"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.
Kondo T, Sato F, Tsuzuki N, Yamada K.Cervical vertebral stenotic myelopathy (CVSM), a common cause of cervical spinal cord compression, is a neurological disease characterized by general proprioceptive ataxia and weakness of hindlimbs that tends to develop in young adult Thoroughbred horses. Although male horses seem to be at increased risk for CVSM, the mechanism for the occurrence of sex differences in the prevalence of CVSM is still poorly understood. Hence, we hypothesized that sex differences in the development of cervical spinal cord and spinal canal would affect the development of CVSM. This study aimed to evaluate sex dif...
Kilcoyne I, Magdesian KG, Guerra M, Dechant JE, Spier SJ, Kass PH.Gastrointestinal disease has been associated with shedding of Salmonella with previous studies demonstrating that horses with colic have a higher risk of acquiring and shedding Salmonella organisms. Objective: The purpose of this study was to determine the prevalence of and risk factors associated with Salmonella shedding in a colic population at a referral clinic. Methods: Retrospective case-control study. Methods: For each colic case that was positive for Salmonella (n = 56), two colic cases (n = 112) that tested negative for Salmonella, were enrolled as controls. Associations between va...
Zhang M, Wei K, Wu Z, Sun J, Hu J, Deng S, Tao J.There is considerable confusion concerning the relationships among species of Sarcocystis found in donkeys and horses. Here, we describe a Sarcocystis species in Chinese donkeys (Equus asinus). Sarcocysts were found in 12 of 32 (37.5%) adult donkeys. By light microscopy, they were divided into two types, thin-walled and thick-walled. The thin-walled were macroscopic (up to 320 μm wide) and had short club-like protrusions (up to 2.7 μm long); the thick-walled were microscopic (up to 135 μm wide) and had villar protrusions (up to 5.4 μm long). Ultrastructures of the two types exhibited s...
Khan RZU, Rosanowski SM, Parkes RSV.Hoof morphometry, conformation and shoeing practices have all been associated with lameness in horses. Hoof morphometry in working donkeys in Pakistan has not been objectively measured. Objective: To quantitatively assess hoof morphology in donkeys, to identify factors underlying hoof morphology, and interrelationships between conformation, lameness, and shoeing status. Methods: Cross-sectional study. Methods: Donkeys were assessed in-harness using a modified five-point lameness scale by two veterinarians and digital photographs of front hooves taken alongside a grid. Factor analysis was used ...
Matsumoto T, Okumura S, Hirata S.This study aimed to apply radar technology to a large quadruped animal. We first developed a non-contact respiration measurement system using millimeter-wave array radar for a horse in standing position. Specifically, we measured the respiration of a stationary domestic horse in stables. Simultaneously, we measured the respiration rate using infrared thermography and developed a method for analyzing the radar information while verifying the rate of agreement. Our results suggested that the radar technology detected breathing and accurately measured the respiration of a horse, despite variation...
MacNicol JL, Renwick S, Ganobis CM, Allen-Vercoe E, Weese JS, Pearson W.The equine gastrointestinal (GI) microbiota is intimately related to the horse. The objective of the current study was to evaluate the microbiome and metabolome of cecal inoculum maintained in an anaerobic chamber or chemostat batch fermenter, as well as the fecal slurry maintained in an anaerobic chamber over 48 h. Cecal and fecal content were collected from healthy adult horses immediately upon death. Cecal fluid was used to inoculate chemostat vessels (chemostat cecal, = 11) and vessels containing cecal fluid (anaerobic cecal, = 15) or 5% fecal slurry (anaerobic fecal, = 6) were maintain...
Jorge-Smeding E, Warnken T, Grob AJ, Feige K, Pudert T, Leung YH, Go YY, Kenéz Á.Insulin dysregulation (ID) is a determinant of equine metabolic syndrome. Among the sphingolipids, ceramides contribute to the development of ID; however, the cross talk between the liver and adipose tissue (AT) depots and the variation among AT depots in terms of ceramide metabolism are not well understood. We aimed to characterize the sphingolipidome of plasma, liver, and AT (nuchal, NUAT; subcutaneous, SCAT; omental, OMAT; retroperitoneal, RPAT) and their associations with insulin response to oral glucose testing (OGT) in normoinsulinemic and hyperinsulinemic horses. Plasma, liver, and AT s...
Oquendo PS, Silva ESM, Oquendo FMG, Cuervo-Arango J, Beletti ME.The effect of three different hormonal protocols to prepare anestrous recipient mares on embryo survival was evaluated. The first group consisted of only progesterone administration (NE) 4 days before embryo transfer, while the recipients from the other two groups received a single administration of 2.5 mg of oestradiol benzoate (SE) 2 days earlier or 8 mg of oestradiol split in increasing doses for 5 consecutive days (LE) ending 3 days before progesterone treatment. The likelihood of recovering an embryo 2 days after transfer was 46.1% (6/13), 62.5% (5/8) and 85.7% (6/7) for recipie...
Salinger A, Mochal-King C, Clinton K, Priddy LB, Elder S, Fontenot R, Eddy A, Wills R, Jaffe M.Frontal plane slab fractures account for the majority of third carpal bone (C3) fractures in racing and performance horses. Recommended treatment is stabilization with a lagged AO cortical screw. Associated complications are fragment splitting, fragment spinning, and irritation of dorsal soft tissue structures. A novel, headless, cannulated screw with interlocking threads the Headless Compression Screw Fastener (HCSF) has been developed to resist multidirectional forces and bending moments; however, it has not been applied in the horse. Simulated C3 frontal plane slab fractures were created in...
Kellon EM, Gustafson KM.Hyperinsulinemia associated with pituitary pars intermedia dysfunction (PPID) and/or equine metabolic syndrome is well documented to put horses at high risk of laminitis. While dietary control of simple sugars and starch is the most effective therapy to control hyperinsulinemia, some horses fail to respond. Ten horses with hyperinsulinemia refractory to diet control, metformin, levothyroxine, and pergolide (if diagnosed with PPID) were treated with sodium-glucose cotransporter-2 inhibitor canagliflozin (Invokana®). Nine horses were hyperglycemic (>5.5 mmol/l) or had a history of hyperglycemia...
To describe some cardiorespiratory effects of an inspiratory-to-expiratory (IE) ratio of 1:1 compared with 1:3 in ventilated horses in dorsal recumbency. Methods: Randomized crossover experimental study. Methods: A total of eight anesthetized horses, with 444 (330-485) kg body weight [median (range)]. Methods: Horses were ventilated in dorsal recumbency with a tidal volume of 15 mL kg and a respiratory rate of 8 breaths minute, and IE ratios of 1:1 (IE1:1) and 1:3 (IE1:3) in random order, each for 25 minutes after applying a recruitment maneuver. Spirometry, arterial blood gases and dobutamine...
Stonehouse O, Stefanovski D, Bowman B, Sertich PL, Demchur J, Lewis GM, Turner RM, Turner RMO.Nocardioform placentitis (NP) has been associated with mid to late pregnancy loss in mares. To date, disease outbreaks have been described only in central Kentucky, although sporadic, isolated cases have been reported globally. This study describes a series of cases of NP that occurred in a sample population of 299 mares foaling in southeastern Pennsylvania and northeastern Maryland in 2020. These cases coincided with an outbreak of NP that occurred in Kentucky that same year. On farms that reported information on both normal and abnormal foalings, nocardioform organisms/DNA were isolated from...
Burroughs DL, Lorch G, Guo Y, Hill K, Schroeder EL, Cole LK, Phelps MA.Mycophenolate mofetil (MMF) is the prodrug of mycophenolic acid (MPA) which acts as an immunosuppressive agent. During the biotransformation of MMF to MPA, additional metabolites including MPA phenol glucuronide (MPAG), MPA acyl glucuronide (AcMPAG) and MPA phenol glucoside (MPG) are formed. Objective: To define the noncompartmental pharmacokinetic (PK) parameters of three single doses of intravenous (i.v.) MMF and its downstream metabolites in healthy horses. Methods: Six healthy Standardbred mares. Methods: Generic MMF (Par Pharmaceuticals; Chestnut Ridge, NY, USA) was reconstituted and admi...
Intemann S, Reckels B, Schubert DC, Wolf P, Kamphues J, Visscher C.Evidence has already been provided that feed-borne mold spores and endotoxins can trigger chronic, non-infectious respiratory disease if inhaled. Furthermore, deficiencies in feed microbiology are suspected to trigger gastrointestinal and liver disorders in horses, but the connection needs further clarification. Most of the previous studies regarding horse feed hygiene focused on forage, whereas research regarding hygienic quality of concentrates is scarce. In the present study, results of reports on hygienic quality of compound feed and cereals for horses were evaluated secondarily. Results i...
