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.
Infection with Toxoplasma gondii is one of the most common parasitic infections of human being and other warm-blooded animals. It has been found worldwide from Alaska to Australia. Public health organizations repeatedly encourage the collection of accurate data about T. gondii in animals and humans due to its medical importance as a major source of parasitic zoonosis. For these reasons, epidemiological updates on toxoplasmosis in livestock are strongly advised also to plan control strategies. In the present paper, seroprevalence data on T. gondii that have been recorded in livestock from diffe...
Young R, Taylor JE, Kurioka A, Becker M, Louis EJ, Rudenko G.African trypanosomes (including Trypanosoma brucei) are unicellular parasites which multiply in the mammalian bloodstream. T. brucei has about twenty telomeric bloodstream form Variant Surface Glycoprotein (VSG) expression sites (BESs), of which one is expressed at a time in a mutually exclusive fashion. BESs are polycistronic transcription units, containing a variety of families of expression site associated genes (ESAGs) in addition to the telomeric VSG. These polymorphic ESAG families are thought to play a role in parasite-host adaptation, and it has been proposed that ESAG diversity might ...
Polkes AC, Giguère S, Lester GD, Bain FT.Neonatal foals with isoerythrolysis (NI) often die, but the risk factors for death have not been identified. Objective: To identify factors associated with outcome in foals with NI and to identify factors associated with death from liver failure or kernicterus in the same population. Methods: Seventy-two foals with NI examined at referral institutions. Methods: Retrospective case series. Information on signalment, clinical examination findings, laboratory testing, treatment, complications, outcome, and necropsy results were obtained. Results: The overall survival rate was 75% (54 of 72). Liver...
Castagnetti C, Veronesi MC.In the foal, the most common neonatal diseases are responsible for an high non-survival rate. Since intensive care for neonatal foals is usually very expensive an early prognosis for survival at admission or during hospitalization is recommended, as well as a prognosis for future athletic potential. Therefore, prognostic factors for prematurity, septicaemia, other infectious diseases and hospitalized foals are revised and discussed on the base of literature and authors experiences. The advantages and limitations of retrospective and perspective prognostic factors is also presented, and the pos...
Kruger K, Saulez MN, Neser JA, Solberg K.Lead (Pb) intoxication in horses is usually a chronic phenomenon with clinical signs associated with central nervous dysfunction. This report gives details of a case of acute Pb intoxication in a 9-year-old American Saddlebred mare with severe, progressive and ultimately fatal neurological deterioration. During the 4 days of hospitalisation, clinical signs progressed from intermittent headshaking and depression to severe, continuous, uncontrollable manic behaviour. At autopsy, three grey-coloured, hard metal particles were present in the gastrointestinal tract and subsequently found to contain...
Hyera JM, Baipoledi EK.A retrospective serological survey of African horse sickness (AHS) in Botswana covering a 10-year period (1995-2004) is reported. The survey involved horses showing clinical symptoms of the disease; the horses had not been vaccinated against AHS. Over the period surveyed, serological evidence suggestive of infection with AHS virus (AHSV) was found in 99 clinical cases out of which 41.4% (41/99) cases were found during the 1st half (1995-1999) and 58.6 % (58/99) cases were found in the 2nd half of the survey period (2000-2004). These serological findings are discussed in relation to AHSV seroty...
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 ...
A 3-year-old Thoroughbred gelding was examined because of clinical signs of pneumonia and shock. Mucous membrane petechiation and ventral edema were observed and considered to be a result of vasculitis. Epidermal necrosis developed on the distal portions of the limbs. The horse had a persistent high fever that was unresponsive to nonsteroidal anti-inflammatory treatment, and Staphylococcus aureus was isolated from a nasal swab specimen and 2 transtracheal wash fluid samples. Antimicrobial, anti-inflammatory, and supportive treatment resulted in clinical improvement. However, resolution of the ...
Pinkerton ME, Bailey KL, Thomas KK, Goetz TE, Valli VE.A 17-year-old Quarterhorse gelding with a clinical diagnosis of protein-losing enteropathy was submitted for necropsy following a 4-5-month duration of weight loss, decreased appetite, and hypoproteinemia. Gross findings included multiple 1-2-cm diameter ulcers on the luminal surfaces of the duodenum and ileum. Histologic examination revealed individual large, round cells infiltrating much of the mucosal epithelium of the duodenum, jejunum, ileum, and colon in addition to multifocal areas of ulceration. Similar round cells infiltrated Brunner's glands and expanded the submucosa beneath the foc...
