Occasionally, a calf is born with crooked legs, lax or contracted tendons. Many straighten on their own with time and exercise, while others require intervention. Some are so severe the calf must be euthanized.
The challenge is to determine if the cause is nutritional, genetic or due to toxins or infections. Dr. David E. Anderson, associate dean for research, college of veterinary medicine, University of Tennessee, says lupine toxicity is a classic example of a toxin (ingested by the dam at a certain stage of pregnancy) that can cause severe limb abnormalities.
“Large calves tend to have contracted limbs more often than smaller calves. If the cow’s diet is rich in energy and protein in late gestation when the calf is growing fastest, growth rate of bones might not maintain proper relationship with muscles and tendons, and contractures may occur,” he explains.
Some plant toxins cause contractions because they decrease mobility of the fetus as it develops. Normally, the fetus is always moving, but some toxins (in lupine and hemlock) act as a sedative; the fetus isn’t moving, and the joints lock up. As the bones are developing, muscles and tendons are not getting stretched if the fetus isn’t moving.
“Calves born immature [full-term but not fully developed] may have lax, weak tendons with fetlock joints dropping to the ground or the carpus [middle joint of the front limb] bent backwards,” says Anderson.
Some diseases and infections can cause problems during pregnancy and result in abnormal calves. “BVD [bovine viral diarrhea] is the main one we worry about. If a producer has multiple calves affected, we can do tests to help determine the cause,” he says. Working with the veterinarian is the best first step.
Calf with contracted tendons. Photo courtesy of Andy Niehaus.
A genetic link
Dr. Jon Beever, University of Tennessee (professor and director of the Genome Center for the Advancement of Agriculture) says contracted tendons can be genetic. “If people suspect this, the veterinarian might send me a video or photo of the calves. We look at pedigree information and frequency in the herd or breed and try to make an assessment.”
How many years in a row have you bought the same kind of bull from the same breeder? Are you taking a chance on increasing inbreeding? Some abnormalities are caused by recessive genes that get doubled up when sire and dam both carry those genes – which is more likely if they are related.
“With recessives, it takes a while for frequency of that gene to build up in the general population of a breed. When multiple cases show up, it has built up to a point of fairly high frequency,” says Beever.
“Some traits are dominant, however, and it’s fairly easy to get rid of those once you understand they are dominant. You simply need to cull the parent. Dominant traits are easily observable and not very common, whereas a recessive trait can hide for many generations,” he explains.
“Genetics probably shouldn’t be the first thing to consider, but once you start collecting all the evidence, you can eliminate it as a cause or dig deeper,” he says. For instance, some of the milder cases of congenital contractual arachnodactyly (CA), also known as fawn calf syndrome, might just look like a tendon problem. CA is a recessive genetic disorder in Angus cattle affecting connective tissue of muscles, leading to contracture of the upper limb (most obvious in hind limbs) and laxity of joints of the lower limbs – the calf often walking on the backs of the fetlock joints.
Choosing treatments
Dr. Andy Niehaus, Ohio State University professor in the department of clinical sciences, says some calves with limb problems can be helped, especially if the calf can get up and move around. “If it can’t get up and nurse, we must assist. Get the calf up, support it and help it nurse – or bottle feed it or tube feed it – until you can get veterinary assistance,” he says.
A calf with splints on its front legs. Photo courtesy of Andy Niehaus.
For the ones that can get up, exercise and weight bearing help stretch contracted tendons or strengthen weak, lax tendons – and the calf may become normal over time. “Owners often want to put splints on those legs, but improperly applied splints can create more damage,” he explains.
“We might give the calf an injection of BO-SE [vitamin E plus selenium] if the cattle are in a selenium-deficient region. This sometimes helps with tendon issues,” says Niehaus.
“For calves that are so impaired they can’t get around or have a hard time getting up and around, we recommend splinting or casting. Physical therapy can often help, especially with animals that can’t get around. A person can [lay] the calf on its side and stretch the contracted limb for at least 10 minutes several times a day. Stretch it to the point where the calf resists, hold it there for 10 to 15 seconds and let off. Give them a break of about 20 seconds and then do it again. Repeated stretching may help,” he says.
Surgery is a last resort. “We palpate the leg to see where it’s restricted and think maybe, if we cut a certain tendon, it will release the leg so it can move into more normal position. Generally, it’s not that simple, however, and often not very rewarding. We may cut the offending tendon and the leg is still contracted and tight. If you cut too many structures, the calf won’t have adequate support for the leg.” Often the problem is partly in the joint capsules and not just the tendons.
If tendons are lax and the calf is walking on the back of the fetlocks, limit the calf to an area with soft footing or bedding so these joints won’t be damaged. “For some calves, we glue toe extensions or heel extensions to the foot. If tendons are so lax that the calf is walking on the back of the fetlock joint [toes tipped up], we use a heel extension to keep the foot at a better angle and the fetlock up off the ground.” Hopefully the leg will become stronger over time.
Toe extensions on calves can be glued or shaped to help keep the foot from knuckling over because of contracted tendons. Photo courtesy of Andy Niehaus.
A toe extension can help stretch the soft tissues in a contracted limb, but if a contraction is so severe that when the calf puts the foot down it knuckles over anyway, an extension makes it worse. “The foot is already past that point where the front hoof wall is vertical, and if you make the toe longer, the calf trips worse,” he says.
Anderson says splints or braces may also help. “Orthotic braces provide dynamic support so the calf can flex the joint but not overextend it. These are useful for calves with tendon laxity. You want them to be able to move the limb and walk, to stimulate muscles to become stronger and tighten up – and weight bearing can help – but you don’t want those joints to drop so much that they are walking on them.” The dynamic splint, a brace with a hinge, allows the leg to flex but not overextend.
Toe extensions. Photo courtesy of Andy Niehaus.
“And if we can get a contracted limb to extend a little with physical therapy, we try to treat the calf – using physical therapy and time – and splints/braces can be part of the physical therapy,” says Anderson.
In cases where the joint is solidly locked and won’t move, it’s probably been in that position a long time in the uterus. Some of these calves’ legs are so crooked they can’t be born naturally; the legs won’t straighten enough to come through the birth canal – and they must be delivered by C-section.
“Sometimes cutting a tendon can help, but if the limb has been contracted for a long time, the joint capsule may be scarred down and immobile, and releasing the tendon is not enough to get the leg straightened,” says Anderson.
“If we think there’s an abnormality in the bone, we can take X-rays. Portable X-ray machines are digital, allowing the veterinarian to assess the bones when examining a calf on the farm to determine whether it’s something that can be treated,” he says.
