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Topic:Horses
"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.
Science in brief: Report on the first Havemeyer workshop on infectious diseases in working equids, Addis Ababa, Ethiopia, November 2013. The working equid is of vital importance in many low-income countries
where horses, mules and donkeys are the primary means of transport and
traction. Notwithstanding basic husbandry and welfare needs, infectious
diseases compromise the health and welfare of these working animals,
which in turn threatens the livelihoods of the most vulnerable members
of society. A workshop on Infectious Diseases of Working Equids was held in
Addis Ababa, Ethiopia in November 2013, attended by 35 participants
representing academia, nongovernmental organisations (NGOs),
governmental institutions and the ...
Expression of epidermal growth factor receptor and human epidermal growth factor receptor 2 in periocular squamous cell carcinomas of horses. To determine whether epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are expressed in periocular squamous cell carcinomas (SCCs) of horses. Methods: Biopsy specimens of SCCs from 46 horses. Methods: Pathology records were searched retrospectively for biopsy specimens of periocular SCCs obtained from horses. Slides of the specimens were reviewed histologically to confirm the SCC diagnosis and stained for EGFR and HER2 by immunohistochemical methods. For both EGFR and HER2, the immunohistochemical staining intensity and percentage of stain-positive cel...
A specific adenylyl cyclase inhibitor (DDA) and a cyclic AMP-dependent protein kinase inhibitor (H-89) block the action of equine growth hormone on in vitro maturation of equine oocytes. The objectives of this study were firstly to determine whether the stimulatory function of equine growth hormone (eGH) on equine oocyte maturation in vitro is mediated via cyclic adenosine monophosphate (cAMP); and secondly if the addition of eGH in vitro influences oocyte nuclear maturation and if this effect is removed when GH inhibitors are added to the culture. Cumulus-oocyte complexes (COCs) were recovered from follicles <25 mm in diameter and randomly allocated as follows: (i) control (no additives); and (ii) 400 ng/ml of eGH. A specific inhibitor against cyclic AMP-dependent protein ...
Vascular hamartoma in the central nervous system of a foal. Vascular hamartomas are non-neoplastic developmental anomalies of vessels. Cases of cerebral vascular hamartomas have been previously reported in dogs and cats. A 4-week-old Freiberger foal had shown persistent problems with breathing and swallowing since birth, and bilateral laryngeal paralysis was diagnosed. The foal subsequently developed left sided facial nerve paralysis and a secondary corneal ulcer in the left eye. Necropsy revealed a pinkish mass in the obex region of the brain. The mass was further investigated by histology and immunohistochemistry. Histologically, the mass consisted o...
Flow cytometric detection of circulating platelet-derived microparticles in healthy adult horses. To develop a flow cytometric assay to quantify platelet-derived microparticles (PMPs) in equine whole blood and plasma. Methods: Citrate-anticoagulated whole blood from 30 healthy adult horses. Methods: Platelet-poor plasma (PPP) was prepared from fresh whole blood by sequential low-speed centrifugation (twice at 2,500 × g). Samples of fresh whole blood and PPP were removed and stored at 4° and 24°C for 24 hours. Platelet-derived microparticles were characterized in fresh and stored samples on the basis of the forward scatter threshold (log forward scatter < 10(1)) and labeling with anne...
Prevalence of supporting limb laminitis in a UK equine practice and referral hospital setting between 2005 and 2013: implications for future epidemiological studies. The electronic patient records of all equine patients of Rossdales Equine Practice between January 1, 2005 and November 1, 2013 were reviewed to determine the number of cases of supporting limb laminitis (SLL) in a large equine practice and referral hospital setting in the UK and to discuss the implications for future epidemiological studies. The clinical notes were searched electronically for a combination of 'laminitis AND (contralateral OR supporting OR overload OR weight bearing)'. The prevalence of SLL within each identified denominator population and the corresponding 95% CI were calcu...
Buprenorphine provides better anaesthetic conditions than butorphanol for field castration in ponies: results of a randomised clinical trial. A prospective, randomised, blinded, clinical trial in 47 ponies compared butorphanol and buprenorphine administered intravenously with detomidine prior to castration under anaesthesia. Detomidine 12 μg/kg intravenously was followed by butorphanol 25 μg/kg (BUT) or buprenorphine 5 μg/kg (BUP) before induction of anaesthesia with intravenous ketamine and diazepam. Quality of sedation, induction and recovery from anaesthesia, response to tactile stimulation, and surgical conditions were scored. If anaesthesia was inadequate 'rescue' was given with intravenous ketamine (maximum three dose...
