Updated: Mar 15, 2021
Written by Kent Wollert
Is there such a thing as too much protein in a horse's diet? I have always been told that too much protein would cause colic, tying up, laminitis or make a horse "hot". Are these conditions with our horses truly a result of too much protein? I do not believe so. The root cause for these conditions is not protein, it is high levels of starch and sugars in the horse's diet. All starches convert to sugars through the digestion process and this is the root cause of the adverse conditions! Any extra protein that a horse consumes is passed through the system via their urine.
Unlike extra protein, excess starch and sugar that does not get digested in the small intestine is then passed to the large intestine where it ferments at a quicker rate. This in turn will cause a rise in lactic acid and lower the pH balance in the gut. These changes to the level of lactic acid and the pH balance of the horse's gut are contributing factors to tying up and can induce colic in the horse. Too much lactic acid causes cramping and the tying up condition that some horses will experience when they are not active enough to burn through the excess levels of lactic acid. This too is why it is a good idea to cool your horse down after high levels of exercise. This practice will help dissipate lactic acid that can build up during intense levels of activity.
When we look at the body condition of our horses and decide it is inadequate, most have always turned to grains for increasing body cover for the horse. But grains are not always the answer to correcting the poor body condition of the horse. If a horse has visible withers and hip bones are showing, this could be more a lack of muscling rather than fat cover. So, the answer may be a higher level of protein in the horse's diet to rectify the condition through increased muscle mass. One can also evaluate the lack of protein through hoof and coat condition. If a horse's hooves are not growing out and are in poor condition, this could be a result of low protein levels in the horse. This also holds true if the horse is showing poor coat quality.
In conclusion, a horse owner needs to evaluate the starch and sugar levels of the horse's diet when laminitis, colic, tying up or increased excitability are a problem rather than protein levels. More than likely the root cause of the issue is related to starch and sugars since excess protein is released through the horse's urine and not contained within the animal. A horse cannot be given too much protein but it definitely can be provided at inadequate levels. Don't be concerned with too much protein in the diet.