Refeeding the Malnourished Horse

(Kelly R. Vineyard, M.S., Ph.D., Equine Nutritionist - Purina Animal Nutrition)
 

Starved horses can be a product of owner ignorance or economic hardship. Regardless of the reason, a horse may end up in a debilitated state. The goal for the new caretaker is to help the horse return to good health and appropriate body weight as quickly and safely as possible. For responsible caretakers of a starved horse, there are two immediate considerations:

 
• The first step, and the most important one, is to have an equine veterinarian perform a complete physical exam. 

 
• Following the exam, lay out a plan to begin providing the horse with an appropriate diet to facilitate weight gain while avoiding the potential complications that can occur when reintroducing feed to a chronically starved horse.
 
Good veterinary care combined with proper nutrition can successfully bring malnourished horses back to good health, giving them the opportunity to enjoy the promising and productive future they deserve. Though rehabilitation of the malnourished horse may take as little as three months or as long as 10 months or more, depending on the horse’s initial condition, taking a slow and steady approach to refeeding will minimize the occurrence of potential secondary complications.
 
Developing a Refeeding Plan
 
In general, a slow and steady approach should be taken when refeeding the malnourished and debilitated horse. This will avoid overwhelming a digestive and metabolic system that has been greatly impaired by starvation. This is where consulting your veterinarian is very important. He or she can help:
 
• develop a nutritional program,
 
• perform a full physical examination,
 
• check for underlying conditions or diseases, and
 
• assess liver, kidney and gastrointestinal function to identify proper medical treatment.
 
Remember, prior to consulting with your veterinarian, it is important to record initial body weight and take photographs of the horse to document its current condition.
 
Remember Rehydration
 
Because many severely neglected horses may also be dehydrated, treatment should begin, if appropriate, with rehydration; specifically:
 
• If the horse is severely dehydrated but willing and able to drink, offer 2 to 4 liters of diluted salt water (0.5 – 1% NaCl) every 30 minutes until thirst has been abated. This will prevent hyponatremia, a condition that would discourage further voluntary drinking. 
 
• Once the horse has satisfied its thirst, free-choice water can safely be offered. 
 
• If the horse will not drink voluntarily, parenteral or enteral administration of fluids may be necessary in the most severe cases.
 
Refeeding Protocol — The First 10 Days
 
The first 10 days of refeeding are the most important in rehabilitating a severely starved horse, and several approaches need to be considered right away.
 
• For the average 1,100-pound horse, approximately 1.3 pounds of leafy alfalfa should be offered every four hours for the first three days of refeeding. 
 
• Free-choice access to water should be provided at all times. 
 
• The amount of alfalfa can be slowly increased while the number of feedings is decreased from day 4 to day 6, so that by day 6, a total of 16.5 pounds of hay is being offered, divided into three meals per day at eight-hour intervals.
 
After 10 days, the horse should be re-evaluated to determine if weight gain has been established. If the horse has positively responded to the 10-day refeeding protocol, twice-daily feedings can be instituted and free-choice access to alfalfa hay may be allowed. 
 
At this point, concentrates can be slowly introduced, and deworming and correction of dental problems can be addressed. If the horse remains in a guarded state, then continue to provide three meals a day of alfalfa hay until the horse becomes stabilized.
 
Potential Complications — Refeeding Syndrome
 
The first 10 days of refeeding a horse also represent a period where health problems can arise. One potentially fatal result of immediate rehabilitation is refeeding syndrome — a potential complication that everyone refeeding a starved horse should be aware of.  It typically occurs within the first week following the reintroduction of feed in severely underweight horses with a body condition score of less than 3. Refeeding syndrome can fatally affect the heart, kidneys and respiratory system.
 
Horses should be monitored closely for the first 10 days of refeeding for signs of refeeding syndrome. Potential signs include:
 
• Increased muscle weakness
 
• Neurologic dysfunction
 
• Irritability
 
• Aggression
 
If any of these symptoms are observed, a veterinarian should be consulted immediately so that electrolyte imbalance can be corrected through fluid therapy.
 
Potential Refeeding Complications
 
Sometimes a horse may be in such a bad state that it cannot properly chew or ingest the food necessary for rehabilitation. In these cases, there are a few methods to entice feeding.
 
