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.
Morris DD, Crowe N, Moore JN, Moldawer LL.A study was performed to determine whether equine peritoneal macrophages produce interleukin 6 (IL-6) in vitro in response to endotoxin. Peritoneal fluid was collected from 14 clinically normal adult horses and was used as the source of peritoneal macrophages. Macrophages from each horse were isolated and cultured separately in vitro in the absence or presence of various concentrations (0.5, 5, 500 ng/ml) of endotoxin (lipopolysaccharide from Escherichia coli 055:B5). Culture medium supernatants were collected after 3, 6, 12, and 24 hours' incubation and were frozen at -70 C until assayed for ...
Proudman CJ, Edwards GB.A centrifugation/flotation technique for the identification of equine tapeworm eggs is described. It was validated by using faeces samples from 80 horses of known tapeworm status, and had a sensitivity of 61 per cent and a specificity of 98 per cent. The exclusion of false negative results in animals with less than 20 tapeworms increased the sensitivity to 92 per cent. No significant correlation was found between the number of eggs observed and the number of tapeworms present in the horses.
Furr MO, Crisman MV, Robertson J, Barta O, Swecker WS.Immune system dysfunction and immunoglobulin deficiency was diagnosed in a 2-year-old horse with disseminated lymphosarcoma. Prolonged (35 days) parenteral nutrition was delivered to support the horse during a period in which immune function studies could be performed. Correction of nutritional compromise by use of parenteral nutrition did not correct the immunoglobulin deficiency, and results of lymphocyte phenotype testing did not indicate abnormal proportions of leukocytes. Lymphoblast transformation studies were suggestive of a circulating immunosuppressive factor in the horse's serum. Nor...
Bohn A, Papageorges M, Grant BD.Ultrasonography and radiography were used to diagnose bicipital tenosynovitis and humeral osteitis in a horse with a history of lameness of 7 weeks' duration. Surgical exploration confirmed the diagnosis.
Chaffin MK, Schumacher J, Hooper N.A 5-month-old male Quarter Horse was examined because of multicentric, granulomatous, cutaneous lesions of the dorsum and prepuce. The cutaneous lesions were excised, and sodium iodide was administered orally for 2 weeks. Multicentric cutaneous pythiosis was diagnosed by histologic examination and immunoperoxidase staining of excised tissues. By 3 months after surgery, all lesions had healed.
Kerkvliet NI, Wagner SL, Schmotzer WB, Hackett M, Schrader WK, Hultgren B.Investigations into the cause of health problems on a horse-breeding farm led to the discovery of high concentrations (630 to 9,810 mg/kg of bedding) of pentachlorophenol in wood shavings used as bedding for horses over a period of 2 to 4 years. Toxicologic signs in the horses were characteristic of toxic effects associated with exposure of polychlorinated dibenzo-p-dioxins and dibenzofurans. Tissue residue analysis confirmed presence of toxic polychlorinated dibenzo-p-dioxin and dibenzofuran isomers known to be in pentachlorophenol, substantiating the bioavailability of polychlorinated dibenz...
Knottenbelt DC, Harrison LJ, Peacock PJ.Three foals under four weeks old and two under six months old with a history of oesophageal obstruction, had oesophageal strictures of different characters in the rostral cervical oesophagus. One case, which was complicated by severe inhalation pneumonia, was euthanased without any treatment and in another initial treatment by bougienage under general anaesthesia was attempted without success. The four surviving cases were provided with progressively firmer and coarser food, starting with liquid only, over a period of three to four weeks. The treatment is recommended in the early stages of str...
Geor RJ, Becker RL, Kanara EW, Hovda LR, Sweeney WH, Winter TF, Rorick JK, Ruth GR, Hope E, Murphy MJ.Fever, limb edema, and laminitis were observed in horses 18 to 36 hours after they consumed hoary alyssum (Berteroa incana) under field and experimental conditions. Clinical signs were not observed in all horses that had ingested the plant. Diagnosis in the field cases was limited to observation of clinical signs and evidence of plant ingestion in hay or on pasture. In most cases, clinical remission was observed 2 to 4 days after empirical treatment, removal of the plant source, or both.
