The study of diseases in horses encompasses a wide range of conditions affecting equine health, including infectious diseases, metabolic disorders, and genetic abnormalities. These diseases can impact various systems within the horse, such as respiratory, gastrointestinal, and musculoskeletal systems, and can lead to significant health challenges. Research in this area focuses on understanding the pathophysiology, diagnosis, prevention, and treatment of equine diseases. Common diseases studied include equine influenza, equine herpesvirus, and laminitis. This page provides access to peer-reviewed research studies and scholarly articles that explore the etiology, clinical presentation, and management strategies of diseases in horses, contributing to the advancement of equine veterinary medicine.
Hollis AR, Furr MO, Magdesian KG, Axon JE, Ludlow V, Boston RC, Corley KT.Critical illness is associated with hyperglycemia in humans, and a greater degree and duration of hyperglycemia is associated with nonsurvival. Hypoglycemia is also seen in critically ill humans, and is associated with nonsurvival. This might also be true in the critically ill foal. Objective: To investigate the association of blood glucose concentrations with survival, sepsis, and the systemic inflammatory response syndrome (SIRS). Methods: Blood glucose concentrations at admission (515 foals) and 24 hours (159 foals), 36 hours (95), 48 hours (82), and 60 hours (45) after admission were analy...
Aleman M, Puchalski SM, Williams DC, Kass PH, Holliday TA.Facial and vestibulocochlear nerve dysfunction occurs commonly in horses with temporohyoid osteoarthropathy (THO); however, auditory dysfunction has not been thoroughly assessed. Objective: To determine if auditory abnormalities occur in horses with THO. Methods: Eleven diseased and 8 control horses. Methods: This is a prospective study in which brainstem auditory-evoked responses (BAER) were recorded in 11 horses diagnosed with THO through neurologic, endoscopic, radiographic, or computed tomographic examinations. BAER findings were compared with those recorded from 8 adult control horses. Re...
Diallo IS, Hewitson GR, de Jong A, Kelly MA, Wright DJ, Corney BG, Rodwell BJ.Twelve nasal swabs were collected from yearling horses with respiratory distress and tested for equid herpesvirus 1 (EHV-1) and equid herpesvirus 4 (EHV-4) by real-time PCR targeting the glycoprotein B gene. All samples were negative for EHV-1; however, 3 were positive for EHV-4. When these samples were tested for EHV-2 and EHV-5 by PCR, all samples were negative for EHV-2 and 11 were positive for EHV-5. All three samples that were positive for EHV-4 were also positive for EHV-5. These three samples gave a limited CPE in ED cells reminiscent of EHV-4 CPE. EHV-4 CPE was obvious after 3 days and...
Kriegshäuser G, Cullinane A, Kuechler E, Skern T.Equine rhinitis B virus 1 (ERBV1), genus Erbovirus, family Picornaviridae, is a pathogen of horses which causes clinical and subclinical infection of the upper respiratory tract in horses. The virus is widespread in European horse populations and the current standard method for the detection of antibody against ERBV1 is by virus neutralisation (VN). VN tests, however, are labour-intensive and time-consuming, require tissue culture facilities, and generally do not provide same-day results. In this study, a protocol for the high-level expression and purification of recombinant virion protein 1 (...
Zimmerman KL, Crisman MV.This article is presented with two main goals: (1) to provide equine clinicians with a resource for identifying types of serum tests available and (2) to outline briefly the necessary sample type, assay principle, and relative strengths and weakness of the various methods. Specific etiologies are presented and grouped by clinical diagnosis categories, along with brief comments concerning each disorder and its relevant diagnostic assays. This organization provides an abstracted list of infectious disorders commonly considered for the various clinical presentations and a summary of available ser...
Brooks MB.The most common cause of hemorrhage is vascular injury; however, the possibility of hemostatic failure should be considered in the initial differential diagnosis. This article provides an overview of preliminary screening and definitive tests to identify hemostatic defects in horses.
Crisman MV, Scarratt WK.Immunodeficiencies are characterized as primary (genetic) or secondary (acquired). Primary immunodeficiencies are relatively uncommon; however, clinically, they present a significant challenge to the practitioner, especially if the underlying disorder goes unrecognized. Secondary immunodeficiencies may present at any age, but failure of passive transfer in neonatal foals is most commonly encountered. This article provides a general overview of clinical signs and diagnosis of primary and secondary immunodeficiencies currently recognized in horses.
