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.
Mair TS.The clinical features of 18 cases of summer pasture associated obstructive pulmonary disease were reviewed. The horses had signs of obstructive pulmonary disease (expiratory dyspnoea, wheezing and crackling lung sounds and coughing) during the spring, summer or autumn while they were kept permanently at grass with no access to hay or straw, for at least two consecutive years. In nine cases there was a seasonal incidence with the disease occurring during April and May. Eleven of the horses were affected by bouts of severe dyspnoea. Eleven of the horses also suffered from chronic obstructive pul...
Seahorn TL, Groves MG, Harrington KS, Beadle RE.To evaluate chronic obstructive pulmonary disease of horses in Louisiana by assessing the signalment, history, environmental factors, clinical signs, and treatment of such horses. Methods: Epidemiologic mail survey. Methods: 83 of 240 veterinarians contacted by mail agreed to take part in the survey. Veterinarians contacted were listed as mixed-animal or equine practitioners in the 1991/1992 directory of the Louisiana Veterinary Medical Association or had submitted a specimen from a horse to the Louisiana Veterinary Medical Diagnostic Laboratory within the past 2 years. Methods: The survey con...
Reppas GP, Canfield PJ, Hartley WJ, Hutchins DR, Hoffmann KL.An echocardiographical and clinical pathological investigation of the rapid loss of weight by a yearling thoroughbred filly revealed an atrial septal defect, a ventricular septal defect and hyperfibrinogenaemia. A post mortem examination confirmed the cardiac abnormalities and revealed a severe thoracic aortitis. It is proposed that the idiopathic thoracic aortitis contributed to the horse's compromised cardiovascular homoeostasis.
Kirkland KD, Baker GJ, Manfra Marretta S, Eurell JA, Losonsky JM.To document age-related changes in the morphology of the endodontic system, reserve crown, and roots of equine mandibular cheek teeth. Methods: Equine mandibular cheek teeth from horses of various ages were compared, using radiography, x-ray computed tomography, and histologic examinations. Methods: 48 right hemi-mandibles from horses 2 to 9 years old. Methods: Hemi-mandibles were radiographed, imaged by computed tomographic reconstruction, and reformatted. Histologic examination was used to identify and correlate tissue types. Results: Permanent mandibular cheek teeth of the horse, at the tim...
Stegelmeier BL, Gardner DR, James LF, Molyneux RJ.Houndstongue (Cynoglossum officinale), a noxious weed that contains pyrrolizidine alkaloids (PAs), infests pastures and fields in the western United States and Europe. The purpose of this study was to develop techniques to better diagnose PA poisoning and describe the progression of gross and microscopic lesions caused by houndstongue intoxication. Six horses were gavaged daily with a suspension of houndstongue containing 5 or 15 mg/kg total PA for 14 days. Two horses were treated similarly with ground alfalfa as controls. Liver biopsy samples and serum biochemical and hematologic values were ...
Long SE.A 1;30 tandem translocation was found in an 8-yr-old thoroughbred stallion referred because of reduced fertility. The diagnosis was confirmed by GTG and CBG staining. This is the first report of a tandem translocation in the horse.
Marble SL, Edens LM, Shiroma JT, Savage CJ.A 16-hour-old foal was examined because of subcutaneous emphysema, which began developing 3 hours after a routine delivery. Physical examination did not reveal soft-tissue or musculoskeletal trauma, and there were no skin injuries to explain the subcutaneous accumulation of air. Results of CBC and serum biochemical analysis were within reference limits, and findings on endoscopy of the pharyngeal area, trachea, and esophagus were within normal limits other than observation of dorsal pharyngeal compression. A pulmonary bulla, pneumomediastinum, and pneumothorax were detected on thoracic radiogr...
Adeyefa CA.The rapid diagnosis of African horse sickness (AHS) during the incubation period using virus antigens in peripheral blood mononuclear cells (PBMC) and red blood cells (RBC) in a sandwich indirect enzyme-linked immunosorbent assay (ELISA) is reported. PMBC consistently gave higher positive ELISA results than RBC from blood collected during viraemia from clinically affected horses. The potential of the method described for wider application in rapid diagnosis and virus surveillance in susceptible equine populations, particularly in AHS-free and in enzootic areas, for effective control strategies...
