Weight estimation in horses and ponies using a commercial Horse weight tape

Abstract

Introduction It is important for owners and vets to accurately estimate their equines weight in order to administer anthelminitics and antibiotics. Our hypothesis is: the Virbac PAVO Horse Weight Tape will be less accurate estimating the weight of ponies compared to horses.

Materials and methods 20 adult horses, mean age 10 yr (± SD 5), and 20 adult ponies 13 yr (± SD 6) of various breeds were included. The horses were divided into two groups based on height at the withers. The weight was estimated using the Horse Weight Tape followed by weighing on a weight bridge.

Results The mean weight of the horses and ponies was 566.45 kg (± SD 66.70) and 331.35 kg (± SD 153.07), respectively. In horses, the average deviation of the estimation using the Horse Weight Tape was 2. 77 % (± SD 2.46%) and the Pearson correlation between the estimate and the real weight was 0.955 (P<0.01), in ponies this was 8.41 % (± SD 10.93%) and 0.990 (P<0.01). We have calculated correction factors: for horses this is: real weight = 0.963 x estimated weight + 26.3. For ponies this is: real weight = 1.099 x estimated weight -36.47.

Conclusions The correlation for the ponies is higher, probably due to a higher SD of weight with less outliers, in contrast to our hypotheses. The results imply that the Horse Weight Tape is more accurate for horses than for ponies and can lead to under or over dosage of anthelminitics and antibiotics particularly in ponies.