Winter Foot Pain in Metabolic Horses

Veterinarians working with many laminitic horses are well acquainted with the problem but others may be unfamiliar with it.  It’s a laminitis-like syndrome triggered by cold weather.

Horses normally have a very high tolerance for cold.  In all species, cold causes a reflex shunting of blood away from the extremities and toward the core to limit loss of body heat. Healthy horses prevent the hoof from being damaged by low blood/oxygen supply with the use of local arteriovenous shunts – pathways which allow them to divert blood quickly back to the veins for return rather than sending it to the local tissues. When low blood supply reaches a critical level, the arteriovenous shunts to that part of the hoof can close, reperfusing the tissue.

The only adverse effect of cold weather and reduced blood flow to the hoof in healthy horses is slower hoof wall growth. In horses with metabolic issues that result in high insulin levels, it may be a different story.

We don’t know all details of the mechanism but it is clear from research that high insulin can cause laminitis. We also know that even if they have never had a full blown laminitis episode there are similar abnormalities in the structure of their laminae. One thing we do know about it is that levels of endothelin-1 are greatly elevated. This is a chemical in the body which causes blood vessels to contract down. It has also been shown that the vessels in the hoof become more sensitive to other messengers that cause contraction. These changes may interact with cold induced blood vessel constriction to cause a critical interruption of blood supply to the hooves of those horses.

Horses with cold induced hoof pain show obvious lameness and often typical laminitis stance but without bounding pulses or heat in their feet. In milder cases it may be mistaken for the sensitivity to moving over frozen uneven ground that all horses show. However, it doesn’t go away on level surfaces. There is variability in individual sensitivity to cold but signs may appear beginning at 40F [4.4C].

Even horses that usually have their insulin well controlled by a low carbohydrate balanced diet can be susceptible. This may be because cold weather has also been observed to often cause wide swings in insulin levels and/or because of previous damage to the circulation in the feet.

The first step in helping these horses is protecting their extremities from the cold. Leg wraps such as lined shipping boots work well and are safe to leave on because they won’t slip out of place and cause uneven pressure on the tendons [aka “bandage bows”]. Boots with pads and socks or fleece lining are essential.

The horse, pony or donkey can be supported nutritionally by supplements which encourage the production of nitric oxide. Nitric oxide is a vessel dilating messenger that is the natural counterbalance to endothelin-1.  The herb Gynostemma pentaphyllum (Jiaogulan) is a powerful support for nitric oxide. This is helped by providing the precursors for nitric oxide in the form of L-arginine and L-citrulline. Antioxidants also combat oxidative stress which inhibits the activity of the enzyme that produces nitric oxide inside blood  vessels [eNOS – endothelial nitric oxide synthesis].

Winter laminitis has historically been regarded as very difficult to manage but understanding the vascular issues has led to significant strides in helping these horses balance the forces affecting the blood supply to their feet.

Eleanor Kellon, VMD

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Stewardship

It’s been over 5 years since I posted this blog, and about 20 years since I wrote it initially, but some things just don’t change.

The definition of stewardship has not changed since 1913 – “responsibility for taking good care of resources entrusted to one”. We have the responsibility of stewardship for our children, our heritage, our natural resources, and also our horses.

There is no question that any horse choosing to do so could overpower a human and gain his/her freedom. It is only by the horse’s cooperation that we can ride, drive, even touch a horse. When we accept the horse’s willingness to be used, we also accept stewardship.
This is a very different thing from ownership. When we own an object, it is ours to do with as we please. With stewardship, we are bound to take good care.

Legislation covering animal welfare certainly recognizes the stewardship of owners, trainers and caretakers. It only covers cases of flagrant abuse though. True stewardship extends far beyond that. It’s both very complicated and very simple. Stewardship demands that you provide for the horse in a manner that keeps him both mentally happy and physically well.

The fact a horse is alive and breathing does not mean he is happy and well. A true horseperson doesn’t need a course in horse psychology or a battery of lab tests and CAT scans to tell if a horse is mentally and physically well. The look in his eye, the way he carries himself, his interest in his surroundings and his work, the health of his coat and feet tell the story.