McGowan C.Clinical pathology is frequently used in racehorses to screen for "fitness" to race and to screen for disease that may affect performance. The role of clinical pathology in exercise testing of racehorses is important, especially in the area of blood lactate responses to exercise. This article discusses the use of resting and dynamic clinical pathology in the racehorse, especially in respect to investigation of the state of training (or fitness) and detection of subclinical performance-limiting disease.
Axon JE, Palmer JE.The neonatal foal is in a period of transition between fetal and extrauterine life. The clinicopathologic findings in this period often reflect the in utero environment; thus, results need to be interpreted with the knowledge of changes that intrauterine life may produce. These changes can also assist the veterinarian in identifying a foal at high risk for developing clinical problems. The veterinarian should also be aware of the normal variations in clinicopathologic findings that occur as the foal matures. As with results from all diagnostic testing, the clinicopathologic results need to be ...
Savage CJ.Urinary specific gravity (USG) measurements are underused by equine ambulatory veterinarians. Urinary dipstick and USG findings can assist in the diagnosis and prognosis of many disease processes in the horse. Simple methods for measurement of the glomerular filtration rate and urinary biochemical markers can improve equine urinary diagnostic abilities in critical care patients. Fractional excretion of electrolytes and minerals assists in fluid care and in management of nutrition of horses.
van den Boom R, Ducro B, Sloet van Oldruitenborgh-Oosterbaan MM.An Internet-based questionnaire among horse owners was carried out to identify factors affecting the incidence of insect bite hypersensitivity (IBHI) among horses in the Netherlands. Information was obtained for 794 horses of various breeds, but the breed distribution was not representative for the Dutch horse population. Of the horses for which information was available, 56% suffered from IBH and 44% did not. The most common clinical symptoms were pruritus, scaling, and hair loss, occurring mainly at the base of the tail and along the mane. Breed, age, region (and local habitat), stabling, ty...
Egenvall A, Penell J, Bonnett BN, Blix J, Pringle J.Colic is an important cause of morbidity and mortality in horses. In Sweden, an insurance database with diagnostic medical information is maintained on >30% of the nation's horse population. Objective: The objective was to describe the occurrence of colic, defined by costly veterinary care and life claims, in horses at 1 insurance company during 1997-2002. HORSES: All horses (<21 years of age) with complete insurance for veterinary care and life during the period 1997-2002 were included. Methods: Colic was defined as conditions where the main clinical sign was abdominal pain and the prob...
Sun C, Zhang B, Jin J, Montelaro RC.The identification and characterization of a functional cellular receptor for equine infectious anemia virus (EIAV), designated equine lentivirus receptor-1 (ELR1), a member of the tumour necrosis factor receptor protein family, has been reported previously [Zhang, B. et al. (2005). Proc Natl Acad Sci U S A, 102 , 9918-9923]. The finding of a single receptor for EIAV is distinct from feline, simian and human immunodeficiency viruses, which typically utilize two co-receptors for infection, but is similar to avian and murine oncoviruses, which use single receptors. This study sought to determine...
van Galen G, Delguste C, Sandersen C, Verwilghen D, Grulke S, Amory H.Few studies exist about factors affecting the outcome of horses with tetanus. Methods: 31 equids (30 horses and 1 donkey) with a clinical diagnosis of tetanus admitted to the Equine Clinic of the University of Liege between 1991 and 2006. The cases were divided into two groups according to the outcome (survivors and non-survivors). Methods: The clinical data of survivors and non-survivors were compared using an ANOVA (continuous data) or a Fisher's test (discrete data). Results: The survival rate was 32%. Most animals were 5 years or younger, and none had been appropriately vaccinated. The non...
Russell CM, Axon JE, Blishen A, Begg AP.To assist correct decision-making about antimicrobial treatment of equine neonates with septicaemia. Methods: Retrospective study of microbial blood culture results obtained from foals less than 7 days of age. Methods: Microbial blood culture results from foals less than 7 days of age admitted to an intensive care unit between July 1999 and December 2004 were reviewed. Antimicrobial sensitivity was assessed by the Kirby Bauer disc diffusion method. Antimicrobials were defined as an effective first-line choice antimicrobial if greater than 70% of isolates were susceptible. Multiple drug resista...
