Lots of horses (and horse owners) are struggling with metabolic issues, especially this time of year. The text below is from a recent article that we thought was great. Please feel to contact your local experts at The Scoop Feed & Supply with any questions:
Understanding Insulin Dysregulation
“Insulin sensitivity describes the ability of insulin to pull glucose out of the blood and into body tissues. Insulin resistance (IR) is when the normal concentration of insulin fails to facilitate a normal biological response, usually in reference to insulin- mediated glucose disposal. In these circumstances, circulating levels of insulin are elevated, but glucose may remain normal. It takes more insulin to clear the same amount of glucose,” explains Emily Smith. “The beta cells of the pancreas secrete insulin into the blood stream in response to a rise in blood sugar or glucose. Glucose rises in response to the digestion of non-structural carbohydrates (sugars and starch) in the small intestine. When the horse consumes a high-starch meal, the enzymes of the small intestine will break down the starch into individual glucose units. Glucose exits the small intestine and enters the blood stream to be metabolized for energy in the cells of all the different tissues of the body. Insulin communicates with cells, via receptors, to orchestrate glucose uptake into the cells. Insulin attaches to the receptors that then stimulates the cell to make and send special glucose transporters to the cell membrane, creating an opening so glucose can enter the cell. In insulin resistance, there is a diminished response from the receptors or, if obesity exists, a lower density of receptors on the cell surface, so glucose continues to circulate without being allowed to enter the cell to be metabolized. The non-metabolized glucose molecules remain in the blood, and the pancreas responds by sending out more insulin in an attempt to lower blood glucose. Because the cells are resistant to insulin, hyperglycemia and hyperinsulinemia can result.”
Clinical diagnosis of IR generally requires one or more blood tests. Basal, non-fasting serum insulin (i.e., up to 3 hours off pasture or forage) has replaced fasting serum insulin, in part because fasting itself presents a stress on the horse that can disrupt insulin function. There are limitations to basal, non-fasting serum insulin, least of which is correlating responses to different sources, quality or type of pasture and forage. Dynamic tests that follow the serum insulin and glucose response to a standardized amount of sugar do require multiple blood draws but are more sensitive at gauging a horse’s insulin sensitivity. Other lab tests have been used to support a diagnosis of IR, as well
Oftentimes, IR is delineated into two categories: compensated and uncompensated. Compensated insulin resistance is when insulin can be produced at a high enough level that eventually cells respond, allowing glucose to enter the cells and returning blood glucose levels to normal. Insulin levels will appear elevated but glucose will remain normal. Uncompensated insulin resistance is when pancreatic beta cells can no longer secrete enough insulin to counteract the current blood glucose level. Blood glucose will not return to normal. Uncompensated insulin resistance is not as common but is indicative of more serious issues. It can accompany advanced stages of PPID.
Why Diet is Crucial
Diet has a profound impact on horses with metabolic disease and their ability to regain health. In these cases, diet and therapeutic nutrition are used as clinical tools by veterinarians to make a measurable difference in their patients. “Diet is used to modify nutrient and caloric intake to restore homeostasis so that all organ systems are working in harmony to create — and maintain — a healthy horse,” explains Dr. Scoggin. “Because obesity can lead to systemic inflammation, getting a horse to — and keeping them at — a healthy body weight can reduce inflammation.” That reduction in inflammation has the ability to directly influence the various systems and functions within a horse’s body, even the health and integrity of their connective tissue. “The goal of a good insulin resistant dietary program (for horses with metabolic disease) is to reduce dietary sugar and starch, which will lessen circulating blood glucose and decrease insulin output from the pancreas,” says Emily Smith. “In my experience, what helps clients is coming up with a simple, straight-forward plan based off their horse’s blood work. Too many variables in the diet can make it very hard to stay compliant long-term, and it becomes hard to know what is effective.”
At least part of the problem when it comes to the diet and its role in horses developing metabolic problems, is the energy-rich foods being consumed. “Horses today are not ‘work’ animals anymore; they are typically not pulling carriages or other heavy loads for a living. Many contemporary horses are sedentary or used for ‘light’ leisurely activity,” says Smith. “However, they are often fed well over what their metabolic rate can burn through and so, over time, this leads to weight gain and obesity. But it’s not right to vilify horse owners who are trying so hard to make sure their horses are provided for and receiving the best care. I think it’s an educational opportunity and a reminder to look at what a horse is meant to thrive on: forage. Most modern horses do not need the cereal grains we currently feed; those are reserved for hard work, as they were classically used for. The digestive tract of the horse needs fiber at a steady, consistent pace. The horse was designed this way. It may seem counter-intuitive to a lot of people, but these huge animals can not only survive on green fibrous materials but actually thrive on it for many reasons, with a healthy weight being a main benefit.”
Feeding Horses with Metabolic Disorders:
What to Do and What Not to Do
As frustrating as it can be to have a horse suffering from IR or EMS, the distinct silver lining is the fact that, with diet and the correct therapeutic nutrition, these conditions can be successfully managed. A good rule to live by when feeding these horses is that a simplified and wisely-chosen diet can yield significant results, including a decreased weight and reduction in symptoms. “How I like to feed a metabolic horse that is having trouble regulating blood sugar or has high insulin levels on blood work is pretty simple,” says Emily Smith.
1. Start with the Hay
Understanding how much sugar and starch is coming from your hay is important, as is having a good grasp of its mineral content. Some hays are naturally better choices for metabolic horses, and if ever in doubt, a hay or pasture analysis can provide more concrete answers.