Stewardship isn’t just about feeding and routine health care, although that is a major part.
It’s also about serving the horse’s needs as well as our own. There are far too many violations of stewardship happening every day, and they’re not all situations that would fall under the umbrella of obvious abuse. Performance or personality altering drugs, bleeding horses or tying them in uncomfortable positions for hours on end before a show to break their spirit, blocking pain to allow a horse with an injury to work and risk injuring himself further, sending a horse that has served faithfully all his life to a killer auction to squeeze those last few hundred dollars out of him are all breaches of stewardship.

The contemporary veterinarian’s oath is a good example of stewardship. It states:

“Being admitted to the profession of veterinary medicine, I solemnly swear to use my scientific knowledge and skills for the benefit of society through the protection of animal health and welfare, the prevention and relief of animal suffering, the conservation of animal resources, the promotion of public health, and the advancement of medical knowledge.”

Notice there is nothing in there about treating the horse to achieve a set profit margin, or treating the horse to achieve the goals of the owner. Stewardship is a concept that should always be at the forefront. Our horses don’t owe us anything – we owe them.

Eleanor Kellon, VMD

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Bone Health in Older Horses

An increased risk of fractures from falls and decreased bone density in general are familiar consequences of aging in people but not as well researched in horses. However, between clinical experience and what can be found in the literature, there is reason for concern.

A 1979 study [Shorafa, Feaster and Ott] looked at bone mineral content, cortex thickness and fracture resistance in the metacarpal (cannon) bone of horses of various ages. They found mineral content and strength peaked between 4 and 7 years old, then progressively declined.

The 2008 study found here https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2267174/?tool=pubmed found age-related change in the microarchitecture of bone with decreases in the number of trabeculae (structural tubules) and greater distance between them in older horses. This constitutes osteopenia, which is reduced bone mass although not as severe as osteoporosis.

Another  factor in older horses is higher cortisol levels, which occurs from aging alone but especially in horses with PPID [Cushing’s]. Cortisol disrupts the normal balance between bone formation and bone breakdown, ultimately resulting in bone loss.

We can’t completely prevent the osteopenia of aging but there are possible contributing factors that are within our control. Check yearly for laboratory evidence of PPID with ACTH level in September, or any time PPID is suspected.  If PPID develops, be sure to treat adequately so that ACTH remains in the normal range.

Keep your senior moving! In addition to benefits for joint health and mobility, exercise also helps maintain bone density.

While nutrition can’t cure or prevent osteopenia, improper nutrition can definitely make it worse.  The key nutrients are:

  • High quality protein and key amino acids: Bone is built on a scaffold of protein/collagen, which then becomes calcified. Whey and the amino acids lysine and proline address this.
  • Calcium, phosphorus and magnesium: These are the major minerals in bone. Together with balanced trace minerals zinc, copper and manganese they provide for maintenance of bone.
  • Vitamins C, A and D: Critical for formation of collagen and regulation of bone formation.
  • Boron: Needed for normal bone density
  • Strontium: Assists in maintaining a positive balance between bone synthesis and breakdown
  • Silicon: Helps promote homeostatic mechanisms supporting strength in bone and connective tissue

Healthful activity levels, PPID surveillance and optimized nutrition can go a long way in preserving bone strength in older horses.

Eleanor Kellon, VMD

 

 

 

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Is Acorn Toxicity in Horses Real?

Squirrels aren’t the only ones hoovering up the Fall crop of acorns. Horses love them too. A yummy treat courtesy of Mother Nature – or are they harmful?

Many people report their horses regularly indulge in acorns in the Fall with no ill consequences but a small number of horses develop serious, even fatal, illness as a result.

A study from the UK [Smith et al 2015] reports on a series of 9 horses over a 9 year period treated for suspected acorn toxicity.  Five presented with bloody diarrhea and shock, were rapidly euthanized or died. Four had colic and diarrhea. Three of those survived with medical support and the fourth was euthanized.

Post mortem examination of the 6 dead horses showed extensive intestinal and kidney damage. The authors noted toxicity seems to be more of a problem in some years than others, which has also been reported by others. It is unknown if acorns are more toxic certain years or if it is a matter of larger numbers of them being available.

The details of how acorns cause poisoning remain to be determined. Tannic acid is often blamed but in cattle, which are even more sensitive than horses,  dosing with tannic acid does not reproduce the kidney damage. Gallic acid and phenolic compounds are also believed to be involved. The products of bacterial fermentation of acorns in the rumens of cattle and the colon of the horse may be the most active toxins.

The leaves of oak trees are also potentially toxic.  Cattle have been poisoned by consuming oaks leaves in the spring.  There have not been any recognized cases in horses but it’s possible.

