Disease etiology in horses refers to the study of the causes and development of diseases within equine populations. It encompasses various factors, including genetic predisposition, environmental influences, infectious agents, and nutritional imbalances, that contribute to the onset and progression of diseases in horses. Understanding disease etiology is essential for identifying risk factors and implementing preventative measures in equine health management. This topic includes research on pathogen-host interactions, the impact of management practices on disease incidence, and the role of genetic and environmental factors in disease susceptibility. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, contributing factors, and implications of disease etiology in horses.
Kovacs S, Racz B, Sotonyi P, Bakos Z.Atrial fibrillation is the most common arrhythmia in horses causing poor performance. The role of pulmonary vein triggers in the pathogenesis has been identified in horses. Ablation methods have been investigated, but the available information on anatomical, histological and immunohistochemical assessment of the pulmonary vein ostia and the conduction system of the myocardial sleeve is still limited. Objective: The aim of the study was to describe the morphological properties of the myocardial sleeve in healthy horses. Methods: Cross-sectional. Methods: Eighty-three equine hearts were dissecte...
Madrigal-Valencia TL, Saavedra-Montañez M, Pérez-Torres A, Hernández J, Segalés J, Hernández YD, Candanosa-Aranda IE, Pérez-Guiot A....Ovine gammaherpesvirus 2 (OvHV-2), a member of the genus Macavirus, causes sheep-associated malignant catarrhal fever (SA-MCF), a fatal lymphoproliferative disease affecting a wide variety of ungulates in addition to horses. This study described an outbreak of SA-MCF in Mexico and the identification of the OvHV-2 virus in primary rabbit testis cultures through the generation of intranuclear inclusion bodies, syncytia, immunofluorescence (IF), immunocytochemistry (ICC), immunohistochemistry (IHC), endpoint polymerase chain reaction (PCR), and partial sequencing of the ORF75 gene. The animals in...
Hansen S, Otten ND, Nissen SD, Carstensen H, Hopster-Iversen C, Fjeldborg J, Staun SH, Fenner M, Hesselkilde EM, Buhl R.Atrial fibrillation (AF) has been proposed as a risk factor for exercise-induced pulmonary haemorrhage (EIPH) due to increased pressure in the left atrium. Objective: To evaluate if AF was associated with EIPH following a standardised exercise test (SET) to fatigue. Methods: Two-arm controlled experiment. Methods: Ten untrained Standardbred mares mean (standard deviation [SD]) age 6 (2) years performed a SET on the treadmill in sinus rhythm (SR) (SET1) and 25-44 days after induction of self-sustained AF (SET2). AF was induced by tachypacing using a pacing device. Endoscopy, including trachea...
Igel P, Fürst AE, Jackson MA.Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is an increasingly diagnosed degenerative dental disease in aged horses. The primary aim of this retrospective study was to determine the prevalence of EOTRH in horses admitted to the Equine Hospital, University of Zurich, for dental procedures from 2004 to 2017. A secondary goal was to measure and compare interincisal angles on two-dimensional radiographs of horses with EOTRH to determine whether the interincisal angle is associated with age and severity of the disease. Radiographs were assessed for the presence of lysis and/or...
Rockx B, Mire CE.Henipaviruses are emerging zoonotic viruses that can cause outbreaks of severe respiratory and neurological disease in humans and animals such as horses. The mechanism by which these viruses can cause disease remain largely unknown and to date there are no therapeutics or vaccines approved for use in humans. Nipah virus is listed on the World Health Organization R & D Blueprint list of epidemic threats. In order to advance the availability of effective therapeutics and vaccines and medicines that can be used to save lives and avert large scale crises, animal models are required which recap...
Maggi R, De Paolis L, De Santis D, Vellone VG, De Ciucis CG, Fruscione F, Mazzocco K, Ghelardi A, Marruchella G, Razzuoli E.Papillomas are benign epithelial lesions protruding on the epithelial surfaces as finger-like or warty projections. These lesions are often caused by papillomavirus (PV) infection. Congenital papillomas have been reported in foals. However, to date, no evidence of PV infection has been provided. In the present paper, we describe the main clinical-pathological features of a congenital papilloma observed in a foal. In addition, biomolecular tests demonstrated BPV1 infection in the case under study. Such data stimulate further investigations, even on archived samples, aiming to clarifying the eti...
