Leg problems in youngsters are the most common problems that I hear
about. A lot of foals seem to have slightly crooked legs, and often the abnormalities will
correct themselves within a few weeks. Some foals may start out looking good, but develop
problems later, while others seem crooked at birth and improve with age. Some youngsters
may develop an inflammation of the growth plates (See Epiphysitis
for more information). Other youngsters may develop osteochondritis dissecans
(OCD) which is a failure of the cartilage in the growth plates to turn to bone. These
problems are classified together as developmental orthopedic disease (DOD) and
may leave the youngster at risk for early arthritis and other unsoundnesses. To be safe it
is always a good idea to have your veterinarian check your youngster if you notice any
Because of the narrowness of their chests, a lot of newborn foals might
toe out or look knock-kneed then later their legs will appear straighter as they fill out.
Another problem foals will often outgrow is weak flexor tendons that cause the toes to tip
upward. This problem is usually seen in the rear legs of newborn foals, but can affect all
four legs. In severe cases the back of the fetlock may actually touch the ground,
therefore a light wrap might be needed to protect the fetlock from abrasions. If the
condition doesn't improve naturally within a few days you may need to apply a trailer shoe
to help support the foal's foot and force the toe downward.
Leg problems that are seen from the front are often called
"knock-knees" or "bowlegs" and generally involve the knee joint. See Crooked Legs for more information. Leg problems that are seen from the
side are often called "bucked knees" or "contracted tendons" or
"club foot" and are generally confined to the lower leg. See Flexural
Deformities for more information.
The growth plates located at each end of the long bones are also called epiphyseal
plates. An inflammation of these growth plates is called epiphysitis and is
characterized by swelling near the ends of the bones. Although the youngster may be lame
during the active phase of epiphysitis, the lameness diminishes once the area ossifies.
The area will often be permanently enlarged leaving the youngster with knobby knees or
ankles. Epiphysitis usually affects weanlings and yearlings, however it may affect horses
as old as 2-1/2 years of age.
Your veterinarian will probably suggest some changes to your youngster's
diet and will probably prescribe stall rest for four to six weeks. She may also suggest
changes in the way the youngster's feet are trimmed. The dietary changes often include a
reduction in protein and reduction or elimination of grain and concentrates.
Crooked legs, whether knock-knees or bowlegs, are generally caused by abnormalities in
the growth plates. Growth can only occur in these plates of cartilage located at the ends
of the bone. If one side grows faster than the other side the foal will develop crooked
legs. For example, if the growth plate grows faster on the inside of the leg the foal will
Usually the earlier the foal is treated, the better. The growth plate
(cartilage) in the fetlock is replaced with bone by the time the foal is two months old,
therefore surgical correction is virtually impossible after this time. Growth plates in
the knees will continue growing longer, but any necessary surgery should be performed
early for the best chance of success.
Veterinarians will often prescribe strict stall confinement. Exercise
promotes strong, healthy bone, but for a foal with limb deformities exercise can put
uneven stress on the growth plates and make the condition worse.
For mild cases trimming the hoof may be enough to equalize the forces on
the growth plates. However, if done improperly, you may actually make the condition worse
or cause additional problems. Be sure to use a qualified farrier who is willing to consult
with your veterinarian. Mild cases may also respond to splints or casts.
In more severe cases surgery may be required, however to have any effect
the surgery must be performed while the growth plates are still actively growing
(generally before the foal is a couple of months old). Some types of surgery will retard
the growth of areas that are growing too fast and other types of surgery will promote the
growth of areas that are growing too slowly.
Periosteal stripping will promote growth. In this procedure the
periosteum (a membrane enclosing the bone) will be opened over the growth plate on the
side that is growing too slowly. The reduced tension on that side will allow the growth
plate to grow faster thus straightening the leg.
Transphyseal bridging is a procedure in which staples or
connected screws are inserted to bridge across the growth plate on the side that is
growing too fast. These staples or screws will prevent the bone from lengthening on that
side. The veterinarian will need to check the foal regularly and will remove the staples
or screws within about three months to prevent overcorrecting.
Abnormalities of the lower leg often occur when leg bones grow faster than the
attached tendons and ligaments. Sometimes this occurs before birth (congenital) or it may
develop as the foal grows (acquired). When the tendons or ligaments are too short the
joints remain somewhat flexed and the foal looks like he's walking on his tiptoes. In
extreme cases the foal's pastern may knuckle over causing the foal to walk on the front of
the pastern and hoof. These flexural deformities are often seen in the fetlock and coffin
joints and rarely in the knee joints.
In contrast to crooked legs, foals with flexural deformities may require
moderate exercise to help stretch the tendons. Very young foals with mild cases may
improve as they move about. Older foals with mild cases may need some help. Your
veterinarian will probably check for some sort of painful condition that could be causing
the problem and might prescribe Phenylbutazone or another pain reliever. She will probably
also check the foal's diet and suggest some changes. Some cases may respond to corrective
trimming and/or shoeing, or may require a splint or cast.
In more severe cases the foal may require surgery to sever check ligaments
and/or the digital flexor tendon. Although the gap will be filled in with scar tissue, a
blemish may result. A foal's performance ability may also be diminished when a digital
flexor tendon has to be severed.