Hobbs KJ, Johnson PJ, Wiedmeyer CE, Schultz L, Foote CA.Limited information is available regarding endothelial glycocalyx degradation during sepsis in horses. Plasma syndecan-1 concentrations are increased in consequence of sepsis in other species and have been useful for prognostication. Objective: To determine whether plasma syndecan-1 levels are increased in adult horses affected with sepsis. Methods: Retrospective cohort study. Methods: Adult horses were assigned to one of three groups based on results of physical and laboratory examinations, clinical diagnosis, and results of previously described SIRS classification: Group 1 horses included he...
Rivera-Velez A, Huber L, Sinha S, Cohen ND.Rhodococcus equi is a common cause of severe pneumonia in foals. Emergence of macrolide-resistant R. equi isolated from foals and their environment has been reported in the United States. A novel erm(51) gene was recently identified in R. equi in soil from horse farms in Kentucky. Our objective was to determine the effect of the erm(51) gene and associated rpoB mutation on the fitness of multidrug resistant-R. equi (MDR-R. equi) under different nutrient conditions. Bacterial growth curves were generated for 3 MDR-R. equi isolates and 3 wild-type (WTN) R. equi isolates recovered from environmen...
Sievert M, Schuler G, Wehrend A.Due to the time-limited intestinal uptake of colostral immunoglobulins, the suggested treatment of hypogammaglobulinemia in new-born foals is usually plasma transfusion. The aims of this study were twofold: firstly, to investigate the course of serum IgG concentration after plasma transfusion in newborn foals; and secondly, to determine the amount of transfusion required for a significant increase in serum IgG concentration. For this purpose, the IgG concentration was measured in 23 foals at three different points in time: before transfusion, 1 hour after transfusion, and 24 hours after transf...
Ravanetti P, Kühnle C, Lechartier A, Zucca E.To date, only a few reports describe the treatment. The present report describes an extraarticular surgical approach, with the insertion of an absorbable implant, to treat a Subchondral cystic lesion (SCL) in the humeral head 3year old racing Thoroughbred & in the talus of a 11year old Arabian horse. SCLs were radiographically visible and associated with severe lameness. Scintigraphy showed focal intense radiopharmaceutical uptake in both cases, and CT scan revealed signs of osteoarthrosis associated with SCL in the talus. The use of a biocompatible, osteoinductive and osteoconductive implant ...
Dzięgielewska A, Dunislawska A.Mitochondria are an essential part of most eukaryotic cells. The crucial role of these organelles is the production of metabolic energy, which is converted into ATP in oxidative phosphorylation. They are also involved in and constitute apoptosis, the site of many metabolic processes. Some of the factors that negatively affect mitochondria are stress, excessive exercise, disease, and the aging process. Exercise can cause the release of large amounts of free radicals, inflammation, injury, and stress. All of these factors can contribute to mitochondrial dysfunction, which can consistently lead t...
Luczkowiak J, Radreau P, Nguyen L, Labiod N, Lasala F, Veas F, Herbreteau CH, Delgado R.Several anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) monoclonal antibodies (mAbs) have received emergency authorization for coronavirus disease 2019 (COVID-19) treatment. However, most of these mAbs are not active against the highly mutated Omicron SARS-CoV-2 subvariants. We have tested a polyclonal approach of equine anti-SARS-CoV-2 F(ab')2 antibodies that achieved a high level of neutralizing potency against all SARS-CoV-2 variants of concern tested including Omicron BA.1, BA.2, BA.2.12 and BA.4/5. A repertoire of antibodies targeting conserved epitopes in different regi...
Kambayashi Y, Nemoto M, Tsujimura K, Ohta M, Bannai H.Equine coronavirus (ECoV) causes fever, lethargy, anorexia and gastrointestinal signs in horses. There has been limited information about the prevalence and seasonality of ECoV among Thoroughbreds in Japan. Objective: To understand the epidemiology and to evaluate the potential risk of ECoV infection to the horse industry in Japan. Methods: Longitudinal. Methods: The virus-neutralisation (VN) test was performed using sera collected three times a year at 4 months intervals from 161 yearlings and at 6-7 months intervals from 181 active racehorses in Japan in 2017-2018, 2018-2019 and 2019-2020....
Steuer AE, Scoggin K, Stewart JC, Barker VD, Adams AA, Loynachan AT, Nielsen MK.This study aimed to collect information on local and systemic inflammatory responses, and goblet cell-associated components, following anthelmintic treatment with moxidectin and ivermectin in horses naturally infected with cyathostomin parasites. Thirty-six horses aged 2-5 years of age were randomly allocated to three groups. Group 1 received ivermectin/praziquantel (0.2 mg/kg), Group 2 received moxidectin/praziquantel (0.4 mg/kg) and Group 3 were untreated controls. Tissue samples from the Cecum, Dorsal and Ventral Colons were used for histopathological evaluation and preserved for RNA is...
Patterson Rosa L, Martin K, Vierra M, Lundquist E, Foster G, Brooks SA, Lafayette C.Over 40 identified genetic variants contribute to white spotting in the horse. White markings and spotting are under selection for their impact on the economic value of an equine, yet many phenotypes have an unknown genetic basis. Previous studies also demonstrate an interaction between MC1R and ASIP pigmentation loci and white spotting associated with KIT and MITF. We investigated two stallions presenting with a white spotting phenotype of unknown cause. Exon sequencing of the KIT and MITF candidate genes identified a missense variant in KIT (rs1140732842, NC_009146.3:g.79566881T>C, p.T391A) ...
El-Sheikh Ali H, Scoggin K, Murase H, Norris J, Menarim B, Dini P, Ball B.The equine chorioallantois (CA) undergoes complex physical and biochemical changes during labor. However, the molecular mechanisms controlling these changes are still unclear. Therefore, the current study aimed to characterize the transcriptome of equine CA during spontaneous labor and compare it with that of normal preterm CA. Placental samples were collected postpartum from mares with normal term labor (TL group, n = 4) and from preterm not in labor mares (330 days GA; PTNL group, n = 4). Our study identified 4137 differentially expressed genes (1820 upregulated and 2317 downregulat...
Loos CMM, McLeod KR, Vanzant ES, Stratton SA, Bohannan AD, Coleman RJ, van Doorn DA, Urschel KL.The objective of the study was to characterize the temporal changes of phosphorylation patterns of mTOR signaling proteins in response to two dietary protein sources in insulin dysregulated (ID, n = 8) and non-ID (n = 8) horses. Horses were individually housed and fed timothy grass hay and 2 daily concentrate meals so that protein was the first limiting nutrient and the total diet provided 120% of daily DE requirements for maintenance. On sample days, horses randomly received 0.25 g CP/kg BW of a pelleted alfalfa (AP) or commercial protein supplement (PS). Blood samples were collected before a...
Barshick MR, Gonzalez ML, Busse NI, Helsel PJ, Johnson SE.Satellite cell (SC) activation is defined as the time frame during which the stem cell becomes poised to reenter G1 of the cell cycle. The growth factors and events leading to full mitotic activation in equine SCs remain largely unknown. Insulin-like growth factor I (IGF-I), hepatocyte growth factor (HGF), and fibroblast growth factor 2 (FGF2) are sequentially transcribed during the muscle repair and recovery period following strenuous exercise in adult horses. Expression of IGF-I occurs within 24 h of the postexercise recovery period suggesting it may affect early SC actions. As a first step,...
Schlindwein X, Werneburg I.We compared embryogenesis of five species of domesticated even-toed and one odd-toed ungulate and used a phylogenetic framework to contextualize such comparison. Organ systems that occur relatively earlier in embryogenesis generally have more time to develop and therefore are found to be more mature at birth when compared to structures that appear later in development. We hypothesized that the less mature the animals' organs are at birth, the more they are susceptible to artificial selection. The horse had the most mature organs at birth, followed by cattle, reindeer, sheep/goat, and pig. This...
Busse NI, Gonzalez ML, Wagner AL, Johnson SE.Optimal athletic performance requires meeting the energetic demands of the muscle fibers, which are a function of myosin ATPase enzymatic activity. Skeletal muscle with a predominant oxidative metabolism underlies equine athletic success. Sodium butyrate, a short-chain fatty acid, can affect muscle fiber composition in pigs. To determine if a similar scenario exists in horses, 12 adult Thoroughbred geldings (7.4 ± 0.6 yr of age; mean ± SEM) were fed 16 g of calcium butyrate (CB) or an equivalent amount of carrier (CON) daily for 30 d in a crossover design. Middle gluteal muscle biopsies were...
