Working out your horse's weight

Why do you need to know the weight of your horse in the first place?

Accurate knowledge of the weight of your horse is important for calculating the quantity of feed that should be given. However, this is not the only concern relating to body weight. It is essential to have an, as accurate as possible, estimation of a horse’s weight for many reasons including:

Working out daily feed rations
Help monitor whether or not your horse is receiving too much (by putting weight on) or too little (losing weight) energy for work
To help administer the correct dosage of medications and wormers
It’s important that doses be as accurate as possible. Under-dosing runs the risk of building resistance in bacteria or internal parasites
Overdosing is an expensive waste of medications and can create unpleasant (and unnecessary) side-effects
Supplements and other veterinary medicines that are given orally usually require their dosage to be calculated with regards to bodyweight
A quick drop (especially if it is rapid) may be an indicator of ill health
Transportation with a lorry usually has a maximum weight load which should not be exceeded. Again, this can only be estimated with an accurate measure of each horse’s weight
Monitoring foal growth and avoiding rapid growth spurts

Methods of Weighing

Weighbridge
The most accurate method of weighing your horse is through the use of an equine specific weighbridge. This will give an accurate and quick (within five seconds) reading of bodyweight. Public weighbridges are often available for use at factories and mills. You drive your trailer or lorry onto the weighbridge (with the horse onboard) and make a note of the weight. Then remove the horse and re-weigh the lorry. Subtract the second result from the first to give you the weight of the horse. Equine calibrated weighbridges are presently the only reliable method for determining the weight of pregnant mares and young stock.

Weigh Tape
Weigh tapes are readily available through most equine retail outlets. They are easy to use and if they are used in a consistent manner they are effective for monitoring purposes. They give an estimation of the weight of the horse, but depending upon a number of factors including breed, conformation, fitness etc, their accuracy can vary.

Click here for a useful video on how to use a weigh tape.

When the horse is standing square, the weigh tape should be dropped over the horses belly from the base of his withers and brought underneath him just behind his elbow and foreleg. The reading should be taken where the tape joins the tape (or in some cases from the point of arrow) and will either represent your horse’s weight in kgs or lbs. If the angle where the tape to tape joins forms a vertical line, your tape has been brought too far back producing an inaccurate reading. You want to aim for a slightly back slash angled line (/).

Weight Formula

The weight formula can be more accurate when compared to the weigh tape method. By following a set procedure you will be able to monitor any weight change. As with the weigh tape, you must make sure that your horse is standing square and then using an ordinary measuring tape measure the girth as described above. Record this measurement (in cms).

The next step is to measure from the point of shoulder to the point of buttock. The tape should either follow the contours of the horses body for this measurement or simply be held taut and in place from one point to the next. Whichever method you choose, remain regular and consistent each time you take a measurement. Note this measurement (in cms) and insert your readings into the calculations left:

Keep a record

Each time you measure your horse’s weight keep a record that you can refer back to. Look at how much feed you are giving and see if this relates to his condition, whether you think he is looking a little too thin or too fat. Remember, whether you actually weigh your horse or estimate the weight, that it is done at the same time of day. For example, outside the box on a concrete base, first thing in the morning, before exercise and being fed hard food or hay will aim to keep the parameters for each weighing consistent.

For more horse care tips, check out our other posts in the Welfare and tips section here.