Stummer M, Frisch V, Glitz F, Hinney B, Spergser J, Krücken J, Diekmann I, Dimmel K, Riedel C, Cavalleri JV, Rümenapf T, Joachim A, Lyrakis M....Acute abdominal pain (colic) is one of the major equine health threats worldwide and often necessitates intensive veterinary medical care and surgical intervention. Equine coronavirus (ECoV) infections can cause colic in horses but are rarely considered as a differential diagnosis. To determine the frequency of otherwise undetected ECoV infections in horses with acute colic, fresh fecal samples of 105 horses with acute colic and 36 healthy control horses were screened for viruses belonging to the species by RT-PCR as well as for gastrointestinal helminths and bacteria commonly associated with...
Frontiers in geneticsAugust 14, 2023
Volume 14 1201628 doi: 10.3389/fgene.2023.1201628
Momen M, Brauer K, Patterson MM, Sample SJ, Binversie EE, Davis BW, Cothran EG, Rosa GJM, Brounts SH, Muir P. Spontaneous rupture of tendons and ligaments is common in several species including humans. In horses, degenerative suspensory ligament desmitis (DSLD) is an important acquired idiopathic disease of a major energy-storing tendon-like structure. DSLD risk is increased in several breeds, including the Peruvian Horse. Affected horses have often been used for breeding before the disease is apparent. Breed predisposition suggests a substantial genetic contribution, but heritability and genetic architecture of DSLD have not been determined. To identify genomic regions associated with DSLD, we recr...
Bennet ED, Parkin TDH.Racehorse training and racing schedules in many parts of the United States and Canada were interrupted or otherwise reduced during the first three to six months of 2020. This was an indirect consequence of mitigations to prevent the spread of the pandemic virus COVID-19. Data from the Equine Injury Database, a census-level survey of all race starts made in the USA and Canada, were used to analyse the incidence of fatalities in 2009-2022 among three age cohorts of racehorses within each year. There was a statistically significant increase in the incidence of musculoskeletal fatalities among 2-y...
Cox A, Stewart AJ.Insect Bite Hypersensitivity (IBH, Queensland itch, sweet itch, equine summer eczema) is the most common pruritic disease of horses. It is most often caused by sensitivity to the saliva of spp. of biting midges; however, it can also be caused by hypersensitivity to other insect species. The prevalence of IBH in horses is reported to be as high as 60% in some parts of the world. Due to the severe pruritus and effects of secondary self-trauma, IBH has animal welfare concerns, and there is currently no cure. Management of this condition is life-long, time consuming and costly. New grading system...
Frippiat T, Art T, Tosi I.Airway hyperresponsiveness (AHR) and inflammation are both observed in human and equine asthma. The aim of this study was to assess the timeline and relationship of both features at the subclinical onset of severe equine asthma (SEA). First, the repeatability of the pulmonary function test (PFT) using impulse oscillometry system, and the methacholine bronchoprovocation test (BPT) were assessed at a 1-day interval on six SEA horses in clinical remission and six control horses. Then, clinical and ancillary tests were performed before and after a 1-week low-dust environmental challenge, including...
El-Hage C, Legione A, Devlin J, Hughes K, Jenkins C, Gilkerson J. is an important zoonotic pathogen. Although primarily a pathogen of birds, from which infection can spillover into humans and other mammalian hosts, the importance of as a cause of equine reproductive loss and the risk of infection to humans in contact with infected horses are increasingly being recognised in Australia and elsewhere. Despite the risks to both human and equine health, infection in horses is incompletely understood. This study aimed to update and summarise cases of equine psittacosis in Australia in the period 2018-2022, thus addressing a knowledge gap relating to recent case...