Lan J, Chen P, Liu W, Ren W, Zhang L, Ding Q, Zhang Q, Wang X, Ge J.Severe acute respiratory syndrome coronavirus (SARS-CoV), SARS-CoV-2, and human coronavirus (hCoV)-NL63 utilize ACE2 as the functional receptor for cell entry, which leads to zoonotic infection. Horses (Equus caballus) attracted our attention because the spike protein receptor-binding domains (RBDs) of SARS-CoV-2 and SARS-CoV-2-related coronaviruses bind equine ACE2 (eACE2) with high affinity. Here we show that eACE2 binds the RBDs of these three coronaviruses and also SARS-CoV-2 variants but with lower affinities compared with human ACE2 (hACE2). Structural analysis and mutation assays indica...
Cvitas I, Oberhaensli S, Leeb T, Marti E.Equine insect bite hypersensitivity (IBH) is the most common skin disease affecting horses. It is described as an IgE-mediated, Type I hypersensitivity reaction to salivary gland proteins of Culicoides insects. Together with Th2 cells, epithelial barrier cells play an important role in development of Type I hypersensitivities. In order to elucidate the role of equine keratinocytes in development of IBH, we stimulated keratinocytes derived from IBH-affected (IBH-KER) (n = 9) and healthy horses (H-KER) (n = 9) with Culicoides recombinant allergens and extract, allergic cytokine milieu (ACM) and ...
Shimizu A, Kawano J, Yamamoto C, Kakutani O, Anzai T, Kamada M.Pulsed-field gel electrophoresis (PFGE) was used to determine genetic relationships among 15 methicillin-resistant Staphylococcus aureus (MRSA) isolates from mares with metritis and from a stallion with dermatitis in Hokkaido. All the 15 isolates showed phage pattern 6/47/54/75, coagulase type IV, and enterotoxin type A. The restriction endonuclease SmaI cut their genomic DNAs into 15 or 16 fragments ranging in size from 8 to 630 kb. Fourteen of the 15 isolates showed the same PFGE pattern, whereas the remaining one appeared to be closely related. The 9 human MRSA isolates showing the same phe...
Silva RO, Rupnik M, Diniz AN, Vilela EG, Lobato FC.Clostridium difficile is an emerging enteropathogen responsible for pseudomembranous colitis in humans and diarrhoea in several domestic and wild animal species. Despite its known importance, there are few studies about C. difficile polymerase chain reaction (PCR) ribotypes in Brazil and the actual knowledge is restricted to studies on human isolates. The aim of the study was therefore to compare C. difficile ribotypes isolated from humans and animals in Brazil. Seventy-six C. difficile strains isolated from humans (n = 25), dogs (n = 23), piglets (n = 12), foals (n = 7), calves (n = 7), one c...
Barry S.The ability of non-steroidal anti-inflammatory drugs (NSAID) to inhibit bone healing has been established in experimental animal models using mice, rats, and rabbits. The mechanism of action is largely unknown but stems from prostaglandin inhibition and is likely multifactorial. In human medicine NSAID are known to prevent heterotopic ossification, however the clinical importance of their effects on bone healing remains controversial. Although a small handful of reports suggest that NSAID suppress bone healing in dogs and horses, there is little published information to direct veterinary pract...
Tremaine WH, Dixon PM.The treatments of 277 horses with equine sinonasal disease (1984-1996), described by Tremaine and Dixon (2001), are reported here. Long-term (median duration 24 months) outcomes of treatment of the more common disorders were good, with 92% of horses with sinonasal mycosis, 84% with primary sinusitis, 82% with sinus cysts, 78% with dental sinusitis and 75% with sinonasal trauma reported to have complete remission of clinical signs. However, only 33% of horses with progressive ethmoidal haematoma (PEH) and 12% with sinonasal neoplasia reported long term remission of clinical signs.
Westermann CM, van Leeuwen R, van Raamsdonk LW, Mol HG.Atypical myopathy (AM) in horses is caused by the plant toxin hypoglycin A, which in Europe typically is found in the sycamore maple tree (Acer pseudoplatanus). Owners are concerned about whether their horses are in danger if they graze near maple trees. Objective: To measure hypoglycin A in the most common maple tree species in the Netherlands, and to determine whether concentration of toxin is a predictor of AM in horses. Methods: A total of 278 samples of maple tree leaves, sprouts, and seeds were classified by species. Mean concentrations of hypoglycin A were compared for the type of sampl...
