The Equine Digestive Tract: Designed for Problems?

Section outline

• Select section Welcome!

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  Welcome!

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  Interestingly, the 3 F's of horse management - Freedom Friends and Forage can all have an impact on the horse's digestive system. This course will explain how these things can influence the health of your horse's digestive system.

  While the horse's teeth are an important part of this system, equine dentistry will not be covered in this course as it is such a large topic in its own right.

  • Select activity Course Handout

    

    Course Handout File
• Select section Introduction

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  Introduction

   I once had a client who's horse had been colicky three times in one week, frustrating for sure! On my third visit out to see her horse she exclaimed "horse's guts are just designed all wrong!" Of course that's not really true, we just have to manage it correctly.

   
• Select section Anatomy & Physiology

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  Anatomy & Physiology

   

     The hind gut of the horse acts as a large fermentation chamber which would not function without the resident bacterial population that lives there. Because fermentation occurs in the hind gut,  horses are referred to as hind gut fermenters.

  FUN FACT - In comparison, the rumen of cattle performs a similar function with bacteria fermenting much of the fibrous portion of their feed. Therefore cattle are considered fore gut fermenters as the rumen is the first chamber of the digestive system where food is received after passing through the esophagus from the mouth.

  • Select activity More important facts...

    

  • Select activity Carbohydrates form a large part of the horse's diet

    

  • Select activity Carbohydrate digestion

     

     

• Select section Health Problems Associated with the Digestive System

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  Health Problems Associated with the Digestive System

  Next we'll cover some of the common health problems horses face associated with their digestive system. The problems to be discussed are listed on the diagram below by the segment of the digestive tract where the problem originates. We'll start at the front and work our way to the back of the tract. 

  • Select activity Choke

    When a person experiences choke their airway has become obstructed. What we refer to as choke in horses involves their esophagus becoming obstructed typically with feed material. Because the horse can still breath when it is choking it isn't as immediate an emergency as it is in humans but should still be attended to as soon as possible. Many horses will continue to consume feed when they have just choked. This feed can overflow out of the esophagus and enter the airway with the potential for deadly consequences. If you suspect your horse is choking remove all feed, bedding and water until your vet arrives.

     

  • Select activity Gastric Ulcers

     

     

  • Select activity Impaction Colic

     

    Case of the Unexpected Impaction

    When I think of impactions colic in horses I am always reminded of a case I saw in my first year in veterinary practice....

    I received a call about a horse showing signs of colic. The owners brought the horse in to the clinic for me to examine. When I took the history on the horse there was nothing odd or unusual about it. The horse was a 4 year old gelding living with a small group of herdmates. They had free access to clean good quality water and were fed only a good quality hay (which had been tested) in several feedings per day. 

    Part of my examination included performing a rectal palpation of the digestive tract. It was immediately apparent that the horse's cecum was impacted and the manure I removed from the horse's rectum was quite dry,  coarse and looked like straw. The owners and I were confused by this. I asked the owners again about their hay so they brought in a sample of it. It was quite good looking but did have some coarser pieces in it. Ultimately what we determined was that because this gelding was the least dominant horse in the herd, he was not being allowed to eat until the more dominant horses had finished. They were leaving only the less desirable pieces of coarse stemmy hay for this gelding to eat. He was likely also eating some of the straw bedding the horses were provided in their shelter. This resulted in only this gelding getting an impaction. 

    It is interesting how behaviour and herd dynamics had such an impact on one horse's nutritional status!

  • Select activity Laminitis and other types of Colic

    Yes, laminitis is also the result of digestive tract issues!!

    A discussion about how other types of colic and laminitis occurs requires the understanding of how the horse's digestive system processes carbohydrates which we discussed earlier.

     

• Select section Calculating NSCs

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  Calculating NSCs

  The amount of NSCs your horse gets in its daily diet and per meal has a significant impact on your horse's health. Here's how to calculate how much of your current feed your horse can have per meal.

  We'll compare two commercially available feeds:

  
• Select section Conclusion

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  Conclusion

  While the equine digestive system does have several issues which can occur most of them can be prevented quite simply! A constant supply of quality forage and access to fresh water goes a long way to keeping the system functioning at its best.

   

   
• Select section References

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  References