Managing insulin dysregulation in horses: a role for nutraceuticals

(c) Brian Sedgbeer Dreamstime.com

Insulin resistance (IR) and insulin dysregulation (ID) in horses are major risk factors for developing laminitis; a painful and potentially debilitating condition. While some horses are genetically predisposed to IR, diet also plays a critical role in its development. Because of this, there's growing interest in whether specific dietary strategies, including the use of nutraceuticals, can help reduce the risk.

A recent study led by Caroline Loos and her colleagues at the University of Kentucky's Gluck Equine Research Center, and published in the journal Animals,  explored whether supplementing the diet with a specific combination of nutrients could help improve insulin regulation in horses that are prone to IR. 

The trial involved 16 mature horses with a known history of insulin dysregulation. The horses were split into two groups:

• One group received a nutraceutical supplement containing omega-3 fatty acids, glutamine, vitamin E, and active yeast.
• The other group received a placebo.

Both supplements were given once daily for four weeks. During the study, horses were kept on dry lots, had free access to grass hay, and were also fed a grain concentrate twice daily (providing 0.5 g of starch per kg of body weight per meal).

To assess the horses’ insulin regulation, each underwent a Combined Glucose–Insulin Tolerance Test (CGIT) at the start and end of the trial. The CGIT is a diagnostic test commonly used in equine medicine to evaluate how effectively a horse’s body clears glucose from the bloodstream in response to insulin. During the test, horses receive a bolus (injection) of glucose and insulin, and blood samples are collected over a 150-minute period to track how quickly glucose and insulin levels return to baseline. The faster the return to normal, the better the horse’s insulin sensitivity.

After four weeks of supplementation, horses receiving the nutraceutical showed notable improvements:

• 61% faster glucose clearance compared to the placebo group.
• Shorter time for blood glucose levels to return to normal.
• Lower insulin levels at 75 minutes post-test, indicating reduced hyperinsulinemia.
• Glucose concentrations were also lower at 45 minutes post-test in the supplemented group.

In contrast, horses in the placebo group still had elevated insulin levels 150 minutes after the test, suggesting poorer insulin regulation.

These findings suggest that prophylactic use of specific nutraceuticals may help improve insulin sensitivity and reduce the risk of insulin-associated laminitis, particularly in horses consuming high-starch diets. By supporting faster glucose clearance and lowering insulin levels, this approach may offer a valuable management tool for horses at risk of ID or IR.

While more research is needed to confirm long-term benefits, this study highlights the potential of targeted dietary supplementation in supporting metabolic health in horses.

 

For more details, see:

 

Loos, Caroline, Annette Castelein, Eric Vanzant, Emma Adam, and Kyle R. McLeod. 

Nutraceutical Supplement Mitigates Insulin Resistance in Horses with a History of Insulin Dysregulation During a Challenge with a High-Starch Diet

Animals (2024) 14, no. 23: 3385. 

https://doi.org/10.3390/ani14233385

Survey on SGLT2 Inhibitor Use in Horses with EMS or PPID

(c) Brian Sedgbeer Dreamstime.com

Have you used an SGLT2 inhibitor (one of the          "-flozin" drugs) to treat your horse? If so, the Equine
Cushing's and Insulin Resistance Group (ECIR) invites you to contribute to an important research initiative.

Sodium-glucose cotransporter 2 inhibitors (SGLT2i), such as ertugliflozin and canagliflozin, are increasingly used to manage equine metabolic syndrome (EMS), particularly in horses with laminitis that has not responded to dietary changes. These drugs have shown potential benefits, including reducing serum insulin levels, aiding weight loss, and improving laminitis associated with hyperinsulinemia.

However, concerns have arisen about possible side effects, such as elevated serum triglycerides and liver enzyme levels, lethargy, and increased drinking and urination.

Dr. Kellon of the ECIR Group has created a survey to investigate factors that may influence the outcomes of SGLT2 inhibitor use in horses. This includes individual horse characteristics, comorbidities, and dietary factors that may contribute to or mitigate adverse effects.

If you are an owner, veterinarian, or caretaker of a horse receiving one of these drugs—such as canagliflozin, ertugliflozin, or dapagliflozin—you are encouraged to participate in the survey. Your insights will help enhance understanding and improve the management of metabolic disorders in horses and ponies.