Sander J, Terhardt M, Janzen N, Renaud B, Kruse CJ, François AC, Wouters CP, Boemer F, Votion DM.Equine atypical myopathy is caused by hypoglycin A (HGA) and methylenecyclopropylglycine (MCPrG), the known protoxins of sycamore maple (Acer pseudoplatanus). Various tissues from five atypical myopathy cases were analyzed but only HGA was found. Whether deamination of MCPrG has already occurred in the intestine as the first stage of metabolization has not been investigated. Activation of the protoxins to methylenecyclopropylacetyl (MCPA)-CoA and methylenecyclopropylformyl (MCPF)-CoA, respectively, occurred mainly in the skeletal muscles, as evidenced by very high concentrations of MCPA-carnit...
Luff J, Weingart S, May S, Murphy B.The aetiology of oral squamous cell carcinoma (SCC) in horses is unknown, but papillomavirus infection as well as chronic periodontal disease are suspected to play a pathogenic role. In humans, some oropharyngeal cancers develop in association with human papillomaviruses. Equus caballus papillomavirus 2 (EcPV2) is suspected to play a causal role in the development of equine genital SCC. Given that association, we hypothesized that EcPV2 is associated with the development of oral SCC in horses. We performed standard polymerase chain reaction (PCR) and in-situ hybridization (ISH) for EcPV2 on 31...
Legere RM, Allegro AR, Affram Y, Silveira BPD, Fridley JL, Wells KM, Oezguen N, Burghardt RC, Wright GA, Pollet J, Bordin AI, Figueiredo P....To examine the susceptibility of cultured primary equine bronchial epithelial cells (EBECs) to a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus relative to human bronchial epithelial cells (HBECs). Methods: Primary EBEC cultures established from healthy adult horses and commercially sourced human bronchial epithelial cells (HBECs) were used as a positive control. Methods: Angiotensin-converting enzyme 2 (ACE2) expression by EBECs was demonstrated using immunofluorescence, western immunoblot, and flow cytometry. EBECs were transduced with a lentivirus pseudotyped with ...
Sewgobind S, McCracken F, Schilling M.West Nile virus (WNV) is a positive-sense single-stranded RNA virus belonging to the Flaviviridae family and is maintained in an enzootic cycle between avian hosts and mosquito vectors. Humans, horses and other mammals are susceptible to infection but are dead-end hosts due to a low viraemia. The disease can manifest itself in a variety of clinical signs and symptoms in people and horses from mild fever to severe encephalitis and morbidity. There are no vaccines licensed for human protection, but parts of Europe, North America, Africa and Australia have vaccines commercially available for hors...
Gonzálvez M, Franco JJ, Barbero-Moyano J, Caballero-Gómez J, Ruano MJ, Martínez R, Cano-Terriza D, García-Bocanegra I.The largest epidemic of West Nile virus (WNV) reported ever in Spain in both humans and equines occurred in 2020, affecting 77 humans and 139 equine herds. Here, we aimed to monitor the outbreaks detected in equid herds in Andalusia (southern Spain), the Spanish region where 89.9% of the outbreaks were reported, and to evaluate the virus circulation and risk factor associated with WNV exposure in the affected herds. The first WNV case was detected in mid-July 2020, the number of outbreaks peaked in mid-August and the last one was confirmed on 26th October 2020. WNV lineage 1 was detected in 12...
Fikri F, Hendrawan D, Wicaksono AP, Purnomo A, Khairani S, Chhetri S, Maslamama ST, Purnama MTE.Colic is among the common health issues in equine health management. Gastrointestinal (GI) disorders are the most frequent causes of colic, but dysfunction of other organs and systems inside the abdominal cavity may also contribute. Therefore, it is crucial to identify risk factors for colic of specific etiologies. This study aimed to examine the incidence, risk factors, and best therapeutic management practices for horses with colic. Unassigned: A cohort of 256 horses living in Lamongan, East Java, Indonesia, was randomly recruited based on reports of colic symptoms by owners. Diagnosis and t...
McCue PM, Bisiau C, Divine C, May E.Congential amastia, a medical condition in which mammary tissue fails to develop, was detected in a 3-year-old Quarter Horse mare. The dam of the mare was also afflicted with amastia, suggesting that the condition was due to an inherited genetic mutation as noted in other species. In addition, on presentation the mare had a purulent vaginal discharge secondary to a pyometra.
