Body condition and body weight are two very important metrics for understanding and measuring the health of your horse. Both can be assessed easily and without any expensive equipment.
Body weight alone gives us very little insight into how much stored fat your horse has. For example, a 12hh, 400 kg pony would have a wildly different body condition than a 17hh, 400 kg thoroughbred.
An accurate Body Condition Score (BCS) can tell you whether your horse is underweight, overweight or at an appropriate weight for his or her size.
Equine obesity is an increasingly prevalent health and welfare concern. A recent study reported that over 40% of horses and ponies are considered overweight or obese. 
Research has also shown that ponies have a 3x higher rate of obesity, with Shetland ponies being at the highest risk.  Obesity can increase the risk of many health problems such as laminitis, insulin resistance, and joint problems. 
Conversely, horses that are too thin can experience muscle wasting, poor performance, or difficulties reproducing. Horses with a low BCS may have dental issues, poor appetite or other serious problems that can affect gut health.
Ensuring your horse is at an ideal weight and body condition is critical to their long-term health and well-being. This article will review how to accurately body condition score your horse and the importance of maintaining appropriate body weight.
What is Body Condition Scoring?
Body Condition Scoring is an objective measurement of the amount of subcutaneous adipose tissue that your horse has. A body condition score estimates the amount of body fat that sits directly under the skin.
The scale is designed to provide a consistent method of evaluating a horse’s overall body condition based on observations from specific points on the body of the horse.
Using visual and physical (palpation) techniques, you can gain a better understanding of your horse’s body condition. This will help you determine how best to feed your horse.
Quite often, horse owners only assess body condition by looking for fat cover over the ribs. However, this does not give us a very good picture of the overall body condition score of the horse.
BCS is assessed by looking at and feeling six key areas of fat deposition on your horse.  These six areas were selected as being points most responsive to changes in body fat.
These areas are listed below and can been seen in Figure 1:
- Behind the shoulder
- Rib cover
Figure 1: The six key areas to visually and physically (via palpation) assess when body condition scoring your horse
The Body Condition Scale
The modern BCS system scores your horse on a scale of 1 to 9, with a score of 5 being recognized as ideal. This scale is based on research by Don R. Henneke and colleagues in 1983. 
A previous system used a scale of 1 to 5, but the nine-point scale is more commonly used today.
The score takes into account the fat accumulation compared to muscle tissue at each of the six key regions listed above.
1) Poor (Emaciated)
Horses with a body condition score of 1 are very emaciated and in critical condition with no palpable fat deposits. Bone structure of neck, shoulders, and withers are easily noticeable. Ribs are projecting prominently and boney projection of the vertebrae (spinous processes) are clearly seen along the loins (back) and at the tailhead.
- Overall: Poor condition with no fat tissue felt
- Neck: Visible bone structure
- Withers: Visible bone structure
- Shoulder: Visible bone structure
- Rib cover: Ribs projecting prominently
- Rump: Spinous processes clearly seen
- Tailhead: Tail head, hip joints and lower pelvic bones projecting prominently
2) Very Thin (Very Underweight)
Horses with a BCS score of 2 have slight fat cover that can be felt behind the shoulder. The bone structure of neck and withers is faintly noticeable. The ribs are projecting prominently and there is slight fat covering the boney projection of vertebrae (spinous processes) of the loins (back) and tailhead.
- Overall: Emaciated with slight fat cover in some areas
- Neck: Faintly visible bones
- Withers: Faintly visible bones
- Shoulder: Faintly visible bones
- Rib cover: Ribs projecting prominently
- Rump: Slight fat covering the spinous processes and transverse processes of lumbar
- Tailhead: Bones projecting prominently
3) Thin (Underweight)
Horses with a body condition of 3 are characterized as having slight fat cover between the ribs with the ribs clearly visible. The neck, withers and shoulders are accentuated. On the back, there is a slight fat covering the boney projection of vertebrae (spinous processes), but they are clearly seen. The tailhead is boney but individual vertebrae cannot be seen.
- Overall: Thin with some fat cover but not an adequate amount
- Neck: Accentuated neck
- Withers: Accentuated withers
- Shoulder: Accentuated shoulders
- Rib cover: Slight fat cover over and between ribs; ribs are easily visible
- Rump: Spinous processes easily discernable but with some fat covering; Transverse processes no longer palpable
- Tailhead: Tailhead prominent but individual vertebrae no longer visible; Hook bones are visible but rounded; Pin bones no longer prominent
4) Moderately Thin (Slightly Underweight)
Horses with a body condition score of 4 are considered to have an acceptable body condition, according to the Georgia Department of Agriculture.  The neck, withers and shoulders are not obviously thin, but they may have dip between wither and neck depending on their conformation. A faint outline of ribs can be seen. The spine is clearly shown with a negative crease along the back while tailhead prominence will depend on conformation.
- Overall: Moderately thin with an acceptable amount of fat cover
- Neck: Not obviously thin
- Withers: Not obviously thin
- Shoulder: Not obviously thin
- Rib cover: Faintly visible outline
- Rump: Negative crease along the back; backbone protrudes with a “peaked” appearance
- Tailhead: Varies depending on conformation; Fat can be felt; Hook bones are rounded; Hip joints are not discernable
5) Moderate (Ideal)
A score of 5 is an ideal body condition for a horse. The neck and shoulders blend smoothly into body and the withers are rounded over boney projections of vertebrae (spinous processes). Ribs may not be visibly seen but can be easily felt under the skin. The back is smooth and level with a slight fat covering felt around tailhead.
- Overall: Moderate body condition with ideal fat accumulation
- Neck: Blends smoothly into body
- Withers: Rounded over spinous processes
- Shoulder: Blends smoothly into body
- Rib cover: Ribs are not visibly seen but can be easily felt
- Rump: Back is smooth and level
- Tailhead: Slight fat covering felt around tailhead; fat begins to feel soft to touch
6) Moderately Fleshy (Slightly Overweight)
Horses with a BCS score of 6 have some fat covering along withers, neck (especially along the crest), and behind the shoulders. The ribs are not easily seen but individual ribs can be felt. They may have slight crease down back and the tailh