The survey can be found here www.surveymonkey.com/r/YM5JD9G 

 

See also:

Eleanor M. Kellon, V.M.D. (Equine Nutritional Solutions) 

www.drkellon.com

 

Equine Cushing's and Insulin Resistance Group Inc.

www.ecirhorse.org

Testing for insulin dysregulation after transportation could lead to a false positive result

(c) Anna Cvetkova Dreamstime.com

Recent research indicates that conducting tests to identify insulin dysregulation (ID) in horses after transportation may lead to false positive results.

The oral sugar test (OST) is commonly used to assess insulin dysregulation, a key component of equine metabolic syndrome (EMS). This test involves taking blood samples at specific intervals before and after administering a dose of sugar, typically in the form of corn syrup. By analysing blood glucose and insulin levels, the OST evaluates how the horse’s body processes a sudden intake of sugar.

 

As this is a time-consuming test, it is often more practical to perform it in a clinic setting. However, recent findings have shown that transportation may influence test outcomes, potentially leading to false positives—where a horse with normal insulin function appears to have ID.

 

Dr. Erica Jacquay and Dr. Amanda Adams from the University of Kentucky, in collaboration with the WALTHAM™ Equine Studies Group, conducted a study to examine the effects of short-term transportation on stress parameters and insulin responses to the OST in horses both with and without ID. The research was recently published in the Equine Veterinary Journal.

 

The study involved seven non-pregnant ID mares and seven non-pregnant non-ID mares, all experienced with transportation. The horses were transported in groups for approximately 1.5 hours to and from their home base by the same driver. An OST (0.15 mL/kg body weight Karo Light Corn Syrup) was conducted 24 hours before and 3 hours after the journey.

 

The findings revealed that both serum and salivary cortisol levels significantly increased due to transportation, with no differences observed between ID and non-ID horses. As expected, the ID mares showed higher insulin responses to the OST on both occasions. 

 

However, in 5 out of 7 non-ID mares, post-travel OST insulin levels surpassed the diagnostic threshold for ID, suggesting that these horses could have been mistakenly diagnosed with insulin dysregulation. Additionally, some ID mares showed post-travel T60 OST insulin levels that were more than double their pre-transportation levels.

 

These results imply that real-world testing conditions, including transportation, may lead to misdiagnoses of insulin dysregulation and inappropriate classification of horses as having EMS.

 

“This research is an important step in improving our understanding of insulin dysregulation and EMS,” said Dr Pat Harris, head of the WALTHAM™ Equine Studies Group which provides the science behind the SPILLERS brand. “The findings show that performing an OST three hours after short-term transportation may result in inaccurate ID status, whether testing a new case or monitoring the status of an ID horse. In addition, special care should be given when transporting horses with ID especially those with a history of hyperinsulinaemia- associated laminitis.

 

“Further studies are needed to determine the best timing of diagnostic testing if transporting horses to a veterinary clinic for OSTs.”

 

For more details, see:

 

Jacquay ET, Harris PA, Adams AA. T

he impact of short-term transportation stress on insulin and oral sugar responses in insulin dysregulated and non-insulin dysregulated horses. 

Equine Vet J. 2024.

https://doi.org/10.1111/evj.14403

Warning of possible adverse effects of SGLT2i on horses.

© Brian Sedgbeer Dreamstime.com

A group of veterinary experts have issued a warning regarding the potential adverse effects of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in horses. In a letter published in the Veterinary Record, Bruce McGorum and clinicians from leading veterinary hospitals like the Royal (Dick) School of Veterinary Studies, Edinburgh, Rossdales Equine Hospital, the University of Liverpool, and the Royal Veterinary College expressed their concerns.

These medications, such as ertugliflozin and canagliflozin, are increasingly used to treat equine metabolic syndrome (EMS), particularly in horses with laminitis that hasn't responded to dietary adjustments. While these drugs have shown promise in reducing serum insulin concentrations, promoting weight loss, and managing laminitis related to hyperinsulinemia, concerns have been raised about significant adverse effects.

 

Minor side effects reported include increased serum triglycerides and liver enzymes, dullness, and increased drinking and urination. However, more serious cases have shown markedly elevated serum triglycerides (above 40 mmol/L), increased liver enzymes (such as GGT, GLDH, LDH), and bile acids, indicating potential liver damage or dysfunction. These biochemical changes were also accompanied by clinical signs such as dullness, loss of appetite, gastric impaction, bilateral laryngeal paralysis, hepatic encephalopathy, and, in some cases, death.

 

Due to these risks, the experts recommend that SGLT2 inhibitors be used only in horses that have not responded to adequate dietary or exercise management, or those with severe laminitis. 

