Varje måndag samlar vi de vetenskapliga artiklar om hästar, ponnyer och åsnor som har kommit ut de senaste veckorna, behåller dem som spelar roll för den som tar hand om hästar och berättar i två enkla meningar vad varje studie kom fram till. Sammanfattningarna är på engelska: de skrivs inte på svenska.
A small pilot study tested a disposable spray cap for giving eye medication to horses: bottles kept in a hospital barn and used every 12 hours showed no microbial contamination. Of 5 owner-treated horses, 3 accepted the spray well and 2 did not, with the spraying sound reported as the biggest problem.
Sixteen horses with surgically induced arthritis in one knee (carpal) joint received either a 2.5% polyacrylamide gel injection or saline (8 horses each), and after 70 days lameness and other clinical signs did not differ between groups. Gel-treated joints had better cartilage scores on one carpal bone and, unlike saline-treated joints, did not develop a stiffer joint capsule.
Seventeen healthy adult mares were given killed West Nile virus and tetanus vaccines either under the skin or into the muscle to compare antibody responses and injection-site reactions. West Nile antibodies rose with both routes with no difference between them, tetanus antibodies were already high and did not change, and under-the-skin injections caused more swelling; because of the high starting antibody levels, the authors call the route comparison inconclusive.
Shamonda virus, which has recently spread in Central Europe and caused disease in many cattle herds, was found in the brain and spinal cord of two horses in Germany that had neurological signs such as seizure-like episodes, fever and loss of coordination. Both had severe brain inflammation, but no virus was found in their blood or other organs, and what role horses play in the outbreak is still unclear.
This case report describes a 5-year-old Standardbred trotter gelding with hind-leg lameness and a swollen hock joint caused by a bony growth on a small ledge of bone on the inside of the hock (the sustentaculum tali). The growth was removed with ultrasound-guided surgery from outside the joint, and the horse was back in full-speed training by day 76, with no return of lameness and the joint swelling fully resolved.
Scientists found a new and very different strain of rotavirus B in a foal with diarrhoea in Missouri in 2025, distantly related to the strain first seen in Kentucky horses in 2021 and missed by routine diagnostic testing. When 140 samples from foals with diarrhoea of unknown cause were screened, 6 (4.2%) tested positive for this new strain.
Ten healthy horses were given the sedative trazodone by mouth (7 mg/kg twice daily for two weeks) and, separately, a corn syrup dummy treatment, to see whether the drug affects their blood platelets. No differences were found in platelet count or platelet function, and no side effects were seen.
Using a horse blood-typing test, 56 of 84 donkeys in Italy (66.7%) tested positive for the Ca blood factor, and donkey-to-donkey crossmatch reactions occurred whether or not the pairs shared Ca status, so Ca status alone did not explain them. Donkey plasma reacted with horse red blood cells in every test, while horse plasma reacted with donkey red cells in about two-thirds of tests.
Researchers tested about 970 horses across six German states for tapeworms: eggs showed up in only 0.7% of dung samples, but a saliva antibody test was positive in 20.1% of horses (11.0% with a blood test), with at least one positive horse on 60.4% of yards. Positive saliva results varied widely by region, from 4.0% in Schleswig-Holstein to 42.1% in Brandenburg, and horses aged 1 to 5 years were more likely to test positive than younger or older ones.
On one large farm in Xinjiang, China, 63.5% of 74 young female donkeys were passing worm eggs, and in a trial with 30 of them the wormer albendazole gave an egg count reduction of −24.5% after 14 days, far below the 99% target, so the worms were classed as resistant. A gene test assigned almost all worms to one type, Trichostrongylus, but the method tells equine strongyles apart poorly, so this result is only exploratory.
Researchers added a prebiotic (mannan oligosaccharides) to the feed of 16 nursing Dezhou jennies for 60 days, comparing them with unsupplemented jennies, and looked at their milk and their foals. Supplemented jennies had a lower milk somatic cell count, and their foals tended to gain more weight, had lower total and LDL cholesterol and higher HDL cholesterol, and showed changes in certain gut bacteria.