Acorns pose another potential danger to horses, ponies, donkeys and mules with Equine Metabolic Syndrome [EMS]. In this condition, there are exaggerated insulin responses to simple sugars and starch which can result in laminitis.  Acorns average over 40% starch which is way too much for an animal with EMS.

There is no specific treatment for acorn poisoning. Activated charcoal can help if administered immediately after the acorns are consumed but signs don’t usually appear for a few days after ingestion and at that point it’s too late for charcoal. Charcoal also can’t protect an EMS horse from acorn induced laminitis since it doesn’t have any effect on starch digestion.

After the horse becomes ill, the only treatment is supportive care such as intravenous fluids. Even with intensive treatment the fatality rate is high, as much as 67%. Not all horses become poisoned on eating acorns but that high death rate should be strong motivation to avoid exposure to acorns and oak trees.

Removing acorns as they fall is a full time job. It’s preferable to remove the trees entirely or fence off areas containing acorns in the fall and trim the trees so that leaves are not accessible.  If storms bring down branches, be sure to remove them promptly.

Acorns from the mighty oak are a boon to many species but not worth the risk with a horse.

Eleanor Kellon, VMD

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Mid-Pregnancy Nutrition

When an average size mare delivers she will have produced a 100+ lb foal, an 11 pound placenta, and as much as 16 pounds of fluid. She has also greatly increased the size and thickness of her uterus and blood volume increased about 30% during pregnancy.   The raw materials to build these things didn’t come from thin air.

By the halfway point, the foal is about the size of a Beagle, all organs formed, and rapid growth begins

Providing adequate calories is the easy part. Rapidly dividing cells also have critical needs for amino acids, vitamins and minerals which they must obtain from the placenta. It’s true that the dam will rob her own body tissues if necessary to provide for the fetus (not that this is a very smart management tactic!). It’s also true that the dam cannot provide something she herself does not have. If she starts the pregnancy with low body reserves and her diet is not adequate, the foal will be short-changed and the mare become even more deficient.

Extreme deficiencies result in things like White Muscle Disease and goiter with hypothyroidism in foals. More insidious effects include a higher risk for developmental orthopedic disease like OCD and contractures. Chronic copper deficiency has been linked to uterine artery rupture in mares.

Advice on feeding pregnant mares used to be no special attention to nutrition until the last trimester.  The latest (2007) NRC recommendations begin to allow for increased nutrients in the 5th month but since there are still gaps in the research, there are also gaps in their recommendations. For example, they don’t allow for any increase in zinc or manganese but obviously foals have those essential minerals in their bodies.

Good quality grass hay or pasture should be the bulk of the pregnant mare’s diet. In fact, a hay with 10 to 11% protein and digestible energy (calories) of 0.9 Mcal/lb can meet calorie and protein requirements throughout pregnancy. Even in the last month of pregnancy the  mare would only need to consume a little over 2% of her nonpregnant body weight to meet her needs. For every 1% below 10% in the protein, the mare needs 45 grams of supplemental protein per 10 lbs of hay. For example, if a 9% protein hay and she’s eating 20 lbs, she needs 2 x 45 = 90 grams of supplemental protein. A common range for protein in good quality grass hay is 8 to 12%.

If you don’t know the protein level in your mare’s hay, it’s wise to supplement. “High” (14%) feeds won’t help because they have 2.5 to 3 times more calories than hay but not 2.5 to 3 times more protein so you feed a lot less. Choose a supplement with a blend of vegetable and whey sources, guaranteed levels of lysine and methionine. If you assume 8% protein, a  mare eating 20 lbs/day will need 180 g of protein = 450 g of a 40% protein supplement (1 pound).

You may want to meet part of your extra protein needs with a combination protein and mineral supplement. As a rule of thumb, the pregnant mare will need double her baseline mineral intake at the time of greatest  demand so  look for a supplement with at least 5% calcium and 225 mg copper per 1 lb serving. A pound of it will provide about 112 g of protein if 25% protein.

Do not stop your mare’s  usual mineral supplements when she is pregnant. You still need to have her eating a balanced diet base. The above supplementation is for the additional needs of pregnancy. Compared to what is already invested, this is cheap insurance. A breeding farm client of mine once described foals from mares managed this way as “robust”.  How many 1 week-old foals look like this?

