"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
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...
Patton ME, Andrews FM, Bogers SH, Wong D, McKenzie HC, Werre SR, Byron CR.Ileus is a common life-threatening problem in horses, and currently available treatments may be ineffective. The purpose of this study was to determine whether bit chewing, a form of sham feeding, decreases the gastric emptying time (GET), small intestinal transit time (SITT), and total orocecal transit time (OCTT) in clinically normal horses in a prospective crossover study. Nine healthy horses were acclimated and fed a standardized diet. Following 24 h of fasting, self-contained video endoscopy capsules and acetaminophen were administered into the stomach via a nasogastric tube. Each horse u...
Ferraro A, Hartnack S, Schwarzwald CC.Echocardiographic diagnosis of pulmonary hypertension (PH) in horses is usually based on Doppler interrogation of tricuspid (TR) or pulmonic regurgitation (PR). This study aimed at investigating two-dimensional echocardiographic (2DE) variables, including pulmonary artery diameter (PAD) and pulmonary artery distensibility index (PADI), to diagnose PH. Methods: 41 healthy horses; 82 horses with TR or PR and normal intracardiac pressure gradients; and 35 horses with TR or PR velocities indicating PH. The 2DE variables were compared between groups, cut-offs for the diagnosis of PH were determined...
Bertin FR, Frank N, Breuhaus BA, Schott HC, Kritchevsky JE.Equine thyroid disorders pose a diagnostic challenge in clinical practice because of the effects of nonthyroidal factors on the hypothalamic-pituitary-thyroid axis, and the horse's ability to tolerate wide fluctuations in thyroid hormone concentrations and survive without a thyroid gland. While benign thyroid tumours are common in older horses, other disorders like primary hypothyroidism or hyperthyroidism in adult horses and congenital hypothyroidism in foals are rare. There is a common misunderstanding regarding hypothyroidism in adult horses, especially when associated with the clinical pro...
Bohlman T, Waddell H, Schumaker B.The occurrence of zoonotic infections following an animal exposure continues to be an important consideration for all patients, especially those within agricultural communities. Streptococcus equi subspecies equi (S. equi subsp. equi) is a bacteria known to cause a common infection called 'Strangles' in horses. This article highlights a new case of pneumonia and bacteremia in a patient caused by S. equi subsp. equi following strangles exposure in a horse. Rarely has there been reported horse to human transmission of subsp. equi. Methods: A 70-year-old woman attended a rural emergency departmen...
Hoblick S, Denagamage TN, Morton AJ, McCarrel TM.Post-anaesthetic fever is a known complication of general anaesthesia, however, its incidence in horses undergoing elective magnetic resonance imaging (MRI) is unknown. Objective: To determine the incidence of post-anaesthetic fever in horses undergoing elective orthopaedic MRI and determine whether prophylactic antimicrobial therapy would be associated with a reduction in the incidence of post-anaesthetic fever. We hypothesised that prophylactic antimicrobials would be associated with a reduction in the incidence of post-anaesthetic fever. Methods: Retrospective cross-sectional study. Methods...
Hobbs SJ, Serra Braganca FM, Rhodin M, Hernlund E, Peterson M, Clayton HM.In the sport of dressage, one or more judges score the combined performance of a horse and rider with an emphasis on the technical correctness of the movements performed. At the end of the test, a single score is awarded for the 'general impression', which considers the overall performance of the horse and rider as a team. This study explored original measures that contributed to the general impression score in a group of 20 horse-rider combinations. Horses and riders were equipped with inertial measurement units (200 Hz) to represent the angular motion of a horse's back and the motions of a r...
Pozharskiy A, Abdrakhmanova A, Beishova I, Shamshidin A, Nametov A, Ulyanova T, Bekova G, Kikebayev N, Kovalchuk A, Ulyanov V, Turabayev A....Horses are traditionally used in Kazakhstan as a source of food and as working and saddle animals as well. Here, for the first time, microarray-based medium-density single nucleotide polymorphism (SNP) genotyping of six traditionally defined types and breeds of indigenous Kazakh horses was conducted to reveal their genetic structure and find markers associated with animal size and weight. The results showed that the predefined separation between breeds and sampled populations was not supported by the molecular data. The lack of genetic variation between breeds and populations was revealed by t...