Fenner K, Caspar G, Hyde M, Henshall C, Dhand N, Probyn-Rapsey F, Dashper K, McLean A, McGreevy P.We propose that the anthropomorphic application of gender stereotypes to animals influences human-animal interactions and human expectations, often with negative consequences for female animals. An online survey was conducted to explore riders' perceptions of horse temperament and suitability for ridden work, based on horse sex. The questionnaire asked respondents to allocate three hypothetical horses (a mare, gelding and stallion) to four riders compromising a woman, man, girl and boy. Riders were described as equally capable of riding each horse and each horse was described as suitable for a...
van Galen G, Saegerman C, Marcillaud Pitel C, Patarin F, Amory H, Baily JD, Cassart D, Gerber V, Hahn C, Harris P, Keen JA, Kirschvink N, Lefere L....Appropriate management of atypical myopathy (AM) requires the establishment of an accurate diagnosis and prognosis. Furthermore, preventive measures to avoid AM need to be refined. Objective: The aims of the study were as follows: 1) to improve the diagnosis of AM; 2) to identify prognostic predictors; and 3) to refine recommended preventive measures based on indicators of risk factors. Methods: An exploratory analysis of cases in Europe between 2006 and 2009 reported to the Atypical Myopathy Alert Group was conducted. Based on clinical data, reported cases were allocated into 2 groups: ...
Goodman SA, May SA, Heinegård D, Smith RK.The effect of strain and transforming growth factor beta on equine tendon fibroblasts (tenocytes) was assessed in vitro. Tenocytes were isolated from flexor and extensor tendons of horses from foetal to 10 years of age. These cells were cultured until confluent on collagen-coated silicone dishes. Cyclic biaxial strain of 9+/-1% was applied at 0.5 Hz for 24 hours with or without added TGFbeta1 or 3 (10 ng/ml). Proliferation and synthetic responses were dependent on the tendon of origin. Neither strain nor TGFbeta caused flexor tenocytes to proliferate significantly, while strain alone did proli...
Turell MJ, Beaman JR, Neely GW.The vector competence of Aedes taeniorhynchus (Wiedemann) and four strains of Aedes albopictus (Skuse) was assessed for eastern equine encephalitis (EEE) virus isolated from Ae. albopictus collected in Polk County, Florida. Both species became infected with and transmitted EEE virus by bite after feeding on 1-d-old chicks that had been inoculated with EEE virus (viremia = 10(10.1) plaque-forming units [PFU] per ml of blood). However, when fed on an older chick with a lower viremia (viremia = 10(6.1) PFU per ml of blood), Ae. albopictus was significantly more susceptible to infection (90%, n = ...
Zsoldos RR, Kotschwar A, Kotschwar AB, Rodriguez CP, Peham C, Licka T.The rectus abdominis (RA) and oblique external abdominal (OEA) muscles are both part of the construction of the equine trunk and thought to be essential for the function of the spine during locomotion. Although RA activity at trot has previously been investigated, the relationship between OEA and RA at walk and trot has not yet been described. Objective: To document abdominal muscle activities during walk and trot, and test the hypothesis that muscle activity at walk would be smaller than at trot. Methods: Six horses (8-20 years old, 450-700 kg) were used for surface electromyography (EMG) mea...
Florindo HF, Pandit S, Lacerda L, Gonçalves LM, Alpar HO, Almeida AJ.Strangles is a bacterial infection of the Equidae family that affects the nasopharynx and draining lymph nodes, caused by Streptococcus equi subspecies equi. This agent is responsible for 30% of all worldwide equine infections and is quite sensitive to penicillin and other antibiotics. However, prevention is still the best option because the current antibiotic therapy and vaccination is often ineffective. As S. equi induces very strong systemic and mucosal responses in convalescent horses, an effective and economic strangles vaccine is still a priority. In this study the humoral, cellular and ...
Franklin SH, Van Erck-Westergren E, Bayly WM.Horses are elite athletes when compared with other mammalian species. In the latter, performance is limited by cardiovascular or musculoskeletal performance whereas in athletic horses it is the respiratory system that appears to be rate limiting and virtually all horses exercising at high intensities become hypoxaemic and hypercapnoeic. This is due to both diffusion limitation and a level of ventilation inadequate for the metabolic level that enables horses to exercise at these intensities. In conjunction with these blood gas changes, total pulmonary resistance increases and the work of breath...