Schinköthe J, Gerlach K, Ulrich RG, Brehm W.A 12-y-old Shetland Pony was presented with a mucus-secreting fistula in the right paralumbar fossa. Surgery was performed to unravel the origin of the fistula. The horse died under anesthesia and was forwarded to autopsy. The right kidney was markedly atrophic and fibrotic, consistent with unilateral end-stage kidney. The right ureter was markedly thickened, but with luminal continuity leading into the urinary bladder where a partial obstruction caused by nodular para-ureteral fat necrosis was evident. The lumen of the cutaneous fistula was continuous with the right ureter; therefore, we diag...
Bromberger CR, Costa JR, Herman M, Hernandez JM, Albertino LG, Alves CEF, Borges AS, Oliveira-Filho JP.Aural plaques have been linked to Equus caballus papillomavirus (EcPV). Ten types of EcPVs have already been described; however, only EcPVs 1, 3, 4, 5, and 6 have been observed in association with aural plaques. Accordingly, the objective of this study was to evaluate the presence of EcPVs in equine aural plaque samples. A total of 29 aural plaque samples (from 15 horses) were collected and assessed for the presence of the DNA of these EcPVs by PCR. Additionally, 108 aural plaque samples used in previous research were evaluated for the presence of EcPVs 8 and 9. Previously described primers we...
Kašpárková N, Bártová E, Žákovská A, Budíková M, Sedlák K.Lyme disease, caused by some strains of bacterial spirochetes Borrelia burgdorferi sensu lato (Bbsl), affects humans but also domestic animals including horses. The primary pathogens in horses in Europe are B. afzelii, B. garinii and B. burgdorferi sensu stricto. To our knowledge, there are no data available on the seropositivity of B. burgdorferi s.l. in horses from the Czech Republic. In this country, horses are mainly used for sport, breeding, and recreational riding in areas where vectors of B. burgdorferi s.l. are present, which is why they are frequently at risk of infection. The aim of ...
Shapter FM, Granados-Soler JL, Stewart AJ, Bertin FR, Allavena R.Crofton weed (Ageratina adenophora) is a global and highly invasive weed, with ingestion causing severe respiratory disease in horses, leading to irreversible and untreatable pulmonary fibrosis and oedema. While reports of equine pneumotoxicity remain common in Australia and New Zealand, equine pneumotoxicity may be underdiagnosed in other countries where Crofton weed is endemic but poorly differentiated. The pathogenesis of Crofton weed toxicity following ingestion has been well described in a number of different animal models, including rodents, rabbits, and goats. However, induced toxicity ...
Peat FJ, Kawcak CE, McIlwraith CW, Keenan DP, Berk JT, Mork DS.Subchondral lucencies (SCLs) in the distal aspect of the medial femoral condyle (MFC) of young Thoroughbred horses are a source of controversy on presale radiographs. There is limited scientific evidence regarding the risk of progression and impact on future racing performance. Objective: To (1) identify the prevalence of MFC SCLs on sales repository radiographs in yearling and 2-year-old Thoroughbreds; (2) identify any association between grade of MFC SCL and future racing performance and (3) monitor changes in MFC SCL grades between yearling and 2-year-old sales. Methods: Prospective cohort ...
Huggins L, Norris J, Conley A, Dini P.Abnormal or undesired mare behaviours are often assumed to be associated with ovarian abnormalities. Objective: We aimed to determine the incidence of abnormal behaviours and their association with concentrations of one or more ovarian hormones associated with a granulosa cell tumour (GCT). Methods: Retrospective descriptive. Methods: A total of 2914 hormonal profile samples submitted with the words behave, behaviour, or behaving in the submission history were analysed. The association between reported abnormal behaviours and concentrations of testosterone, anti-Müllerian hormone (AMH), inhib...
