination findings; analysis of feed; and clinical pathologic data, which may include normocalcemia, normal to increased serum phosphorus, and increased...
Trotter GW.Numerous conditions, including trauma, infection, neoplasia, and developmental problems, can affect the paranasal sinuses. Successful resolution of these problems is predicated upon a thorough diagnostic workup to ensure the most accurate presumptive diagnosis. Surgical intervention is enhanced by using approaches that allow wide access to sinus compartments. Rigorous postoperative management is also important to a successful outcome.
Bogdan JR, Morley PS, Townsend HG, Haines DM.This study has tested the effect of using homologous or heterologous equine influenza A virus isolates to evaluate serum antibody levels to influenza A virus in vaccinated and naturally-infected horses. In addition, the potential effect of antigenic selection of virus variants in egg versus tissue culture propagation systems was studied. Serum antibody levels in samples from horses recently infected with a local influenza A virus isolate (A/equine 2/Saskatoon/1/90) or recently vaccinated with a prototype isolate (A/equine 2/Miami/1/63) were assessed by hemagglutination inhibition and by single...
Rossdale PD.This review summarises comparative aspects of equine pregnancy and birth. The allantochorion covers the entire endometrial surface of the mare's uterus and the placenta is microcotyledonary and epitheliochorial in structure. The foetus has, therefore, to pass through the allantochorion at birth. The umbilical cord has amniotic and allantoic portions and remains intact after delivery, enabling an arterial venous circulation to be maintained for several minutes. Maternal IgG does not cross the placental barrier and passive transfer post-natally is essential for immune status. Gestation in Thorou...
Ramsay WN.The non-haem iron concentration was estimated in post-mortem liver samples from 51 horses (age range 1-25 years). Two were normal and 49 had been suffering from conditions that were not expected to have had long-term effects on iron metabolism. Muscle samples (splenius and biceps femoris) from 23 of these horses were also analysed. There was a highly significant age-related increase in the non-haem iron concentration in the liver (r = 0.635, p < 0.001), but not in the muscles, in which the iron concentration was much lower than in the liver.
Clark-Price SC, Rush BR, Gaughan EM, Cox JH.A 2-year-old female Quarter Horse was evaluated for hind limb lameness, fever (40 degrees C [104 degrees F]), and lethargy of 2 weeks' duration. Hypoproteinemia characterized by hypoalbuminemia and hyperfibrinogenemia was detected. Abdominal ultrasonography revealed thickening of the right dorsal colon wall. Treatment was instituted for putative right dorsal coliis. Lameness evaluation localized signs of pain to the lumbar vertebrae or pelvis. Radiography performed with the horse standing and nuclear scintigraphy revealed no abnormalities. Ventrodorsal pelvic radiography revealed a focal area ...
Sánchez J, Gonzalo-Orden JM, Ginja MM, Oliveira PA, Reyes LE, Serantes AE, Orden MA.An Andalusian Stallion with left hind limb lameness had a radiolucent lesion in the medullary cavity of distal tibial metaphysis. After euthanasia for other disease, the tibia was examined with magnetic resonance (MR). The MR imaging sequences were characterized by a double line sign, although showing quite different lesion area intensities. Histologically, the lesion was compatible with medullary infarction being characterized by normal spongy bone, areas of abundant fibrous tissue and numerous necrotic adipocytes in various stages of destruction.
Tulamo RM, Maisi P.To establish concentration of hyaluronate (HA) in tracheal lavage fluid from healthy horses and horses with chronic obstructive pulmonary disease (COPD). ANIMALS AND SAMPLES: Tracheal lavage fluid samples (n = 42) from 18 horses, 11 with COPD, and 7 control horses. Methods: Clinical examination of the respiratory tract, tracheal lavage, and blood sample collection were performed on horses without clinical signs of respiratory tract disease and horses with clinical signs of COPD. In some horses, 1 to 5 repeated examinations were performed at 1-week intervals. Tracheal lavage fluid samples were ...
Gomez DE, Buczinski S, Darby S, Palmisano M, Beatty SSK, Mackay RJ.Use of different analyzers to measure electrolytes in the same horse can lead to different interpretation of acid-base balance when using the simplified strong ion difference (sSID) approach. Objective: Investigate the level of agreement between 2 analyzers in determining electrolytes concentrations, sSID variables, and acid-base disorders in sick horses. Methods: One hundred twenty-four hospitalized horses. Methods: Retrospective study using paired samples. Electrolytes were measured using a Beckman Coulter AU480 Chemistry analyzer (PBMA) and a Nova Biomedical Stat Profile (WBGA), respectivel...
