Question
I have a young Friesian gelding with delayed gastric emptying. He has access to pasture year-round for 4-8 hours daily, though the amount of grass depends on the season. He is given grass hay in the field during the winter and in his stall year-round. I feed him a vitamin/mineral supplement and additional vitamin E on top of that. My horse has a good appetite, but I feel this might not be the best diet for a horse with delayed gastric emptying. He seems tired, lying down more than he ever did. I’d like your thoughts on the best diet for him.
Answer
Horses of Friesian breeding are prone to delayed gastric emptying, known also as gastroparesis. The exact mechanism is yet to be completely understood, but it appears to have something to do with a breed-specific increase in collagen degradation that may affect stomach wall motility.*
Diagnosis of gastroparesis is difficult in mature horses. Repeated abdominal ultrasound, for example, might indicate a persistently enlarged stomach, and contrast radiography can be useful in certain cases, especially when dealing with ponies and small horses. Nuclear scintigraphy shows the most promise as a diagnostic tool given its accuracy, sensitivity, and ease of use. In most situations, gastroparesis is identified during exploratory gastroscopy when stomach contents are discovered after an appropriate period of fasting.
Because the problem occurs infrequently, little information is available about how to best nourish affected horses. Research has shown that one key to easing the passage of forage and feed is to reduce the particle size of feedstuffs introduced to the stomach.
Nourishing horses with gastroparesis may include or combine some of the following strategies:
- Reducing hay consumption by incorporating a mash of ground roughage sources with small particle size like hay pellets, soyhull pellets, and coconut meal;
- Feeding only hay with low neutral detergent fiber, such as soft, leafy hay that is not overmature;
- Feeding smaller, more frequent meals (4-6 meals per day);
- Offering a ration balancer, as research indicates that nutrient deficiencies are common with chronic or long-term gastroparesis;
- Removing feeds high in fat from the diet, as fat slows gastric emptying;
- Avoiding “sweet” or “textured” feeds; feed only pelleted or extruded feeds in which the particle size is small;
- Maximizing turnout to allow access to fresh grass, which has gut-stimulating effects and high moisture content; and
- Ensuring the horse’s teeth are in sound condition with no abnormalities that would prevent proper grinding.
If a horse with gastroparesis is colicking regularly or showing signs of discomfort after every meal, then the horse may require a significant change to its diet, such as switching him to an all-mash diet for a couple of months. The mash could include a mix of hay pellets and low-fat senior feed or any combination of the abovementioned small-particle roughages with a pelleted ration balancer. A sloppy mash should be served three or four times daily. No coarse hay should be offered, but access to green grass (not mature winter grazing) is acceptable. After two months, gradually introduce appropriate feedstuffs, such as orchardgrass with soft, leafy, fine-stemmed texture.
*Hewetson, M., and C.J. McGuire. 2022. Equine squamous gastric disease and delayed gastric emptying – the chicken or the egg? Equine Veterinary Education 34(9):460-466.