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Do You Need an Oral Sugar Test to Diagnose EMS?

It has been established that high blood insulin is responsible for about 90% of all laminitis cases and best current estimate is 10 to 15% of the equine population is at risk of EMS – Equine Metabolic Syndrome.  A central component of EMS is elevated insulin.

Not all overweight horses have EMS

Some (not all) EMS horses are overweight and have abnormal fat deposits, especially along the  crest of the neck. These are indicators but to confirm you need to document abnormal insulin.

If you have done any reading on EMS diagnostic tests you have probably found many different testing options. A common statement these days is that the oral sugar test is best – but is it?

The original test suggested for documenting abnormally high insulin was a fasting insulin level. The oral sugar test was born after the realization that baseline insulin when fasting missed a lot of cases.  There is no question it’s better than a fasting insulin level, but is it the best and only option?

There are several multi-step tests for insulin function and response to insulin which involve placement of a catheter and evaluating the response to intravenous injection of glucose and/or insulin by taking a varying number of blood samples. Because of their expense and the time involved, simple testing involving minimal time and preferably only one blood draw are more appropriate for screening horses in the field.

The value of field screening tests is established by comparing the results to those obtained from the more intricate but more accurate intravenous tests. The “gold standard” test is the FSIGTT – frequently sampled intravenous glucose tolerance test. Dunbar et al 2016 showed the OST had a 0% sensitivity in detecting insulin resistance compared to FSIGTT when using  the common cutoff for peak insulin of 60 uIU/mL. When the threshold was  lowered to 45 uIU/mL, sensitivity improved to 14%.  This means for every 100 positive horses detected by FSIGTT, only 14 were found with OST.

In 2005, Dr. Trieber’s group used the FSIGTT to develop the proxies RISQI (reciprocal of the square root of insulin) and MIRG (modified insulin to glucose ration). These are calculations using insulin or insulin and glucose results from a single blood draw to approximate the results  from FSIGTT.  When put to the test in a year-long study of 160 ponies being maintained on pasture, either proxy had a sensitivity of at least 64%. When the two were combined with one other marker of EMS such as obesity, sensitivity rose to 74%.  The proxies correctly predicted ponies at risk of laminitis in 84.6% of the cases.

The OST has also been tested to see if it could differentiate between ponies that had previously had laminitis versus never had laminitis. At the usually used dosage of 0.15 mL of Karo syrup/kg of body weight there was no significant difference. There was also no significant difference between groups at 0.30 mL/kg of body weight.  At 0.45 mL/kg there was a significant difference but this would amount to a bit over 4 oz for a 1000 lb horse.  Only 8 ponies were used in this study and sensitivity compared to FSIGTT has not been determined. Cutoff values for determining a positive test have also not been established for this dosage.

Newer is not always better.  The ECIR group https://ecir.groups.io/g/main has been using the proxies since 2006 and before that the G:I (glucose insulin ratio) proxy, which was also shown to have good correlation with FSIGTT in Trieber’s original publication.  Another option is to use nonfasting insulin with the horse having access to hay or pasture only. However, instead of the 20 uIU/mL upper limit of normal currently recommended we use the ranges established by the large pony field trial.  So far, we see no reason to change.

Eleanor Kellon, VMD

 

 

 

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All About Antioxidants

Do you remember when antioxidants were all the rage as the latest and greatest thing in supplements?  Other topics catch most of the headlines these days but antioxidant activity still underlies some of the effects of currently popular ingredients like curcumin and even cannabinoids.

The horse’s natural diet is rich in antioxidants.

Oxygen free radicals, aka reactive oxygen species (ROS) are oxygen-containing products of metabolism which are missing an electron, making them unstable. Normal cellular metabolism, immune system activities, exercise and cellular clean up after injury all generate ROS. Diets high in fat or carbohydrate, metabolism of drugs and toxins also generate oxidative stress, as do chronic health problems.

These substances will attack proteins, DNA, structural  membranes both inside and around cells to steal an electron. The molecule attacked then becomes a free radical itself and a chain reaction can be started. The process weakens and can even destroy the cells under attack.

Antioxidants protect against ROS by donating an electron to stabilize them and prevent attack on the tissues. Antioxidants can be either fat soluble, located primarily inside the structure of membranes, or water soluble, protecting the watery environment inside and outside the cells.