Ekfalck A, Rodriguez H, Obel N.LAMINITIS after abdominal surgery is a well known
complication that may occur after the horse has recovered from
colic (McIlwraith and Turner 1987). We had the opportunity to
examine a horse with post-surgical laminitis with a peracute
course whose early death made it possible to gain material from
the acute stage for histopathological investigations. We consider
that our observations may be of some value for colleagues
interested in the pathogenesis of laminitis.
Logas D, Kunkle G, Calderwood-Mays M, Frank L.An 8-year-old gelding, with a 1-year history of intense pruritus only after exercise, was diagnosed as having cholinergic pruritus. Provocative testing, using exercise and hot-water baths to increase core body temperature, assisted in the diagnosis. Cholinergic pruritus in human beings is a variant of the more common syndrome, cholinergic urticaria, which is characterized by intense pruritus and pinpoint urticaria. With cholinergic pruritus, intense itching results without urticaria. Specific diagnostic laboratory tests have not been developed.
Bergfelt DR, Woods JA, Ginther OJ.Characteristics of spontaneous embryonic loss in 21 mares were compared with those of 52 contemporary mares that maintained pregnancy. Embryonic losses were, in retrospect, grouped according to day of loss and length of the interovulatory interval, respectively, as follows: group 1, less than or equal to day 20 and less than or equal to 30 days (n = 10); group 2, less than or equal to day 20 and greater than 30 days (n = 3); and group 3, greater than day 20 and greater than 30 days (n = 8); ovulation was day 0. Mean diameter of the embryonic vesicle in group 1 was smaller (P less than 0.05) on...
Perkins NR, Robertson JT, Colon LA.A 15-year-old Standard-bred mare was examined because of signs of abdominal discomfort in late gestation. Palpation per rectum revealed tight broad ligaments above and below the uterus, with the right broad ligament running across the top of the uterine body down toward the left, ventral side of the abdomen. A diagnosis of counterclockwise uterine torsion was made and surgical correction was approached via a left, flank laparotomy with the horse standing. The uterus was repositioned and a uterine tear encompassing 180 degrees of the uterine surface was found in the lateral, uterine body just c...
Weaver JC, Stover SM, O'Brien TR.The sites of bony attachment of the tendons, ligaments, and fibrous portion of the joint capsules of the equine metacarpophalangeal (fetlock) joint region were determined by gross dissection. These sites were transposed to standard radiographic views of the fetlock joint to yield illustrations that can be used as an aid in the diagnosis of soft tissue pathology from radiographs. Evidence of direct attachment of the common digital extensor tendon to the proximal phalanx was not found. Branches of the superficial digital flexor tendon were found to insert only on the middle phalanx. The recently...
van Muiswinkel K.Based on three clinical cases, the history and the clinical and radiological aspects of osteochondrosis in horses are discussed. The prognosis, therapy and consequences with regard to athletic soundness and use for breeding are described.
Sweeney CR, Humber KA, Roby KA.Tracheobronchial aspirates obtained from 66 healthy Thoroughbred racehorses in training at the same track were examined. Twenty-seven percent of the horses had greater than 20% neutrophils in the aspirate. Eosinophils, mast cells, giant cells, and Curschmann's spirals of mucus were observed in 94, 83, 65, and 42% of the horses, respectively. Hemosiderophages were observed in 86% of the horses, half of which had previous confirmation of exercise-induced pulmonary hemorrhage. Although fungal elements were seen in 70% of the horses, bacteria were detected in only 3% of the horses. The authors con...
Folz SD, Hanson BJ, Griffin AK, Dinvald LL, Swerczek TW, Walker RD, Foreman JH.Ceftiofur sodium was evaluated as a therapy for respiratory infections in horses. This cephalosporin antimicrobial was administered intramuscularly every 24 h and at a dose of 2.2 mg/kg (1.0 mg/lb) of body weight. The efficacy of ceftiofur sodium was compared with that of a positive control drug, ampicillin sodium (recommended dose of 6.6 mg/kg [3 mg/lb], given every 12 h). Both treatments were continued for 48 h after clinical symptoms were no longer evident (maximum of 10 days). Fifty-five (55) horses with naturally acquired respiratory infections were included in the study; 28 were treated ...
