Feeding the special needs horse: Let’s talk about metabolic horses
There is an increasing prevalence in the occurrence of metabolic diseases in horses, and so the science and research world has spent quite a bit of time working to learn more about these diseases and how to manage, treat and prevent them.
Metabolic disease is a simple term used to indicate a disturbance in normal chemical processes in the body that are necessary for survival.
So, what are the most common metabolic diseases? The most common ones we think of are EMS, PPID (Equine Cushing’s) and then perhaps also PSSM, but we’ll talk about PSSM last.
The consequences of this metabolic disturbance can vary depending on which process is disturbed, but any metabolic disturbance usually has a ripple effect throughout the body. This can lead to a variety of other issues throughout the body. So when you have a horse with metabolic problems its important to not just treat the obvious symptoms but also think about other underlying issues that might be occurring. The only solution for metabolic diseases is to take away the cause so that metabolism can normalize on all the different levels
What’s the difference between the terms ID and IR?
There are two terms used to describe metabolic diseases in horses: Insulin Dysregulation and Insulin Resistance. While these two terms are often used interchangeably, they actually do not mean the same thing.
Insulin Dysregulation (ID) is a collective term for abnormalities in insulin metabolism and function, which include irregularities in insulin biosynthesis, release and/or clearance, as well as alterations in insulin action. Because of these abnormalities, the most typical symptom in horses is hyperinsulinemia (this means excess levels of insulin circulating in the blood relative to the level of glucose).
As insulin function can be affected at several different levels, Insulin Resistance (IR) specifically refers to a decreased sensitivity of tissues to insulin stimulation. So based on that, think of ID as a more general umbrella term to describe a wide variety of conditions associated with abnormal insulin metabolism.
Another disease: PSSM
Another condition that is commonly categorized as a “metabolic disease” is Polysaccharide Storage Myopathy (PSSM), which is actually a muscle disease. It is often spoken of in the same category as metabolic diseases because the PSSM horse also has issues with insulin, but in contrast to the EMS horse, the PSSM horses is extremely sensitive to insulin.
In the coming weeks we will dive deeper into each disease, and more specifically, what factors you need to pay attention to when making feeding decisions for these horses.