Rock KD, Polera ME, Guillette TC, Starnes HM, Dean K, Watters M, Stevens-Stewart D, Belcher SM.Central North Carolina (NC) is highly contaminated with per- and polyfluoroalkyl substances (PFAS), in part due to local fluorochemical production. Little is known about the exposure profiles and long-term health impacts for humans and animals that live in nearby communities. In this study, serum PFAS concentrations were determined using liquid chromatography high-resolution mass spectrometry and diagnostic clinical chemistry endpoints were assessed for 31 dogs and 32 horses that reside in Gray's Creek NC at households with documented PFAS contamination in their drinking water. PFAS were detec...
Nielsen MK, Leathwick DM, Sauermann CW.Over the past three decades, equine strongylid egg reappearance periods (ERPs) have shortened substantially for macrocyclic lactone anthelmintics. The ERPs of ivermectin and moxidectin were originally reported in the 8-10 and 12-16 week ranges, respectively, but several recent studies have found them to be around 4-5 weeks for both actives. This loss of several weeks of suppressed strongylid egg output could have substantial implications for parasite control. This study made use of a computer simulation model to evaluate the impact of shortened ERPs on the anthelmintic performance of ivermecti...
Azhar M, Gadahi JA, Bhutto B, Tunio S, Vistro WA, Tunio H, Bhutto S, Ram T.Babesiosis is a protozoal disease affect livestock and pet animals such as cattle, buffaloes, sheep, goats, horses, donkeys, mules, dogs, and cats. It causes severe economic losses in livestock as well as in pet animals. A large number of dairy animals are imported in order to fulfill the demands of milk, milk, meat and its products. In addition, different pet animals are transported from Pakistan to various parts of the world, therefore, it is important to identify the current status and distribution of babesiosis throughout Pakistan in order to control the disease and draw attention for futu...
Murray MJ, Schusser GF, Pipers FS, Gross SJ.Gastroscopic examinations were performed on 67 Thoroughbred horses in training at a race track and repeat examinations performed in 35 horses, 2 to 3 months later. Horses were age 2-9 years and included 16 two-year-olds, 32 three-year-olds and 19 horses > or = 4-years-old. Forty-two of the 67 horses had raced within the 2 months before the initial examination and the remaining 25 horses were in training. Sixty-two of the 67 horses (93%) had one or more lesions present in the gastric mucosa and lesions were present in all of the 42 horses that had raced. Thirty-two of the 35 horses, examined...
Herrera HM, Dávila AM, Norek A, Abreu UG, Souza SS, D'Andrea PS, Jansen AM.In order to better understand the enzootiology of trypanosomiasis caused by Trypanosoma evansi in the Brazilian Pantanal we examined domestic and wild mammals by microhematocrit centrifuge technique (MHCT), immunofluorescence antibody test (IFAT) and polymerase chain reaction (PCR). T. evansi infection was detected in all species sampled with exception of the sheep and the feral pig. High parasitemias were observed in capybaras (5/24), coatis (18/115), horses (31/321) and dogs (3/112). Among these species, only the capybaras did not develop anemia. Low parasitemias, only detected by PCR, were ...
Lavoie JP, Maghni K, Desnoyers M, Taha R, Martin JG, Hamid QA.Heaves in horses shares many similarities with human asthma, including lower airway inflammation, reversible airway obstruction, and bronchial hyperresponsiveness. Extrinsic asthma is an allergic response to environmental allergens and a similar immunologic mechanism may be implicated in heaves. It is now recognized that a Th2 subset of CD4+ lymphocytes is associated with allergic diseases such as atopic asthma. The purpose of this study was to determine whether airway inflammation in heaves is associated with a pattern of expression of cytokine suggestive of a Th2 type response. The expressio...
Johnson BJ, Stover SM, Daft BM, Kinde H, Read DH, Barr BC, Anderson M, Moore J, Woods L, Stoltz J.Necropsies were performed on 496 horses that had a fatal injury or illness at a California racetrack during the period February 20th 1990 to March 1st 1992. The primary cause of death was categorised by breed, activity at time of injury or illness and organ system affected. Most of the submissions were Thoroughbred horses (432) and Quarter Horses (46). Most of the injuries occurred while racing (42%) and in training sessions (39%); with fewer non-exercise (12%) and accident (7%) related injuries or illnesses. Musculoskeletal injuries accounted for 83% of the Thoroughbred and 80% of the Quarter...