Nyaoke AC, Navarro MA, Fresneda K, Diab SS, Moore J, Lyras D, Awad M, Uzal FA.Enteric disease in horses may be caused by a variety of microorganisms, including several clostridial species. (previously ) has been frequently associated with gas gangrene in humans and several animal species, including horses. However, its role in enteric diseases of animals has not been fully determined. We describe herein 7 cases of enteric disease in horses associated with infection. Grossly, the small and/or large intestines were necrotic, hemorrhagic, and edematous. Microscopically, there was severe mucosal necrosis and hemorrhage of the small and/or large intestine of all horses. w...
Watson JC, Wilson AM.Three muscles from the proximal equine forelimb were dissected in order to investigate their potential to contribute to proximal limb mechanics. Muscle mass, fibre length, tendon mass and tendon length were measured from biceps brachii, triceps brachii, supraspinatus and lacertus fibrosus (biceps lateral head mass 171-343.4 g and fibre length 0.5-0.8 cm; biceps medial head mass 283-500 g and fibre length 2.2-4 cm; biceps tendon mass 121.8-260 g and tendon length 35-44 cm; triceps long head mass 3200-6663 g and fibre length 19-26.3 cm; triceps lateral head mass 513.8-1240 g and fibre length 17....
Daniels RS, Skehel JJ, Wiley DC.The amino acid sequence of the haemagglutinin of A/equine/Miami/63 (H3N8), the prototype influenza virus of the H3 subtype from horses, is deduced from the nucleotide sequence of virus RNA and compared with the sequences of haemagglutinins of viruses of this subtype isolated from humans [X-31 (H3N2)] and from birds [A/duck/Ukraine/63 (H3N8)] and with the sequence of the haemagglutinin of A/equine/Fontainebleau/79 (H3N8) a virus isolated from a recent outbreak of equine influenza. The amino acid sequence differences detected are discussed with reference to the structure of the molecules, their ...
Robert C, Valette JP, Degueurce C, Denoix JM.The purpose of this study was to demonstrate the feasibility of surface electromyography in the horse and to correlate electromyographic activity with kinematic data. Surface electromyography of seven hindlimb muscles was recorded in five horses at trot on a treadmill. Simultaneously, kinematic analysis of the hindlimb was performed using a three-dimensional system and a unidirectional accelerometer was attached to the hoof. Electromyographic activities of the gluteus medius, vastus lateralis and two parts of the biceps femoris started in the late part of the swing phase and ended in the late ...
Naundrup PJ, Svenning JC.Megafaunas worldwide have been decimated during the late Quaternary. Many extirpated species were keystone species, and their loss likely has had large effects on ecosystems. Therefore, it is increasingly considered how megafaunas can be restored. The horse (Equus ferus) is highly relevant in this context as it was once extremely widespread and, despite severe range contraction, survives in the form of domestic, feral, and originally wild horses. Further, it is a functionally important species, notably due to its ability to graze coarse, abrasive grasses. Here, we used species distribution mod...
Prescott JF, Nicholson VM.The minimal inhibitory concentrations of penicillin G, ampicillin, gentamicin, erythromycin and rifampicin were determined for nine strains of Corynebacterium equi. The effect of combinations of any two of these antibiotics on the killing of these strains was determined at antibiotic concentrations achievable in horses using recommended drug dosages (ampicillin 4.0 microgram/ml, gentamicin 1.0 microgram/ml using recommended drug dosages (ampicillin 4.0 microgram/ml, gentamicin 1.0 microgram/ml and erythromycin 0.25 microgram/ml). Penicillin G was used at 4.0 microgram/ml and rifampicin at 0.06...
Lanata A, Nardelli M, Valenza G, Baragli P, DrAniello B, Alterisio A, Scandurra A, Semin GR, Scilingo EP.We examined the Autonomic Nervous System (ANS) activity of horses in response to human body odors (BOs) produced under happy and fear states. The ANS response of horses was analyzed in terms of Heart Rate Variability (HRV) features extracted in the frequency domain. Our results revealed that human BOs induce sympathetic and parasympathetic changes and stimulate horses emotionally, suggesting interspecies transfer of emotions via BOs. These preliminary findings open the way to measure changes in horse's ANS dynamics in response to human internal states via human BOs, and allow us to better unde...