Latham E, Scherrer NM, Stefanovski D.To compare the measurement of intraocular pressure in horses with clinical ocular disease using three tonometry devices. Conclusions: All three tonometers showed strong agreement, however, the TonoVet and the TonoVet Plus carried the strongest agreement with the TonoVet Plus having slightly higher measurements overall compared with the TonoVet. Due to small variations between devices, it is recommended that the same device be used for serial measurements of intraocular pressure. However, all three devices are appropriate to use in horses presented for ophthalmic evaluation.
Bampidis V, Azimonti G, Bastos ML, Christensen H, Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of star anise oil from the fruit (without or with the presence of plant leaves) of Illicium verum Hook.f., when used as a sensory additive in feed and water for drinking for all animal species. For long-living and reproductive animals, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) considered of low concern the use of the additive in complete feed at 0.6 mg/kg for laying hens and rabbits, 1.0 mg/kg for sows and dairy cows, 1.6 mg/kg f...
Hepworth-Warren KL, Estell K, Cowles B, Amodie D, Crisman M.Serum amyloid A (SAA) is a major acute phase protein in horses which could be a useful tool for assessing clinical response to treatment of bacterial pneumonia in adult horses.
Zaitseva S, Dagurova O, Radnagurueva A, Kozlova A, Izotova A, Krylova A, Noskov S, Begmatov S, Patutina E, Barkhutova DD.The Buryatian horse is an ancient breed and, as an indigenous breed, they have unique adaptive abilities to use scarce pastures, graze in winter, and survive in harsh conditions with minimal human care. In this study, fecal microbiota of Buryatian horses grazing in the warm and cold seasons were investigated using NGS technology on the Illumina MiSeq platform. We hypothesized that the composition of microbial communities in the feces of horses maintained on pasture would change in the different seasons, depending on the grass availability and different plant diets. We conducted microhistologic...
Jondeau C, Guyonnet A, Losada A, Laloy E, Reyes-Gomez E, Le Dudal M, Chahory S.To describe a case of lipogranulomatous conjunctivitis in a horse. Methods: A client-owned 12-year-old Standardbred gelding presenting with chronic conjunctivitis and palpebral masses. Methods: Complete ophthalmic examination, surgical excision, histopathology, and bacterial culture of biopsy samples were performed. Results: Upper and lower eyelids of both eyes were affected, with multiple yellow-to-white nodules on the palpebral conjunctiva, adjacent to the eyelid margin. Nodule removal was achieved via partial tarsal plate excision. Histopathological examination revealed granulomatous inflam...
Amory H, Cesarini C, De Maré L, Loublier C, Moula N, Detilleux J, Saulmont M, Garigliany MM, Lecoq L.The objective of this retrospective study was to evaluate the clinical significance of fecal quantitative real-time polymerase chain reaction (qPCR) results when taking the cycle threshold values (Ct) into account. The study included 120 qPCR-positive fecal samples obtained from 88 hospitalized horses over a 2-year period. The mean Ct of the qPCR test was evaluated in regard to (1) clinical outcome and (2) systemic inflammatory response syndrome (SIRS) status (no SIRS, moderate SIRS, or severe SIRS) of the sampled horses. An ROC analysis was performed to establish the optimal cut-off Ct valu...
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...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of an essential oil from the leaves and twigs of Eucalyptus globulus Labill. (eucalyptus oil) when used as a sensory additive in feed and water for drinking for all animal species. The FEEDAP Panel concluded that the use of eucalyptus oil is safe at the following concentrations in complete feed: 12 mg/kg for chickens for fattening, 18 mg/kg for laying hens, 16 mg/kg for turkeys for fattening, 22 mg/kg for piglets, 26 mg/kg for pigs for fattening, 32 mg/kg for ...
Burns JJ, MacMillan KM, John E.Respiratory disease is common in the horse population and is often associated with poor performance in equine athletes. Despite their outstanding strength and aerobic capacity, little regard is given to draft horses and the respiratory disorders they may encounter when performing athletic activity. For this reason, the objectives of this study were: (1) to determine the prevalence of exercise-induced pulmonary hemorrhage (EIPH), tracheal mucus (TM) and recurrent laryngeal hemiplegia (RLH) in a population of competitive draft pulling horses, and (2) to determine if there was an association betw...