Allen GP.To identify risk factors associated with development of clinical neurologic signs in horses exposed to equine herpesvirus-1 (EHV-1). Methods: 36 adult horses. Methods: Blood samples collected before and after challenge inoculation with nonneuropathogenic or neuropathogenic EHV-1 were analyzed for leukocyte-associated viremia, serum neutralizing antibody, and EHV-1-specific cytotoxic T-lymphocyte precursors (CTLPs). Associations between variables and neurologic disease and correlations between age category or breed and development of neurologic disease were examined. Results: 9 horses developed...
Cowled B, Ward MP, Hamilton S, Garner G.Australia experienced a large outbreak of equine influenza in August 2007. Nearly 10000 premises were infected during the epidemic. We used spatial and temporal analytical techniques to describe the epidemic, to quantify important descriptors of the epidemic, and to generate hypotheses about how the epidemic progressed and which control tools assisted in eradication. Spatio-temporal epidemic curves revealed three phases in the epidemic: dispersal, local spread and disease fade out. Spatial dispersal of infection rapidly declined immediately after national movement restrictions were introduced....
Bamford NJ, Potter SJ, Harris PA, Bailey SR.Breed-related differences may occur in the innate insulin sensitivity (SI) of horses and ponies, an important factor believed to be associated with the risk of laminitis. The aim of this study was to measure the glucose and insulin responses of different breeds of horses and ponies in moderate body condition to a glucose-containing meal and to compare these responses with the indices of SI as determined by a frequently sampled intravenous glucose tolerance test (FSIGT). Eight Standardbred horses, 8 mixed-breed ponies, and 7 Andalusian-cross horses with a mean ± SEM BCS 5.0 ± 0.3 of 9 were us...
Bertuglia A, Lacourt M, Girard C, Beauchamp G, Richard H, Laverty S.The role of osteoclasts in osteochondral degeneration in osteoarthritis (OA) has rarely been investigated in spontaneous disease or animal models of OA. Objective: The objectives of the current study were to investigate osteoclast density and location in post-traumatic OA (PTOA) and control specimens from racehorses. Methods: Cores were harvested from a site in the equine third carpal bone, that undergoes repetitive, high intensity loading. Histological and immunohistochemical (Cathepsin K and Receptor-activator of Nuclear Factor kappa-β ligand (RANKL)) stained sections were scored (global an...
Hotchkiss JW, Reid SW, Christley RM.Recurrent airway obstruction (RAO) is a commonly encountered respiratory condition of horses. Despite this, the epidemiology of this predominately manageable and reversible disease in Great Britain has been largely ignored. Objective: To estimate the prevalence of RAO in the general horse population of Great Britain and to investigate possible risk factors for RAO associated with management or early life. Methods: Horse owners were surveyed using a self-administered postal questionnaire that contained a risk-screening questionnaire (RSQ) designed to identify horses with RAO. These owners were ...
Bruno L, Nappo MA, Ferrari L, Di Lecce R, Guarnieri C, Cantoni AM, Corradi A.Nipah virus (NiV) infection is a viral disease caused by a Henipavirus, belonging to the Paramyxoviridae family, responsible for a zoonosis. The course of the disease can be very serious and lead to death. NiV natural hosts are fruit bats (also known as megabats) belonging to the Pteropodidae family, especially those of the genus. Natural infection in domestic animals has been described in farming pigs, horses, domestic and feral dogs and cats. Natural NiV transmission is possible intra-species (pig-to-pig, human-to-human) and inter-species (flying bat-to-human, pig-to-human, horse-to-human)....
Kulkarni MA, Berrang-Ford L, Buck PA, Drebot MA, Lindsay LR, Ogden NH.In Canada, the emergence of vector-borne diseases may occur via international movement and subsequent establishment of vectors and pathogens, or via northward spread from endemic areas in the USA. Re-emergence of endemic vector-borne diseases may occur due to climate-driven changes to their geographic range and ecology. Lyme disease, West Nile virus (WNV), and other vector-borne diseases were identified as priority emerging non-enteric zoonoses in Canada in a prioritization exercise conducted by public health stakeholders in 2013. We review and present the state of knowledge on the public heal...