Adeyefa CA.The precipitin response of the mitogen produced by Strongylus vulgaris arterial larvae was investigated. IgG (T) from the sera of horses naturally infected with S. vulgaris adults and arterial larvae recognised the presence of two antigenic components of the mitogenic fractions. The results obtained seem to confirm that these antigens are immunogenic in stimulating the production of increased levels of IgG(T) in infected animals, and showed that the procedures could be used as immunological tools in the diagnosis of S. vulgaris infection.
Stover SM, Johnson BJ, Daft BM, Read DH, Anderson M, Barr BC, Kinde H, Moore J, Stoltz J, Ardans AA.Twenty-one horses had a complete unilateral humeral fracture during race training or racing at a California racetrack during the period 24 February 1990 to 10 July 1991. Fractures occurred approximately equally in left and right limbs, and in males and females. Most fractures occurred during training, and in 2- and 3-year-old horses. Only 5 of 16 Thoroughbred horses with known racing records had previously raced more than once, and their mean time between races was less than the time between their last race and fracture (P = 0.07). Ten of 13 humeri studied further had gross evidence of periost...
McConnico RS, Brownie CF.Two horses with red maple (Acer rubrum) toxicity responded to treatment with high doses of vitamin C (ascorbic acid), in addition to blood transfusions, and intravenous fluid therapy. The clinical course included Heinz body anemia, marked methemoglobinemia, depression, and evidence of severe tissue anoxia. Clinical recovery was dramatic with stabilization achieved 36 hours following the initiation of ascorbic acid therapy.
Everett KA, Chaffin MK, Brinsko SP.A diaphragmatic hernia in which 90% of the large colon had herniated through a 16-cm linear tear in the diaphragm was found in a 12-year-old Quarter Horse mare. Clinical signs included lethargy and exercise intolerance. Diagnosis of diaphragmatic hernia was made based on careful thoracic auscultation, combined with ultrasonographic and radiographic examination of the thorax.
Richet G.P. Rayer (1795-1867) had never thoroughly published his experimental studies on the contagion of glanders. His recently un-earthed hand written papers allow us to depict his experimental approach and its results. He was not the first who transmitted glanders from a patient to horses or donkeys. But he did it systematically with glander secretions from acute and chronic cases. Whatever was the disease of the donors the transmitted forms were unpredictably either chronic or acute. His conclusion was that the two forms were two symptomatic aspects of a unique disease. Clinically dormant states we...
Prasad A, Kumar V, Kumar B.Theileria equi is a tickborne hemoparasite that can cause severe illness in equids. In this report, we are describing a condition of acute bilateral hyphema in a 4-month-old Kathiawari filly infected with T. equi. The horse showed clinical signs such as fever, lethargy, icterus, tachycardia, tachypnea, and bilateral hyphema. Laboratory diagnosis revealed anemia and thrombocytopenia. Atypical clinical manifestation of bilateral hyphema, to our knowledge, has never been reported so far in equids infected with T. equi. The diagnosis was confirmed by microscopic examination of Geimsa-stained blo...
Huskamp B.The paper considers the general principles of intestinal surgery in the horse and illustrates a theatre layout suitable for this purpose. The problems of locating and reducing obstructions of the small and large intestine are discussed, with particular emphasis on incarcerations of the small bowel and the techniques of jejunal and ileal re-implantation after bowel resection.
Anderson JD, Leonard JM, Zeliff JA, Garman RH.A 16-year-old Thoroughbred gelding was evaluated for respiratory disease and found to have a primary lung tumor on postmortem examination. A tentative antemortem diagnosis was made on the basis of results of radiography and cytologic examination of a needle aspirate guided by ultrasonography. A histologic diagnosis of bronchioalveolar adenocarcinoma was made. Thoracic neoplasia is rare in horses. The most frequently reported primary pulmonary tumor is the granular cell tumor.