Rule EK, Boyle AG, Stefanovski D, Anis E, Linton J, Lorello O.Equine granulocytic anaplasmosis (EGA) is a common disease in adult horses, but clinical disease in foals is rarely reported. The relationship between equine maternal and neonatal antibodies to Anaplasma phagocytophilum is unclear. Objective: That mares in an endemic region would be seropositive for A. phagocytophilum and that mare and foal serum IgG concentrations for A. phagocytophilum would correlate. Additionally, we hypothesized that foal IgG concentrations for A. phagocytophilum acquired by passive immunity would decline by 6 months of age. Methods: Twenty-two healthy mare-foal pairs. ...
Stefaniuk-Szmukier M, Piórkowska K, Ropka-Molik K.Equine metabolic syndrome (EMS) has become an important issue in modern veterinary medicine and is linked to the common, extremely painful, most-of-the-time performance-terminating hoof laminitis. The growing knowledge in the field of genetic background, inducing environmental factors, diagnosis, treatment and maintenance of affected equines led us to summarise the available information to be used not only for scientific purposes but for fieldwork. In horses, the clinical presentation of EMS includes: obesity or local fat deposition, bilateral lameness or hoof rings attributed to ongoing or pr...
Lavado RA, Lewis J, Montgomery JB.Laminitis is a severely debilitating and life-threatening condition that occurs as a consequence of different primary triggering factors. Continuous digital hypothermia (CDH) is recommended in horses at risk of, or diagnosed with, acute laminitis due to its several physiological and biochemical alterations that may be positive for the prevention and early treatment of the condition, representing a low risk of adverse effects. Modulation of the inflammatory response, profound vasoconstriction, and prevention of tissue damage are the most notable protective effects of cryotherapy on the lamellae...
Amairia S, Jbeli M, Mrabet S, Jebabli LM, Gharbi M.Sarcocystis spp. and Toxoplasma gondii are two apicomplexan protozoa that infect a broad range of vertebrates, however, little is known about the infection of equids with these parasites. A total of 184 slaughtered equids from slaughterhouses of Bizerte and Tunis located in Northern Tunisia, were examined for meat infections with Sarcocystis spp. and T. gondii by PCR. The prevalence of infections with Sarcocystis spp. and T. gondii were 38% (95% CI: 31-45) and 39.7% (95% CI: 32.6-46.7), respectively. The highest prevalence of infection with Sarcocystis spp. was observed in donkeys (48.6%; 95%C...
Cassady KR, Minter LJ, Gruber EJ.Field veterinarians and researchers studying wild species, such as the southern white rhinoceros, often work in remote areas with limited access to standard laboratory equipment, hindering the ability to measure serum analytes.
Objectives: The first objective was to produce an inexpensive, manually operated centrifuge that could accept standard laboratory tubes by modifying a consumer-grade salad spinner with low-cost materials. The second objective was to compare biochemistry analysis results obtained from equine and southern white rhinoceros serum separated by traditional laboratory and m...
Lu H, Zhang W, Sun S, Mei Y, Zhao G, Yang K.Grazing is a common approach to rearing. We investigated the effects of supplementation during grazing on milk yield and composition, blood biochemistry, and fecal microflora in Yili horses. The control mares grazed normally, while those in groups I and II received 1 kg/d of concentrate and 1 kg/d of concentrate + 0.4 kg/d of coated FA, respectively. Milk volumes were significantly higher in groups I and II than in the control group, and among the previous two, milk volumes were significantly higher in group II than in group I. Milk fat, lactose, and protein levels were significantly higher in...
Nocera I, Sorvillo B, Sgorbini M, Aliboni B, Citi S.Few studies have established the normal radiographic anatomical development of the donkey foal and, to date, no data are available for mules. Our aim was thus to evaluate the radiographic development of the fore digit and carpal joint in the mule foal from 0 to 3 months of age. Ten forelimbs of five healthy full-term mule foals were included. Radiographs of the fore digit lateromedial and dorsopalmar and the carpus dorsopalmar were performed weekly for the first month of age, and bi-monthly during the following two months. Fore digit growth plate closure times, morphological, angular, and line...