Controlling the misuse of cobalt in horses. Cobalt is a well-established inducer of hypoxia-like responses, which can cause gene modulation at the hypoxia inducible factor pathway to induce erythropoietin transcription. Cobalt salts are orally active, inexpensive, and easily accessible. It is an attractive blood doping agent for enhancing aerobic performance. Indeed, recent intelligence and investigations have confirmed cobalt was being abused in equine sports. In this paper, population surveys of total cobalt in raceday samples were conducted using inductively coupled plasma mass spectrometry (ICP-MS). Urinary threshold of 75 ng/mL a...
Genotyping of Burkholderia mallei from an outbreak of glanders in Bahrain suggests multiple introduction events. Glanders, caused by the gram-negative bacterium Burkholderia mallei, is a highly infectious zoonotic disease of solipeds causing severe disease in animals and men. Although eradicated from many Western countries, it recently emerged in Asia, the Middle-East, Africa, and South America. Due to its rareness, little is known about outbreak dynamics of the disease and its epidemiology. Results: We investigated a recent outbreak of glanders in Bahrain by applying high resolution genotyping (multiple locus variable number of tandem repeats, MLVA) and comparative whole genome sequencing to B. mallei i...
A nonterminal equine mandibular model of bone healing. To develop a nonterminal large animal bone defect model for assessing the efficacy of regenerative and pharmacologic treatments designed to enhance bone healing. Methods: In vivo experimental. Methods: Adult gelding horses (n = 6). Methods: Under general anesthesia, using radiographic guidance, 13.5 mm diameter bilateral, full thickness mandibular defects were created in 6 horses using a custom surgical jig and coring bit. After 16 weeks, under general anesthesia, 23 mm diameter cores that encompassed the original healing defects and surrounding parent bone material were removed for evaluation...
Ergot alkaloid intoxication in perennial ryegrass (Lolium perenne): an emerging animal health concern in Ireland? Four primary mycotoxicosis have been reported in livestock caused by fungal infections of grasses or cereals by members of the Clavicipitaceae family. Ergotism (generally associated with grasses, rye, triticale and other grains) and fescue toxicosis (associated with tall fescue grass, Festuca arundinacea) are both caused by ergot alkaloids, and referred to as 'ergot alkaloid intoxication'. Ryegrass staggers (associated with perennial ryegrass Lolium perenne) is due to intoxication with an indole-diperpene, Lolitrem B, and metabolites. Fescue-associated oedema, recently described in Australia, ...
Second carpal bone slab fracture and subluxation of the middle carpal joint in a horse subsequent to arthrodesis of the carpometacarpal joint. To report complications of arthrodesis of the carpometacarpal (CMC) joint using a drilling technique in an adult horse. Methods: Case report. Methods: Horse (n = 1). Methods: A 12-year-old Quarter Horse mare with CMC osteoarthritis (CMC-OA) had arthrodesis under general anesthesia in right lateral recumbency. Under fluoroscopic guidance, a 4.5 mm drill bit was inserted at 3 drilling sites 5-6 cm into the CMC joint and was fanned 30-45° in the plane of the joint and 5-10° in the long axis of the limb to destroy articular cartilage and expose the subchondral bone. Results: The horse pr...
Age and group residence but not maternal dominance affect dominance rank in young domestic horses. We present a study focused on those factors influencing dominance position in young horses, with emphasis on the role of the mother. Horses, as other group-living polygynous mammals, form stable linear dominance hierarchies based on agonistic interactions. Higher dominance positions are believed to be connected, in both sexes, to better condition and higher reproductive success. Many variables play a role in forming the dominant-submissive relationships between horses; however, the maternal effect on the dominance position of the offspring still remains unclear, as do the possible mechanisms o...
Global evolution of Equidae and Gomphotheriidae from South America. The contemporary South American mammalian communities were determined by the emergence of the Isthmus of Panama and by the profound climatic oscillations during the Pleistocene. Horses and gomphotheres were 2 very conspicuous groups of immigrant mammals from North America that arrived in South America during the Pleistocene. The present study compiles updated data on the phylogeny, systematics and ecology of both groups in South America. The horses in South America are represented by 2 genera, Hippidion and Equus, as are the gomphotheres, represented by Cuvieronius and Stegomastodon. Both gene...
