The Overweight Horse

Special Care and Nutrition

Feeding is one of the most rewarding chores of horse ownership. But many horses, given the opportunity, will eat far more than they need, tipping the scale into an unhealthy balance. No matter how much your horse enjoys eating, you do it a disservice by overfeeding. Excess pounds put a strain on virtually every body system. A far kinder strategy is to supply food and exercise in proper amounts to keep your horse fit and healthy.

Maintaining the ideal weight is not always easy however. Some horses are what we call “easy keepers.” They require minimal calories to maintain optimal body condition. Ponies, in particular, seem to store excess energy as fat. Many adult horses too — especially those in their middle years — begin to retain unneeded weight due to reduced activity and a slow-down in metabolism. When weight gain becomes extreme, we classify the horse as obese.

HAZARDS OF OBESITY Excess weight and over-nutrition have a number of potentially negative effects, including:

  • Increased stress on the heart and lungs
  • Greater risk of laminitis or founder
  •  Increased risk of developmental orthopedic (bone and joint) problems in young, growing horses
  • More strain on feet, joints and limbs
  •  Worsened symptoms of arthritis
  •  Less efficient cooling of body temperatures
  •  Fat build-up around key organs which interferes with normal function
  •  Reduced reproductive efficiency
  •  Greater lethargy and more easily fatigued

EVALUATING BODY CONDITION When it comes to a horse’s ideal body condition, beauty is often in the eye of the beholder. For example, a competitive endurance horse is usually leaner than a show-fit halter horse.

Because “fitness” is subjective, equine health care professionals utilize a “Body Condition Scoring” system to talk in relative terms. The horse’s physical condition is rated on visual appraisal and palpation (feel) of six key conformation points: (See illustration) A—the amount of flesh or fat covering along the neck, B—The withers, C—down the crease of the back, D—at the tailhead, E—ribs, F—and behind the shoulder at the girth. Scores range from 1-9, from poor to extremely fat.

CONDITION SCORES Score of 1—Poor: Animal extremely emaciated; spinous processes, ribs, tailhead, tuber coxae (hip joints), and ischia (lower pelvic bones) projecting prominently; bone structure of withers, shoulders, and neck easily noticeable; no fatty tissue can be felt.

Score of 2—Very Thin: Animal emaciated; slight fat covering over base of spinous processes; transverse processes of lumbar vertebrae feel rounded; spinous processes, ribs, tailhead. tuber coxae (hip joints) and ischia (lower pelvic bones) prominent; withers, shoulders, and neck structure family discernible

Score of 3—Thin: Fat buildup about halfway on spinous processes; transverse processes cannot be felt; slight fat cover over ribs; spinous processes and ribs easily discernable; tailhead prominent, bat individual vertebrae cannot be identified visually; tuber coxae (hip pints) appear rounded but easily discernable; tuber ischia (lower pelvic bones) not distinguishable; withers, shoulders and neck accentuated.

Score of 4—Moderately Thin: Slight ridge along back; faint outline of ribs discernible; tailhead prominence depends on conformation, fat can be felt around it; tuber coxae (hip joints) not discernible; withers, shoulders, and neck not obviously thin.

Score of 5—Moderate: Back is flat; ribs not visually distinguishable bat easily felt; fat around tailhead beginning to feel spongy; withers appear rounded over spinous processes; shoulders and neck blend smoothly into body.

Score of 6—Moderately Fleshy May have slight crease down back; fat over ribs spongy; fat around tailhead soft; fat beginning to be deposited along side of withers, behind shoulders, and along sides of neck.

Score of 7—Fleshy May have crease down back; individual ribs can be felt, but noticeable filling between ribs with fat; fat around tailhead soft; fat deposited along withers behind shoulders, and along neck.

Score of 8—Fat Crease down back; difficult to feel ribs; fat around tailhead very soft; area along withers filled with fat; area behind shoulder filled with fat; noticeable thickening of neck; fat deposited along inner thighs.

Score of 9—Extremely Fat Obvious crease down back; patchy fat appearing over ribs; bulging fat around tailhead, along withers, behind shoulders, and along neck; fat along inner thighs may rob together; flank filled with fat.