Kusliy MA, Yurlova AA, Neumestova AI, Vorobieva NV, Gutorova NV, Molodtseva AS, Trifonov VA, Popova KO, Polosmak NV, Molodin VI, Vasiliev SK....This study focuses on expanding knowledge about the genetic diversity of the Altai horse native to Siberia. While studying modern horses from two Altai regions, where horses were subjected to less crossbreeding, we tested the hypothesis, formulated on the basis of morphological data, that the Altai horse is represented by two populations (Eastern and Southern) and that the Mongolian horse has a greater genetic proximity to Eastern Altai horses. Bone samples of ancient horses from different cultures of Altai were investigated to clarify the genetic history of this horse breed. As a genetic mark...
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...
Faivre C, Wong DM, Villarino NF, Court M, Gold JR.To determine the pharmacokinetics and clinical safety of acetaminophen after oral administration of 40 mg/kg q 12 hours or 60 mg/kg q 24 hours for 14 days. Methods: 12 healthy light-breed neonatal foals. Methods: 6 foals received acetaminophen at 40 mg/kg q 12 hours and 6 foals received 60 mg/kg q 24 hours for 14 days. The study dates were January 31 to April 15, 2023. Physical examinations were performed daily. Plasma disposition of acetaminophen was determined after the first, mid-point drug administration. Hematology and biochemistry analysis was performed before the study, day 7, and the l...
Oliver A, Wulster K, Stefanovski D, Spriet M, Ciamillo S, Ford M, Kulp J, van Eps A.Measure 18F-FDG uptake in digital tissues of healthy horses subjected to different ambulatory conditions between the time of injection and positron emission tomography (PET) scan acquisition. Methods: 8 healthy adult horses. Methods: Horses were walked (AMB) or tied in stalls (NONAMB) immediately after injection with ∼1.5 MBq/kg 18F-FDG until scan acquisition using a randomized crossover design. Steps were quantified using accelerometers. Standardized uptake values (SUV; mean and maximum) in digital tissues including the dorsal lamellae (proximal, middle, and distal), quarter lamellae (media...
Straticò P, Hattab J, Guerri G, Carluccio A, Bandera L, Celani G, Marruchella G, Varasano V, Petrizzi L.Owner complaints of estrus-related behavior in mares are a common cause of referral for laparoscopic ovariectomy. Granulosa cell tumors are a common neoplastic condition affecting the equine ovary, causing behavioral changes at rest and reduced performance. The reported success rate of ovariectomy in treating behavioral disorders is 64-86%. The aim of this study was to retrospectively evaluate the long-term follow-up of laparoscopic ovariectomy in mares in our case series, focusing on the owner's perspective of the behavior of the mares after surgery. In addition, the histopathological feature...
Matas Riera M, Cardenas Nadal M, Martínez-Sogues L, Ferrer L.Dermatological clinical signs have been seldom reported in the literature secondary to equine leishmaniasis. This case depicts the clinical signs, treatment, and outcome of a young horse with a pink, elevated lesion on the ventromedial quadrant of the cornea. A corneal cytology was performed and revealed the presence of leishmania amastigotes reaching the diagnosis of keratitis secondary to leishmania. Surgical resection was recommended but the owner declined the procedure, and the lesion was treated with a topical antimonial for 6 weeks. The lesion reduced remarkably during the first weeks ...
Bell C, Rogers S, Taylor J, Busby D.A key welfare problem for horses is that people commonly fail to recognise, and consequently neglect to resolve, equine behavioural signs of distress, worsening the welfare of the horse and potentially putting the safety of the handler at risk as a result. Members of equestrian Facebook groups were asked to view six videos and assess the horse's behaviour in each; the authors selected the videos and considered each video to demonstrate behaviour associated with negative affective states. An additional six equine behaviourists also completed the survey as an "expert comparison group" from whom ...
Ryan D, McKemie DS, Kass PH, Puschner B, Knych HK.The increasing availability of cannabidiol (CBD) and anecdotal reports of its anti-inflammatory effects has garnered it much interest in the equine industry. The objectives of the current study were to (1) describe the pharmacokinetics of oral CBD in exercising thoroughbreds, (2) characterize select behavioral and physiologic effects, and (3) evaluate effects on biomarkers of inflammation using an ex vivo model. This study was conducted in a randomized balanced 3-way crossover design with a two-week washout period between doses. Horses received a single oral dose (0.5, 1, and 2 mg/kg) of CBD...
