Sunday, March 03, 2024

Advances in endocrinology take centre stage in latest EVJ

The endocrine system plays an essential role in balancing the horse's health. Unfortunately, it is
prone to malfunction.

The March issue of the Equine Veterinary Journal (EVJ) highlights the latest work advancing veterinary understanding of equine endocrinology.


In a press release, EVJ guest editor Melody de Laat, said “Knowledge, diagnosis and treatment of equine endocrinopathies has improved dramatically over the past 25 years, with progress driven by the publication of peer-reviewed papers and the application of evidence-based medicine.” 


Obesity, PPID (Equine Cushing’s), insulin dysregulation (ID), thyroid disorders and the effects of corticosteroid administration are all covered. Articles include:


  • ·     The BEVA Primary Care Clinical Guidelines provide evidence-based recommendations for the diagnosis and management of PPID, directed at equine practitioners in an ambulatory setting. The evidence review supports clinical signs such as hyperhidrosis, regional adiposity, epaxial muscle atrophy, laminitis, weight loss, recurrent infections or delayed healing, behaviour changes, or polyuria and polydipsia as prompts for moderate suspicion of PPID in animals of more than 10 years of age. The review supports the assessment of basal plasma ACTH concentrations or ACTH responses to exogenous thyrotropin-releasing hormone (TRH) administration. It also supports the use of pergolide as a therapy for PPID.

  • ·   Lumbar vertebral bone density is decreased in horses with pituitary pars intermedia dysfunction explores the infrequent finding of pathological fractures in aged horses with advanced PPID.

  • ·       Influence of feeding and other factors on adrenocorticotropin concentration and thyrotropin-releasing hormone stimulation test in horses and ponies and Clinical implications of imprecise sampling time for 10- and 30-minute thyrotropin-releasing hormone stimulation tests in horses stresses the importance of exact timing when these samples are collected. 

  • ·      Obesity and obesity-associated metabolic disease conditions in Connemara ponies in Ireland showed a 50% prevalence of laminitis in obese ponies. 

  • ·       Development of a body condition index to estimate adiposity in ponies and horses from morphometric measurements presents an alternative method for measuring adiposity.

  • ·          Associations between feeding and glucagon-like peptide-2 in healthy ponies looks at the role of glucagon-like peptide-2 in the development of hyperinsulinaemia in ID.

  • ·         Expression of the GCG gene and secretion of active glucagon-like peptide-1 varies along the length of intestinal tract in horses demonstrates that both the large and small intestines are sites of equine GLP-1 secretion and that the genetic coding is identical in horses with and without ID.

  • ·            Relationships between total adiponectin concentrations and obesity in native-breed ponies in England and Short-term induced hyperinsulinaemia and dexamethasone challenge do not affect circulating total adiponectin concentrations in insulin-sensitive ponies show that total adiponectin is not as strongly correlated with body condition, body shape and breed as expected and inducing short-term ID does not alter total adiponectin concentrations. 

  • ·            Factors associated with insulin responses to oral sugars in a mixed-breed cohort of ponies and Epidemiological investigation of insulin dysregulation in Shetland and Welsh ponies in Australia determine that the insulin response to oral sugar is associated with multiple variables but cannot be predicted from the physical appearance. 

  • ·            Insulin, but not adiponectin, is detectable in equine saliva using an automated, commercial assay in a pilot study in the UK demonstrates that insulin is measurable in equine saliva, but this method is not currently a viable alternative to blood. 

  • ·        The effect of pre-dosing with metformin on the insulin response to oral sugar in insulin-dysregulated horsesshows the lack of efficacy of metformin (dosed at 30 mg/kg) on the insulin response to an oral sugar test.

  • ·           Intra-articular trimacinolone acetonide injection results in increases in systemic insulin and glucose concentrations in horses without insulin dysregulation shows that intra-articular triamcinolone does not result in circulating insulin concentrations likely to induce laminitis in insulin-sensitive animals. 

  • ·           Diagnosis and management of thyroid disorders and thyroid hormone supplementation in adult horses and foals reviews thyroid gland pathophysiology in adult horses and foals, blood thyroid hormone concentrations and the use of T4 supplementation in equine practice. 


“This robust collection reflects the continual dedication of equine veterinary researchers to developing our understanding of equine endocrinology,” said Professor Celia Marr, Editor of the EVJ. “Such work is enabling the application of evidence-based medicine to improve the diagnosis, management, treatment and quality of life of animals with endocrine disorders.”


The March issue is available to read free:

Friday, March 01, 2024

Funding offered for Cushing’s and Insulin Resistance research

The Equine Cushing's and Insulin Resistance Group Inc. (ECIR Group) is now accepting
 funding requests for 2024. These proposals should focus on researching Equine Metabolic Syndrome/Insulin Resistance (EMS/IR) and Pituitary Pars Intermedia Dysfunction (PPID). 

The ECIR Group's mission is to improve the well-being of equines with metabolic disorders through a blend of basic research and practical clinical experience. Their primary objective is to prevent laminitis. 


"Quality scientific research is critical to the continuous advancement of knowledge to benefit metabolic equines." said Dr. Kathleen Gustafson, ECIR Group Inc. Research Director. "Our goal in 2024 is to fund research and encourage collaboration between scientists, scholars, veterinarians, and hoof care professionals to positively affect the health and welfare of these equines."


"Through the sharing of their in-the-barn experience, ECIR Group supporters have helped build effective protocols for metabolically challenged equines." said current President, Nancy Collins. "It is an honor that now, through member financial support, the ECIR Group has expanded to also fund equine metabolic research."


Proposals seeking funding should focus on EMS and PPID, covering topics such as diagnosis, diet, hoof care, exercise (referred to as DDT/E) and preventing laminitis. Any proposals meeting these criteria will be considered.


Applications must be submitted via the research portal. Deadline for submission is May 31, 2024.


Researchers will find more information at

Joint Helicopter Command Horse Rider Safety Survey

 Are you a horse rider? Do you have friends or family members who also enjoy riding horses?
You can help promote horse and rider safety by completing an online survey.

The United Kingdom Ministry of Defence Joint Helicopter Command (JHC) is collaborating with the British Horse Society (BHS) to raise awareness about a crucial initiative concerning horse and rider safety.


Helicopters present a significant risk of startling horses. Due to their flight instincts, horses can easily become alarmed by sudden movements or loud noises, prompting them to flee from potential threats. The sudden appearance and noise of a helicopter can trigger such a response in horses, potentially leading to hazardous situations for both the animals and individuals involved.


Understanding the natural instincts and sensitivities of horses is crucial, as it allows pilots and horse owners to take necessary precautions to ensure the safety and well-being of horses in areas where helicopters are present.


As part of ongoing efforts, JHC, in partnership with The British Horse Society, has developed the Horse Riding Safety Survey aimed at collecting valuable insights from riders across the UK. 


As a member of the horse-riding community, you can help to shape future safety measures by completing the survey.

To take part, go to:

Thursday, February 29, 2024

Lameness main cause of vetting “failures”

(c) Henktennapel
Research from the Royal Veterinary College (RVC) has found that lameness ranks as the most common adverse
finding in pre-purchase examinations (PPEs) conducted on horses in the UK.

The aim of the prepurchase examination is to carry out a thorough clinical examination of the horse on behalf of the potential purchaser to identify any cliiinical issues that might make the horse unsuitable for its intended purpose, whether that be elite competitions, breeding, or leisure riding.


In the United Kingdom, PPEs generally consist of either a two stage (two stage vetting [2SV], i.e., general physical examination at rest and basic trot in-hand) or a five stage-examination (five stage vetting [5SV], i.e., general physical exam at rest and after exercise, lameness evaluation including strenuous exercise with re-evaluation after a period of recovery).


In the United Kingdom, The standard PPE consists of five stages, (five stage vetting [5SV],ie general physical examination at rest; walk and trot in hand;  strenuous exercise; rest and a second trot up)


Sometimes it may not be possible to complete all five stages or the purchaser may request a limited examination, in which case the examination can be limited to the first two stages (two stage vetting, 2SV).


PPEs yield recommendations based on the veterinary surgeon's assessment at the time of examination. As such, PPEs are largely subjective and often the subject of impassioned debate.

Despite their widespread use in equine practice, PPEs have been the subject of limited research.


The research team from the Royal Veterinary College (RVC), comprising Dr. David Bolt, Senior Lecturer in Equine Surgery; Dr. Jason Tupper, Head of the RVC Equine Practice; and Annabel Shelton, a graduate of RVC's BVetMed program in 2023, scrutinised 133 PPE certificates belonging to a mixed, non-racing horse population sourced from three primary equine practices. 


The analysis encompassed an evaluation of the examination format (e.g., 2SV or 5SV), use of diagnostic imaging modalities (e.g., radiographs), purchase price, animal characteristics, intended use of the horse, PPE outcomes, and any prejudicial findings uncovered during the examination.

They found that a 5SV was performed on 68.5% of horses compared to 34.1% which underwent a 2SV.


Of the 133 horses examined, 57.1% had prejudicial findings, the most common of which was lameness. Other prejudicial findings included diagnostic imaging findings (14.5%); respiratory system findings (6.6%); skin conditions (5.3%); and cardiac abnormalities (3.9%).


Unsurprisingly, horses with a higher purchase price were more likely to undergo the full 5SV, and undergo pre-purchase radiography. They were also more likely to have prejudicial findings identified.


Dr Tupper said: “A pre-purchase examination can discover a number of issues before buying a horse. This study reveals lameness to be the commonest issue. Few horses are perfect when it comes to temperament and health. The vetting process determines the issues and the vet can then help the purchaser weigh up their significance and decide if they can compromise and accept the issues or not. Further studies can now focus on the cost/benefit of radiology as part of the vetting procedure and the potential use of gait analysis.”


The researchers hope that their work will stimulate future investigations into the merits of 5-stage (5SV) and 2-stage (2SV) PPE formats, as well as the diagnostic techniques employed. This will, in turn, help to better inform prospective horse buyers when considering their purchase.


For more details, see:


Prejudicial findings regarding suitability for intended purpose during pre-purchase examinations in a mixed horse population—A retrospective observational study in the United Kingdom. 

Shelton AV, Tupper J, Bolt DM. 

Equine Vet J. 2024.

Wednesday, February 14, 2024

Effect of day length on growth

 Can the growth and maturation of yearling Thoroughbreds be accelerated by artificially extending the day length? A Japanese study has been exploring this possibility.

Hokkaido, the mostly northerly of Japan's main islands, is the primary breeding ground for over 97% of Thoroughbreds in the country. Hokkaido experiences cool summers and cold winters, with shorter days during the winter season.


Mutsuki Ishimaru and colleagues conducted a study to examine the impact of artificially extending daylight on changes in body composition in young Thoroughbreds raised and trained in Hidaka, Hokkaido, Japan. 


The study involved 73 horses aged 21-24 months.


The treatment group, comprising 41 horses (22 colts and 19 fillies), underwent extended photoperiod (EP) treatment from December 20 to April 15. This was achieved by placing a 100-watt white bulb in each horse box, providing 14.5 hours of light and 9.5 hours of darkness. 


A control group of 32 horses (16 colts and 16 fillies) remained under natural light conditions with no additional lighting. All horses had 1-2 hours of pasture time daily and followed a standardised training program.


The research team assessed body weight (BW), rump fat thickness (RFT), fat-free mass (FFM), and percentage of fat (%F) as indicators of body composition. 


In the control group, there was a moderate increase in BW and FFM, but no significant difference in BW and FFM between December and later months. In contrast, the EP group exhibited continuous growth until April, with significantly higher BW and FFM in February, March, and April compared to December.


The researchers suggested that the hypothalamic-pituitary-gonadal axis was activated earlier in the EP group, leading to elevated circulating IGF-I or gonadal hormones. 


They concluded that young Thoroughbreds under extended photoperiod conditions in Hokkaido may tolerate more high-intensity training than those under natural light conditions during the winter season. Additionally, there is potential for these horses to perform at an early stage in 2-year-old racing.


For more details, see:



Effects of an extended photoperiod on body composition of young Thoroughbreds in training. 

Mutsuki Ishimaru, Atsushi Okano, Akira Matsui, Harutaka Murase, Kenji Korosue, Kentaro  Akiyama, Kazuyoshi Taya. 

Journal of Veterinary Medical Science, (2024), Vol 86, pp 58-65, 


Friday, February 09, 2024

Study: Curly Horses promote immune tolerance in allergic individuals

(c) Dawny16161
 American Bashkir Curly Horses are claimed to be hypoallergenic, but this has not been clinically proven. 

The origin of these horses remains uncertain, with their additional name "Bashkir" stemming from the misconception that they were originally imported from Russia to America. Some theories suggest a Spanish immigrant origin in South America.

Established in 2010, Curly Farm Klappholz combines Dr. Wolfgang Mitlehner's medical practice specialising in internal medicine, allergology, pulmonary, and bronchial medicine with a holiday home and riding school featuring Curly horses. This facility provides a safe environment for allergic riders to interact with and ride Curly Horses.


Dr. Mitlehner has conducted studies on allergic patients who have ridden Curly horses to investigate their allergic responses to these animals.The work culminated in a report published in the journal Pneumologie


This collaborative study involved Susanne Mitlehner from Curly Farm Klappholz, Dr. Wolfgang Mitlehner, Alexandra Mitlehner, Hans Caspar Mitlehner, Peter Stoll, and Ines Swoboda from the University of Applied Sciences in Vienna, along with Monika Reissmann from Humboldt-University of Berlin.


The team examined the impact of exposure to Curly Horses on 141 patients allergic to horses by assessing their lung function and nasal patency during interactions with the animals. They discovered that repeated engagement with Curly Horses, including activities such as riding and grooming, resulted in a reduction in allergic riders' reactivity. This improvement was evidenced by enhancements in FEV1, PEF, and PNIF measurements.


PNIF, FEV1, and PEF are standard measures used to evaluate nasal obstruction, allergic rhinitis, and lung function, particularly in conditions like asthma.


Repeated interactions with Curly Horses, including riding and grooming, resulted in decreased reactivity among allergic riders, as evidenced by improvements in FEV1, PEF, and PNIF measurements.


Further visits, involving extended periods of riding totalling up to 40 hours or more, continued to reduce reactivity to Curly Horses. It's noteworthy that allergic reactions to horses occurred in only 72 out of 1312 riding hours, with the majority occurring within the initial ten hours of riding.


In a subset of 41 out of the 141 patients, additional investigation explored whether repeated exposure to Curly Horses could induce tolerance to other horses. These patients participated in a tolerance induction study and underwent annual testing for horse allergy using a nasal provocation test. The results revealed that exposure to Curly Horses led to immune tolerance to other horses in 88% of patients who completed the study.


Dr Mitlehner elaborates “To understand the mechanism causing hypoallergenicity, we performed IgE immunoblots to determine whether Curly Horse hairs contain IgE binding proteins.” 


IgE immunoblots play a significant role in allergy diagnostics. By examining the pattern of IgE antibodies adhering to various allergens on the membrane, clinicians can identify the specific allergens to which a patient is sensitized. This information is vital for diagnosing allergies and formulating suitable treatment plans, such as allergen-specific immunotherapy (allergy shots) or recommendations for allergen avoidance.


The study revealed no differences in IgE reactivity between Curly and non-Curly Horses. Additionally, patients participating in the immune tolerance induction study did not exhibit reduced IgE reactivity to hairs from Curly or non-Curly Horses, despite having developed tolerance.


“However, we did find increasing levels of anti-horse IgG antibodies in the study patients.” Dr Mitleehner added.


“Overall, our data strongly suggests that continuous exposure to Curly Horses can induce immune tolerance, rendering these patients non-reactive to horses. The reason for the reduced clinical allergenicity of Curly Horses remains unclear, but the data suggest that blocking IgG antibodies may be of importance for immune tolerance development.”


For more details, see:


Horse allergy: Curly Horses can mediate immune tolerance

Alexandra Mitlehner, Caspar Mitlehner, Monika ReiƟmann, Peter Stoll, Ines Swoboda, Wolfgang Mitlehner

Pneumologie (2024); 78(01): 47-57


Thursday, February 08, 2024

Assessing the effects of chiropractic manipulation

 Chiropractic care in horses involves the application of manual manipulations, adjustments, and therapies to address musculoskeletal issues and promote overall well-being.

It is believed to offer several potential benefits, including improved range of motion, reduced pain, enhanced performance, and a positive impact on the horse’s overall well-being. 


While anecdotal evidence suggests positive outcomes, scientific research on the efficacy of chiropractic care in horses is limited. Some studies have shown potential benefits, but more research is needed to establish its effectiveness conclusively.


A study by Olivia Lorello and colleagues investigated the effect of chiropractic manipulation on stride characteristics and heart rate, and on rider-perceived quality of ridden work.


Thirty-eight hunter-jumper (show jumper) horses were recruited for a blinded randomised controlled trial. All horses participating in the study had no reported performance or medical issues.


Exercise tests were conducted the day before and two days after either chiropractic treatment or a sham procedure. Each horse was ridden by its regular rider in their typical riding setting. Riders were unaware of the treatment administered to their horse.


During the tests, horses wore fitness trackers and parameters such as stride length, rate, and symmetry, as well as heart rate were monitored. Each horse-rider combination underwent the test protocol four times.


Complete sets of before and after data were available for analysis from 27 horses.


More riders reported an improvement in the quality of the ridden work after chiropractic treatment than after sham treatment.


However, the research team found no difference in measurements of stride length, stride rate, stride symmetry, or heart rate between the two treatment groups.


They suggest that the quantitative variables chosen may not have enough sensitivity in a group of sound horses that were in routine ridden work when entering the study.


Additionally, differences in terrain, weather conditions, and rider characteristics among horses may make small changes difficult to identify. 


They suggest more sophisticated and in-depth motion measurements may be valuable for this purpose.



For more details, see:


Chiropractic effects on stride parameters and heart rate during exercise in sport horses

Lorello, Olivia; Rule, Emily; Haughan, Joanne; Wang, Kai; Niu, Mutian; Brown, Kara; Navas de Solis, Cristobal

Equine Veterinary Journal (2024)