This early, not yet peer-reviewed pilot study fitted six horses with custom 3D-printed plastic shoes glued to the hoof and tracked their movement and hoof loading over a seven-week shoeing cycle. All shoes stayed on for the full seven weeks, with no consistent changes in the measured movement or force values, though the hoof balance patterns shifted over the cycle.
Post-mortem findings were reviewed for 72 Thoroughbred and Quarter Horse racehorses in California that suffered a catastrophic tear of the ligaments just below the fetlock (distal sesamoidean ligaments) in a front leg, mostly while racing (61 horses). This injury made up only 1.4% of catastrophic musculoskeletal injuries, and the affected Thoroughbreds had longer careers, more time off and less high-speed work in the year before injury than comparison horses.
Postmortem reports from 394 racehorses (366 Thoroughbreds, 28 Standardbreds) examined in Pennsylvania between 2017 and 2025 showed that catastrophic musculoskeletal injury was the most common cause of death, accounting for 74% of Thoroughbreds and 54% of Standardbreds. Most were leg fractures around the fetlock: front-leg sesamoid bones in Thoroughbreds and the long pastern bone of the hind legs in Standardbreds.
Researchers tracked heart rate in 14 three-year-old Czech Warmblood stallions over 18 weeks of training (1,003 sessions across six types of exercise), and heart rate and estimated energy use differed between exercise types, with the highest estimated energy use per session during free jumping and on the horse walker and the lowest during lunging. Daily energy needs worked out from feeding guidelines (about 114 MJ/day) were higher than estimates based on heart rate (about 96–100 MJ/day).
Five rider-horse pairs took four one-hour lessons in a riding programme that uses several motor-learning techniques to teach clear body language for steering, with riding filmed across 13 exercises before and after. Both three independent assessors and the riders themselves scored performance significantly better after the lessons, an early sign that the programme may help with direction control.
AI-assisted video gait analysis of 128 sport horses found that 7.02% of the Thoroughbreds carried the Fragile Foal Syndrome gene variant, more than the 1.4% reported before. In a small matched group of 20 horses (8 carriers, 12 non-carriers), carriers kept the hoof on the ground for a larger share of each stride, a subtle gait difference the authors link to stretchier connective tissue.
Researchers reviewed 30 eyes from 28 horses with recurring immune-mediated keratitis (a long-term inflammation of the cornea, the clear front of the eye) treated with a dye-and-laser procedure called photodynamic therapy. About 83% of eyes stayed free of flare-ups at 1 year and about half at 2 years, but 18 of 30 eyes eventually relapsed, and surface wounds on the cornea after treatment were common (22 of 30 eyes), all of which healed.
This tutorial explains how listening to a sport horse's heart with a stethoscope before exercise can screen for heart problems, which the authors believe may be a cheap, worthwhile way to help prevent heart events and sudden death during exercise. The main thing to listen for is an irregularly irregular heartbeat, treated as atrial fibrillation until shown otherwise, followed by worrying heart murmurs, illustrated with audio, video and ECG examples.
Eight healthy horses were given the painkiller butorphanol (0.1 mg/kg) or salt water as an injection under the skin of the neck, and their sensitivity to heat and pressure was tested for up to 8 hours. Butorphanol caused mild, short-lived sedation with acceptable effects on heart and breathing, but it did not consistently reduce the horses' sensitivity to pain.
Researchers tested an automatic hay feeder in 3 group-housed mares and 4 individually stabled horses: in the group, rank strongly decided who got to the feeder, and more hay was left over than with hay on the ground. In the stabled horses, the shortest opening times meant less time eating and more pawing, rubbing and biting at the feeder (pawing up to 7–8 times more often), and a schedule of 40 minutes open and 20 minutes closed seemed to give the best balance.
Researchers watched 9 young Mangalarga Marchador horses for 72 hours before and after each of two chiropractic sessions, held 35 days apart. After the sessions, the horses spent less time awake and more time lying flat on their side, though the study had no untreated comparison group and did not measure brain activity to confirm actual sleep.
On one stud farm, 288 healthy newborn foals had their navel stump treated with one of six disinfection routines, and 40 (13.9%) developed navel infection (omphalitis). Hypochlorous acid twice daily had the fewest cases (2 of 47, 4.3%) and was the only routine with significantly fewer infections than the overall rate, while chlorhexidine once daily had the most (11 of 53, 20.8%); all affected foals recovered after antibiotics.