Halliwell RE, McGorum BC, Irving P, Dixon PM.An enzyme-linked immunosorbent assay (ELISA) was used to quantify isotype-specific antibody to Micropolyspora faeni and to Aspergillus fumigatus in the sera and bronchoalveolar lavage fluid (BALF) of normal horses, horses with chronic obstructive pulmonary disease (COPD) and horses with other chronic respiratory diseases. Elevated antibody levels were not detected in the sera of affected horses. However, both IgE and IgA antibody to both allergens was significantly elevated in BALF in COPD affected horses sampled both when symptomatic and asymptomatic. Elevated levels were also found in animal...
MacLachlan NJ, Balasuriya UB, Hedges JF, Schweidler TM, McCollum WH, Timoney PJ, Hullinger PJ, Patton JF.Equine arteritis virus (EAV) is the causative agent of equine viral arteritis, an apparently emerging disease of equids. In this study, the antibody response of horses to the structural proteins of EAV was evaluated using gradient-purified EAV virions and baculovirus-expressed recombinant EAV structural proteins (G(L), G(S), M, N) as antigens in a Western immunoblotting assay. Thirty-three sera from horses that previously had been naturally or experimentally infected with EAV were evaluated, including samples from mares, geldings, and both persistently and nonpersistently infected stallions. S...
Hooper PT, Ketterer PJ, Hyatt AD, Russell GM.Laboratory examinations of equine morbillivirus included experimental reproductions of the disease caused by the virus by transmission of mixed lung and spleen taken from two field equine cases into two horses and by inoculating tissue culture virus into a further two horses. The most distinctive gross lesions of the diseases that developed in three of the horses was that of pulmonary edema characterized by gelatinous distension of subpleural lymphatics. Histologically, the lesions in the lungs were those of serofibrinous alveolar edema, alveolar macrophages, hemorrhage, thrombosis of capillar...
Nasir L, Reid SW.The sarcoid is a benign locally invasive dermal fibroblastic lesion, commonly affecting horses and donkeys. The aetiology of the equine sarcoid is equivocal. Bovine papillomaviral (BPV) DNA (type 1/2) is frequently demonstrable in equine sarcoid tumour biopsies. However, the exact role of the virus in the disease process and its contribution to the phenotypic differences in sarcoids is not known. It was sought to assess the transcriptional activity of BPV-1 found in sarcoid tissues. Of 20 tumours examined, 18 were positive for E2 expression and ten positive for L1 expression. Viral oncogenes E...
Watts AE, Nixon AJ, Yeager AE, Mohammed HO.A consistent and clinically relevant model for the induction of core lesions confined to the mid-metacarpal superficial digital flexor tendon (SDFT) has not been previously reported. Injection of bacterial collagenase is commonly used but often results in large, irregular and inconsistent lesions that disrupt the superficial tendon layers and epitenon. Objective: To develop and evaluate a new injection technique for collagenase induction of SDFT injury. Methods: Collagenase gel was injected into a physical columnar defect created by longitudinally placing a curved 16 gauge 8.89 cm needle in ...
Morris DD.Endotoxemia remains the leading cause of death in horses, being intimately involved in the pathogenesis of gastrointestinal disorders that cause colic and neonatal foal septicemia. Endotoxins, normally present within the bowel, gain access to the blood across damaged intestinal mucosa, or endotoxemia occurs when gram negative organisms proliferate in tissues. Endotoxins are removed from the circulation by the mononuclear phagocyte system, and the response of mononuclear phagocytes to these lipopolysaccharides (LPS) play an important role in determining the severity of clinical disease. Macroph...
Akerreta S, Calvo MI, Cavero RY.To collect, analyze and evaluate the ethnoveterinary knowledge about medicinal plants in a northern Iberian region (Navarra, 10,421 km(2), 620,377 inhabitants). Methods: Field work was conducted between 2003 and 2007, using semi-structured questionnaire and participant observation as well as transects walks in wild herbal plant collection areas. We performed semi-structured interviews with 667 informants (mean age 72; 55.47% women, 44.53% men) in 265 locations, identified the plant reported and analyzed the results, comparing them with those from other territories. Results: Out of 287 species ...
