Angular Limb Deformities (ALD)
What Can We Do About Crooked Legged Foals
As we enter the foaling and breeding season, we are sure to encounter foals with “not so straight legs”. To some degree this could be a self correcting situation and then there are many foals that will require “help” to get them straight.
The causes contributing to “ALD” fall into two main categories; 1) Perinatal factors (those issues that develop before and surrounding the time the foal is born), and 2) Developmental factors (those issues that develop following the time of birth). Of these two categories, we tend to see most foals with ALD that are premature or dysmature foals; they have incomplete mineral development of their bones and joint structures. Or, intrauterine malpositioning of the foal that leads to weakness and laxity of the soft tissue structures surrounding the joints.
Angular limb deformities most frequently are associated with the knees (knock-knee), but the deformity can also be encountered in the hock and fetlock. Location identification of the deformity is important since each area/location has specific time intervals that we can intervene and achieve successful outcome or correction. Severity of the ALD can be broadly classified as mild, moderate and severe. This classification is also helpful in determining the time, but also the technique to intervene to achieve correction of the legs.
Diagnosis of ALD is very straight forward. Does the foal stand squarely on its limbs, both from the front as well as a side view? Or, does the leg deviate in one direction or the other as it goes from the body to the ground surface. Most foals are born with a mild deviation of the knee (generally, no more than 5 degrees), that within the first 2 to 4 weeks of life will correct. Anything beyond this should be evaluated to preserve the future soundness as an adult. It is always wise to x-ray any premature foal, even if it is straight or foal with moderate to severe deformity to assess bone maturity and development.
Treatment Techniques once the ALD is identified
Nonsurgical -
- Stall Rest or Confinement with Limited Exercise: This is used for mild to moderately affected foals that have normal maturation of bone or mineral content. Foals should be re-evaluated every two weeks to assess correction of their ALD.
- Support Bandaging, Splints or Cast: This technique is used for foals that lack proper mineral content of bones and joints as seen on x-rays or with extreme joint laxity.
Surgical -
- Growth Acceleration – Periosteal Transection/ “Stripping”: This is a minor surgical procedure that is performed to help straighten a crooked leg. This procedure is performed between 2 weeks of age to 3 month of age; ideally around 30 days of age.
- Growth Retardation – “Screws & Wires”: These are surgical implants that will arrest bone growth on one side of the leg to allow the other side to catch up. These implants must be removed or the leg can turn the other way once the original correction is achieved. This technique is usually reserved for severe ALDs.
Timing is important, all fetlock ALDs must be managed prior to 30 days of life since this is our window of opportunity to affectively achieve correction. Where as knees and hocks, can be successfully managed by up to 3 months of life and achieve correction.
If there is any doubt or should you have any questions in regards to a foal with ALD, please contact us for an examination or a consultation.