Dacre IT, Shaw DJ, Dixon PM.Histological measurements of dimensions of primary, regular secondary and irregular secondary dentine, pulp diameter and assessment of the levels of predentine, resting lines and enlarged areas of intertubular dentine were performed in apically infected mandibular and maxillary cheek teeth (CT). These examinations showed significantly reduced regular and irregular secondary dentine thickness in diseased as compared to control CT, with 21/26 infected maxillary CT and 15/18 infected mandibular CT having reduced regular secondary dentine (varying between 27.4% and 89.1% reduced secondary dentine ...
Carroll JF, Schmidtmann ET.The American dog tick, Dermacentor variabilis (Say), was the only ixodid tick found feeding on horses in Montgomery County, Md., from May to August. Average tick burdens were low (less than one tick per horse per week), but >80% of 33 horses examined weekly were exposed to tick feeding during the summer. Of the 98 ticks collected, 78% were attached to the tail and 12% were present in the mane. Host-seeking adult D. variabilis were active on vegetation in pastures from May to early August, with most specimens along hedgerows, woods margins, and horse paths.
Ruoff WW, Baker DC, Morgan SJ, Abbitt B.DIABETES mellitus is an uncommon disease in the horse and,
when reported, is frequently secondary to Cushing’s disease
(King, Kavanaugh and Bentinck-Smith 1%2; Loeb, Capen
and Johnson 1966; Tasker, Whiteman and Martin 1966;
Baker and Ritchie 1974; Pauli, Rossi and Straub 1974; Moore,
Steiss, Nicholson and Orth 1979). Diabetes mellitus, associated with chronic pancreatitis, was reported in a horse with
hyperglycaemia, glycosuria and ketonuria (Jeffrey 1969).
Other reported cases were not examined fully to determine the
underlying cause of hyperglycaemia (Jorgenson 1921 ; Wilkinson 195...
Tannahill VJ, Cardwell JM, Witte TH.Colic is a common and potentially life-threatening condition of horses. Multiple risk factors have been previously identified and it is known that a careful management routine can help reduce colic rates. The British military working horse population represents a unique cohort of horses that are intensively managed with a strict regimen. This retrospective study examined the incidence and mortality rate of colic within this population, as well as the signalment of affected horses, and compared these with the general population. Data for 717 horses over a five-year period (2008-2012) were analy...
Van Hoogmoed L, Rodger LD, Spier SJ, Gardner IA, Yarbrough TB, Snyder JR.To determine whether peritoneal fluid pH, glucose concentration, and lactate dehydrogenase activity can be used to differentiate horses with septic peritonitis from those with nonseptic peritonitis. Methods: Prospective study. Methods: 46 horses, including 10 healthy horses, 15 horses with septic peritonitis, and 21 horses with nonseptic peritonitis. Methods: Peritoneal fluid and blood samples were analyzed for pH, glucose concentration, and lactate dehydrogenase activity. Complete blood cell counts were performed, and peritoneal fluid samples were submitted for bacterial culture. Results: Hor...
Geiger T, Gerhards H, Wollanke B.Equine recurrent uveitis (ERU) is typically caused by chronic intraocular leptospiral infection in warm-blooded horses in central Europe. The most effective therapy for leptospiral-induced ERU is the surgical removal of diseased vitreous (vitrectomy). Since vitrectomy is a highly specialized and invasive surgery, the indication must be determined very carefully. In order to obtain evidence of intraocular leptospiral infection by laboratory diagnostics in questionable leptospiral ERU-cases, sampling of aqueous humor is required, because serum tests using microscopic agglutination test (MAT) are...
Young SS, Hall LW.Total respiratory impedance was measured rapidly and noninvasively in conscious horses over the frequency range 3 to 40 Hz by the forced random noise method. The shape of curve of impedance versus frequency in horses was markedly different from that of humans. Respiratory resistance was readily found as the real part of impedence and both its absolute value and frequency dependence are useful indices of pulmonary function. It was difficult to obtain meaningful results in intubated animals with the method because of the mechanical properties of the endotracheal tube itself.
Song J, Song R, Wang P, Zhang Y, Yan Y, Zhou J, Chahan B, Liao M.The erythrocytic-stage surface protein equi merozoite antigen 1 (EMA-1) of Theileria equi is a major candidate for the development of a diagnostic antigen for equine piroplasmosis. In this study, BALB/c mice were immunized with purified recombinant EMA-1 to prepare monoclonal antibody (mAb) against T. equi EMA-1, and 1 mAb 5H2 was obtained that showed good reaction with infected red blood cells (RBC) in the indirect immunofluorescence assay (IFA). To develop a rapid serological detection method for T. equi infection in Xinjiang Uygur Autonomous Region, China, recombinant EMA-1 originating from...