Deeg CA, Ehrenhofer M, Thurau SR, Reese S, Wildner G, Kaspers B.Equine recurrent uveitis (ERU) is the most serious eye disease in horses worldwide. Despite the fact that ERU is generally considered to be immune mediated, a detailed description of the histopathology of the posterior part of ERU eyes is lacking. Here, we examined sections of paraffin-embedded eyes using histological and immunhistological methods. Twenty seven eyes of 20 horses with ERU and 30 eyes of 15 healthy control horses were included in this study. We could consistently demonstrate an involvement of the retina and the choroid in all examined eyes of horses with spontaneous ERU. In eyes...
Wilson WD.Myeloencephalopathy is an uncommon manifestation of equine herpesvirus 1 (EHV-1), but it can cause devastating losses during outbreaks on individual farms. Clinical signs of neurologic disease reflect a diffuse multifocal hemorrhagic myeloencephalopathy secondary to vasculitis and thrombosis. Sudden onset and early stabilization of signs, including ataxia, paresis, and urinary incontinence; involvement of multiple horses on the premises; and recent history of fever, abortion, or viral respiratory disease in the affected horse or herdmates are typical features, although there is considerable va...
van Loon JP, de Grauw JC, van Dierendonck M, L'ami JJ, Back W, van Weeren PR.Intra-articular administration of morphine as a local analgesic and anti-inflammatory drug is widely used in human medicine. In equids, little is known about its clinical analgesic and anti-inflammatory efficacy. Objective: To use an inflammatory orthopaedic pain model to investigate the analgesic and anti-inflammatory effects of intra-articularly administered morphine as a new treatment modality in horses with acute arthritis. Methods: In a crossover study design, synovitis was induced in the left or right talocrural joint by means of intra-articular injection of 0.5 ng lipopolyssacharide (LP...
Rikihisa Y, Pretzman CI, Johnson GC, Reed SM, Yamamoto S, Andrews F.Ehrlichia risticii has a close antigenic relationship to E. sennetsu. Sera of ponies experimentally infected with E. risticii, the etiologic agent of Potomac horse fever, consistently reacted with E. sennetsu, a human pathogen, in indirect fluorescent-antibody (IFA) testing, while human E. sennetsu convalescent serum reacted with E. risticii by IFA testing and immunoferritin labeling of cells infected in vitro. Two ponies injected intravenously with live E. sennetsu did no develop clinical illness. Subsequent injection with live E. sennetsu did not develop clinical illness. Subsequent injectio...
Müller J, Feige K, Wunderlin P, Hödl A, Meli ML, Seltenhammer M, Grest P, Nicolson L, Schelling C, Heinzerling LM.Melanoma is a disease with high incidence in gray horses and has limited therapeutic options in metastatic disease. Gene therapy has shown some success in animal models and human patients. A randomized double-blind, placebo-controlled study was conducted to investigate 2 treatment options using cytokine-encoding plasmid DNA in horses with metastatic melanoma to induce immunologic antitumor effects. Adult gray horses with spontaneously occurring metastatic melanoma (n=26) were included in the study. Treatment of 26 gray horses with metastatic melanoma consisted of interleukin-18-encoding plasmi...
Proudman CJ.The records of 200 colic episodes, collected prospectively, over a two year period, from first opinion cases, were analysed and compared with a control sample selected at random from the same population. Analysis by colic type revealed 72% spasmodic/undiagnosed; 7% surgical; 5.5% flatulent; 5% pelvic flexure impactions; 9.5% other implications and 1% colitis. A possible predisposing cause was identified in 43% of the spasmodic/undiagnosed cases. The total incidence of colic in each age group showed no statistically significant differences from the control population. Stallions were significant...
Nelson GJ.The neutral lipids of the erythrocytes were investigated in several common mammals: cow, dog, goat, horse, pig, rabbit, rat, and sheep. Cholesterol content was determined by gas-liquid, thin-layer, and column chromatography, the last in conjunction with the IR spectrophotometry. The three methods yielded similar results. In every species investigated, cholesterol was the major neutral lipid; cholesteryl esters, triglycerides, and free fatty acids were detected only in trace amounts. It is concluded that these substances may have been contaminants from plasma lipoproteins or leukocytes rather t...