Zhang J, Go YY, MacLachlan NJ, Meade BJ, Timoney PJ, Balasuriya UB.Comparative sequence analysis of a series of strains of equine arteritis virus (EAV) of defined virulence for horses, ranging from the horse-adapted virulent Bucyrus (VB) strain to a fully attenuated vaccine strain derived from it, identified 13 amino acid substitutions associated with attenuation. These include 4 substitutions in the replicase proteins and 9 in the structural proteins. Using reverse genetic techniques, these amino acid substitutions were introduced into a virulent infectious cDNA clone pEAVrVBS derived from the VB strain of EAV. Inoculation of horses with the recombinant viru...
Hollis AR, Wilkins PA, Palmer JE, Boston RC.Bacteremia in sick foals is associated with survival, but the association of bacteremia and diarrhea is not reported. Objective: Neonatal foals with diarrhea will commonly be bacteremic. Methods: One hundred and thirty-three neonatal foals. Methods: Records of all foals <30 days of age presenting with diarrhea between January 1990 and September 2007 were reviewed. Results: Sixty-six of 133 foals (50%) were bacteremic at admission, with 75 isolates from the 66 samples. The blood culture from a further 18 foals (13.5%) grew coryneform bacteria. Nine foals (6.8%) had 2 or more organisms grown on ...
Walsh C, Gangloff M, Monie T, Smyth T, Wei B, McKinley TJ, Maskell D, Gay N, Bryant C.LPS signals through a membrane bound-complex of the lipid binding protein MD-2 and the receptor TLR4. In this study we identify discrete regions in both MD-2 and TLR4 that are required for signaling by lipid IVa, an LPS derivative that is an agonist in horse but an antagonist in humans. We show that changes in the electrostatic surface potential of both MD-2 and TLR4 are required in order that lipid IVa can induce signaling. In MD-2, replacing horse residues 57-66 and 82-89 with the equivalent human residues confers a level of constitutive activity on horse MD-2, suggesting that conformational...
Loynachan AT, Bryant UK, Williams NM.A 35-year-old horse was submitted to the necropsy service at the University of Kentucky Livestock Disease Diagnostic Center. At necropsy, multiple 1-4-cm-diameter cystic structures were incidentally identified unilaterally in the right renal medulla and the cortex. On histologic examination, the cystic structures compressed the normal renal architecture, were lined by tall columnar epithelium that formed occasional papillary projections, and contained large amounts of mucicarmine and periodic acid-Schiff-positive mucinous material. The masses were diagnosed as renal mucus-gland cystadenomas. T...
Davidson A, Traub-Dargatz JL, Magnuson R, Hill A, Irwin V, Newton R, Waller A, Smith K, Callan RJ, Meehan M, Owen P, Salman M.Previously published studies have neither used nor reported the results of an indirect enzyme-linked immunosorbent assay (iELISA) to measure serologic responses in natural outbreaks of strangles. The concept of using serologic responses to identify persistent carriers of Streptococcus equi has been proposed but not scientifically evaluated. The specific aims of the current study were to determine the duration and level of truncated fibrinogen-binding protein-specific (SeM allele 1) antibody production in ponies involved in a natural outbreak of strangles and to determine if test results from t...
Van den Eede A, Martens A, Lipinska U, Struelens M, Deplano A, Denis O, Haesebrouck F, Gasthuys F, Hermans K.Methicillin-resistant Staphylococcus aureus (MRSA) infections do occur in equine patients. Little is known, however, about their origin and the general equine MRSA colonization status. In West European horses in particular, neither the colonization rate nor the present strains or their antimicrobial susceptibility patterns are known. In the present study, a sample of 110 (Belgian, French, Dutch and Luxemburg) horses presented at a Belgian equine clinic was screened for nasal MRSA carriage. An indirect culturing protocol using a 0.001% colistin and nalidixic acid containing broth was compared t...
Huang L, Zhu W, Saunders CP, Macleod JN, Zhou M, Stromberg AJ, Bathke AC.Identification of biomarkers among thousands of genes arrayed for disease classification has been the subject of considerable research in recent years. These studies have focused on disease classification, comparing experimental groups of effected to normal patients. Related experiments can be done to identify tissue-restricted biomarkers, genes with a high level of expression in one tissue compared to other tissue types in the body. Results: In this study, cartilage was compared with ten other body tissues using a two color array experimental design. Thirty-seven probe sets were identified as...
Fransson BA.This article reviews the etiology, diagnosis, and treatment of rectal perforation and rectocutaneous fistula in small animals. In addition, the literature regarding use of enterostomy in small animals is reviewed and comparative aspects of this procedure in humans and horses are presented. A case report of rectal perforation leading to rectocutaneous fistula formation and the use of colostomy in the management of the case is presented.
Brown SL, Arkins S, Shaw DJ, Dixon PM.The angle between the occlusal surface of the tooth and the horizontal plane of 687 cheek teeth from the skulls of 22 horses without gross dental disorders and 11 horses with dental disorders were measured by using stiff malleable wire as an imprint. Each measurement was repeated five times and the mean angle was recorded. In the normal skulls, the mean occlusal angles of the mandibular cheek teeth ranged from 19.2 degrees at the Triadan 06 position to 30 degrees at the 11 position, and these angles were significantly greater than the occlusal angles of the opposing maxillary cheek teeth (rang...
Ireland JJ, Roberts RM, Palmer GH, Bauman DE, Bazer FW.Research on domestic animals (cattle, swine, sheep, goats, poultry, horses, and aquatic species) at land grant institutions is integral to improving the global competitiveness of US animal agriculture and to resolving complex animal and human diseases. However, dwindling federal and state budgets, years of stagnant funding from USDA for the Competitive State Research, Education, and Extension Service National Research Initiative (CSREES-NRI) Competitive Grants Program, significant reductions in farm animal species and in numbers at land grant institutions, and declining enrollment for graduate...
Kuwano A, Tanaka K, Kawabata M, Ooi Y, Takahashi T, Yoshihara T, Reilly JD.A survey was carried out into white line disease in 1781 Thoroughbred racehorses kept in stables at the Japan Racing Association (JRA) Miho Training Center (MTC) September-October 1996. The survey was conducted while horses were being shod by farriers. The horses that still exhibited damaged white lines after regular trimming were diagnosed as having white line disease. The factors recorded were age, sex, number of diseased horses, number of diseased hooves, number of lesions by region over the bearing border of the hoof and the classified length of such lesions. The percentage of total diseas...
Gardner RB, Hart KA, Stokol T, Divers TJ, Flaminio MJ.A 5-week-old Fell Pony colt was examined for fever, lethargy, and anemia. The colt had been lethargic for 1 week before examination, had continued to nurse, had a temperature of 104°F (40°C), and was treated with ceftiofur (5 mg/kg IM q12h). Approximately 36 hours before examination, the colt developed watery diarrhea. Blood work performed by the referring veterinarian on the day of admission revealed a PCV of 10%.
Zimmerman KL, Crisman MV.This article is presented with two main goals: (1) to provide equine clinicians with a resource for identifying types of serum tests available and (2) to outline briefly the necessary sample type, assay principle, and relative strengths and weakness of the various methods. Specific etiologies are presented and grouped by clinical diagnosis categories, along with brief comments concerning each disorder and its relevant diagnostic assays. This organization provides an abstracted list of infectious disorders commonly considered for the various clinical presentations and a summary of available ser...
Kapdi A, Dhanze H, Sahu A, Singh V, Kumar MS, Bhilegaonkar KN, Gulati BR.Japanese encephalitis (JE) is a mosquito borne flaviviral zoonoses, causing fatal disease in equines and humans. JE is endemic in most of the states of India with occurrence of human cases every year. The horses are not vaccinated against JE in India and thus they are at more risk of acquiring the disease. Due to nonavailability of indigenously developed ELISA and high cost of imported kits, regular sero-surveillance is not being carried out to assess the true picture of JE virus in equine population of India. Therefore, a recombinant NS1 protein based indirect IgG ELISA was developed with the...