King S, Rajko-Nenow P, Ashby M, Frost L, Carpenter S, Batten C.African horse sickness was confirmed in horses in Thailand during March 2020. The virus was determined to belong to serotype 1 and is phylogenetically closely related to isolates from South Africa. This is the first incidence of African horse sickness occurring in South East Asia and of serotype 1 outside of Africa.
Ostlund EN, Crom RL, Pedersen DD, Johnson DJ, Williams WO, Schmitt BJ.After the 1999 outbreak of West Nile (WN) encephalitis in New York horses, a case definition was developed that specified the clinical signs, coupled with laboratory test results, required to classify cases of WN encephalitis in equines as either probable or confirmed. In 2000, 60 horses from seven states met the criteria for a confirmed case. The cumulative experience from clinical observations and diagnostic testing during the 1999 and 2000 outbreaks of WN encephalitis in horses will contribute to further refinement of diagnostic criteria.
Wood JL, Newton JR, Chanter N, Mumford JA.Respiratory disease is important in horses, particularly in young Thoroughbred racehorses, and inflammation that is detected in the trachea and bronchi (termed inflammatory airway disease [IAD]) is more significant in this population in terms of impact and frequency than other presentations of respiratory disease. IAD, which is characterized by neutrophilic inflammation, mild clinical signs, and accumulation of mucus in the trachea, may be multifactorial, possibly involving infections and environmental and immunological factors, and its etiology remains unclear. This 3-year longitudinal study ...
Ross PF, Rice LG, Plattner RD, Osweiler GD, Wilson TM, Owens DL, Nelson HA, Richard JL.Ninety-eight samples of feeds associated with 44 cases of equine leukoencephalomalacia (ELEM) and 83 samples of feed associated with 42 cases of a porcine pulmonary edema syndrome (PPE) were analyzed for fumonisin B1 (FB1). For comparison purposes, 51 feed samples not associated with PPE or ELEM were also analyzed. Feed associated with ELEM contained FB1 ranging from less than 1 microgram/g to 126 micrograms/g with 75% of the cases having at least 1 sample above 10 micrograms/g. Feeds associated with PPE ranged from less than 1 microgram/g to 330 micrograms/g with 71% of the cases having at le...
Thiel PG, Marasas WF, Sydenham EW, Shephard GS, Gelderblom WC, Nieuwenhuis JJ.Fumonisins B1 (FB1) and B2 (FB2), two structurally related mycotoxins with cancer-promoting activity, were recently isolated from corn cultures of Fusarium moniliforme MRC 826. These toxins have been reported to be produced also by isolates of F. proliferatum. Contamination of foods and feeds by F. moniliforme has been associated with human esophageal cancer risk, and FB1 has been shown to be the causative agent of the neurotoxic disease leukoencephalomalacia in horses. Because of the toxicological importance of the fumonisins, the potential to produce FB1 and FB2 was determined in a study of ...
Cohen ND.A prospective study was conducted to describe the causes of and farm management factors associated with disease and death in a population of foals in Texas. Data from 2,468 foals at 167 farms were provided by veterinarians for all 12 months during 1991. Among 2,468 foals, 116 deaths were reported (4.7%). Pneumonia was the most commonly reported cause of death, followed by septicemia. When considered as a group, musculoskeletal disorders (traumatic, infectious, or deforming problems) represented the most common cause of all reported deaths. Daily risk of death was greatest during the first 7 da...
Kamm JL, Nixon AJ, Witte TH.Understanding the expression of catabolic and anabolic genes during osteoarthritis progression should help to identify the major mediators of the disease. Objective: To compare the cytokine and anabolic marker concentrations in synovium, synovial fluid and cartilage between normal and osteoarthritic joints. Methods: Carpi from horses age 2-11 years were used. Tissues were harvested at the time of surgery or euthanasia, and RNA was isolated for RT-PCR analysis. Tumour necrosis factor alpha (TNFα), interleukin-1beta (IL-1β), aggrecanase 1 (ADAMTS-4), aggrecanase 2 (ADAMTS-5), matrix metallopro...
