A Complete Guide – Assess your Horse’s Weight-carrying Ability

When purchasing a horse remember that both conformation and frame size will affect the horse’s strength. Good weight-carrying conformation positively affects horse strength. Poor weight-carrying conformation negatively affects horse strength. So two fit horses could have the same height and weight but this does not mean they will be equally strong.

The two standard methods of assessing horse strength are:

• Measuring the front cannon bone circumference
• 20% of the horses fit body weight.

For more about these standard methods skip to the link below.

However, the first method underestimates the strength of thick-set horses. The second method works best with small light-framed horses and overestimates the strength of tall thick-set horses. Hence conformation and frame size must be used to calculate horse strength.

Looking at Horse Conformation and Frame Size.

To identify these attributes first look at the weakest parts of horse anatomy. The limbs and loins are the weakest parts of the horse, so good limb and loin conformation will help the horse to carry a heavy rider. The horse’s back, between the withers and the loins, also has a bearing on strength.

There are 9 horse strength considerations:

1. Forearm length and width
    
2. Gaskin length and width
    
3. The flatness and circumference of cannon bones
    
4. Cannon bone angulation in relation to the ground
    
5. Frame size in relation to the cannon bones
    
6. Hocks, knees, and fetlock sizes
    
7. Pastern length, circumference, and slope
    
8. Loin length and width
    
9. The backs shape and depth

An experienced person will be able to assess these considerations at a glance. Remember, it is unlikely that a horse has the perfect weight-carrying conformation and small deviations are not a problem.

Use this diagram to locate the horse parts mentioned in this article and hone your assessment skills.

3. The flatness of Cannon Bones and the Cannon Bone Circumference

Cannon bones must appear flat when viewed from the side and not round. This means the tendons running down the back of the cannon bone are set a greater distance from the actual cannon bones. This gives a mechanical advantage over round cannon bones. In addition, bigger circumferences of the lower leg make for stronger horses.

The hind end provides impulsion so the back leg cannon bones must be larger than the front leg cannon bones:

• Look for flat cannon bones with a good circumference
• Make sure the rear cannon bones have a greater circumference than the front cannon bones by at least half an inch

4. The Angle of the Cannon Bones in Relation to the Ground

When a horse stands square, his cannon bone should be vertical to the ground from the front and side. This permits greater strength.

• Look for vertical cannon bones in the front and back legs

5. Frame Size in relation to the Cannon Bones

For strength, the circumference of the cannon bone just below the knee must be enough for the horse’s frame. Assess this when the horse is in a lean condition. Many tall and big-built horses do not have enough bone below the knee. This is called being overtopped and this always reduces strength.

• 7.5 to 8 inches of bone is enough for a small lightweight horse
• The average horse needs between 8.5 and 9 inches of bone
• Large horses require at least 9.5 inches of bone

6. The Size of Hocks, knees, and Fetlocks

Large joints permit wide muscle attachment, which is a mechanical advantage.

• Knees must appear large and flat when viewed from the front
• Fetlocks must appear large but not puffy
• Hocks must appear large and flat when viewed from the side

7. Pastern Length, Circumference, and Slope

Long over-sloping pasterns make a comfortable ride and absorb footfall concussion but they are weak. Upright pasterns are strong but cause too much foot concussion. Narrow pasterns are a weakness.

• Look for a medium pastern length with a good circumference
• The angle should be about 45 degrees to the ground
• The circumference should be no more than 1 inch less than the circumference at the middle of the cannon bone

8. Length and Width of the Loins

Strong loins are very important. The distance between the last full rib and the SI joint must be short. For strength, the loins must also be wide at their narrowest point.

• For additional strength look for short and wide loins
• Loin width is not calculated when a horse is overweight

9. The Back Shape and Depth

Deep-bodied horses with straight backs are stronger.

• Horses with shallow bodies and not enough depth through their loins are weaker
• Avoid sway-backed horses

The most important metrics

A horse’s weight-carrying capacity is affected by all of the above considerations. The most important are:

• The amount of bone below the knee and whether this is flat
• The loin dimensions
• Muscling and length of forearms and gaskins
• Body frame size.

Real World Examples: