Evaluating Your Horse's Weight

By Juliet M. Getty, Ph.D.

Planning to medicate your horse? Deworm? Calculate feed? You absolutely need to know how much he or she weighs. But without a commercial scale, how do you do that? A weight tape provides an estimated weight, but for a closer approximation, Dr. Juliet Getty shares this handy formula for figuring your horse's weight using a tape measure:

  1. Measure heart girth in inches (circumference of the horse's body just behind the shoulder and at the middle of the withers, where the saddle girth would be)
  2. Measure length in inches - a straight line from the point of shoulder to the point of buttocks.
  3. Formula: Weight (in lbs) = (Girth X Girth X Length) divided by 330 (To obtain weight in kg, measure length and girth in cm. Use the above formula, except divide by 11,900, instead of 330.)

View diagram[i] on page 168 of Dr. Getty's comprehensive reference book, Feed Your Horse Like A Horse 

Weight is not the only important diagnostic tool to measure your horse's health. You'll want to consider his Henneke body condition score, too; a horse can be of normal weight and still develop regional fat deposits along the crest of the neck, back, shoulder, and tail head, indicating insulin resistance. Along with other useful information about a horse's "weighty matters," instructions for using the Henneke system are on page 173 of Feed Your Horse Like a Horse. You can also view a helpful demonstration in this Purina video at https://youtu.be/sXe1TxC5ukc .

Monitoring your horse's weight helps you know how well your weight loss plan is working. Keep in mind, however, that measurements tell you nothing about the source of weight loss. Your horse may be losing muscle instead of fat, especially if you are limiting his amount of forage intake. Conversely, horses fed forage free-choice will naturally produce more gas, creating a "hay belly;" the measurements will make it appear as though your horse is gaining weight, when in fact, it is gas that is causing abdominal distention. This is normal and healthy.

[i] Copyright Dr. Robin Peterson



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