Chiejina SN, Mason JA.Several incidents of diarrhoea and loss of weight occurred in adult horses during the spring of 1976. Detailed investigation of one typical case suggested that maturation of inhibited larvae of Trichonema spp was responsible.
Pipers FS, Reef V, Wilson J.Ventricular septal defects in a foal, a 2-year-old filly, and 2 calves were demonstrated with M-mode and two-dimensional real-time echocardiography. The studies were performed with the animals unsedated, either standing or in lateral recumbency. Cardiac windows were located between the 4th and 7th intercostal spaces, approximately at the level of the olecranon. In each case, the septal defect was visualized high in the membranous portion of the interventricular septum. Defects were visualized by use of sector scanning or linear-array ultrasonic equipment, with transducer frequencies of 2.25 to...
Al-Mashat RR, Taylor DJ.Thirty-three species of bacteria were isolated from the gastrointestinal mucosa of 23 adult horses and two foals. The bacteria isolated could be related to gross and microscopical lesions in some cases. Clostridium perfringens type A, Actinobacillus equuli, Salmonella typhimurium and Campylobacter coli biotype 1 could all be associated with gastrointestinal lesions. C jejuni biotype 1 and Aeromonas hydrophila were both recovered in this study and have been identified as causes of enteritis in horses or in other species. The case of C coli enteritis appears to be the first such report. The diff...
Diana A, Freccero F, Giancola F, Linta N, Pietra M, Luca V, Salamanca G, Cipone M, Chiocchetti R.Ultrasonographic morphometry of wall layers is commonly used in veterinary patients with suspected small intestinal disease, however published studies comparing this method with histopathology in horses are limited. This prospective, methods comparison study compared the qualitative and quantitative characteristics of small intestinal wall layers using ex vivo high-frequency ultrasound versus histopathology in a sample of 16 horses. Transverse section images of duodenum, distal jejunum, and ileum were acquired with a high-frequency linear transducer (7-15 MHz). Transverse histological cryosec...
Lindsay-McGee V, Massey C, Li YT, Clark EL, Psifidi A, Piercy RJ.Equine exercise-associated myopathies are prevalent, clinically heterogeneous, generally idiopathic disorders characterised by episodes of myofibre damage that occur in association with exercise. Episodes are intermittent and vary within and between affected horses and across breeds. The aetiopathogenesis is often unclear; there might be multiple causes. Poor phenotypic characterisation hinders genetic and other disease analyses. Objective: The aim of this study was to characterise phenotypic patterns across exercise-associated myopathies in horses. Methods: Historical cross-sectional study, w...
Widmer A, Fürst A, Bettschart R, Makara M, Geyer H, Kummer M.This clinical report describes two horses with bilateral maxillary fractures following dental treatment. The fractures occurred during dental treatment by a veterinarian, and both had rostral, transverse, and complete bilateral maxillary fractures with instability and minimal displacement. The fractures were repaired using bilateral intraoral wiring with the patients under general anesthesia. The postoperative period was without complications and the fractures healed as expected. Maxillary fractures during or after routine dental treatment are rare, but can occur, especially in older horses. A...
Stefanovski D, Robinson MA, Van Eps A.Insulin dysregulation (ID) is the most important risk factor for the development of laminitis in horses and therapies to control it are needed. Objective: To assess the effects of a single dose of the synthetic GLP-1 analog exenatide on postprandial insulin dynamics. We hypothesized that exenatide would improve insulin sensitivity and lower postprandial blood insulin concentrations. Methods: Randomized, crossover, experimental study. Methods: Six horses (3 mares, 3 geldings; 2 with normal insulin regulation [NIR] and 4 with mild ID). Methods: Horses completed both study arms: subcutaneous admi...
Hoffman AM.Respiratory diagnostic instruments previously available only to referral centers should be converted into miniature, portable, wireless medical devices for use in practice. Internet and wireless connections of these instruments should expedite the process of seeking second opinions and in general information sharing. We are moving into a world of greater objectivity that should free us from speculation in some areas, yet open new avenues for research and innovation in others.
