What happens during starvation?
A normal horse uses stored fats and carbohydrates for energy, exercise and all normal body functions. These fats and carbohydrates
are constantly replenished through adequate dietary intake. Starvation interrupts the replenishment of body stores so the
horse initially uses all stored and available fats and carbohydrates. If starvation is halted at this point, a thin horse
will generally recover fully, once given access to feed.
Horses that are chronically starved, however, will begin to use protein when fats and carbohydrates are used up. A starving
body cannot select which tissue protein will be metabolized for energy; "consequently, the starved body uses protein, not
only from skeletal muscle, but also from vital tissues such as the heart and gastrointestinal tissues," Stull explains.
As time passes, the horse's condition becomes more precarious. "When it loses more than 50 percent of its body weight, the
prognosis for survival is extremely poor," according to Stull.
Re-feeding starved animals requires that caretakers refrain from killing them with kindness.
The natural first reaction is to want to give it access to good, rich food and to allow it to "eat itself back to health."
But nothing could be worse. Feeding concentrated calories to a starving horse likely will result in "Re-feeding Syndrome"
and death in three to five days.
Such high-caloric feeding causes a rise in insulin, Stull and other nutritionists explain. The insulin peak encourages the
storage of carbohydrates into cells for future use, but also causes magnesium, calcium, potassium and phosphorous to be drawn
into cells. The intracellular distribution of these electrolytes can have serious consequences because in starved individuals
electrolytes have been depleted, so that they barely have enough for normal function.
When potassium, magnesium and phosphorus become depleted in the general circulation, a cascade of events can occur, leading
to kidney failure, respiratory failure, cardiac collapse and death.
The problems starved horses face are similar to those of performance horses suffering from "exhausted horse syndrome" due
to a loss of electrolytes incurred during maximal exercise, usually in hot weather.
Hypokalemia can result in weak muscles and neurologic dysfunction. Poor heart-muscle function, seizures and coma also can
occur. Hypomagnesaemia can produce nervous, irritable or aggressive horses, and hypophosphatemia can result in hemolytic anemia.
Simple diet recommended
Because of the importance of reducing insulin elevation while re-feeding and because of the extreme sensitivity of starved
horses to concentrations of potassium, magnesium and phosphorus, the best diet to use is surprisingly one of the simplest.
"The best approach to re-feeding a starved horse is to give frequent (every 4 hours) meals of high-quality alfalfa hay," Stull
One pound or about one-sixth of a flake at each meal will provide a good source of protein to begin rebuilding the body. Because
alfalfa is high in calcium, magnesium and phosphorus, it helps provide electrolytes that reduce the risk for catastrophic
This diet should be maintained for 10 days, though the amount of alfalfa can be increased (up to four pounds) and the number
of feedings decreased (to three) for Days 4 through 10.
After 10 days the horse can be fed as much alfalfa as it will eat in two feedings, and it should be allowed access to a salt
or electrolyte mix. Feeding grain or other supplements should be avoided until the horse is well on its way to recovery, which
can take 60 to 90 days.
Full return to normal body weight may require three to five months. Caretakers are urged to be patient and to go slowly because
overly aggressive feeding and the introduction of calories too early will worsen the prognosis for recovery.
Even with the best of situations and attention to proper diet, the odds often are not in favor of severely starved horses.
Researchers in the Veterinary Services and Animal Industry branches of the Manitoba Agriculture, Food and Rural Initiatives
report that "about 20 percent of severely malnourished horses can be expected to die in spite of attempts at re-feeding."
In an article titled, "Chronically starved horses: predicting survival, economic and ethical considerations," these researchers
looked at the case of 45 chronically starved horses that were impounded under the Manitoba Animal Care Act, evaluated and
rehabilitated and then sold at auction.
Detailed records of the cost of this action included transport, carcass disposal and use of a dedicated rehabilitation paddock,
feeding, medication and antiparasite medication.
Costs were not even closely covered by the eventual sale of the surviving horses, the researchers say. While sensitive to
the differing value placed on horses as opposed to other large-animal species, the researchers debate the ethics of managing
severely starved and at-risk horses. They question whether early euthanasia may be a more reasonable option for some starved
horses, given the difficulty in rehabilitation, time required and the cost to rescue organizations.
"Future policy direction," they write, may require a balance between fiscally responsible management of welfare cases
and what is considered acceptable to the public at large."
Prevention of starvation cases is the best solution, and education is the key to prevention.
Veterinarians are encouraged to accept their role in owner education, providing nutritional and management consultation when
possible. When faced with re-feeding a starved horse, veterinarians are reminded to take a long-term approach and be aware
of the specific requirements and needs of these unique animals.
Marcella is an equine practitioner in Canton, Ga.