Fifteen equine vets (11 of whom finished all three rounds) worked together to adapt the human air quality index (AQI) for horses, agreeing that both healthy horses and those with health problems may suffer short- and long-term effects from polluted air. They drew up practical guidance on daily care, training and competing for each AQI level, but noted it relies largely on non-horse data and that horse-specific research is needed.
This commentary looks at large solar and wind energy projects being planned near Thoroughbred stud farms in Ireland, and notes that direct evidence on how they affect mares, foals and youngstock is still limited. Drawing on what is known about horses' sensitivity to noise, sights, dust and sudden disturbance, the authors argue for a cautious planning approach that includes equine-specific assessment and independent veterinary input.
Researchers at one equine hospital put fluorescent marks on surfaces in examination rooms and stalls to check how well cleaning removed them, and photo-based measurement agreed closely with judging by eye. After cleaning staff received feedback, cleaning improved in the examination rooms (especially two orthopaedic treatment rooms) but not in the stables, and bacterial counts were not linked to how much of the marks was removed.
A preprint, not yet peer reviewed, describes two horses in Switzerland with brain and spinal cord inflammation linked to Shamonda virus, a virus that recently caused a large outbreak in cattle in Western Europe and had not been described in horses before. Virus genetic material was found in the brain tissue of both horses, and its sequence matched the virus from the Swiss cattle outbreak.
This review looks back over 20 years of research on medical treatments for osteoarthritis in horses, a joint disease that permanently damages cartilage, since a similar review in 2006. It describes how options have grown, including orthobiologic and cell-based therapies, and how treatment has shifted from mainly easing symptoms towards trying to change the course of the disease.
A preprint case report describes Shamonda virus, recently emerged in Central Europe, found in the brain and spinal cord tissue of two horses in Germany that had shown seizure-like episodes or fever and unsteadiness, and both had severe brain inflammation. The virus was not found in their blood or other organs, and the authors say diagnosing it in living horses is currently only possible to a very limited extent.
Two laboratory tests for the hormone ACTH, used to help diagnose PPID (equine Cushing's), were compared in 17 horses (4 young, 8 older and 5 with confirmed PPID), before and after a TRH stimulation test. Results differed widely: after TRH, one test flagged 2 of the 5 PPID horses and none of the older horses, while the other flagged all 5 PPID horses and 5 of the 8 older ones, so the choice of test could change whether a horse was classed as having PPID.
This preprint, not yet peer reviewed, used a climate-based model to map where West Nile virus and Usutu virus, both spread by mosquitoes, could transmit across England and Wales, and projected that suitability for both rises over time, more steeply under higher-emission scenarios. Cases of West Nile virus in horses were predicted to be most likely in southeast England, especially around Newmarket, because of its dense horse population.
Eight horses with a temporary, induced front-foot lameness were given intravenous phenylbutazone at 2.2, 4.4 or 8.8 mg/kg, or saline. The 4.4 and 8.8 mg/kg doses reduced lameness and heart rate for up to about 12 hours with no difference between them, while 2.2 mg/kg helped only briefly compared with saline.
Records of 123 horses treated for peritonitis (inflammation of the abdominal lining) at a UK referral hospital found that 74% survived to discharge, 90% when the peritonitis was primary versus 50% when it was secondary to another problem. A higher heart rate and blood-stained abdominal fluid on arrival were linked to lower survival, ponies did better than horses, and a third of survivors had complications such as colic or fever after going home.
Researchers tested whether an antibiotic eye ointment (erythromycin and colistin) applied after racing prevents eye surface inflammation (keratitis) in Thoroughbred racehorses, comparing it with eye flushing alone or a plain petroleum jelly ointment. After turf races, keratitis was less common with the antibiotic ointment (0.55% vs 6.25% with flushing alone, and 0% vs 8.18% in a randomised comparison of about 300 races), but after dirt races there was no significant difference.