 

Additionally, they advise against using these medications in horses with pre-existing liver disease or hyperlipaemia and emphasize the importance of regular monitoring of diet, liver enzymes, serum triglycerides, and bile acids. Horse owners should be educated about the signs of hyperlipaemia and the potential risks involved in the use of these drugs.

 

Further research is needed to fully understand the risk factors and adverse effects of SGLT2 inhibitors in horses. Until then, their use should be restricted to cases where other treatment options have failed.

For more details, see:

B C McGorum, J A Keen, S McCullagh, CM Marr, C MacKenzie, H Carslake, N Menzies-Gow, Bettina Dunkel, M Hewetson, J Reed, E Knowles.

Potential adverse effects of SGLT2i in horses 

Veterinary Record (2024) vol 195, 253

Do endocrine disorders affect anthelmintic performance?

Recent research indicates that insulin dysregulation may affect the performance of anthelmintics
like ivermectin. This suggests that horses with such endocrine disorders might be more prone to parasitic infections.

In a study conducted by Martin Nielsen and colleagues at the University of Kentucky, the response to ivermectin was evaluated in horses with insulin dysregulation (ID), pituitary pars intermedia dysfunction (PPID), or neither condition. 

 

The study population was part of a special herd at the University of Kentucky’s Department of Veterinary Science, which included horses with and without these endocrine disorders. These horses were kept in permanent paddocks without pasture rotation or enhanced hygiene practices and received routine anthelmintic treatments: ivermectin in March or April and July or August, and moxidectin/praziquantel in November.

 

The study focused on senior horses (aged 13 years and over) and those with or without PPID, ID, or both. Out of 47 horses in the research herd, 19 met the criteria for inclusion. These horses, all with positive faecal worm egg counts, were treated with ivermectin at the recommended dose of 200 mcg/kg. Faecal samples were collected before treatment, two weeks post-treatment (for the Faecal Egg Count Reduction Test, or FECRT), and then weekly until worm eggs reappeared in the faeces (Egg Reappearance Period, or ERP).

 

Two laboratory tests were employed to assess the response to ivermectin: the Faecal Egg Count Reduction Test (FECRT) and the Egg Reappearance Period (ERP). For the FECRT, a reduction of at least 99.7% in worm egg counts is considered effective two weeks post-treatment. The ERP for ivermectin is typically 8-10 weeks.

 

The study found no significant differences in the effectiveness of ivermectin between the groups. However, the small sample size may have made it difficult to detect any potential differences. Overall, ivermectin was highly effective, with all horses showing a greater than 99.7% reduction in worm egg counts at the two-week mark. 

 

Nonetheless, the researchers observed that the ERP was shorter in horses with ID and those with both PPID and ID, at six and seven weeks respectively, compared to eight weeks for both the PPID-only and healthy control groups.

 

They suggest that their findings indicate a need for further investigation of the possible influence of endocrine disorders on anthelmintic performance in horses.

 

 

For more details, see:

 

M.K. Nielsen, C.A. Finnerty, N.E. Ripley, A.E. Page, M.E. McClendon, A.A. Adams,

Ivermectin performance in horses diagnosed with equine endocrine disorders,

Veterinary Parasitology, (2024) Vol 328,110182,

https://doi.org/10.1016/j.vetpar.2024.110182

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:

 

https://beva.onlinelibrary.wiley.com/toc/20423306/2024/56/2

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 ecirhorse.org research portal. Deadline for submission is May 31, 2024.

 

Researchers will find more information at https://www.ecirhorse.org/research-proposals.php

Lean animals can also be at high risk of laminitis, concludes new study

It’s not just obese ponies who can be at high risk of laminitis, a newly published study has
confirmed. Obesity, despite its significant health hazards, may not be a reliable indicator of poor metabolic health and associated laminitis risk, because lean animals have been shown to be at high risk too.  

Adiponectin, a hormone coming from fat deposits, can be measured in the blood, and is thought to improve sensitivity to insulin.  Previous work has shown that low blood concentrations of adiponectin reflect an increased risk of laminitis.  Decreased concentrations of the hormone have been found in association with obesity, but this new work has shown that decreased levels of adiponectin can also be found quite commonly in lean, native-breed ponies.