The body has a variety of antioxidant enzymes such as catalase and  SOD – superoxide dismutase. These are manufactured by the cells, as are the important intracellular antioxidants N-acetyl-cysteine, glutathione and alpha-lipoic acid. Vitamins Niacin, C, E and A have potent antioxidant activity.

Foods can also supply plant based antioxidants.  The horse’s diet is naturally rich in plant antioxidants such as carotenoids, flavonoids and polyphenols. Fresh green plants of all types have high levels, even grass. For example, Bermuda Grass is a sacred plant in India, where it is called Durva.

While excess ROS can be harmful, a healthy horse’s body is one that has a correct homeostatic balance between antioxidants and free radicals. This balance is called the cellular redox state. The goal isn’t to eliminate them entirely because at proper levels they have important activities such as stimulating the production of antioxidants, cell to cell signalling, modulation of gene function and enzyme activity.

The first step in ensuring your horse has adequate antioxidant defenses is correct intake of B vitamins, vitamin C, vitamin E and vitamin A/carotene as well as the amino acid L-glutamine and minerals copper, zinc, magnesium and selenium.

If nutrition has been optimized and the horse needs more antioxidant support, look to rich plant sources such as:

  • Grape seed and skin
  • Berries
  • Turmeric
  • Garlic
  • Ginger
  • Ginkgo
  • Boswellia
  • Spirulina

as well as isolated plant compounds such as quercetin or mixed bioflavonoids.

Supporting antioxidant activity is one of the best things you can do in a natural approach to health because it enables the horse’s body to use it’s own homeostatic system of checks and balances to protect itself.

Eleanor Kellon, VMD

 

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Please Stop Anthropomorphizing

A common technique with writers or advertisers is to connect with their audience by using something familiar and important to them. That’s why pet foods are gourmet, stew, dinner, etc. when the dog would actually be happier (and healthier) with a raw chicken neck.  We also need to be careful about making assumptions for our horses based on our own feelings and preferences. Diet issues is a good example here too.

Horses have an instinctive drive to eat high starch items

If your horse is obese or has metabolic syndrome are you causing suffering and unhappiness if you don’t feed sweet feed or other grains? The horse has an instinctive drive to select foods with higher starch or sugar content because in pastures that correlates with grasses that have the most calories and better digestibility. Calories = survival.

However, that drive can shoot them, quite literally, in the foot. Given unlimited access to grain any horse will overeat resulting in laminitis, colic and potentially death. They won’t stop until it’s too late. Grains can have a place in the feeding of some hardworking horses but they are not part of the horse’s evolutionary diet and the horse does not naturally need, or crave, very high starch or sugar foods and treats.

What about grazing? Don’t horses need to constantly eat for their mental and physical health? No. Horses in their feral environment spend so much time grazing because grass is about 80% water and often poor nutritional quality. There are no calories in water.  The horse has to eat that much just to get the calories needed.

By comparison, hay is a very concentrated source of calories since it is only about 10% water.  The horse has to eat 4.5 times more grass than hay to get the same number of calories. Furthermore, hay is harvested at the peak of its nutritional value. If the horse is grazing grass that is overly mature and has already gone to seed the horse will need to eat even more.

Horses that do not have EMS can have free choice access to hay and they will limit their intake to what they need to maintain a normal body condition. Those horses are eating a lot less in terms of poundage than they would if they were on pasture. They don’t eat constantly just because it’s there.

The EMS horse on the other hand does not have a normal “Off” switch that tells him when to stop eating.  It’s necessary to restrict his access to only provide what is needed to maintain a normal body condition.  This isn’t a diet.  It’s feeding a normal amount of food for their level of exercise.  If overweight, the vast majority of even EMS horses will gradually reduce to a normal body condition with this approach. Think of it as normalizing, not depriving.

Many people have the most trouble with keeping an EMS horse off pasture or muzzling them.  They think it’s cruel, unnatural, and the horse can’t possibly have a happy life without it. Food is not a substitute for companionship, grooming or exercise. It’s important to provide those things too. When there is a pressing medical need to adjust the horse’s eating, it’s irresponsible to ignore that.

Horses do not use food as a reward or to soothe themselves the way people may. Their instincts don’t always align with the domesticated environment they find themselves in but the horse can have a good life without giving in to providing food choices which can harm them.

Eleanor Kellon, VMD

 

 

 

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Supplementing Fading Pastures

As Autumn settles in, the composition of pasture grasses begins to change. The horses are still interested in grazing, and grasses may still largely be green, but the nutrition is not the same.

