The nutritional requirements of horses after colic surgery or other gastrointestinal illnesses have not been determined. Primary considerations include requirements for energy (calories) and protein. In most situations, the energy requirement for a healthy adult horse at a maintenance level of activity can be met if the horse consumes between 1.5% and 2.5% of its BW per day as hay. However, the energy needs of hospitalized horses are probably much lower because of reduced energy expenditure. When energy supply from carbohydrate and fat is limited, muscle protein will be used for energy contributing to a loss of lean body mass. Therefore, in developing a nutritional plan, first ensure that minimal energy needs are being met and then ensure the protein requirements are being met.
Horses with simple colic (i.e., no specific diagnosis) rarely need special dietary management. Feed and water should be withheld during the colic episode, with resumption of normal feeding after the colic signs have resided. An evaluation of diet may be indicated when there is suspicion that diet or feeding practice contributed to the episode of colic. Some recommend the withholding of grain feedings for a few days to limit gas production in the hindgut. Horses recovering from intestinal surgery can resume feeding when there is clinical evidence of intestinal motility.
Initially, the horse should be fed small amounts (500g) of good quality forage (e.g., grass hay, Lucerne) four to six times daily with a gradual increase in the volume of feedings over the following days providing the horse tolerates the increase in feeding. Alternatively, the horse may be allowed to graze pasture for 20–30 min several times throughout the day or be provided a highly digestible, low-bulk, pelleted feed such senior feeds. Grains should be avoided for at least 10–14 days post-surgery (or colic) because of concern that an excess of starch may disrupt an already disrupted hindgut microbial community.
Small Intestinal Disorders
Disorders of intestinal motility are of primary concern after small intestinal surgery. Fresh grass (hand grazing) and mashes or slurries made from Lucerne pellets or pelleted complete feeds are suitable feedstuffs. Molasses may be added to the mash or slurry to enhance palatability of the ration. Small meals (500g) should be fed every 3–4 h, again in an effort to minimize physical stress at the surgery site. In uncomplicated cases there should be a gradual introduction to long-stem hay after 3–4 days of soft diet feeding. Bran mashes are not recommended for horses during the early phases of recovery from small intestinal surgery because of the adverse effects of high bulk feeds on the healing of incision sites.
Large Intestinal Disorders
Horses with impaction of the large intestine should not be fed until after resolution of the impaction. Fresh grass, Lucerne pellets, chopped Lucerne hay, and other sources of highly digestible fiber are preferred. Diarrhea is a complication of all types of colic surgery, but the risk seems to be highest in horses undergoing surgery for large intestinal disorders. Horses fed grass hay were one half as likely to develop severe diarrhea as horses not fed grass hay. Horses should be fed small amounts of grass or soft grass hay at frequent intervals (every 2–3 h) as early as 12 h post-surgery providing there is no evidence of complications. First cut hay is preferred because of higher dry matter digestibility compared with more mature forages. No grain or concentrate should be introduced until 10–14 days post-surgery. However, the feeding of a low bulk pelleted feed may be beneficial during this period. If additional calories are needed for weight maintenance, a “fat and fiber” concentrate rather than grain or sweet feed is recommended. After your horse has been treated for colic, it is important to monitor signs carefully. Note attitude, water intake, passage of manure (consistency and amount) and gas, urination, gut sounds, gum color (pink is normal), hydration (check gum moisture and skin pinch on point of shoulder), and temperature (less than 38 degrees C). Look for any signs of discomfort such as pawing at the ground, looking or kicking at the belly, a distended or tucked-up abdomen, lying down frequently or rolling.
Most horses drink 30-38 litres of water per day during the summer and 22-30 litres during the winter. Horses that colic usually have a reduced water intake that may last several days. Cool, clean water should be provided for your horse – if the horse does not drink, try providing a bucket of flavored water in addition to the bucket of fresh water. You can flavor a five gallon bucket with 2 tablespoons salt and either 1/8 cup of molasses, 1 can frozen apple juice concentrate, 1 can of carrot juice or 1 can of gatorade.
Geor, R.J. 2007. How to Feed Horses Recovering from Colic. AAEP Proceedings. Pp 196.