This winter has been unusually cold in some areas, with temperatures well below freezing for many days in a row. This extreme cold weather can be particularly dangerous to animals that live outdoors. The Michigan State University Veterinary Teaching Hospital is reporting an increase in the number of animals presenting with starvation and problems related to exposure.

As temperatures continue to remain unusually cold it is also important to remember that your animals require more calories to maintain body temperature and body weight. Once an animal's body condition has deteriorated it might no longer be strong enough to eat enough food to survive. Remember, older animals with poor dentition (teeth) and young animals might require more feed, and might need to be fed separately from other horses to ensure adequate intake.

Points to remember

The average inactive horse needs to eat 1.5 to 2% of its body weight in food per day to just maintain weight without any other energy demands. In the winter, the amount needed will increase as the demand to keep warm will increase the amount of energy the horse expends. This means that the average 1,000 lb horse in good condition needs at least 20 lbs of hay during normal weather and might need as much as 35 to 40 lbs of hay and grain products during cold weather! If your horse is considered underweight the amount of feed should be calculated based on his ideal weight, not his current weight. While hay diets are ideal, certain animals will require grain, complete feeds, or fat supplements to maintain body weight.

Remember, during extremely cold weather, to provide extra (free choice) hay, as this will generate more energy and comfort than just increasing the grain (concentrate) portion of the diet. Just the physical aspect of moving and eating will make the horse more comfortable. The hay fermenting in the large intestinal tract will generate heat and finally, the horse will utilize the calories absorbed from the feed.

Separate young, old, or debilitated horses as the dominant horse will frequently eat most of the food provided resulting in some horses being healthy and others facing malnutrition.

Blankets and shelters will help decrease energy demands. However, remember that a blanket hides the body condition so it is important to place your hands under the blanket and remove it at least every week or so to assess body condition.

Old horses with poor dentition might require complete pelleted feeds that are easily broken down, as they might be unable to adequately chew hay. Determine the amount to feed based on the horse's ideal weight, and keep in mind that more will be needed if severe energy demands are present.

Water intake is also very important during the winter. Many horses will suffer from impaction colics due to inadequate water intake. Because they have sensitive teeth, older horses might require the water to not only be frost free, but warmed.

Body condition score

The body condition scoring (BCS) system is based on a 1 through 9 scale and is designed to assess a horses overall condition. Horses with a BCS less than a 4 are at increased risk of hypothermia and starvation, especially when the weather conditions cause an increase in energy demands just to maintain weight. If an individual is already thinner than desired (BCS < 4), they will not have adequate body mass (fat) to help with insulation from the cold or provide a supply of energy when the diet is lacking and demands are higher than expected.

To determine your horse's BCS you must touch your horse, especially in the winter as winter hair can hide a horse's true BCS, often until it is too late to successfully correct the weight loss. Feel over the ribs, neck, shoulder area, mid spine, hips, and tail head. If your horse's ribs over the widest part of the barrel are easily felt with little or no tissue between the skin and ribs, the BCS is below 4. This horse is suffering from malnutrition and is at a high risk of hypothermia when the temperature drops, particularly if the wind chill is high and little to no shelter is available.

For more information on body condition and feeding horses during the winter, please contact your veterinarian.

Article courtesy Judy Marteniuk, DVM, MS, equine extension veterinarian, and Elizabeth Carr, DVM, PhD, Dipl. ACVIM, ACVECC, equine clinican, Veterinary Teaching Hospital, College of Veterinary Medicine, Michigan State UniversityDuring the winter it is imperative that you monitor your horses' body weight by putting your hand on them frequently! Furry coats make visual assessment of body condition impossible--the only way you can assess your animals' condition is by touch.