Bleumink-Pluym NM, ter Laak EA, Houwers DJ, van der Zeijst BA.The ability of Taylorella equigenitalis, the causative agent of contagious equine metritis, to invade and replicate in equine derm cells was studied. The kinetics of invasion and replication were determined for four T. equigenitalis strains. On the basis of these experiments, a simpler assay in which the invasive as well as the replicative properties of a particular strain could be determined was developed. This assay was used to characterize 32 strains, which had previously been typed by field inversion gel electrophoresis of genomic restriction fragments. The invasiveness of T. equigenitalis...
Gu X, Meleka-Boules M, Chen CL.A capillary electrophoresis technique was developed for the separation of synthetic glucocorticoids and the determination of dexamethasone and flumethasone in horse urine. Pretreatment of the sample using a dexamethasone affinity column resulted in low background that enabled the authors to detect levels as low as 1.1 ng/mL and 2.7 ng/mL for dexamethasone and flumethasone in horse urine, respectively. The developed method was used to detect dexamethasone in horse urine samples after the injection of a therapeutic dose of dexamethasone for up to 12 hr postinjection. The optimum conditions for c...
Zamos DT, Schumacher J, Loy JK.Nasopharyngeal conidiobolomycosis caused by Conidiobolus coronatus was diagnosed in a horse after endoscopic and histopathologic examinations of a biopsy specimen. The fungal lesions in the nasopharynx were substantially reduced in size after intralesional injection of amphotericin B through the biopsy channel of a videoendoscope in combination with i.v. administration of sodium iodide and oral administration of potassium iodide during a 2-month period. Endoscopy performed 15 months after initial examination revealed regression of the granulomatous masses in the nasopharynx and complete disapp...
Tvedten HW, Korcal D.The differential leukocyte counts performed by an automated hematology analyzer, the Technicon H-1E Hematology System, and traditional microscopic method (M-Diff) from blood samples of 129 horses, 40 cattle, and 140 cats were compared. The comparison was repeated after selected subsets of data were created by deleting samples with certain patterns suggesting error with the automated differential cell count (A-Diff). The two methods had good comparison of results for neutrophils and lymphocytes in all three species. Results for equine monocytes correlated moderately well between the two methods...
Tangkawattana P, Karkoura A, Muto M, Yamano S, Taniyama H, Yamaguchi M.Numerous rod bodies were found in a heart sample from a 33-year-old pony by a conventional electron-microscopic technique. The rod bodies were concentrated in localized areas of both atria and ventricles, without a specific pattern of distribution. The rods appear to have a typical crystalline-like structure which presumably contains actin backbone filaments and alpha-actinin as major protein constituents. Diminution, fragmentation, and disorganization of the myofibrils, random expansion of electron-dense materials, especially at the fasciae adherens of the intercalated disc, an increase of in...
Schenck PA, Chew DJ, Brooks CL.It has been previously shown that Ca(I) concentration is stable in serum collected from healthy horses for 10 days if stored at 40 degrees C. This may not be true for horses with abnormal Ca(I) concentrations. Thus the stability of ionized calcium (Ca(I)) concentration and pH measurement in serum from horses with both normal and abnormal Ca(I) concentrations stored for various times at 40 degrees C and -10 degrees C was evaluated. Our results indicated that serum Ca(I) concentration was stable throughout 7 days of cold or frozen storage, after being received by the Clinical Chemistry Laborator...
Keg PR, Schamhardt HC, van Weeren PR, Barneveld A.The practice of applying diagnostic nerve blocks relies on the assumption that the blocks in themselves do not alter the horse's gait. This assumption has recently been challenged. In the present paper a series of sequential nerve blocks (low palmar digital block, abaxial sesamoid block, high palmar block) was applied to clinically sound horses. Before and after each block the gait was clinically scored and Ground Reaction Forces (GRF) were measured. Clinical scoring did not change after any of the nerve blocks. None of the GRF variables changed significantly except for a slight alteration of ...
Miserez R, Frey J, Krawinkler M, Nicolet J.A polymerase chain reaction (PCR) for identification of Taylorella equigenitalis was developed. The oligonucleotide primers are based on the DNA sequence of the rrs gene of T. equigenitalis, encoding for the 16S ribosomal RNA. Analysis of 21 strains of T. equigenitalis from England, USA and Switzerland showed an amplification product of 410 bp with identical Sau3A restriction profile. The sensitivity of the PCR-Assay was estimated to detect 50 to 500 bacteria of T. equigenitalis in a mixture with frequently found contaminants. Further analysis of culture from 60 genital swabs, taken in the cou...
