ew research suggests that a simple weigh tape could provide horse owners with a more accurate and consistent estimate of their horse’s body weight than a commonly used measurement formula when access to weighing scales is not available.
Accurately knowing a horse’s weight is important for a range of everyday management decisions, from calculating feed requirements to administering medication and monitoring changes in body condition.
However, access to calibrated weighing scales is not always practical, meaning many owners and professionals rely on indirect methods such as weigh tapes, measurement formulas or simply estimating weight visually.
A new study compared a commercial weigh tape and the Carroll and Huntington morphometric formula against measurements taken using a calibrated digital scale.
Researchers monitored six healthy adult crossbred horses every week for 63 days. During the study, the horses gained an average of 17.2kg, allowing the researchers to assess not only how accurately each method estimated weight, but also how effectively it tracked changes over time.
Weigh tape came closest
Both indirect methods tended to overestimate the horses’ actual body weight, but the weigh tape performed considerably better.
On average, the weigh tape overestimated weight by 2.48%, compared with 9.89% for the formula. The weigh tape also showed a stronger correlation with measurements from the digital scales and demonstrated lower variability during the study.
Errors associated with the formula remained between 37.2kg and 45.6kg, while the minimum error recorded for the weigh tape reduced from 8.33kg at the start of the study to 5.66kg by day 63.
The researchers concluded that although both methods produced estimates within what they considered clinically acceptable limits, the commercial weigh tape offered greater accuracy, lower variability and better consistency when monitoring horses over time.
They suggest that when weighing scales are unavailable, a weigh tape should therefore be considered the preferred of the two methods assessed.
Consistency still matters
The researchers also highlight the importance of standardising how measurements are taken. The accuracy of weigh tapes can be affected by factors including tape positioning, breed, body condition, age and reproductive status.
The study was small, involving just six horses under controlled conditions, so the findings should not be assumed to apply equally to every horse or pony. However, they provide useful evidence that regularly using a weigh tape in a consistent way may be a practical option for owners wanting to monitor changes in their horse’s weight when scales are not readily available.