Three horses in different parts of France had skin lesions, some resembling sarcoids, that turned out to be leishmaniasis caused by the parasite Leishmania martiniquensis, the first documented cases in the country. In all three the disease stayed limited to the skin: one healed on its own, one after surgical removal and one after injections of meglumine antimoniate into the lesion.
Seven healthy horses were given a bacterial toxin (LPS) that slows the gut, with and without the oral drug mosapride, in a blinded trial where each horse received every treatment. The toxin caused fever, a fast heart rate and a sluggish, swollen gut, while mosapride partly restored gut movement and reduced stomach distension and intestinal wall thickening.
Researchers cultured windpipe wash samples from 165 horses with equine asthma in Poland and grew bacteria in 117 of them (70.9%), most often Streptococcus zooepidemicus, Pseudomonas aeruginosa and Klebsiella pneumoniae. A positive culture was not linked to the season or month of sampling or clearly to airway neutrophil levels, and the authors note that finding bacteria does not by itself prove an infection.
Twenty-four healthy female donkeys were given a bacterial toxin to mimic endotoxaemia and then received flunixin, DMSO or no treatment; flunixin eased belly pain, kept gut movement going and brought appetite back sooner than DMSO, and reduced early signs of kidney stress. Two blood markers, NGAL and B2M, rose within 1–2 hours, before the standard kidney test (creatinine) changed, suggesting they may flag early kidney injury in donkeys.
Among 52 horses with signs of asthma (34 confirmed by lung-wash testing), neither allergy skin tests nor 23 inflammation markers in the blood helped diagnose asthma or tell its types apart. One type, mast-cell asthma, was found more often at locations with unhealthy air quality (24.1% versus 10.3% expected).
Blood samples taken in 2011 from 278 horses in four Indigenous communities of Costa Rica were tested for antibodies, a sign of past exposure, to several equine viruses. Antibodies were found to equine herpesvirus 4 in 91.2% of horses tested, West Nile virus in 58.9%, equine infectious anaemia in 16.6%, equine herpesvirus 1 in 6.6%, influenza in 5.1% and equine arteritis in 3.0%; these figures reflect 2011, not today.
Rabies test results from 204 cattle and 56 horses with neurological signs in Rio de Janeiro State, Brazil (2020–2024), were compared with local land use and livestock numbers. Most cases and positive results were in cattle, and municipalities with more pasture had more cases and positive tests, while those with more shrubland had fewer.
This preprint, not yet peer reviewed, reports that 15% of young Swedish trotting racehorses were passing roundworm (Parascaris) eggs, more often at 1–2 years than at 3–4, and that raised eosinophils (a type of white blood cell) in lung fluid were the most common airway finding, seen in 31.3% of two-year-olds versus about 10% of three- and four-year-olds. Only 1 of 10 horses with this lung inflammation had a roundworm infection, compared with 2 of 10 healthy horses, so no clear link was shown.
Pennsylvania horse owners checked their horses for ticks over two years and collected 413 ticks, including American dog, blacklegged and longhorned ticks, the last found for the first time in one county. In a trial with 50 horses, physical barriers, especially untreated fly boots and masks, were linked to fewer attached ticks.
This preprint, not yet peer reviewed, tested 1,414 horse samples from Punjab, Pakistan, over one year for Theileria equi, a tick-borne blood parasite, and found infection peaked in March (43.3%) and October (37.3%) and was lowest in April (6.5%). Infection was more common in areas with many horses and rose with temperature and humidity above 60%; among the tests compared, ELISA picked up the most cases and PCR gave the fewest false positives.
Eight Welsh Mountain ponies were switched between four haylages over a structured three-day changeover, and chemical markers in their urine and droppings were tracked. Their metabolism adapted to each new haylage within 5 days, with the changes driven by the forage's chemical make-up, most clearly for a young ryegrass haylage.
Thirty-two young Quarter Horses (2–3 years old) in moderate work were fed their grain either as two meals a day or as small automated portions every hour for 10 hours a day. In an 8-hour after-feeding test in 10 of these horses, those on hourly portions had lower blood sugar and insulin peaks and a lower overall insulin response than those fed twice daily.