Kato M, Higuchi T, Orita Y, Ishikawa Y, Kadota K.A hepatic malignant tumour composed of both hepatocellular and cholangiocellular elements was studied histologically, immunohistochemically and electron microscopically in an 18-year-old Thoroughbred mare. Bile canaliculi and alpha-fetoprotein were useful in identifying the hepatocellular element, and mucin and keratin were good markers of biliary differentiation. The simultaneous presence of bile canaliculi and mucin-producing cells in most of the neoplastic lesions suggested that this tumour arose from a stem cell with capacity to differentiate into hepatocytes and biliary epithelium.
Khosravi M, Kavosh F, Taghavi-Moghadam A, Ghaem-Maghami S, Pirali-Kheirabadi K, Rahimi-Feyli P, Navid-Pour S, Amin-Pour A, Arbabi F.No abstract available
Platt H, Whitwell KE.A form of generalized fat necrosis and steatitis occurs in pony and donkey foals. The clinical and pathological features of this disorder are described and its possible relationship to a similar condition in the Thoroughbred foal, and to yellow Fat Disease in other species, is discussed.
Ruggles AJ, Ross MW, Freeman DE.Sixteen horses with suspected paranasal sinus disease had endoscopic examination of the paranasal sinuses with a 4.0 mm arthroscope either while standing and sedated (14 horses) or under general anesthesia (two horses). Endoscopic diagnosis included sinusitis (four horses), sinus cyst (three horses), hemorrhage (three horses), neoplasia (three horses), and tooth root abnormalities (two horses). No abnormalities were detected in one horse. Endoscopic findings concurred with the radiographic findings in 13 horses (81%). Samples of sinus contents for bacteriologic (eight horses) and histologic ex...
Geiser DR.There are several beneficial physiologic and therapeutic effects of hyperbaric oxygen therapy (HBOT). The indications list for the use of HBOT in the horse has been developed through extrapolation from a review of human indications and from anecdotal clinical experiences. Hyperbaric therapy is a safe treatment option with very few side effects when administered properly.
Lawson GH, McPherson EA, Murphy JR, Nicholson JM, Wooding P, Breeze RG, Pirie HM.The sera of horses affected and not affected with chronic obstructive pulmonary disease (COPD) were examined for precipitins to Micropolyspora faeni and Aspergillus fumigatus. Precipitins to both antigens were not restricted to COPD cases but occurred more frequently in animals affected with COPD. Many animals without detectable precipitins responded clinically to inhalation challenge with these antigens.
Collins J, More SJ, Hanlon A, Duggan V.This report describes the progression in welfare standards for horses on a horse farm in the Republic of Ireland between 2007 and 2009. Visits to the farm were undertaken and information, in the form of written notes and digital recording of observations and examinations, was gathered in consultation with officials from the Gardaí (the Irish police), the Department of Agriculture, Fisheries and Food and the Irish Society for the Prevention of Cruelty to Animals. Further independent veterinary corroboration of clinical findings and laboratory support occurred following seizure of the horses. T...
Evans MJ, Hamer JM, Gason LM, Irvine CH.Twelve acyclic mares of various ages (2-29 years) and parity (maiden-multiparous) were given oestradiol-17 beta i.m. (winter 1982) or progesterone i.m. (winter 1983) to induce changes in the endometrium consistent with oestrus and dioestrus, respectively. After hormone treatment, mares were inoculated intrauterine with 50 ml saline containing 5 X 10(5) Streptococcus zooepidemicus bacteria, 51Cr-labelled 15-micron microspheres, and 500 mg charcoal (Groups E + B and P + B) or microspheres and charcoal only (Groups EC and PC). At 5 h after inoculation uteri were flushed with 50 ml saline containi...
Stickle RL, Erb RE, Fessler JF, Runnels LJ.Unilateral ovariectomy was performed on 3 mares affected with granulosa cell tumors. Tumor fluid in each mare was found to contain estrogen, testosterone, and progesterone. In 2 mares, preoperative blood plasma concentrations of these hormones were comparable to those of a series of clinically normal mares. The other mare, which had a history of aggressive, masculine behavior, had higher testosterone content in the tumor fluid and in the preoperative blood sample. After surgical removal of the tumors, each mare developed follicles and ovulated with the remaining ovary. Each was eventually bred...