Foal limb deformities
What are limb deformities in relation to foals?
In simple terms, these are abnormal leg conditions which make it difficult for the foal to stand correctly.
When foals are born they must be presented front feet first, like superman, with the head just behind. If this is not the case, then an experienced member of the foaling team or veterinarian can manipulate the limbs into position. Even if the foal is presented correctly there can still be problems with the limbs after birth. Additionally in some cases the conditions outlined below can present in older foals if they are not correctly fed, grow abnormally, get injured or have too much exercise. Weak bones and various soft tissue conditions can also cause deformities to occur in later stages of growth.
Below we discuss what some conditions are and how to treat them. There are plenty of other conditions however these are some of the more commonly seen. As always if you suspect something isn’t quite right with your mare or foal ALWAYS contact your veterinarian, early treatment = better prognosis.
Do you know if your own horse was born with a limb deformity? Often the foals born with these conditions will strengthen up in a few days and after 6months with correct feeding, farriery and management you would never be able to know!
Fun fact: Did you know most foals can stand within an hour of being born and will start to look for milk from mom soon after.
Firstly we have angular limb deformities coming from the carpal bones. Carpal valgus is where the lower limb deviates to the outside of the horses “knee” aka carpus. Carpal varus is when the limb deviates to the inside of the horses carpus. Fetlock varus is when the limb deviates to the inside of the horses fetlock. There is also a condition called “windswept” which is where the limbs are slanted in one direction, this is often associated with the foal having long hind limbs which have been sat an an angle in the womb. Most of these foals strengthen on their own with the help of a little remedial farriery. If they do not strengthen over time, then in simple cases the farrier can apply extensions/support and in complex cases the veterinarian can do surgery to pin and plate the legs in the correct place.
1. Tendon Laxity and Ligament Laxity
Laxity in tendons and ligaments is fairly common and often strengthens up with controlling the amount of exercise the foal is doing. Sometimes a bandage is placed on the leg to help with straightening and support to the distal limb structures. Over time the legs get stronger and straighten out until the are no signs of weakness and the foal is completely normal. The images below show how the limb can be very lax and the hoof completely turned up.
Flexor tendon laxity, as shown as presented (A) and on a radiograph (B).
The images below show how the farrier can add in an extension to help straighten the hoof-pastern alignment so the foal walks with the weight distributed correctly.
Flexor tendon laxity causing the upwards rotation of the hoof (left) and correction (right) .
2. Tendon contracture
This condition causes the tendon to be very tightly constricted. This usually presents as a club foot, fetlock or carpal contracture. The degree of severity varies case to case and in the worse cases, surgery may be necessary to lengthen the effected tendons or ligaments. The foot will often be unable to touch the floor and will be flexed backwards, depending on where the contracture is depends on the severity of the case. The foal will have difficulty standing or in some cases will be completely unable to stand and will need splints and 24/7 monitoring. Foals need to get the important colostrum post-foaling so this may need to be bottle fed to help give the foal some additional nutritional support and energy.
Tendon contracture from contracted and unable to flex the foot forwards, to normal (A-C). (Image from VeterianKey)
The images below show how the foal can have a contracture of the DDFT causing the hoof to touch the ground at the toe but not the sole. Using corrective farriery and support, the leg overtime straightens up to look completely normal. This will need monitoring as the foal grows to ensure there is no additional problems following the contracture, but most foals make a full recovery.
Image showing a club foot (tendon contracture) correction using remedial farriery. (Image credit to imprint equine hoof care)
3. Immature cuboidal bones
In this condition the foals bones are not solid at birth. The foal should either stay lay down or be given supportive splints to keep the bones in place to help them solidify correctly, if the bones deform this can cause a multitude of problems. X-rays are best to monitor how the bones and growth plates are forming. Controlled exercise, corrective trimming and careful monitoring usually gives this condition good prognosis.
A foal with splints for treatment of immature cuboidal bones (J.Auer)
The hock X-ray images below are curtesy of a study performed on thoroughbred foals to track the progress from foal to the sales. There were variations of bone growth between each horse and only 46% of foals were considered to have complete bone mineralization at birth. In the hock (tarsus) some evidence of this still remained at 300 days old. The study concluded that perhaps if all foals were x-rayed at a young age, the correct exercise management could prevent radiographic abnormalities of the cuboidal bones (usually of the hock) when the thoroughbreds are x-rayed pre-sale. Have a read to find out more!
https://eqmedical.com/wp-content/uploads/2018/03/Cuboidal-Manuscript.pdf
Santschi, E.M., Prichard, M.A., Whitman, J.L., Strathman, T.A., Batten, C.A., Canada, N.C. and Morehead, J.P., 2018. Survey radiography of the carpus and tarsus in neonatal Thoroughbred foals and appearance at 6 months of age. Journal of equine veterinary science, 63, pp.55-60.
3 images showing 3 different foals hocks (tarsals). In the left image you can see the bones are not developed, with large spacing in-between the inter-tarsal joints. The middle image is slightly underdeveloped. In the right image the bones are mature and as they should present on a ‘normal’ x-ray of a foal hock.
4 images of the same foal. In the first image at 1 day old the foals hock (tarsus) is immature and the bones are weak. The foal was confined to a small round pen and exercise was strictly controlled. By 120 days the foals hock was ‘normal’ and the bones had strengthened up dramatically.
Kinesiology taping for foals?
New research suggests that kinesiology taping could help foals with angular limb deformities to provide support without invasive techniques. The images below show some success with the tape, however more research needs to be developed into if this is the best way forwards or just a good addition to a studs toolbox. Have a look at the link below for more information on the study.
https://www.fysiotape.nl/wp-content/uploads/2018/08/Kinesiology-poster-standsafwijking-veulen.pdf
A foal with carpal valgus conformation, helped to be corrected with kinesiology taping to the carpus.
How can we treat these conditions?
Growth plates in each joint will close at different times and it is important to treat the condition before the plates close as to alter the growth angles. For example, in the fetlock it should be treated before the foal reaches 2 months where as the carpus should be treated before 6 months. X-rays are the gold standard to see what is going on under the skin and make sure that the corrections are helping the limbs. Surgery can be an option for the most severe cases however it is best to try and manage the condition using corrective farriery, splints and electrotherapies.
Physiotherapy can additionally be used to help treat abnormal foal conditions with range of motion exercises, joint mobilisations, massage, fascial release, stretching, kinesiology taping, laser therapy, and more…
Always consult your veterinarian and they can advise the best plan of action to take for your mare and foal.