 

In this latest study, led by Marine Barnabé , data collected during three previous studies involving native-breed ponies, were retrospectively analysed.  Funding for the study was provided by Waltham Petcare Science Institute and the Royal Veterinary College Mellon Fund. An open-access report is published in the Equine Veterinary Journal

 

Total adiponectin was compared between 734 ponies of different body condition score (BCS) classification (ideal-weight, overweight, and obese), breed, and body shape, with and without a history of laminitis. Age, breed, sex, weight, height, and weight:height ratios were recorded. BCS was assessed on a scale of 1 to 9 and was determined by a single assessor. Blood samples were collected from non-grain fed but not forage fasted animals to determine basal insulin and total adiponectin. 

 

The results showed that total adiponectin was weakly positively correlated with BCS, height, weight, and weight:height ratio. There were significant differences in adiponectin concentrations in ponies with different BCS group classification, body shape, and breed. More of the obese (54.6%) than ideal-weight ponies had normal total adiponectin concentrations and a greater percentage of ideal-weight (38.6%) than obese ponies showed low adiponectin concentrations. 

 

“This study together with our previous work has provided us with the important take-home message that you cannot presume that just because your horse or pony is lean or of ideal bodyweight it is automatically at reduced risk,” said Sarah Nelson, Product Manager at Mars Horsecare, home of the SPILLERS brand. 

 

“They may still have insulin dysregulation and/or low adiponectin concentrations and so be at an increased risk of laminitis. If you are concerned it is important to speak to your vet and have your horse or pony tested. It’s also advisable to contact your nutrition advisor to ensure you provide the best diet to manage your individual.”

 

Another valuable initial observation from the study was the significant difference in total adiponectin concentrations between ponies of different body shapes. The middle-heavy body shape was associated with higher total adiponectin concentrations than both other shapes, suggesting this fat accumulation pattern may be less detrimental in ponies. This is similar to research in humans that has shown increased thigh fat or a ‘pear’ shape may be protective against insulin resistance compared to increased visceral fat or ‘apple’ shape. However, more work is needed to investigate these initial findings.

 

Barnabé  concludes that body condition scoring and other morphometric measures of obesity do not reliably reflect circulating total adiponectin concentrations and should not be used to assess metabolic risk factors for EMS or endocrinopathic laminitis in ponies. 

 

“Basal hyperinsulinaemia and hypoadiponectinaemia may be highly prevalent in lean native-breed ponies and circulating concentrations of both these hormones should be measured in animals with predisposing factors, regardless of BCS.”

 

She added: “Understanding the modifiable factors that are associated with total adiponectin concentrations may help to identify targets for preventive or therapeutic intervention, with the goal of reducing the development of endocrinopathic laminitis in at-risk horses and ponies.” 

 

For more details, see:

 

Relationships between total adiponectin concentrations and obesity in native-breed ponies in England

Marine A. Barnabé, Jonathan Elliott, Patricia A. Harris, Nicola J. Menzies-Gow

 Equine Veterinary journal (2023)

https://doi.org/10.1111/evj.14013

Prevalence of laminitis in Norwegian ponies

New research highlights the problem of laminitis in the Norwegian Nordlandshest/Lyngshest pony breed.

Ponies, in general, are prone to laminitis and field observations suggest Norwegian breeds are no exception

 A recent study by Sigrid Lykkjen, Ingrid Hunter Holmøy from the Faculty of Veterinary Medicine at the Norwegian University of Life Sciences, and Linda Koldal Stenbakk from the Forus Hesteklinikk, sheds light on the prevalence and risk factors associated with laminitis within this pony breed. A full report of the study is published in Acta Veterinaria Scandinavica

 

The Nordland or Lyngshest, native to Norway, is typically small to medium-sized, standing at 12 to 14 hands (48 to 56 inches or 122 to 142 cm) at the withers. With a compact and muscular build, these ponies are well-suited for tasks in challenging mountainous terrains, commonly employed in riding, driving, and therapeutic riding programs.

 

The study aimed to assess the prevalence and risk factors for laminitis in the Norwegian Nordlandshest/Lyngshest pony breed. To address the question, the research team used questionnaires distributed among members of the Norwegian Nordlandshest/Lyngshest breed association..

 

Analysis revealed age, sex, and regional adiposity as notable risk factors for laminitis. Moreover, the level of exercise and outdoor housing was significantly correlated with a reduced prevalence of laminitis.

 

For horses over nine years old, the lifetime prevalence of laminitis approached 20%. However, the overall lifetime prevalence across the entire population was comparatively lower. The researchers attributed this lower prevalence to the study's inclusion of a substantial number of young animals (24% aged five years or less), suggesting their contribution to the overall lower incidence of laminitis.

