Being overweight can be a very dangerous state of affairs — not only for people, but for horses, too.
Carrying extra weight places increased stress on the skeletal system of the horse and may lead to an increased risk of laminitis, osteoarthritis, heat intolerance and certain types of colic.
But keeping the weight off a tubby horse is not as easy as it sounds — it involves time and planning and comprises more than just reducing calorie intake.
Weight loss programmes also need to consider that horses are trickle feeders and cannot be left for long periods without forage. However, taking steps such as soaking hay in water before feeding it to reduce sugar and starch content, using small-holed hay nets and slow feeders to slow-down intake, introducing more exercise if the horse or pony is sound, using grass muzzles to allow them some access to pasture and removing rugs so they can spend energy keeping themselves warm, can all help.
“It can be very easy for some animals to gain weight and extremely difficult for them to lose weight, especially when limited facilities are available,” says Dr Pat Harris, a veterinary specialist in equine nutrition from the Equine Studies Group, Waltham Centre for Pet nutrition.
That’s where using a Body Condition Score (BCS) system comes in, and Harris recommends using the Henneke System, a 9-point scale that includes visual observation and palpation in six areas of the body: neck, behind the shoulder, withers, ribs, loin/back and tailhead.
A numerical value is assigned based on the fat accumulated in all six areas.
Firstly, an initial observation should be taken from both the side and back of the horse at a distance of about 2.5m. This provides a general overview of the body shape and enables the assessor to look for the possible presence or absence of key bony ‘landmarks’ – e.g. the hips or ribs.
Whilst a visual inspection can give an indication of the BCS, anatomical differences as well as variations in hair coat means that the assessor must run their hands over the different areas of the horse’s body to determine the correct final condition score.
Palpation of the fat storage sites at the 6 key body areas (neck, withers, shoulder, ribs, back and tailhead) should be performed in a consistent way, for example, starting with the neck and then moving to the tail. Each area is assessed and independently scored against the 9-point scale to take into account individual differences in regional fat deposition. The individual scores for observation and palpation are then added up and divided by 6 to give the final overall score for the animal.
The final scale ranges from 1-9 with 1 defined as ‘poor’ and 9 as ‘extremely fat’. Both a severely underweight (taken as a BCS of 3 or less) or obese (defined as a BCS of 7 or more out of 9) result are associated with a higher risk of health problems
As a guide for leisure horses and ponies, Harris recommends a BCS of 5 tending to 6 towards the end of summer and around 5 tending to 4.5 at the end of winter. It is important for all horse owners to learn to carry out a BCS effectively so that horses at risk can be identified as soon as possible so appropriate changes in nutrition and management can be put in place, and/or veterinary/nutritional advice is sought.
But Harris says that BCS scoring is only a part of weight management. Especially for some of the more obese animals and at least initially during a weight management programme, it is really important to be aware that the body condition score may not actually reduce despite them losing weight most likely because, at this stage, they lose the ‘invisible’ internal fat first rather than the external fat that we can palpate.
Therefore, Harris recommends regularly measuring and recording belly girth and rump width (taking care the horse is fully comfortable with the procedure). In addition, periodic and accurate body weight measurement (preferably using a calibrated weighbridge at a local veterinary practice), can be extremely helpful to ascertain early on if the management changes are having a positive effect.
“Looking forward, we are working hard to find ways to identify those animals that are more resistant to losing weight than others so that we can better advise on the optimal weight management programme for an individual animal,” Harris said.
“I hope that new techniques will become available that will enable us to quickly and routinely measure the % Body fat in any animal which will not only enable better monitoring, but also the determination of disease risk level according to body fat content.”
Description of individual body condition scores: