Weight tapes have always entailed a tradeoff: They’re portable and easy to use, yet they aren’t especially accurate. But a study from Scotland shows that—used properly—a weight tape can be helpful for managing a horse’s condition and protecting his health.

University of Edinburgh researchers worked with a British feed company to investigate the utility of weight tapes, which are designed to be wrapped around the barrel to “measure” a horse’s heaviness in pounds or kilograms.

The study

The researchers reviewed the records from 1,716 horses seen by the feed company’s consultants over a two-year period. In addition to documenting each horse’s height, breed, type (heavy-, medium- or light-boned) and body condition score, the consultants took readings using both a weight tape and a portable livestock scale.

As expected, the researchers found weight tapes were far less precise than livestock scales. “For example, for every 0.5 increase in body condition score unit—using the 1 to 9 Henneke scoring system—the weight tape on average will add an extra 1.24 kilograms (2.7 pounds) to the reading in horses with the same actual bodyweight,” explains Katie Grimwood, MS. “Since we identified that the weight tape generally underestimates, it is possible that overweight horses (a body condition score of 6 and above) are perhaps more likely to have a more accurate reading.”

Interpretation and mathematics

At the same time, she says, “we found that the weights of heavy- and medium-boned horses were generally underestimated on the tape compared to those that are light-boned.” In other words, larger horses—draft types, for example—are likely to be heavier than a weight tape shows.

But, Grimwood says, these patterns are predictable enough to derive a reasonable approximation of weight with a tape. You’ll just need to do some additional math.

“Bigger or stockier breeds are more likely to be underestimated on the weight tape,” she explains.  “A crude way to adjust for this would be to add on an extra 5 to 10 percent after you have used your weight tape. It’s not ideal, of course, but it’s a start.”

A baseline

Even without additional calculations, weight tapes can provide vital information about a horse’s health.

“They are useful in identifying changes in your horse’s condition. You might not pick these up on when you see your horse every day,” Grimwood says. She advises owners to take a horse’s measurement every two weeks. Then those readings can serve as a baseline to detect subsequent weight loss or gain.

In fact, she says, “Once you have built up a year’s worth of weight-tape readings, you will have a profile of your horse’s potential seasonal weight loss and gain. That can help you prepare for the following year.”

If you have access to a livestock scale, a tape can be even more useful. “If the opportunity arises to accurately weigh your horse using a scale, we recommend that you take a reading from your weight tape at the same time,” says Grimwood. “This will then give you a better idea of the accuracy of your own tape. You can then continue monitoring gains and losses when a scale is not available.”

Reference: “Factors affecting weigh tape reading in the measurement of equine body weight,” Animals, April 2023.