• Grass hay is a great place to start.
• Alfalfa can, often surprisingly, have a very low nonstructural carbohydrate (NSC) content and can be used in the diet as well if the horse is not sensitive to it.
• Hays will likely vary in their nutrient profile, so a forage analysis is recommended.
• Oat and Barley hay can be good examples of grain hays to avoid.
• Hay pellets or unmolassed beet pulp are excellent carriers for supplements. Beet pulp contains soluble fiber and has one of the lowest glycemic indices of common feeds, even lower than some grass hays. Beet pulp should be soaked before feeding and rinsed until water runs clear.
• If a hay is higher than the desired NSC level or if it is unknown, soak hay for 30-60 minutes to remove some of the soluble sugars. Colder water will require a longer soak time. Discard the water before feeding.
2. How Much Hay Should You Feed Horses with IR or EMS?
Horses should be fed 1.5 to 2 percent of their body weight daily and no less than 1 percent of their body weight in long-stem forage. Although it may be tempting to drastically reduce hay to help facilitate weight loss, severely cutting back can actually worsen insulin resistance and result in serious health complications. Not having access to hay can also be stressful, and these horses should be managed with as low stress as possible as stress increases cortisol, which can increase insulin resistance. Consistently available hay is good for digestive well-being as well as keeping blood sugar levels even.
3. Is the Horse Overweight?
If the horse is overweight and needs to lose weight, they still must be fed no less than 1.5 percent of their body weight daily. Consider a slow feeder. With a slow feeder, the horse can still have free choice access to forage, it just slows them down and elongates the time it takes to go through the same amount of hay. Beta Lip-Ox®, which offers L-carnitine, can be a helpful supplement to facilitate weight loss.
4. Supplements That Support Metabolic Health
In addition to helping to support healthy levels of glucose and insulin, providing a balanced, comprehensive supplement like Platinum Performance® Equine can ensure the horse is receiving key micro-nutrients, including omega-3 fatty acids, vitamins, minerals and antioxidants. For advanced levels of magnesium citrate and chromium yeast, Platinum Metabolic Support can be fed in conjunction with Platinum Performance® Equine.
5. Pay Attention to Pasture
Horses that have access to pasture should graze with caution as sugar and starch levels can vary widely between seasons, months and even within the same day. The safest grazing time in terms of sugar and starch levels is the early morning hours when the night temperatures are above 40° F. Sugar and starch levels increase as the grass is exposed to sunlight with levels peaking in the late afternoon. The grass uses these carbohydrates as fuel for itself during the dark hours and by morning, the levels are at their lowest. Anything that stresses grass such as drought, overgrazing, very short mowing or cold weather will make the grass hold on to sugar and starch for self-preservation and thereby increasing NSC levels.
6. Avoid Grains, Concentrates and Treats
Cereal grains should not be fed to an insulin resistant horse. Cereal grains, such as oats, corn and barley, are high in starch, which breaks down to glucose and consequently elevates insulin. Many feeds that are advertised as low-starch or controlled starch may actually have a combined sugar and starch level in the teens or higher and may be unsuitable to feed to an insulin resistant horse. Refrain from giving treats, even healthy ones, until the horse is at a normal weight.
The Role of Therapeutic Nutrition
A healthy diet based on high-quality forage with low sugar and starch content is key to re-establishing and maintaining a healthy weight in horses. Beyond that, however, are certain therapeutic nutrients that can play a significant role in both preventing metabolic problems and also supporting horses who are experiencing poor metabolic control. Omega-3 fatty acids and antioxidants play a critical part in helping to keep systemic inflammation in check, helping to combat oxidative stress and feeding the body with healthy anti-inflammatory fats. Further, nutrients such as chromium — to support healthy glucose tolerance and normal blood sugar levels — and magnesium — crucial for the metabolism of carbohydrates, proteins and fats as well as the function of insulin — can be extremely beneficial for horses that are borderline IR or that have been diagnosed with EMS. In borderline IR horses or those with a genetic predisposition to having metabolic problems, Platinum Performance® Equine can be recommended to help maintain normal blood glucose and insulin levels, as well as to provide the antioxidants and omega-3 fatty acids necessary for a healthy level of managed inflammation. For some clinical cases, Platinum Metabolic Support is recommended, however, if medically required, Platinum Chromium Yeast or Platinum Magnesium Citrate can be provided independently. PPID cases that may require weight gain can benefit from Platinum Healthy Weight as a pure source of omega-3 rich flax oil infused with vitamin E. Platinum Hoof Support can also be an excellent tool when laminitis is a concern or has been diagnosed.
The combination of a healthy diet with therapeutic nutrients can produce tremendous results in horses with metabolic problems. “In some instances, the results have been profound,” says Dr. Scoggin. “I’ve seen middle-aged broodmares turn into ‘spring chickens’ when you get their weight and metabolic issues under control. They cycle better, breed better and carry their pregnancy better. They are thus more likely to produce a better foal, raise that foal and turn around and get in foal. Thus, metabolic management can have a ripple effect that can resonate through numerous breeding seasons and generations. All these considerations are particularly important in Thoroughbreds because we ask the mares to carry all of their own pregnancies and the stallions must breed each of these mares. In many instances, we are asking these horses to reproduce past their reproductive prime and into their twenties. Managing their metabolic issues early and often keeps these horses healthy and allows them to maintain a lengthy breeding career,” explains Dr. Scoggin.