Livestock as a potential biological control agent for an invasive wetland plant. Invasive species threaten biodiversity and incur costs exceeding billions of US$. Eradication efforts, however, are nearly always unsuccessful. Throughout much of North America, land managers have used expensive, and ultimately ineffective, techniques to combat invasive Phragmites australis in marshes. Here, we reveal that Phragmites may potentially be controlled by employing an affordable measure from its native European range: livestock grazing. Experimental field tests demonstrate that rotational goat grazing (where goats have no choice but to graze Phragmites) can reduce Phragmites cover f...
Laparoscopic-guided compared to skilled instructor support for student rectal examination training using live horses in the veterinary curriculum. To evaluate the veterinary student learning outcome of 2 methods of equine rectal examination training. Methods: Randomized prospective study. Methods: Veterinary students (3rd and 4th year; n = 40) and practicing equine veterinarians (n = 10). Methods: Year 1: Group 1 (n = 11) and Group 2 students (n = 10) received skilled instructor (SI) and laparoscopic-guidance (LG), respectively, during rectal exam instruction. All students were tested on rectal identification of 4 abdominal organs. Year 2: One group of students (n = 19) was trained and subsequently tested using each technique, first SI, ...
Serum insulin-like growth factor 1 in the aging horse. Insulin-like growth factor 1 (IGF-1) has important roles in anabolic processes in the musculoskeletal system and has been reported to decrease with age in both people and horses. Objective: The objective of this study was to determine serum IGF-1 levels in the aging horse from early to late adulthood (age range 5-27 years). Methods: Healthy horses (n = 72) were used in a cross-sectional study, while 37 paired serum samples were available for a longitudinal study. Serum IGF-1 protein was determined using an ELISA kit validated for use in equine samples. Results: No association was found betw...
Thoroughbred horses in race training have lower levels of subchondral bone remodelling in highly loaded regions of the distal metacarpus compared to horses resting from training. Bone is repaired by remodelling, a process influenced by its loading environment. The aim of this study was to investigate the effect of a change in loading environment on bone remodelling by quantifying bone resorption and formation activity in the metacarpal subchondral bone in Thoroughbred racehorses. Sections of the palmar metacarpal condyles of horses in race training (n = 24) or resting from training (n = 24) were examined with light microscopy and back scattered scanning electron microscopy (BSEM). Bone area fraction, osteoid perimeter and eroded bone surface were measured withi...
The prevalence of abnormal breathing patterns during exercise and associations with dynamic upper respiratory tract obstructions. There is very limited published information on the prevalence and significance of abnormal breathing patterns adopted during canter/gallop. Objective: The aim of this study was to report the prevalence of abnormal breathing patterns during canter/gallop and to investigate whether these may be associated with dynamic upper respiratory tract (URT) obstructions. Methods: Retrospective analysis of clinical records. Methods: Simultaneous audio and URT videoendoscopy recordings from 365 horses referred for treadmill evaluation were analysed. Results: Thirty percent of horses had an abnormal breathin...
The distribution pattern of Halicephalobus gingivalis in a horse is suggestive of a haematogenous spread of the nematode. The majority of Halicephalobus gingivalis-infections in horses have been fatal and are usually not diagnosed before necropsy. Therefore, knowledge about the nematode and the pathogenesis of infection in horses is limited. This has resulted in an on-going discussion about the port of entry and subsequent dissemination of H. gingivalis within the host. The present case of H. gingivalis-infection in a horse was diagnosed ante mortem. Post mortem findings, the distribution pattern of H. gingivalis nematodes in the brain, a high prevalence of inflammation in close relation to blood vessels, and the...
Disposition and metabolic profile of the weak androgen Dehydroepiandrosterone (DHEA) following administration as part of a nutritional supplement to exercised horses. In order to ensure the welfare of performance horses and riders as well as the integrity of the sport, the use of both therapeutic and illegal agents in horse racing is tightly regulated. While Dehydroepiandrosterone (DHEA) is not specifically banned from administration to racehorses in the United States and no screening limit or threshold concentration exists, the metabolic conversion of DHEA to testosterone make its presence in nutritional supplements a regulatory concern. The recommended regulatory threshold for total testosterone in urine is 55 and 20 ng/mL for mares and geldings, respec...