Williams KJ, Maes R, Del Piero F, Lim A, Wise A, Bolin DC, Caswell J, Jackson C, Robinson NE, Derksen F, Scott MA, Uhal BD, Li X, Youssef SA, Bolin SR.Pulmonary fibrosis and interstitial lung disease are poorly understood in horses; the causes of such conditions are rarely identified. Equine herpesvirus 5 (EHV-5) is a gamma-herpesvirus of horses that has not been associated with disease in horses. Pathologic and virologic findings from 24 horses with progressive nodular fibrotic lung disease associated with EHV-5 infection are described and compared with 23 age-matched control animals. Gross lesions consisted of multiple nodules of fibrosis throughout the lungs. Histologically, there was marked interstitial fibrosis, often with preservation ...
Wilson AM, Goodship AE.Mathematical modelling of tendon thermodynamics predicted that the temperature of the central core of the equine superficial digital flexor tendon would plateau at 11 degrees C above the tendon surface temperature during a sustained gallop. A mean temperature differential (between tendon core and surface) of 5.4 (S.E. +/- 1.0) degrees C was demonstrated in vivo in four horses. Peak intra-tendinous temperatures in the range 43-45 degrees C were recorded. Temperatures above 42.5 degrees C are known to result in fibroblast death in vitro [Hall (1988) Radiobiology for the Radiologist, 3rd Edn., pp...
Margalit E, Sadda SR.A variety of disease processes can affect the retina and/or the optic nerve, including vascular or ischemic disease, inflammatory or infectious disease, and degenerative disease. These disease processes may selectively damage certain parts of the retina or optic nerve, and the specific areas that are damaged may have implications for the design of potential therapeutic visual prosthetic devices. Outer retinal diseases include age-related macular degeneration, pathologic myopia, and retinitis pigmentosa. Although the retinal photoreceptors may be lost, the inner retina is relatively well-preser...
Fielding CL, Higgins JK, Higgins JC, McIntosh S, Scott E, Giannitti F, Mete A, Pusterla N.Equine coronavirus (ECoV) is associated with clinical disease in adult horses. Outbreaks are associated with a low case fatality rate and a small number of animals with signs of encephalopathic disease are described. Objective: The aim of this study is to describe the epidemiological and clinical features of two outbreaks of ECoV infection that were associated with an high case fatality rate. Methods: 14 miniature horses and 1 miniature donkey testing fecal positive for ECoV from two related disease outbreaks. Methods: Retrospective study describing the epidemiological findings, clinicopatholo...
Rodriguez M, Hooghuis H, Castaño M.The aetiology, pathogenesis and epizootiology of African horse sickness (AHS) are reviewed with special reference to recent outbreaks in the Iberian peninsula. AHS is a highly fatal insect-borne viral disease of Equidae. It is caused by an Orbivirus (family Reoviridae) and nine serotypes are recognised. Outbreaks occurred in central Spain in 1987 and in southern regions of the Iberian peninsula in 1988, 1989 and 1990. All were associated with serotype 4 of the virus, whereas other occurrences of AHS outside Africa have all been caused by serotype 9. The clinical picture in the outbreaks was ma...
Ivester KM, Couëtil LL, Zimmerman NJ.Inhalant exposure to airborne irritants commonly encountered in horse stables is implicated in the pathogenesis of inflammatory airway disease (IAD) and recurrent airway obstruction (RAO), non-infectious, inflammatory pulmonary disorders that impact the health and performance of horses across all equine disciplines. IAD and RAO have overlapping clinical, cytological, and functional manifestations of the pulmonary response to organic dust and noxious gases encountered in the barn environment. Study of these diseases has provided important but incomplete understanding of the effect of air qualit...
Wise LN, Pelzel-McCluskey AM, Mealey RH, Knowles DP.Equine piroplasmosis, caused by the parasites Theileria equi and Babesia caballi, is a globally important disease, affecting a large percentage of the world's horses. This article serves as a review of these divergent parasites. Discussed are the clinical presentation of disease, diagnosis, and treatment. Special attention is given to the current disease status specifically in North America.