McGowan CM, McGowan TW, Patterson-Kane JC.The aim of this study was to determine the prevalence of equine polysaccharide storage myopathy (EPSM) in two populations of horses in the UK. Biopsy specimens from 94 horses presented to an abattoir (population 1), and 46 horses with neuromuscular disorders presented to a university referral hospital (population 2) were obtained over a period of 4years. Histological sections were examined by a veterinary pathologist for lesions including abnormal polysaccharide inclusions in myofibres. In population 1, a diagnosis of EPSM was made in 8% and non-specific myopathy in 33% of horses. In populatio...
Allison CJ.A chronic wasting disease in a 16 month old Welsh pony filly is described. The animal died 26 days after the onset of illness which commenced with a sub-acute colic and was characterised by progressive loss of appetite and weight. Post-mortem examination revealed a total invagination of the caecum into the colon and it seemed logical to assume this invagination occurred at the start of the illness. A review of the literature showed that total caecal invagination produces 2 distinct clincal syndromes. It can occur either as an acute illness characterised by severe colic and death after about 10...
Kelmer G, Catasus CT, Saxton AM, Elliot SB.The feasibility of maintaining indwelling intravenous catheters in the saphenous, cephalic or palmar digital vein of horses for seven days to infuse antimicrobial drugs was investigated in 18 horses. The horses were randomly assigned to six groups according to the vein catheterised and whether they received amikacin or erythromycin. None of the catheters was replaced more than once, and 11 of the 18 catheters remained patent for all seven days. Neither the drug administered nor the vein catheterised significantly affected the survival of the catheter. In all but three cases, complications, inc...
Dubey JP, Miller S.A 10-year-old pony died 5 days after the onset of a nervous disorder. Necropsy revealed a yellowish area of discoloration (1.5 by 1 cm) in the medulla oblongata. Microscopically, necrosis and nonsuppurative myeloencephalitis were found in the medulla oblongata. Immature and mature meronts (25 by 10 microns) were seen in neural tissue and in capillaries of the brain stem. Organisms were similar structurally to those seen in equine protozoal myeloencephalitis of horses.
Davidson EJ, Martin BB, Parente EJ.3 racehorses were evaluated because of poor performance or abnormal noise originating from the upper portion of the respiratory tract. Results: During maximal exercise, initial dynamic videoendoscopy of the upper respiratory tract revealed complete arytenoid cartilage abduction in 2 horses and incomplete but adequate abduction of the left arytenoid cartilage in 1 horse. Subsequent exercising endoscopic evaluation revealed severe dynamic collapse of the left arytenoid cartilage and vocal fold in all 3 horses. Results: 2 horses were treated with prosthetic left laryngoplasty and raced successful...
Burns TA.Nutrition plays an important role in equine health, including that of the foot. Deficiencies and excesses of dietary components can affect the growth and function of the foot and have been associated with important podiatric diseases. The recognition, prevention, and treatment of specific notable nutritional diseases of the foot are discussed, as well as information regarding specific ingredients included in supplements meant to improve equine hoof quality. Ensuring provision of a balanced diet, maintaining horses in appropriate body condition, and seeking guidance from an equine nutritionist ...
du Preez S, Raidal SL, Doran GS, Nielsen SG, Hughes KJ.This study was performed to determine the consistency of exhaled breath condensate (EBC) hydrogen peroxide (HO), pH and leukotriene B (LTB) measurements in asymptomatic horses and to define the influence of environmental and animal factors on these variables. Intra- and inter-day consistency for both HO and pH measurements were adequate, with intraclass correlation coefficients ≥0.8, whereas the consistency for LTB was poor. HO was influenced by ambient temperature (T), humidity, time of day and collection location (all P<0.01), while pH was influenced by respiratory rate during EBC colle...
Freeman DE.Guttural pouch diseases pose serious challenges in diagnosis and treatment. Complications from treatment are common and often life-threatening, largely because the unique anatomy of the guttural pouches brings them into intimate contact with the nervous, respiratory, and cardiovascular systems. There is little forgiveness for surgical errors, and so the surgeon should focus on ways to anticipate and prevent them. As with any disease, errors in diagnosis can set the stage for many surgical errors and must be recognized. This article deals with errors that can be expected after the most common s...
