Virbac is proud to announce that its leading range of horse wormers Equimax®, Equimax® LV and Strategy-T® are now available in doses large enough to treat all horses weighing up to 700kg.

Most wormers on the market in Australia only treat a horse up to 600kgs, some as little as 450kg. Most people underestimate weight by approximately 20%. This means that many horses may be unintentionally under-dosed with wormer simply because a more accurate weight estimation method has not been used.

(1) A recent survey of Australian horses was conducted with regards to their size and weight to get an accurate picture of the “average” Australian horse. This survey sampled many horses from different breeds and uses and produced some interesting findings. One thing that was very clear from the survey was that horses in Australia are generally heavier than it was thought. • 1 in 2 horses less than 14hh (ponies) were over 300kg (2) • 1 in 6 over 14.2hh were over 600kg

(2) • 1 in 2 horses over 16.1hh were over 600kg (2) It is interesting to note that this survey was conducted during drought conditions, and therefore the majority of horses were of average body condition. There was only one horse in the survey larger than 17 hands, so large animals were not actively sought.

Before dosing with a wormer horse need to have their weight accurately estimated using a set of scales, a weight tape or the weight estimating formula. It is important if using a weight tape to calibrate it first using the formula as some have been shown to be more accurate than others.

The formula is: Weight = Girth (cm)2 x Length 11877

This survey indicated that a significant proportion of horses will be underdosed if only one syringe of wormer is administered. Virbac has taken into account this evolution in bodyweight by modifying its syringes to accommodate the treatment of horses that weigh up to 700kgs in a single dose.

For more information on worming please contact Virbac on 1800 009 847.

1 Ellis, J.M. Hollands, T. 1998. Accuracy of the different methods of estimating the weight of horses. Veterinary Record 143 335-336 2 Results of national weight survey 2007 (data on file).