Poore LA, Le Roux C, Carstens A.A definitive diagnosis of extensive suture line exostoses affecting the nasofrontal, nasolacrimal, nasomaxillary, frontolacrimal, lacrimozygomatic and lacrimomaxillary suture lines in a 7-year-old Thoroughbred mare with chronic bilateral epiphora and facial deformation was achieved using standing computed tomography (CT) examinations. Positive contrast dacryocystorhinography using CT revealed partial bilateral obstruction of the nasolacrimal ducts. Minimally displaced depression fractures of the right nasal bone, the right maxillary bone and right frontal bone were also demonstrated. The cosme...
Gerros TC, McGuirk SM, Biller DS, Stone WC, Ryan J.Cholelithiasis is the most common cause of biliary obstruction in horses. Proposed mechanisms include ascariasis, biliary stasis, ascending biliary infection, and changes in bile composition. In this horse, a foreign body acted as the nidus for bile-salt deposition and ascending cholangitis. Clinical signs (intermittent abdominal pain, icterus, and pyrexia) in conjunction with high serum activity of enzymes indicative of obstructive biliary disease led to a tentative diagnosis of cholelithiasis. Ultrasonography was used to confirm the diagnosis. Postmortem examination revealed a 7-cm wooden st...
Reich L.Horses' kicks can produce two types of head and neck injuries: injuries of the mid-face and injuries of the larynx. Typical cases as seen by the author are presented. The treatment of mid-face injuries is performed according to principles of plastic surgical repair. After frontal-nasal injuries, a revision of the nasal septum must be done. Involvement of the larynx requires external layer repair of mucosa and cartilage.
Fielding CL, Mayer JR, Dechant JE, Epstein KL, Magdesian KG.Trauma from dog attacks has been associated with mortality rates as high as 23% in some species. However, the prognosis and clinical features of this type of injury have not been described in equids. Objective: To describe survival rate, signalment, clinical features, and biochemical results in equids presented for emergency care after presumed dog attacks. We hypothesized there would be differences between survivors and nonsurvivors. Methods: A total of 28 equids presented for presumed dog attacks from 3 referral centers. Methods: A retrospective study was performed using data from 3 hospital...
Merchan A, Barrett EJ, Rodgerson DH.A technique for hand-assisted laparoscopic removal of cystic calculi in male horses is described. Three cystic calculi ranging from 5 to 10 cm in diameter were removed successfully using bilateral para-inguinal laparoscopic portals assisted by a human hand within the abdomen, effectively sealing the midline incision. Long-term follow-up information obtained from referring veterinarians and owners indicated that the patients returned to their previous activity level and had no recurrence of clinical signs in the following 6 to 12 months. Key clinical message: Hand-assisted recumbent laparoscopy...
Rossano MG, Kaneene JB, Schott HC, Sheline KD, Mansfield LS.Equine protozoal myeloencephalitis (EPM) is a neurological disease of equids that is caused by infection of the central nervous system with Sarcocystis neurona. Veterinarians diagnose EPM by performing a neurological examination and by ordering Western blot tests for antibodies to S. neurona in the blood and/or cerebrospinal fluid (CSF). The negative predictive value of the Western blot test is generally accepted to be high for both serum and CSF. If the agreement between serum and CSF test results is strong, serum tests could be used to substitute for CSF tests in some cases. The purpose of t...
Zhu D, Zeng ZL, Peng D, Chen X, Zhao LB, Zhang YY, Xu MM, Zhan QL, Yu JP, Xie P.To investigate the epidemiological pattern of Borna disease virus (BDV) infection in horses and to analyze the phylogenetic tree of derived BDV in Yili, Xinjiang. Methods: We established a modified nested RT-PCR (nRT-PCR) to detect BDV p24 segment in peripheral blood mononuclear cells (PBMCs) and brain tissues of 120 horses in Yili, Xinjiang. Positive products were analyzed by sequencing and homology analysis. Results: The positive rate of BDV infection was 2.5% in both PMBCs and brain tissues at the same time. The gene sequence revealed in positive PCR samples was more than 93%, identical to ...
Meier AD, de Laat MA, Reiche DB, Sillence MN.Endocrinopathic laminitis, related to equine metabolic syndrome and insulin dysregulation, causes marked pain and suffering in horses and represents a substantial cost to the horse industry. This study investigated the effect of feeding a diet high in nonstructural carbohydrates on concentrations of active glucagon-like peptide-1 (aGLP-1), total insulin-like growth factor-1 (IGF-1), and high-molecular-weight (HMW) adiponectin, in insulin-dysregulated ponies. Thirty-seven ponies were challenged with this diet for up to 18 d to induce hyperinsulinemia. Hormone concentrations were measured in se...
Gliatto JM, Alroy J.A horse with malignant lymphoma (histiolymphocytic) and cutaneous amyloidosis is described. The lymphoma involved the dura mater of the spinal cord and some of the peripheral lymph nodes. Multifocal amyloid deposits were present in the skin and subcutis of the ventral abdomen but not within the lymphoma cell infiltrates or in the viscera.