Hausberger M, Fureix C, Bourjade M, Wessel-Robert S, Richard-Yris MA.Play remains a mystery and adult play even more so. More typical of young stages in healthy individuals, it occurs rarely at adult stages but then more often in captive/domestic animals, which can imply spatial, social and/or feeding deprivations or restrictions that are challenging to welfare, than in animals living in natural conditions. Here, we tested the hypothesis that adult play may reflect altered welfare states and chronic stress in horses, in which, as in several species, play rarely occurs at adult stages in natural conditions. We observed the behaviour (in particular, social play) ...
Christensen JW, Beekmans M, van Dalum M, VanDierendonck M.The effects of hyperflexion on the welfare of dressage horses have been debated. This study aimed to investigate acute stress responses of dressage horses ridden in three different Head-and-Neck-positions (HNPs). Fifteen dressage horses were ridden by their usual rider in a standardised 10-min dressage programme in either the competition frame (CF), hyperflexion ("Low-Deep-and-Round"; LDR) or a looser frame (LF) in a balanced order on three separate test days. Heart rate (HR), heart rate variability parameters (HRV), behaviour and rein tension were recorded during the test. Salivary cortisol c...
MacLachlan NJ, Balasuriya UB, Hedges JF, Schweidler TM, McCollum WH, Timoney PJ, Hullinger PJ, Patton JF.Equine arteritis virus (EAV) is the causative agent of equine viral arteritis, an apparently emerging disease of equids. In this study, the antibody response of horses to the structural proteins of EAV was evaluated using gradient-purified EAV virions and baculovirus-expressed recombinant EAV structural proteins (G(L), G(S), M, N) as antigens in a Western immunoblotting assay. Thirty-three sera from horses that previously had been naturally or experimentally infected with EAV were evaluated, including samples from mares, geldings, and both persistently and nonpersistently infected stallions. S...
van Zyl A, Daniel J, Wayne J, McCowan C, Malik R, Jelfs P, Lavender CJ, Fyfe JA.Two horses were diagnosed as having Mycobacterium ulcerans infections. The first was a 21-year-old Quarterhorse-cross mare living in Mallacoota (a coastal town near the border of New South Wales and Victoria, Australia) that presented with lichenification, hair-loss and oedema on a fetlock, which subsequently ulcerated, as well as a non-healing ulcer on the wither. The second horse was a 32 year-old Standardbred gelding from Nicholson, near Bairnsdale, Victoria, that had an ulcerated lesion on its caudal thigh. Histologically, there were characteristic changes seen with M. ulcerans infections ...
Kornaś S, Cabaret J, Skalska M, Nowosad B.A 11-year survey on helminth intestinal infection of horses was done in seven provinces of southern Poland. 21,641 faecal samples were collected from horses of different age, sex, breed and management system originating from 84 farms. Age was the major factor influencing the cyathostome egg excretion, the maximum being observed in yearlings and second year horses. Parascaris was found mostly in foals and yearlings. The main factor for Anoplocephala was the access to pasture. The level of cyathostome egg shedding (EPG) could be related to sex (geldings had higher values of EPG), breed (Thorough...
Patel JR, Edington N, Mumford JA.Subtype-1 isolates of Equine herpesvirus-1 (EHV-1) from a quadriplegic horse and from an aborted foetus were compared with each other and with a subtype-2 respiratory isolate. All 3 isolates were detected in the epithelium and macrophages of the respiratory tract. Both the paresis and foetal subtype-1 isolates replicated in the epithelium of the ileum and this correlated with the recovery of virus from faeces in vivo. The paresis subtype-1 isolate also had a predelection for vascular endothelial cells, particularly in the nasal mucosa, but also in the lungs, central nervous system, adrenal and...
Locke MM, Penedo MC, Bricker SJ, Millon LV, Murray JD.The progressive loss of colour in the hair of grey horses is controlled by a dominantly inherited allele at the Grey locus (GG). In this study, two paternal Quarter Horse (QH) families segregating for the GG allele were genotyped with a set of 101 microsatellite markers spanning the 31 autosomes and the X chromosome. This genome scan demonstrated linkage of Grey to COR018 (RF=0.02, LOD=12.04) on horse chromosome 25 (ECA25). Further chromosome-specific analysis of seven total QH families confirmed the linkage of Grey to a group of ECA25 markers and the map order of NVHEQ43-(0.24)-UCDEQ405-(0.09...
