Page 58 - New Mexico Winter 2021

limb than hind, but can be seen, like with ALD, in a variety of joints. Locoweed and Sudan grass consumed by the mare have been implicated as
a cause of FLD, as has the position of the foal in utero. Teratogenic agents, genetic predisposition, and gestational diseases developed while pregnant, like influenza, have also been blamed. Infectious polyarthritis, as can occur with
sepsis in neonatal foals, can also contribute to development of FLD. This digital hyperflexion presents as a very upright or even knuckled over appearance of the limb when viewed from the side. The degree of FLD can be assessed
in relation to the ability to correct the flexion manually. If the limb can be easily straightened, the prognosis is generally better. Severe flexion of the carpus may be irreducible causing the foal to be unable to stand. This would be considered an emergency, as a foal who cannot stand will not be able to nurse without assistance. And as we know, a foal who cannot nurse normally for whatever reason is at high risk for developing failure of passive transfer and all the terrible sequela that occur secondary to that.
Treatment of FLD generally is approached from a conservative management strategy first with surgical options available for those foals who do not respond appropriately. A multipronged approach to treatment is often the most successful with the ultimate goal being stretching of the tendon. Bandaging with or without splints or
casts are traditionally used to induce tendon
laxity and to apply continuous stretching of the tendon by keeping the limb in extension. Close monitoring, particularly if splints or casts are used, is imperative as bandage sores are easy to create if the splits are not padded well or if shifting occurs. Bandage sores create their own issues and make dealing with the FLD more difficult. Your veterinarian likely will also recommend the use
of the antibiotic Oxytetracycline administered IV over the course of 1-3 treatments in addition to bandaging or splinting. This medication causes relaxation of the tendons which can be rapid and usually quite dramatic. Typically, this works better in younger foals, as the response is decreased with age. Manipulation of the hoof by trimming down the heels and applying toe extensions also assists in this stretching process. As you can imagine, stretching these short tendons can be painful,
so pain management with non-steroidal anti- inflammatories is usually recommended as well. NSAIDs and oxytetracycline can be hard on the kidneys so monitoring of bloodwork in these
foals is a good idea. Surgical options are available for these foals, but happily most respond well to conservative treatment. Those older foals who develop acquired FLD and thus may not respond to conservative treatment, may benefit from surgical intervention if nutritional changes do not produce resolution of the FLD.
Tendon laxity, or digital hyperextension,
is the problem that most all of us have likely experienced. You’ll see these foals as very down
in their pasterns or fetlocks, in front or behind,
or sometimes all 4 limbs. Most of these foals will respond well to controlled exercise and will correct as they become stronger, similar to those ALD foals who change on their own in a short period of time. It is important to remember that these foals should not be bandaged or splinted as bandages induce further laxity and will make the problem worse. Instead, if foals have severe laxity (ie: the back of their fetlock touches the ground) the use
of heel extensions can be extremely beneficial to restore more normal pastern alignment. There are commercially available glue on shoes (IBEX Babi- cuff ) that work great for these cases, but something as simple as popsicle sticks taped to the foot can readily be used as a heel extension. The worst part about this management strategy is keeping the heel extensions on the foal, as they often will step on the heel extension and pull it off.
As they say, “success is where preparation
and opportunity meet” and while knowing
this information sure won’t prevent problems during this foaling season, I hope you will feel more prepared to successfully navigate those bumps along the way. Remember, time and your veterinarian are your friend when dealing with limb abnormalities in your newborn foal. And most of these little guys will grow up to be normal, and if we are lucky, speedy racehorses!
Above, left: Tendon laxity, or digital hyperextension, will be evident in foals down in their pasterns or fetlocks, in front or behind, or sometimes in all 4 limbs. Above, right: If flexural limb deformity is present at birth, it is considered congenital. However, FLD can develop as an acquired problem during rapid growth, typically between 4 weeks and 4 months of age or around 1 year of age. – Photos provided
56 New Mexico Horse Breeder