Part 2: Implications and
treatments of foal limb
deviations
What are the implications of early limb deviations in foals?
As the foal grows and matures, it is important to observe for any signs of conditions which may have been associated with rapid growth rates. These include:• Contracted tendons.
• Epiphysitis.
• Angular limb deformities.
• Defects in bone ossification (e.g. Osteochondrosis OCD, subchondral bone cysts, wobblers syndrome).
The veterinary surgeon should be asked to evaluate the foal’s feet and limb conformation for abnormalities, at approximately one month old, in conjunction with farrier work.Regular hoof trimming, however, typically is not required until the foal is six to eight months old.Should foals with limb deformities and deviations be kept stabled or kept outdoors?
This question is very commonly asked, where a foal has an angular limb deformity. Unfortunately there is no single solution to these problems as they tend to vary on a case by case basis. However foals with severe limb deformities should always be kept indoors. This is to prevent the potential consequences of the foal galloping which can result in further damage and worsening of the problem. Continued exercise in a foal with an angular limb deformity can cause compression of the growth plate where it is taking more pressure at a specific point due to deformity.Although some compression is said to stimulate growth, too much compression can actually impede growth.If the bones are not fully formed, there is a risk that exercise may cause them to be crushed due to the uneven load that is placed on the joint due to the laxity. Also, the restricted use of the deformed limb places extra pressure on the other limb/s.While owners are reluctant to keep a mare and foal indoors for 24 hours a day it may unfortunately, in many cases, be an essential part of the rehabilitation for the foal with limb deformities.What criteria influence the decision on the treatment type in a foal with angular limb deformities?
Treatment options are either: a) Conservative/non-surgical
b) Surgical.
The treatment of the various forms of angular limb deformities differs for each horse depending on such factors as: • Location of the deformity
• Age of the foal
• Severity of the deformity
• Body type
• Risk factors
• Time, etc
It is important to remember that only certain types of deformities are amenable to conservative therapy such as rest and corrective trimming and shoeing. This makes the physical examination all the more important.For mild deviations, conservative treatment is recommended for an extensive period, provided the condition does not show any deterioration. However, severe deviations impairing locomotion or those showing deterioration should be corrected immediately. A decision as to whether to interfere with a limb is governed by a tight time frame.When an angular deformity arises as a result of either posture, abnormal bone growth or from injury, there is a very limited time frame in which correction can be achieved. The growth plate of the radius, just above the knee, grow very little after about five or six months of age and the growth plates above the fetlocks stop growing at about three months. If correction of a bent leg is to be undertaken, it is essential that surgery is carried out before bone growth at these sites finishes.X-rays are often essential to establish the exact location and degree of angulation, and also whether there has been incomplete ossification of the bones, which could affect the prognosis. The remaining growth potential of the joint also has to be taken into account. The foal’s age will govern most of these factors. So if a decision on surgery is taken it must be carried out before the growth plates have closed. What is the timeframe for surgery on a knee or on a fetlock?
In the case of fetlocks, surgery is best done before three months approximately, while knee and hock intervention is most effective before six months. A rule of thumb used by some veterinary surgeons is to only attempt conservative therapy up to two-three weeks of age for the fetlock and up to two-months months of age for the carpus and tarsus. At this time periosteal stripping is strongly considered in many of these cases. By four weeks for the fetlock, and four months for the carpus/tarsus, some type of surgery will probably be necessary in all but the very mild angular deformities. What effective conservative treatments are used on foals with limb deviations?
After assessment has been carried out the appropriate type of treatment/rehabilitation programme is initiated. Treatment should initially always involve management changes. These may include restricting a foal’s exercise to reduce concussion, curbing food intake to prevent sudden growth spurts, regular foot trimming and, where necessary, corrective shoeing, under close monitoring by the veterinary surgeon.It is important that the foal is not allowed to get “top heavy” as this places extra pressure on the already deformed, weak limbs.