Adams AA, Breathnach CC, Katepalli MP, Kohler K, Horohov DW.A number of model systems have been employed to investigate age-associated changes in immune function. The purpose of the current study was to characterize senescent T cells and to investigate the inflamm-aging phenomenon both in vitro and in vivo using the old horse as a model. We examined whether decreased T cell proliferation induced by Con A is caused by increased apoptosis. We also utilized intracellular CFSE to analyze changes within each round of cell proliferation, in particular cytokine production. Intracellular staining with flow cytometry, RT-PCR, and ELISA were used to measure pro-...
Lavoie JP, Bullone M, Rodrigues N, Germim P, Albrecht B, von Salis-Soglio M.Inhaled corticosteroids are effective for the treatment of equine asthma but they induce cortisol suppression with potential side effects. Objective: To study the efficacy of ciclesonide, an inhaled corticosteroid with an improved safety profile, on lung function, clinical signs related to airway obstruction, and serum cortisol levels in asthmatic horses exposed to a mouldy hay challenge. Methods: Cross-over placebo controlled, blinded, randomised experiment. Methods: Sixteen horses were enrolled in three subsequent dose-titration studies (8 horses/study) to investigate the effects of inhaled ...
Zhang X, Li C, Nan Z.An evaluation was performed on the influence of mowing height (2.5, 5.0 or 7.5 cm) and mowing frequency (weekly or fortnightly) on levels of ergot alkaloids (ergine and ergonovine) formed in drunken horse grass, Achnatherum inebrians, grown under greenhouse conditions. Samples were taken monthly and alkaloids were extracted and analyzed by reverse-phase HPLC. Alkaloid levels increased more or less linearly with plant age over the first four months following establishment. Levels were higher in samples cut fortnightly compared to those cut weekly, and were higher when plants were cut at a mowin...
Giguère S, Berghaus LJ, Willingham-Lane JM.Pneumonia caused by remains an important cause of disease and death in foals. The combination of a macrolide (erythromycin, azithromycin, or clarithromycin) with rifampin has been the recommended treatment for foals with clinical signs of infection caused by since the early 1980s with, until recently, only rare reports of resistance. Resistance to macrolides and rifampin in isolates of cultured from horses is increasing, with isolates resistant to all macrolides and rifampin now being cultured from up to 40% of infected foals at some farms. This text reviews the available data regarding ant...
Clabough DL, Gebhard D, Flaherty MT, Whetter LE, Perry ST, Coggins L, Fuller FJ.An adult horse infected with a virulent, cell culture-adapted strain of equine infectious anemia virus (EIAV) developed cyclical thrombocytopenia in which the nadir of platelet counts coincided with peak febrile responses. In order to investigate the mechanism of thrombocytopenia during acute febrile episodes, four adult horses were experimentally infected with the wild-type Wyoming strain of EIAV. Platelet counts decreased from baseline as rectal temperature increased. Serum reverse transcriptase activity increased above background levels in all horses, coincident with increase in rectal temp...
Robinson NE, Karmaus W, Holcombe SJ, Carr EA, Derksen FJ.Although subclinical airway inflammation is thought to be common in horses, there is little information on its prevalence and none on risk factors. Objective: To determine the prevalence and risk factors for an increased number of inflammatory cells and for mucus accumulation in the trachea of pleasure horses. Methods: Horses (n = 266) in stables (n = 21) in Michigan were examined endoscopically, once in winter and once in summer 2004. Visible tracheal mucoid secretions were graded 0-5 and inflammatory cell numbers counted in a tracheal lavage sample. Information collected about each horse inc...
Trösch M, Pellon S, Cuzol F, Parias C, Nowak R, Calandreau L, Lansade L.Animals can indirectly gather meaningful information about other individuals by eavesdropping on their third-party interactions. In particular, eavesdropping can be used to indirectly attribute a negative or positive valence to an individual and to adjust one's future behavior towards that individual. Few studies have focused on this ability in nonhuman animals, especially in nonprimate species. Here, we investigated this ability for the first time in domestic horses (Equus caballus) by projecting videos of positive and negative interactions between an unknown human experimenter (a "positive" ...