Twelve healthy young horses were each offered plain water, water flavoured with sweet feed, and water containing a new additive, alongside a bucket of plain water. With the additive they drank about 52 litres a day, compared with roughly 30 litres with plain water and 32 litres with the sweet-feed flavouring, and no side effects were seen.
Six healthy adult crossbred horses were weighed weekly for 63 days on a calibrated scale, with a commercial weigh tape and with a body-measurement formula. Both methods overestimated weight, but the tape was closer (about 2.5% over on average) than the formula (about 9.9% over) and tracked the scale more consistently.
Researchers measured a fat-derived hormone linked to laminitis risk, called high molecular weight adiponectin, in 85 horses and ponies before and after an oral glucose test given in feed: its median level rose from 2.75 to 4.02 µg/mL two hours after the test, while total adiponectin did not change. In 31 ponies, grazing pasture or eating soyabean- or maize-based meals did not change this hormone over 4 hours.
Researchers followed 36 Thoroughbred racehorses in training for 90 days, with 23 going barefoot and 13 staying shod, and photographed their hooves before and after trimming. In the barefoot horses, the heel angle rose from about 30° to 35° and the gap between toe and heel angles narrowed, while the toe angle stayed stable; the shod horses showed no significant changes.
Using a sensor on one front heel, researchers measured heel movement in 15 healthy horses at walk and trot when barefoot, in aluminium nail-on shoes and in glue-on fabric cuff shoes. Heels moved most when barefoot (3.29 mm at the trot), glue-on shoes allowed more movement than nail-on shoes at the trot (2.56 vs 2.12 mm), and both shoe types limited heel movement compared with barefoot.
This preprint, not yet peer reviewed, used airway scope results from 2,721 Standardbred and 1,902 Thoroughbred racehorses in Canada to check whether air pollution is linked to bleeding in the lungs during exercise (EIPH). Higher ozone levels about a week before racing or training were linked with higher odds of bleeding (23% per 10 ppb rise) and of moderate or severe bleeding (41%); older horses were also more likely to bleed, and furosemide use was linked with lower odds of moderate or severe bleeding.
This preprint, not yet peer reviewed, compared two gaits of the Mangalarga Marchador breed, the marcha batida and the marcha picada, in 135 ridden horses. At the same speed (3.88 m/s) stride length and timing were the same, but the batida relied mostly on diagonal pairs of legs and the picada mostly on same-side pairs, and the authors report that the measurements did not match the current breed standard description.
Researchers looked back at 19 horses that had screws placed to repair slab fractures of the carpal (knee) bones other than the third carpal bone; 10 of these fractures came from falls, six of them while recovering from anaesthesia. Of these horses, 88% survived beyond a year, 53% returned to their previous level of work and 71% of owners were satisfied.
Stewards checked noseband tightness with the new FEI measuring device on 523 horses at the 2025 British Dressage Championships, and 95% of nosebands were loose enough to pass. The Swedish noseband was the most common type (39%), and 96% of horses stood calmly for the check.
Nine mares each received eight protocols, from the standard 250 µg dose of the ovulation drug histrelin down to 25 µg, injected into muscle or at two acupuncture points, or no treatment. Ovulation within 48 hours occurred in 87.5–100% of cycles with any histrelin dose, against 37.5% with no treatment; in this small pilot, injecting at acupoints showed no advantage over muscle injection of the same low dose.
Artiklarna hittas via Europe PMC, som indexerar PubMed och de viktigaste preprintservrarna. Varje titel länkar till själva artikeln, och en artikel märkt ”Öppen tillgång” kan du läsa gratis.
Sammanfattningarna är skrivna av AI, artiklarna är det inte. Varje artikel är de forskares verk som skrev den. Sammanfattningen på två meningar under titeln skrivs av Claude Opus 5.5, en AI-modell från Anthropic, utifrån artikelns sammandrag. Här visas den på engelska, eftersom sammanfattningarna inte skrivs på svenska. En sammanfattning kan utelämna det viktigaste eller få en detalj fel: öppna artikeln innan du litar på ett resultat, och tala med din veterinär innan du ändrar hästens skötsel på grund av en enda studie. En preprint har ännu inte granskats av andra forskare. När Claude inte är tillgänglig skriver Mistral Small 3.1 sammanfattningen i stället.
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