Im Hof V, Gehr P, Gerber V, Lee MM, Schürch S.We measured the surface tension in the trachea of the non-anaesthetised horse from the spreading behaviour of fluid drops, using videotracheoscopy. To do this, we placed small oil drops onto the tracheal wall with a thin Teflon tubing inserted into a videocolonoscope used in humans. Either 5 ml of saline (control) or 5 ml of bovine lipid extract surfactant (BLES) at 4 mg/ml were administered. Tracheal surface tension was 31.9 +/- 0.54 mN/m (Mean +/- SEM, n = 30) in the control experiments and 24.5 +/- 0.51 mN/m (Mean +/- SEM, n = 21) in the entire trachea after the administration of BLES. Thes...
Fraga M, Perelmuter K, Delucchi L, Cidade E, Zunino P.Lactic acid bacteria (LAB) are important members of the human vaginal microbiota and their presence is considered beneficial. However, little is known about native vaginal bacteria in other animal species such as the horse. The aim of this work was to quantify the vaginal lactic acid bacteria and lactobacilli of mares and to establish if selected equine vaginal lactic acid bacteria, particularly Lactobacillus and Enterococcus spp. strains, could exhibit potential as probiotics. The vaginal lactic acid bacteria and lactobacilli of 26 mares were quantified by plate counts. Five strains (three La...
Beckers KF, Schulz CJ, Childers GW.Advances have been made to standardize 16S rRNA gene amplicon based studies for inter-study comparisons, yet there are many opportunities for systematic error that may render these comparisons improper and misleading. The fecal microbiome of horses has been examined previously, however, no universal horse fecal collection method and sample processing procedure has been established. This study was initialized in large part to ensure that samples collected by different individuals from different geographical areas (i.e., crowdsourced) were not contaminated due to less than optimal sampling or ho...
Al-Haidar A, Farnir F, Deleuze S, Sandersen CF, Leroux AA, Borde L, Cerri S, Amory H.Little is known about the effect of various animal's signalment variables on echocardiographic reference values in the equine species. This study was performed to evaluate the effect of sex, breed, age and body weight (BW) on echocardiographic measurements in the equine species. Echocardiography was performed on 212 ponies or horses of various breeds, aged from 1 day to 37 years old (mean±SD: 7.8 ± 5.8 years), BW 38-890 kg (mean ± SD: 421 ± 133 kg), and free of cardiac disease. Fifty of those animals aged from 2 months to 35 years old (mean ± SD: 11.6 ± 6.4 years old); BW 77-662 kg (mean...
Taylor AH, Mair TS, Smith LJ, Perkins JD.The influence of synovial fluid culture on short- and long-term prognosis of cases with septic synovitis requires study. Objective: Horses with a positive bacterial culture from septic synovial fluid are less likely to survive or return to successful athletic function than those with a negative bacterial culture from septic synovial fluid. Methods: Records of mature horses presented to 2 equine referral hospitals for investigation of suspected septic synovitis were examined. Horses (n=206) were included in the study if synovial fluid was submitted for full laboratory examination, including bac...
Gasser RB, Williamson RM, Beveridge I.Anoplocephala perfoliata is the commonest tapeworm parasite of horses and is incriminated as a significant cause of clinical disease (e.g., ileocaecal intussusception, caeco-caecal intussusception and/or caecal perforation), particularly in horses chronically infected with large numbers of worms. The high prevalence (approximately 20-80%) of the parasite in some countries suggests an increased risk of clinical cases. In spite of research, there is still a paucity of information regarding the pathogenesis of the disease, the epidemiology of the parasite in different geographical regions and the...
Mata F, Johnson C, Bishop C.Bit and bridle accessories improperly fitted in ridden horses can cause oral trauma such as bone spurs, commissure ulceration, and tongue lacerations. This study was used to identify, grade, and compare the types of oral traumas commonly found within polo ponies and race horses. Injuries were assessed visually and by palpation on the tongue, lips' commissures, and interdental space. A total of 50 polo ponies and 50 race horses were sampled in the South of England. A Poisson model was successfully fitted to the data (p < .001), and the variables of discipline (p < .001), injury type (p &l...
Klein C, Troedsson MH, Rutllant J.The process of water movement in the excurrent duct system of the male reproductive tract is pivotal for establishment of male fertility. The objective was to elucidate expression of aquaporin (AQP) water channels in the stallion reproductive tract. Real-time RT-PCR detected expression of AQP0-5 and AQP7-11 in testis, epididymis, and ductus deferens of mature stallions. There were two main expression patterns: (1) higher expression in testis than in epididymis and ductus deferens (AQP0, -4, -5, -8, -10, and -11); and (2) lower expression in testis than in epididymis and ductus deferens (AQP1, ...