Interspecies comparison of subchondral bone properties important for cartilage repair. Microfracture repair tissue in young adult humans and in rabbit trochlea is frequently of higher quality than in corresponding ovine or horse models or in the rabbit medial femoral condyle (MFC). This may be related to differences in subchondral properties since repair is initiated from the bone. We tested the hypothesis that subchondral bone from rabbit trochlea and the human MFC are structurally similar. Trochlea and MFC samples from rabbit, sheep, and horse were micro-CT scanned and histoprocessed. Samples were also collected from normal and lesional areas of human MFC. The subchondral bone...
Serological investigation of transplacental infection with Neospora hughesi and Sarcocystis neurona in broodmares. The aim of the present study was to investigate the likelihood of transplacental transmission of Neospora hughesi and Sarcocystis neurona in foals, born from seropositive mares. Three broodmares with persistent N. hughesi infection gave birth to eight healthy foals over a period of 7 years. These foals were seropositive to N. hughesi prior to colostrum ingestion, with titers ranging between 640 and 20,480, measured by indirect fluorescence antibody test (IFAT). Of 174 foals born at another farm to mares with a high seroprevalence to S. neurona, only one (with a pre-colostrum antibody tit...
Interacting effects of age, density, and weather on survival and current reproduction for a large mammal. Individual-based study of natural populations allows for accurate and precise estimation of fitness components and the extent to which they might vary with ecological conditions. By tracking the fates of all 701 horses known to have lived on Sable Island, Canada, from 2009 to 2013 (where there is no predation, human interference, or interspecific competition for food), we present a detailed analysis of structured population dynamics with focus on interacting effects of intraspecific competition and weather on reproduction and survival. Annual survival of adult females (0.866 ± 0.107 [[Formu...
Evidence of Toxoplasma gondii exposure among horses in Korea. The present study investigated the seroprevalence of Toxoplasma gondii (T. gondii) antibodies by ELISA in horses reared in Korea. Serum samples were collected from 2009 through 2013 from 816 horses reared in Korea. Analysis was performed using a commercial toxoplasmosis ELISA kit to detect anti-T. gondii antibodies. Overall, 24 out of 816 horses (2.9%) were seropositive for T. gondii. The result was analyzed by age, gender, breed and region. Significant differences were observed according to breed and region (P<0.05). This is the first nationwide serological investigation of T. gondii in ho...
Isolation of equine endothelial cells and life cell angiogenesis assay. Arterial or venous thromboses are frequent clinical complications with the risk of fatal progression. Recent studies suggest the disruption of angiogenesis in the course of thrombus resolution as the underlying pathomechanism. Very similar to the situation in human patients, equine vessels have been described to be particularly susceptible to thrombosis. In contrast to humans, equine donors are readily available to obtain organs and tissues for isolation of endothelial cells. Objective of this study was to isolate equine endothelial cells and develop an angiogenesis assay from primary cultures...
Characterization and outcome following excision of masses in the nictitating membranes of horses: 50 cases (1998-2012). To determine the histologic findings associated with masses in the nictitating membranes (third eyelids) of horses and to identify prognostic factors associated with recurrence and the outcome. Methods: Retrospective case series. Methods: 50 horses with masses in a third eyelid. Methods: Medical records of horses with partial or complete excision of a third eyelid and submission for histologic evaluation between September 1998 and November 2012 were reviewed. Horses were included if follow-up information for at least 1 year after surgery was available. Information regarding signalment and trea...
A Saint Louis encephalitis and Rocio virus serosurvey in Brazilian horses. Arboviruses are an important public health problem in Brazil, in especially flaviviruses, including the Saint Louis encephalitis virus (SLEV) and the Rocio virus (ROCV), are especially problematic. These viruses are transmitted to humans or other vertebrates through arthropod bites and may cause diseases with clinical manifestations that range from asymptomatic infection, viral hemorrhagic fever to encephalitis. Methods: A serological survey of horses from various regions of Brazil using an enzyme-linked immunosorbent assay (ELISA) with recombinant SLEV domain III peptides and ROCV E protein a...
Hand-assisted laparoscopic repair of a grade IV rectal tear in a postparturient mare. An 8-year-old multiparous Thoroughbred broodmare was admitted for evaluation of a rectal tear sustained during parturition. Results: On initial evaluation, the mare had mild signs of abdominal discomfort. A full-thickness rectal tear located 30 cm cranial to the anus and extending approximately 15 cm longitudinally along the surface of the small colon between the 4 and 6 o'clock positions, when viewed from behind, was diagnosed on examination per rectum. Results: Laparoscopic evaluation of the abdomen was performed to assess the tear and extent of peritoneal contamination. A hand-assisted repa...