All grasses have a natural growth cycle and preferred growing conditions  during which they will take a few weeks to grow to full height, develop and then drop seed.  The stage of active growth and before the grass has set seed is when hay should be cut for peak nutritional value.

After full height is reached and seed begins to form, the caloric value, carbohydrate level and protein in the plant start to drop.  Fiber and lignin begin to rise, decreasing digestibility overall. Mineral levels may drop and the minerals present may be less bioavailable because of complexation with fiber.  Levels of vitamin E and fat progressively fall.  The fat loss is almost exclusively  the more fragile omega-3 fats.

For horses being maintained on pasture, the signs of declining nutritional value include:

  • Weight loss
  • Loss of “bloom” (duller, dry coat)
  • Poor hoof quality
  • Appearance of hoof abscesses
  • Low energy
  • Slowed growth in young animals

Horses with poor hind gut function may show a distended abdomen, increased gas and/or loose manure or increased free fluid with manure.

It’s better to start supplemental feeding before you see any of these signs. Offer hay in a covered feeder or in hay bags in shelters. When pasture quality is adequate, they will eat very little or ignore it. A growing interest in hay is a strong indicator pasture nutrition is lacking.

All horses should receive vitamin E, 1000 to 2000 IU/day, preferably in an oil base.  Begin supplementing a high omega-3, flax based product at 2 to 6 oz/day. Horses on mature stands of grass should all be supported with an essential amino acid supplement of L-lysine, D,L-methionine and L-threonine.  As the pasture ages and begins to lose the bright green color, a concentrated quality protein supplement based on soy and whey should be added if supplemental feeds are not meeting protein requirements.  When in doubt about protein and fiber levels, a short pasture analysis can be obtained very inexpensively. Ask your local agricultural extension agent.

If you know when and what to supplement, your pastured horses can keep that Spring glow of health all year long.

Eleanor Kellon, VMD

 

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Insulin Problems – Forget about NSC

Hay or pasture is a major component of any horse’s diet, and is likely to be virtually the complete diet in animals that are obese.  Since insulin resistance is often part of the reason why a horse or pony becomes obese, it’s important to know how to determine if their diet contains a safe amount of carbohydrate but not all carbohydrates are created equal.

Carbohydrates in forage plants include soluble and insoluble fiber (cellulose, hemicellulose, pectins, galactans, beta-glucan), starch, simple and complex sugars and fructans. NSC = Non-Structural Carbohydrates. These are plant cell carbohydrates that are free in the cell and not part of the cell wall.  NSC includes starch plus water soluble carbohydrates – simple sugars, plant sugars and fructans.

So far it sounds like looking at NSC would be smart if you have a horse with high insulin. The problem is, NSC also includes things that do not influence insulin, most  notably fructans. https://wp.me/p2WBdh-gn.  By including fructans in the evaluation of a forage’s safety/suitability, many perfectly appropriate hays are being rejected and owners are spending a lot more time, analysis fees and energy than they need to be.

The answer is to look at the tests that are most relevant to insulin rising – starch and ESC.  ESC = Ethanol Soluble Carbohydrates.  It is the best measure of the simple sugars that can trigger an insulin response when they are digested and absorbed.

Does it make that much difference?

Evaluation of 221 grass  hay samples from Oregon (K. Gustafson, personal communication) showed if using 10% NSC as a cutoff for hays that would need to be soaked or not used, 87% would be called a problem. If the threshold is raised to 12% NSC, 70% were identified as problematic.  When 10% ESC + starch was used as the guideline, only 4% were an issue. Hays passing the 10% or less ESC + starch test were subsequently fed to horses diagnosed as having Equine Metabolic Syndrome without issues.

An argument is sometimes made that NSC should be used because the other carbohydrates contribute calories and most of these horses need to lose weight or have their calorie intake controlled.  However, a lot more than fructan goes into determining the DE [Digestible Energy = calories] of a forage and the hay analysis also actually provides a DE number. That is what should be used to determine caloric content and how much to feed, not NSC.

The take-home message here is that the scientific studies on Equine Metabolic Syndrome and laminitis are all now clearly showing that insulin is the issue. When evaluating possible hays for these horses, the focus needs to be on elements that can cause an insulin rise – ESC + starch. It’s time to stop talking about NSC.

Eleanor Kellon, VMD

 

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