Injuries, poor conformation, improper feet trimming, excessive exercise, and
overfeeding are the common causes for leg abnormalities. Growing horses are particularly
sensitive to dietary imbalances and deficiencies.
Epiphysitis is commonly seen in youngsters who are fed heavily and rapidly
gaining weight. Dietary imbalances and improper exercise are also implicated. Occasionally
an injury to one leg causes the youngster to compensate by putting excessive weight on
another leg which then leads to epiphysitis. The pain associated with epiphysitis may
cause the youngster to alter the way he stands and moves and may eventually lead to
Some experts believe flexural deformities may be caused by a vitamin or
mineral deficiency in the mare's diet during pregnancy or by an imbalance or deficiency of
calcium, phosphorus, vitamin A or vitamin D in the foal's diet. Rapid weight gain,
particularly combined with limited exercise, has also been implicated.
Deficiencies of copper and zinc have led to problems with bone growth.
Unfortunately feeding adequate amounts of these minerals to the youngster may not
compensate for deficiencies occurring during the mare's pregnancy.
Feeding excessive amounts of concentrates has been linked to several types
of bone diseases in young horses, including epiphysitis and osteochondrosis. Feeding
excessive protein may cause excessive urination of calcium, resulting in a calcium
deficiency. A calcium deficiency could lead to leg problems such as epiphysitis and
contracted tendons. A phosphorus deficiency during pregnancy has also been found to cause
leg problems in foals.
Signs to watch for:
heat or swelling or enlargement in any joint
crookedness in any leg
upright pasterns or knuckling over
upright hoof / hooves
lying down a lot or having trouble getting up
youngsters who do not run and play
signs of discomfort such as a preoccupied look in the eyes or wrinkled
Providing a proper diet and not overfeeding (such as preparing for a futurity) are
probably the most effective preventative measures. Nutritional problems may have started
during pregnancy, therefore be sure to provide a complete and balanced ration starting
before breeding the mare. Providing the nutrients in a proper balance is the most
important. You may also want to have your feed tested. You should also provide nutrients
in a form that the animal can use. Inorganics, such as copper sulfate or zinc oxide, are
mostly indigestible minerals - something like feeding nails as a way to provide iron.
Although alfalfa is the food of choice for many farms, it contains high
levels of molybdenum and zinc which can suppress copper. Alfalfa also contains high levels
of calcium in comparison to phosphorus, often at a ratio of 5 to 1 when the ideal ratio is
1-1/2 to 1. Furthermore alfalfa often contains high levels of protein, sometimes over 20
percent. Some experts suggest feeding no more than 12 percent. Commercial foal rations
also contain high levels of protein. Good quality grass hay, perhaps with a small amount
of alfalfa, is much safer feed for youngsters.
Feeding large amounts of concentrates or grain can also cause problems. A
large meal of concentrates may cause an insulin rush followed by a blood sugar crash and
glandular system stress. Grains are also an acid-producing food that causes the body to
pull minerals from the bones to buffer the bloodstream.
You should avoid allowing youngsters free choice access to concentrates. A
study by the University of Saskatchewan, Saskatoon, Canada, found that allowing youngsters
unlimited access to concentrates during their first two years resulted in a higher
incidence of structural unsoundness than in youngsters fed measured amounts in a balanced
Some additional suggestions to prevent problems:
Avoid sudden changes in feed, including sudden increases in amount. If
you notice a growth spurt starting, cut back a little on the amount of feed.
Worm youngsters only when necessary. Some ingredients in commercial
wormers may lead to toxicity in the liver thus contributing to a thyroid hormone
deficiency and problems with calcium absorption.
Don't feed oil to broodmares or youngsters because it may interfere with
absorption of vitamins A and D.
If you have a youngster that has already developed leg problems, check
with your veterinarian, but you may want to consider the following suggestions:
Reduce or eliminate alfalfa and replace with good quality grass hay.
Reduce or eliminate the amount of concentrates and grains fed. If you do
continue feeding grain, switch to a plain, rolled grain or Dynamite Complete Pelleted Grain Ration.
Provide a high quality vitamin and mineral supplement, such as Dynamite or Dynamite Plus.
Provide Ester-C -
approximately 3 teaspoons per day - because it contains high levels of buffered vitamin C
which is important in the repair of bones, connective tissues and muscles.
Provide sulfur such as in MSM -
approximately 4 teaspoons per day - because sulfur has an important relationship with
protein, is found in insulin (the hormone that regulates carbohydrate metabolism), and is
needed for metabolism and strong nerve health.
Provide free access to trace minerals, such as found in 1 to 1 or 2 to 1 Free Choice, to provide
commonly deficient elements necessary for proper development of bone, ligaments, tendons,
and connective tissue.
Provide a probiotic, such as Dyna-Pro - approximately 3 cc per day - to
help maximize digestive efficiency. (Dynamite
Plus already contains a dose of Dyna Pro. Regular Dynamite contains higher levels of vitamins and
minerals, but no Dyna-Pro.)
Confine youngsters showing signs of epiphysitis or having crooked legs.
Give moderate exercise to youngsters with flexural deformities. Avoid working any
youngster in small circles or in deep footing.
The information given here is to help you learn more
about your horse and not to replace your veterinarian's advice.