 

In conclusion, the researchers emphasize that laminitis poses a considerable welfare challenge within the Nordlandshest/Lyngshest pony breed.

 

“The identified risk factors, namely age, sex, and regional adiposity, underscore the importance of heightened diagnosis and monitoring of EMS/insulin dysregulation in the breed. Additionally, the findings highlight the necessity for enhanced owner education and awareness of strategies aimed at reducing the risk of laminitis.”

 

For more details, see:

 

Prevalence and risk factors for laminitis within the Norwegian pony breed Nordlandshest/Lyngshest

Sigrid Lykkjen, Linda Koldal Stenbakk & Ingrid Hunter Holmøy 

Acta Veterinaria Scandinavica (2023) vol 65, Article number: 22 

Insulin Dysregulation: not limited to overweight ponies

  

Body condition score alone does not reliably predict the risk of a pony developing laminitis
according to recent research. 

 

The study, by Edd Knowles, Post-doctoral researcher at the Royal Veterinary College (RVC) and Internal Medicine Specialist at Bell Equine Veterinary Clinic. with colleagues at the RVC, and Pat Harris of the Waltham Equine Studies Group, is published in the Equine Veterinary Journal.

 

The findings show that insulin dysregulation (ID), which is linked to an increased risk of laminitis, may occur in ponies across a wide range of body conditions, ages and levels of exercise, not just in those that are overweight. The study also showed that ID was less common in ponies that undertook more exercise, including low-intensity activities.

 

Insulin is a hormone produced by the pancreas. The release of insulin is the signal for cells, largely in muscle and liver tissue to absorb glucose (sugar) from the blood. Insulin dysregulation (ID) is a term that includes a high basal or ‘resting’ insulin (in the blood), an exaggerated insulin response to consuming starch and/ or sugar and tissue insulin resistance (a failure of cells to respond to insulin). 

 

An association between ID and laminitis is well-established, and early detection of ID is likely to be useful in helping to prevent the disease.

 

In this study, the concentration of insulin was measured in the blood of ponies before and sixty minutes after they were given, orally, a sugar syrup (an oral sugar test (OST)). 

 

A total of 1763 OSTs were taken from 367 non-laminitic ponies over four years. The ponies were visited and tested in the Spring and Autumn unless they developed laminitis. Various physical parameters were recorded at the time of each OST including weight, height, body length, neck length, heart girth, belly girth, body condition score and cresty neck score. Owners/carers were asked to complete a questionnaire concerning the specific characteristics, diet, management, duration and intensity of exercise and health for each pony at each visit. 

 

The study concluded that associations between InsulinT60 and physical and owner-reported variables were limited. Season, owner-reported and physical features only explained 10%– 27% of the differences in InsulinT60 risk status in the study population.

 

The findings support previous work that suggested body condition scoring alone was not sufficient to determine insulin dysregulation (ID) status and emphasises the value of using an oral sugar test to screen for ID status.

 

Lead author Edd Knowles stated: “Our work has shown that while physical and owner-reported features can be used to identify ponies with a higher risk of ID, veterinarians should not limit testing for ID to ponies in which these risk factors are present. Doing so would miss identifying ponies at moderate to high risk of laminitis.” 

 

The study also indicates that relatively small increments in equine exercise routines may be beneficial. 18% of samples from ponies that were reported to do no trotting exercise were in the high-risk InsulinT60 category compared with only 9% of samples from those reported to undertake 1–2 h of trotting per week. 

 

This finding supports earlier research, on the benefits of low intensity exercise, conducted in collaboration with the WALTHAM® Equine Studies Group, which provides the science behind SPILLERS®,

 

“This work confirms that while body condition is a useful indicator, we can’t simply assume that ponies with obvious physically apparent attributes such as excess weight are the only group likely to have ID,” said Sarah Nelson, Product Manager at Mars Horsecare, home of the SPILLERS brand. 

 

“We must consider multiple variables when targeting ponies for ID screening, in order not to miss those potentially at increased risk of laminitis, who may have a ‘healthy’ body condition score.” 

 

“The association with even low-level exercise is also an important practical management message for horse owners” she added.

 

For more details, see:

 

EJ Knowles, PA Harris, J Elliott, Y-M Chang, NJ Menzies-Gow.

Factors associated with insulin responses to oral sugars in a mixed-breed cohort of ponies. Equine Vet J. 2023.

https://doi.org/10.1111/evj.13983

Chance to help Equine Cushing's research

 

Horse owners and carers can help research into the underlying causes of Pituitary Pars Intermedia Dysfunction (PPID) also known as Equine Cushing’s Disease, a condition common in older horses and ponies. Typical signs include a long curly hair coat and weight loss. The condition is associated with a range of problems the most serious of which is laminitis. 