Richter PJ, Kimsey RB, Madigan JE, Barlough JE, Dumler JS, Brooks DL.Ehrlichia equi, a rickettsia described from horses in California 30 yr ago, causes equine granulocytic ehrlichiosis throughout the Americas and possibly Europe. Here, we report experimental transmission of E. equi from infected to susceptible horses through bites of western blacklegged ticks, Ixodes pacificus (Cooley & Kohls). In preliminary field studies, only I. pacificus consistently infested horses and vegetation at 3 locations with contemporary cases of equine ehrlichosis, and in particular, I. pacificus was the only species found attached to all of the infected horses. Exposure to bites ...
Mizobe M, Kondo F, Kumamoto K, Terada T, Nasu H.Rapid and quantitative analytical methods for bilirubin using high-performance liquid chromatography (HPLC) with UV detection were developed for samples from equines at a meat inspection site. Sharp HPLC peaks for bilirubins, unconjugated bilirubin (UCBL) and conjugated bilirubin (CBL), were obtained using a simple mobile phase of methanol:0.5 M Tris-HCl buffer (65:35, v/v, pH 7.4). A variable wavelength detector set at 450 nm, 0.01 AUFS and a recorder set at 4 cm/min were used for detection. Peaks for UCBL and CBL occurred at 7.1 min and 4.9 min, the lower limits of detection ranged between 0...
Burkhard MJ, Baxter G, Thrall MA.A precipitate was observed on the blood films of horses (15 of 16) and one cow given a peritoneal infusion of 1 % sodium carboxymethylcellulose (SCMC) solution to prevent abdominal adhesions. The intensity of the precipitate seen 2 to 3 days post-infusion strongly correlated with the administered dose of SCMC (range 0.96 to 11.7 ml/kg). The dose given was inversely correlated with bodyweight and the most prominent precipitates were seen in foals. The precipitate was observed as early as 24 hours and persisted for as long as 9 days after SCMC administration. Fibrinogen was the only hematologica...
Sellon DC, Walker KM, Russell KE, Perry ST, Covington P, Fuller FJ.Equine infectious anemia virus is a lentivirus that replicates in mature tissue macrophages of horses. Ponies were infected with equine infectious anemia virus. During febrile episodes, proviral DNA was detectable, but viral mRNA was not detectable. As cultured blood monocytes from these ponies differentiated into macrophages, viral expression was upregulated. In situ hybridization confirmed that viral transcription occurred in mature macrophages.
Denoix JM, Busoni V.The ultrasonographic anatomy of the accessory ligament of the superficial digital flexor tendon (AL-SDFT) in the horse is presented. Comparison between anatomical sections of isolated limbs and ultrasound scans of the distal antebrachium in sound horses enabled the authors to establish the normal reference ultrasonographic images of this structure. The AL-SDFT inserts 7-14 cm above the antebrachiocarpal joint on the palmaromedial aspect of the radius. Ultrasonographically it appears as an uniformly echogenic structure located deep to the median artery. The knowledge of ultrasonographic anatomy...
Fadok VA.Scaling and/or crusting are common clinical findings associated with equine skin diseases. Scaling and crusting may be associated with pruritic or nonpruritic dermatoses. This article focuses on those conditions that are usually nonpruritic in horses. They include the infectious dermatoses, the keratinization/seborrheic disorders, photosensitization, and the immunologic/inflammatory disorders, including pemphigus foliaceus, equine exfoliative eosinophilic dermatitis and stomatitis, and equine histiocytic dermatitis (sarcoidosis). Clinical signs that help differentiate the various disorders are...
Rush BR, Hoskinson JJ, Davis EG, Matson CJ, Hakala JE.To determine whether pulmonary distribution of aerosolized technetium Tc 99m pentetate is improved after inhalation of a single dose of albuterol sulfate in horses susceptible to recurrent airway obstruction (heaves). Methods: 6 horses with heaves and 4 horses with normal respiratory tract function. Methods: Images were obtained during ventilation of horses at baseline (maximal change in pleural pressure during tidal breathing [deltaPpImax] >15 cm H2O) and after aerosolized albuterol sulfate (360 microg) administration, with a 24-hour washout period between experiments. The deltaPpImax was ...
Landolt GA.Acute poisoning and envenomation often represent a diagnostic and therapeutic challenge. Although identification ultimately may benefit the affected animal, treatment frequently must commence before an etiologic diagnosis is established. Therefore, the goals for the management of acutely intoxicated horses must be focused on emergency intervention and stabilization of the patient, prevention of further exposure, and aggressive decontamination. This article reviews the treatment steps that should be considered during the management of horses experiencing poisoning or envenomation.
Machado M, Miguel MP, Terra JP, Ferreira JA, Riet-Correa F, de Castro MB.An outbreak of acute poisoning of horses by Enterolobium contortisiliquum pods is reported in the state of Goiás, Brazil. Three horses presented apathy, hyporexia, prostration, jaundice, recumbency and died in 24-48 hours. The main pathological findings were a yellowish liver with an enhanced lobular pattern, multifocal hepatic necrosis mostly in the midzones of lobules and sometimes with a random distribution across the hepatic lobes and swelling of hepatocytes. E. contortisiliquum trees has a wide distribution in South America and cases of poisoning have not been reported in horses.
Chen JW, Uboh CE, Soma LR, Li X, Guan F, You Y.To evaluate whether urine supernatant contains amplifiable DNA and to determine factors that influence genotyping of samples from racehorses after storage and transportation. Methods: 580 urine, 279 whole blood, and 40 plasma samples obtained from 261 Thoroughbreds and Standardbreds. Methods: Genomic DNA was isolated from stored blood and urine samples collected from racehorses after competition. Quantified DNA was evaluated to determine whether 5 equine microsatellite loci (VHL20, HTG4, AHT4, HMS6, and HMS7) could be amplified by use of PCR techniques. Fragment size of each amplified locus wa...
Cheville NF, Prasse K, van der Maaten M, Boothe AD.A newborn foal developed generalized cutaneous mastocytosis characterized by multiple elevated nodules of mast cells in skin and basophil hyperplasia in bone marrow. Skin lesions began as small aggregates of mast cells that progressively enlarged, ulcerated, and regressed spontaneously. Eosinophil infiltration, collagen necrosis, and fibroplasia were characteristic of advanced lesions. Many new lesions developed during the first month of life but numbers progressively diminished. Large numbers of mast cells were present in biopsies of lymph node, spleen and bone marrow. Discrete aggregates of ...
Sinclair R, Mumford JA.An antigen capture enzyme-linked immunosorbent assay (ELISA) was developed for the detection of equine herpesvirus type-1 (EHV-1) antigens in nasal swab specimens. The test was designed as a solid phase, amplified sandwich assay in which an EHV-1 specific monoclonal antibody was used to capture virus antigen and polyclonal antisera used to detect antigen bound to the test plates. Eight monoclonal antibodies were tested for their ability to capture virus antigen and one was selected for routine use. The sensitivity and specificity of the ELISA was compared with that of virus isolation using swa...
Lohmann KL, Lewis SR, Wobeser B, Allen AL.Three cases of penetrating metallic foreign bodies causing peritonitis in horses are reported. These cases were presented with varying clinical complaints and duration of clinical signs. Entry of foreign bodies into the abdominal cavity through the skin and body wall is reported for the first time. Corps étrangers métalliques pénétrants comme cause de péritonite chez 3 chevaux. Trois cas de corps étrangers métalliques pénétrants ayant causé une péritonite chez des chevaux sont signalés. Ces cas ont été présentés avec des plaintes cliniques différentes et une durée variable de...
Cable CS, Ducharme NG, Hackett RP, Erb HN, Mitchell LM, Soderholm LV.To investigate whether upper airway sounds of horses exercising with laryngeal hemiplegia and alar fold paralysis have distinct sound characteristics, compared with unaffected horses. Methods: 6 mature horses. Methods: Upper airway sounds were recorded in horses exercising on a high-speed treadmill at maximum heart rate (HR(MAX)) under 3 treatment conditions (ie, normal upper airway function [control condition], and after induction of left laryngeal hemiplegia or bilateral alar fold paralysis) in a randomized crossover design. Fundamental frequency, spectrograms using Gabor transform, and inte...