• If a horse is unable to properly chew alfalfa hay due to tooth problems, then alfalfa cubes or pellets soaked in water (on an equal weight basis) may be substituted for alfalfa hay during the initial refeeding period. 
 
• If the horse refuses alfalfa hay products completely, then substituting other types of hay or soaked non-molassed beet pulp along with small amounts of Purina® Equine Senior® may entice the horse to consume more feed. It can be a challenge to encourage the inappetent, malnourished horse to eat feeds with a low glycemic index, but it is important to experiment until the right combination is found for that particular horse. 
 
• In severe cases of inappetence, the provision of enteral nutritional support, such as Purina® WellSolve® Well-Gel®, may be called for. 
 
Long-term Feeding Plan
 
Once the initial refeeding period has proven successful, a long-term plan may be put into place. The refeeding protocol should be dictated by the digestible energy (DE) requirement of the horse and the amount of weight that needs to be gained. When introducing concentrate feeds, start by feeding very small amounts in multiple meals per day. Increase the daily quantity of concentrate feed very slowly, by no more than a total of 0.5 – 1 lb per day, until you reach the desired feeding level. Table 1 shows the daily DE requirements for mature horses at different levels of metabolism. 
 
For the DE requirements of growing, pregnant or lactating horses, the 2007 NRC should be consulted. It takes approximately 9 megacalories (Mcal) DE above the horse’s maintenance requirement to induce 1 pound of weight gain, and approximately 35 to 44 pounds of gain are required for an increase of one body condition score (BCS). 
 
For example, if a 1,200-pound horse (ideal body weight) is currently a 3 BCS with a desired BCS of 5.5, then 110 pounds of gain would be required over a 110-day period at a desired rate of gain of 1 pound/day. Therefore, the horse must be fed a ration that provides 9 Mcal/day above the daily maintenance requirement (a total of 27.1 Mcal/day) for 110 days to gain 110 pounds and increase from a 3 BCS to a 5.5 BCS.
 
Table 1. Daily maintenance DE requirements of mature horses (NRC 2007)*
 
Desired bodyweight(lbs.)      Minimum (Mcal)     Average (Mcal)     Elevated (Mcal)
 
800                                               11.0                          12.0                     13.2
 
1,000                                            13.8                           15.1                    16.5
 
1,200                                            16.6                           18.1                    19.8
 
1,400                                            19.3                           21.1                     23.1
 
*Minimum maintenance applies to sedentary horses due to confinement or limited voluntary activity, average refers to alert horses with moderate voluntary activity, and elevated applies to nervous horses or those with high levels of voluntary activity.
 
Once the target daily DE intake has been established, deciding which feeds to provide that requirement depends on several factors. 
 
• The use of high-quality forages should be maximized whenever possible, but pasture should be introduced slowly and conservatively, similar to the way a native horse would be introduced to lush spring pasture. 
 
• For horses with suspected digestive problems due to old age or as a consequence of starvation, feeding a highly digestible and well-fortified complete feed such as Purina® Equine Senior® will facilitate digestion and absorption, and maximize the horse’s ability to extract nutrients from the feed. 
 
• If no underlying renal or liver dysfunction is present, calorie-dense, fat-added concentrates can also be used to meet daily DE requirements. Depending on the horse’s preference and the current forage program, Purina® Strategy®, Omolene
 
#500® and Ultium® Competition or Growth formulas are highly fortified fat-added feeds that may be utilized, in addition to Amplify® high-fat supplement. When introducing any horse to a fat-added diet, the inclusion of a fat-added feed or supplement should begin slowly to allow for adequate adaptation. If refeeding a young growing horse, a conservative approach should be taken when bringing the youngster back to a full ration to prevent the occurrence of developmental orthopedic disease that can sometimes be induced by a compensatory growth spurt. Strategy®, Omolene #300® and Ultium® Growth are all appropriate feeds to rehabilitate the growing horse. 
 
Conclusion
 
There is still much to learn about the physiology and feeding management of the starved horse; however, taking a slow and steady approach to refeeding will minimize the occurrence of potential secondary complications. 
 
It is also important to remember that rehabilitation of a malnourished horse will vary and largely depends on the horse’s initial condition. Fortunately, good veterinary care combined with a proper nutritional approach, as outlined above, can successfully return a malnourished horse to good health.