Equine Science Update
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Written by Mark Andrews/Edited press release. Published online 26.08.10
 © Copyright Equine Science Update  2010
Measuring weight loss
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Belly girth measurements are a better way to assess early weight loss according to recent research.

One of the problems faced by owners of overweight horses, is monitoring the response to weight loss programmes. Obviously weighing the horse would be ideal but is often not possible. Weigh tapes placed around the heart girth (just behind the elbow) may not detect any change despite a decrease (or increase ) in body weight, because that is not where the excess fat is deposited.

Two recent weight loss studies have both shown that belly girth* measurements are more closely related to changes in bodyweight in early weight loss (after the first week of feed restriction) as opposed to the more commonly used heart girth measurements. They may even be more accurate than some ultrasound fat measurements.

A study1 conducted last year by researchers at the Department of Veterinary Clinical Science at the University of Liverpool and supported by World Horse Welfare, highlighted the need for a more accurate method for monitoring early weight loss in overweight ponies rather than relying on conventional equine body condition scoring.

A further study2 comparing two practical weight loss protocols for the management of overweight and obese horses and ponies was conducted earlier this year by the Department of Veterinary Clinical Science at the University of Liverpool. It was funded by the government-initiated Knowledge Transfer Partnership and the WALTHAM Equine Studies Group. It confirmed that the proportional change in belly girth was more closely associated with changes in body weight than the proportional change in heart girth in the early stages of weight loss.

Dr Caroline Argo and Alex Dugdale of the Department of Veterinary Clinical Science at the University of Liverpool said: “It is important for owners to understand that early weight loss is not immediately recognisable as a change in the horse or pony’s overall appearance or body condition score. However, owners do need some assurance that measures taken to promote weight loss are being effective. Simply measuring belly girth at regular (weekly) intervals can provide this. Without such reassurance, we might be inclined to either give up or more alarmingly, harmfully increase our efforts to induce weight loss.”

Clare Barfoot, the research and development manager for SPILLERS® and a member of the research team for the second study continued: “Our findings clearly support the concerns raised in the initial study on the accuracy of using conventional body condition scoring or heart girth measurements to monitor early weight loss. Although weigh tapes used around the heart girth can estimate bodyweight they are not as reliable in picking up early weight changes in weight loss programmes. Measurements around the belly girth have proved to be a more reliable way to monitor weight loss although it is important to ensure that the initial measurement is taken a week after food restriction to accommodate initial losses in gut fill and water, and that measurements are taken in a standard way at a similar time of day.”

Samantha Lewis, Right Weight Manager for World Horse Welfare, commented: “This research will be of great benefit to owners who are taking steps to help their horses lose weight by enabling them pick up on changes at an earlier stage. While weightapes used at the heart girth can be useful to obtain estimates of body weight, changes in belly girth may be more sensitive for monitoring early changes in weight when obese ponies are encouraged to lose weight.”

The researchers are still working on validating a more accurate body condition scoring system, based on the findings. In time they hope to be able to create a more effective weight loss assessment method for owners to use.

* Taken at the widest point of the belly; approximately two thirds of the way between the point of the shoulder and the point of the hip.

1 Managed weight loss in obese ponies: evaluating weight change, health and welfare, A Dugdale, G Curtis, C McG Argo, (Department of Clinical Science, University of Liverpool, UK), PA Harris  (Equine Studies Group WALTHAM Centre for Pet Nutrition, UK).

2 CG Curtis, AHA Dugdale,  D Grove-White and  C.McG Argo. (University of Liverpool, UK) PA Harris. (Equine Studies Group WALTHAM Centre for Pet Nutrition, UK) CF Barfoot. (Mars Horsecare UK Ltd)