Jeske Noordergraaf, VMD

May 2006

Nothing is more exciting than having your mare foal after all the waiting you have done.  After a few tries the foal finally gets up but the legs are all crooked.  Is this a problem, will the legs straighten out or do we need to intervene? 

When you think about how big a foal is and how long the legs are, it is a miracle that foals have straight legs at all, but if a foal is born with or rapidly acquires an abnormality or disease related to the musculoskeletal system, rapid adjustments must be made to allow the foal to grow and respond so that future athletic performance will be minimally compromised.  It is sad to see an adult horse with crooked legs that will cause lifelong problems due to arthritis when the problem could have been dealt with at an early age.

Angular limb deformities are defined as a lateral or medial deviation of the limb.  The most common abnormalities are seen in the front legs at the carpus or knee with the foal being knock-kneed (carpus valgus) or bowlegged (carpus varus).  This may be a result of the bones in the joint not having fully developed or from the foal being in an abnormal position in the uterus.  It may also result from asymmetrical growth of the distal radius growth plate.  It is important to correct the angular limb deformity well in advance of growth plate closure and early enough to prevent secondary damage to the carpal bones and the other joints distal to the carpus.  Common treatments include casting the leg at a very early age,  periosteal stripping to allow the slower side to catch up to the more rapidly growing side or even putting metal across the joint, again to slow down the growth.  If your foal has this problem, be proactive and have x-rays taken of the joint to determine if the bones in the joint are all mature and to measure the angle between the bone above the joint and below the joint. 

Foals that are down at the fetlock have laxity in the flexor tendon.  Both front legs, both hind legs or all four legs can be affected.  These foals generally rock back onto the back portion of the hoof wall and heel bulbs such that the pastern hyperextends and the fetlock drops and the toe flips upward.  Most foals are only mildly to moderately affected and will spontaneously correct within the first few days of life as they start to move around and strengthen their muscles.  Therefore, these foals generally do not need to be treated unless they do not improve or if they get worse.  If they do not improve, lowering the heels may help or applying a shoe with heel extensions may also help.  It is important to be observant that the back of the fetlock or pastern is not down on the ground, with the foal developing sores there and ending up with an infection.

Contracted tendons cause foals to be too upright, usually in the fetlock joint, but other joints may also be involved.  This deformity can happen in just one or in both front or back legs. Usually it is present at birth but it can be acquired within one year.  This deformity refers to a joint that cannot be straightened.  If the foal can stand on the affected leg and the carpus, fetlock or coffin joint is involved, often no therapy is needed and the problem will resolve in four to five days.  If the limb is more severe, a combination of splinting and medical treatment will be needed.  For foals that cannot get up or stand, more aggressive treatment is needed but these can heal fully.

Windswept foals have one back leg bent in one direction (varus) and the other leg bent in the other (valgus).  Looking at these foals, it appears as if the wind is sweeping them away, hence the name.  These foals usually straighten out on their own with controlled exercise.

These are just some of the common problems seen with newborn foals and youngsters.  If you have any questions, don’t hesitate to have your veterinarian come out and examine your foal. X-rays are very useful as the angles can be measured between the joints.  They also help us determine if the bones are all normal.  It is always better to treat a problem early then to end up with a horse with arthritis. 

Don’t forget the overall health of your foal.  Foals need to nurse and absorb the colostrum within hours of birth, they need to pass the sticky meconium and the mare needs to expel the placenta within a few hours of birth also.  Have fun and enjoy your beautiful new baby.