Researchers at the University of Melbourne are conducting a survey of horse owners as part of a broader, major international project to improve the understanding and knowledge of the fundamental causes of the condition, in order to improve early diagnosis, treatment, husbandry and nutritional management.

 

The short online survey is designed to better understand how owners manage horses or ponies with PPID, and what the important factors are for them including: the ability to feed separately and cost of medications.

 

Lead researcher at the Melbourne Veterinary School, Dr Nicolas Galinelli said that it was important to gain a better understanding of current management practices when it comes to PPID. 

 

“We need to get a broader sense of what is working for horse owners so that we can improve health outcomes for these animals both in terms of the early recognition of PPID signs and in the way we determine the most appropriate treatment, management and nutrition.”

 

“PPID affects approximately 20 per cent of horses and is slightly more common in ponies. Sometimes it is treated with specific drugs that target the excessive production of hormones from the pituitary gland, whilst other owners may choose to only treat the clinical signs of the disease such as laminitis. Adapting the diet can also be helpful. We want to understand how owners make treatment decisions and which decisions are having the best outcomes,” Dr Galinelli said.

 

Veterinary pharmacology expert, Professor Simon Bailey added that the survey will ask owners about what factors are important for them in treating PPID, including the cost and side-effects of medications and the ability for horses to be fed separately. He said “We encourage owners to get in touch once our results have been finalised and published. We are keen to help share this information with the equine community and thank them for their support.” 

 

The research, supported by the Australian Research Council, is being undertaken by the Melbourne Veterinary School and Queensland University of Technology with industry partners including WALTHAM Petcare Science Institute (UK), Boehringer Ingelheim (Germany) and The Liphook Equine Hospital (UK).

 

The results from this anonymous survey will provide valuable information and contribute to improved targeted education of the horse owning public.

 

To complete the survey, go to:

 

https://melbourneuni.au1.qualtrics.com/jfe/form/SV_0GPNcsoVqyB6lo2

Testing for insulin dysregulation

Horses with Equine Metabolic Syndrome (EMS) are susceptible to laminitis associated with insulin dysregulation (ID). Advanced cases have markedly elevated resting insulin levels (Basal Insulin Concentration: BIC), and the diagnosis is straightforward. It is quick and easy to carry out a basal insulin test, only requiring a single blood sample. 

Unfortunately, it may not detect many early cases of ID which can have resting insulin levels within the normal reference range.

This may lead owners to conclude that changes to diet and management are not required.

There is a need for a simple test that can be used by ambulatory veterinarians at the owners’ premises to identify more of those suspect cases of EMS that are missed by the BIC test.

Researchers in the Netherlands investigated to see if using an Oral Sugar Test (OST) would be more useful than BIC for detecting ID.

Linda Van Den Wollenberg and colleagues, studied 90 adult horses, of various breeds, used for recreational purposes, and maintained at the owners’ premises in the Netherlands and Belgium. Their work is published in the Journal of Equine Veterinary Science.

The researchers collected blood samples before and 75 minutes after administering sugar solution (0.45g/kg of commercially available corn syrup.)

They compared the number of horses classified as "ID-positive", "ID-suspect", and "ID–not diagnosed" according to the basal insulin concentration (BIC) (>50mU/L; 20-50mu/L and

There was a significant difference in outcome of the results of the two tests. 

The oral sugar test proved to be more useful than the basal insulin concentration. BIC classified 3 horses as ID-positive and 6 horses as ID-suspect (a total of 9/90, 10%). In contrast, the OST classified 25 of the 90 horses (28%) as ID-positive. 

The researchers conclude that, under field conditions, the OST is preferred over the BIC for use as a screening test for ID.

They add that “In addition, our results support the assumption that obese horses and “easy keeper” breeds have a higher tendency of having ID.” They suggest: “further studies are required to assess the repeatability of the OST as we performed it, under different circumstances and within an individual.”

For more details, see:

Comparison of Two Diagnostic Methods to Detect Insulin Dysregulation in Horses Under Field Conditions.

Linda Van Den Wollenberg, Veerle Vandendriessche, Kees van Maanen, Guillaume H.M.Counotte

Journal of Equine Veterinary Science (2020) Vol 88, 102954

https://doi.org/10.1016/j.jevs.2020.102954