WHAT’S IDEAL? For most horses, body condition scores in the Moderate to Moderately Fleshy range, (scores of 5 and 6) are ideal. However, keep in mind that the job of your particular athlete also has a bearing on what weight is appropriate for maximum performance. Polo, race and endurance horses might be perfectly fit with body condition scores of 4 (moderately thin), while a body condition score of 7 (fleshy) may be required for success in the show ring. However, by feeding a horse to a level of 8. you are staffing to push the limits of good health. Horses with scores of 8 and 9 are definite candidates for a weight reduction plan.

WEIGHT REDUCTION You hold the keys to controlling your horse’s weight. You’ll need to enforce sound nutrition management, become dedicated to a regular exercise program, and use restraint when measuring the ration.

When implementing a weight loss program, it’s important to do it in such a way so as not to stress the horse. Changes in both exercise and nutrition should be gradual.

By increasing the amount of exercise, you can rev-up the horse’s metabolic engine and burn more calories. By shifting to a lower-calorie diet, you can create an “energy deficit” so that the horse begins to utilize its fat reserves as fuel. However, even though the ration provides fewer calories, it should be balanced so that it continues to provide all the essential nutrients. Develop a program that will allow your horse to reduce its weight without any negative side effects.

Here are some guidelines to get you started:

  •  Be patient. Weight reduction should be a slow, steady process so as not to stress the horse or create metabolic upsets.
  •  Make changes in both the type and amount of feed gradually Reduce rations by no more than 10% over a 7 to 10 day period.
  •  Track your horse’s progress by using a weight tape. The tapes are remarkably accurate and provide a good way to gauge weight loss. When the horse ’s weight plateaus, gradually cut back its ration again.
  •  Step up the horse’s exercise regimen. Gradually build time and intensity as the horse’s fitness improves. Some horses are natural pasture potatoes. Ride, long, drive or work the horse on a treadmill rather than rely on free choice exercise.
  •  Provide plenty of clean, fresh water so the horse’s digestive and other systems function as efficiently as possible and rid the body of metabolic and other wastes.
  •  Select feeds that provide plenty of high quality fiber but are low in total energy. Measure feeds by weight rather than by volume to determine appropriate rations.
  •  Select feeds that are lower in fat since fat is an energy-dense nutrient source.
  •  Switch or reduce the amount of alfalfa hay fed. Replace with a mature grass or oat hay to reduce caloric intake. This will also satisfy the horse’s need to chew, reduce boredom, and provide fill for its stomach.
  •  Feed separate from other horses so the overweight horse doesn’t have a chance to eat his portion and his neighbor’s too. In extreme cases of obesity, caloric intake may also need to be controlled by limiting pasture intake.
  •  Balance the horse’s diet based on age and activity level. Make sure the horse’s vitamin, mineral and protein requirements continue to be met. A supplement may be added to the ration to compensate for lower quality, less nutrient dense feeds.

HELP FOR HAY BELLIES A “hay belly” may or may not be associated with true obesity. Many horses, especially the very young and old, may exhibit hay bellies without an associated build-up of body fat. Hay bellies are a distention of the abdominal area due to the volume of grass or hay the animal consumes. The belly expands to handle the load.

To eliminate a hay belly, you need to reduce the total volume of feed that passes through the system. A well-balanced complete feed may be a good way to reduce total volume without adversely affecting the amount of fiber and nutrients required for proper digestion and nutrition.

MAINTAINING PROPER WEIGHT Once your horse has reached his ideal body condition, maintaining the proper weight is a gentle balancing act. You will probably need to readjust your horse’s ration to stabilize its weight. Exercise will continue to be a key component in keeping the horse fit. Because obesity can effect a horse’s health, keep a good line of communication open with your veterinarian. Schedule regular check-ups, especially during the weight reduction process.

This brochure was developed by the American Association of Equine Practitioners through a grant from the following Educational Partners.

Bayer Corporation, Agriculture Division Animal Health, Shawnee Mission, Kansas 66201 © 1996 Bayer Corporation

Purina Mills, Inc., Horse Business Group 1401 S. Hanley, St. Louis MO 63144 © 1996 Purina Mills, Inc.