Neck Circumference Measurement
The neck circumference is measured at ½ the distance between the poll and the withers with the neck held in a relaxed position. Height is measured from the ground to the withers. The neck circumference-to-height ratio can be used to determine neck crest adiposity. A horse may be considered to have a “cresty” neck with a ratio greater than 0.63 and greater than 0.68 in ponies.
Neck circumference (inches) ÷ Height at withers (inches) = Neck circumference to height ratio
Example: Neck length (poll to withers) = 36 inches, take neck circumference measurement at the half-way point between the poll and withers (at the 18 inch mark in this horse)
Neck circumference = 40 inches
Example: Neck circumference to height ratio = Neck circumference (40 inches) ÷ Height at withers (62 inches) = 0.64
Body Weight Measurement
A body weight estimate can be determined based on body length and girth measurements. The body length is measured from the point of the shoulder to the point of the buttock as shown below and the girth is measured immediately behind the slope of the withers. The following formula is used to estimate body weight based on these measurements.
Weight (in lbs) = [girth (inches) x girth (inches) x body length (inches)] ÷ 330
Example: Weight (in lbs) = [girth (76inches) x girth (76inches) x body length (67inches)] ÷ 330 = 1173 lbs
An estimate for determining whether or horse is overweight or obese can be determined by the girth to height ratio.
*A horse is considered OVERWEIGHT if girth divided by height is greater than 1.26, a pony is considered overweight if the number is greater than 1.33.
*A horse is considered OBESE if the number is greater than 1.29 and a pony is considered obese if the number is greater than 1.38.
Example: girth (76 inches) ÷ height (62 inches) = 1.23
*Reference: R.A Carter et al. The Veterinary Journal 179 (2009) 204-210.
*This project was supported by Agriculture and Food Research Initiative
competitive grant no. 2009-55205-05254 from the USDA National Institute of
Food and Agriculture Animal Genome Program.