How to Safely Refeed the Malnourished Horse

least the first ten days of refeeding the horse. A salt block can be offered free choice along with freechoice water. It is advisable to offer water in a bucket rather than automatic waterers initially to allow intake to be monitored.
When the horse is progressing satisfactorily on this regime for three to five days then it is safe to increase meal size and reduce the number of meals being fed. Horses that successfully make it to ten days on a feeding regime like this are at much less risk of developing refeeding syndrome. After ten days it is safe to introduce small amounts of low nonstructural carbohydrate NSC complete feeds again keeping the meal sizes very small. Any manufactured feeds introduced should complement the hay intake of the horse not replace it. Most horses who have been in a refeeding program for at least ten days can safely eat about onehalf a pound of commercial complete feed fed twice a day. This can be increased gradually as needed.
Once you get the horse past the risk of refeeding syndrome it may be advisable to consult with your veterinarian or an equine nutritionist about a more targeted plan for safe weight gain. If the malnourished horse is destined for performance or breeding you may want to have a better estimation as to how long the progression back to healthy body weight might take and the nutritional plan needed to achieve it.
Pasture can vary widely in quality and so be cautious in expecting a horse recovering from starvation to fend for himself in a pasture situation. Grazing should allow the horse to consume sufficient digestible energy from forage to assist in body weight gain. If he has to walk for three hours in order to find a small amount of grass you will have done him no favour by pasturing. The malnourished horse should not be put out in a group situation until he is strong enough to fend for himself against other possibly more aggressive horses. Limit grazing for the malnourished horse to two or three hours at the most initially and as with any horse be very careful of grazing when spring pastures are at their most productive.
Should Fat or Oil be Fed?
Although fat has about 2 25 times the calories of carbohydrates you should avoid feeding high fat feeds or oil for at least two weeks after initiating the refeeding
program. Fat is digested and absorbed in the small intestine of the horse and fat that escapes digestion in the foregut will negatively affect hind gut function. Severely malnourished horses can have problems digesting fat. Feeding high fat feeds too soon after initiating your refeeding program can reduce appetite. 
Remember that while oil provides calories to horses it does not provide protein which is one of the more important nutrients in a refeeding program for a malnourished horse. Protein is the nutrient that will help the horse rebuild muscle. If you are going to supplement fat for calories it is useful to consider feeding a high fat concentrate like flax rice bran or a high fat manufactured feed. Remember as well that if you are feeding the horse supplemental fat it MUST be fed in very small meals.  Keep the inclusion of ground flax or rice bran to no more than onehalf a cup per feeding with a maximum intake of not more than one or two cups per day depending on the progress of the horse. Feed manufactured high fat concentrates according to the manufacturers directions. If you are going to feed supplemental fat to the malnourished horse it may be wise to discuss it with a veterinarian or equine nutritionist first.