How to estimate the weight of your horse to dose correctly
Working out the correct dose for worming horses is done by calculating the horse's weight. It is very important that you try to ascertain the correct weight as incorrect weight estimation may result in over-dosing or under-dosing. Under dosing has recently been highlighted as one of the major factors in resistance being built up to certain active ingredients used in equine wormers. Over-dosing may cause toxicity and colic or other serious complications.
Determining a Horse's Weight
Weigh Scale
Using a weigh scale is the most accurate way to determine a horse's weight. If practical, weigh the horse under the same conditions to reduce misleading fluctuations in the readings. Public weighbridges are available but their location is most likely unsuitable for loading and unloading horses. Using a specific equine weigh bridge is the best course of action which perhaps could be organized by feed suppliers who will undertake yard visits.
Weigh Tape
Using a weigh tape allows you to estimate the weight of your horse or pony either
by
1. Using a simple length measurement.
2. Using a formula to calculate your horse's weight.
Position the weigh tape around your horse; it should lay obliquely from just behind his/her elbows to over the lowest point of his/her withers. Lightly tighten the weigh tape around the horse and read the weight from where the green, free end of the weigh tape finishes. Wrap the tape around the girth of the horse directly behind the elbow, overlapping the ends of the tape and read the resultant weight. Take the reading with the tape snugly in place, once the horse has exhaled.
Tape accuracy is dependent on the user, size of the withers, breed and age. Tapes are not effective on miniature horses and foals. Regular use of the weigh tape will help you keep your horse or pony at the correct weight
An alternative method to calculate a horse's weight is the following formula, which may produce a slightly more accurate measurement than using a weigh tape.
| Adult horses:
(girth measurement in cm) x (girth measurement in cm) x (length measurement in cm) ÷ 11800 = weight in kgs |