Böse R, Peymann B, Barbosa IP.Sera from 60 horses held in breeding herd in Brazil were examined monthly by ELISA, immunofluorescence antibody test (IFAT) and Western blot. All foals had maternal antibodies detectable by ELISA and IFAT, and sero-conversion took place between the 2nd and 5th month of age. The 48 and 50 kDa antigens were recognized first in the course of infection. Of 79 sera taken after sero-conversion 78 reacted with the 48 kDa antigen, 76 with the 50 kDa, 50 with the 70 kDa, 54 with the 112 kDa, 72 with the 141 kDa antigen. In general, sera from horses older than 1 year reacted with all 5 diagnostic antige...
Meek LA.A 40-mm intraocular silicone prosthesis was placed in a horse's globe to control glaucoma. The glaucoma was suspected to be associated with a lens subluxation, but primary glaucoma could not be ruled out. Medical treatment and cyclocryotherapy had been attempted, but failed to decrease the intraocular pressure to a normal value. The prosthesis was placed, via a dorsal scleral incision, after removal of the intraocular contents. The size of the prosthesis was estimated from measurements of the horse's normal left globe and an enucleated, age-matched globe. Silicone prostheses offer a cosmetic a...
Roest HI, de Bruijn CM, Picavet MT, Prins B, Parmentier D, de Zwart GM, Dijkstra YE, van Zijderveld FG.Symptoms, diagnosis and therapy of equine botulism are discussed by the presentation of two detailed reports of horses with neurological symptoms and the results of laboratory investigations over the period 2003-2008 in the Netherlands. In addition a brief summary of the available literature is presented. Prevailing symptoms of botulism in horses include paralysis of the tongue, salvation, dysphagia and paresis and paralysis of the skeletal muscles, as well as signs of colic. Symptoms and prognosis vary with the amount of botulinum neurotoxin (BoNT) involved. For early clinical diagnosis of bo...
Humber KA, Sweeney RW, Saik JE, Hansen TO, Morris CF.Bacillus piliformis infection (Tyzzer's disease) in foals is rarely observed clinically because of the peracute course of the disease. Clinical and clinicopathologic findings as well as information on therapeutic attempts in two foals are described. Clinicopathologic abnormalities common to both cases included leukopenia, hyperfibrinogenemia, metabolic acidosis, and hypoglycemia. Treatment was unsuccessful in both cases.
Hahn CN, Mayhew IG.The precise appearance of ptosis due to lesions at different sites was investigated in experimental ponies. The angles of the eyelashes to the head was used as an objective measurement of ptosis after local anaesthesia of the sympathetic trunk or the palpebral nerve and the administration of an ocular alpha agonist or antagonist. It was shown that ptosis is not an inevitable consequence of palpebral nerve pathology, that ocular alpha antagonists can induce ptosis, and that alpha agonist eyedrops have an inconsistent effect on the equine pupil, but are consistent at reversing ptosis induced by ...
Battelli G, Galuppi R, Pietrobelli M, Tampieri MP.Fecal examinations of horses (Equus caballus) from studs in the province of Udine (Friuli Venezia Giulia region, east-northern Italy), carried out during two periods of the year 1993, revealed coccidian oocysts in six foals, two stallions and one mare. The species was identified as Eimeria leuckarti. This species was reported only once in Italy, more than 20 years ago (1972). For this reason, the prevalence of the parasite and the description of immature and sporulated oocysts are given.
West HJ.In 18 horses there was no effect of age or sex on plasma activities of gamma-glutamyl transferase (gamma-GT), 5'-nucleotidase (5'-NT) and leucine aminopeptidase (LAP). All the enzymes were equally stable after storage for one month at -20 degrees C and there was no significant difference between their activities in serum and plasma in clinically normal horses. The pattern of release of gamma-GT, 5'-NT and LAP into plasma was studied in 114 horses which had a variety of orthopaedic, gastrointestinal, cardiovascular and hepatic (necrosis, lipidosis, neoplasia and cirrhosis) conditions. A definit...
