Congenital Limb Deformities in Calves: Bent Legs, Crooked Limbs, and Joint Contractures

Congenital limb deformities are abnormalities of the legs or joints that a calf is born with. Pet parents and producers may notice bent front legs, crooked lower limbs, knuckling over at the fetlock, twisted joints, or limbs that stay fixed in a flexed or extended position. In some calves, the problem is mainly in the tendons and soft tissues. In others, the bones, joints, or nerves are also affected.

A broad term often used in cattle is arthrogryposis, which means one or more joints are stiff and contracted at birth. Some people also use the term crooked calf disease when calves are born with multiple congenital contractures, sometimes along with spinal curvature or cleft palate. Mild deformities may allow a calf to stand and nurse with help. Severe deformities can prevent normal walking, nursing, or long-term comfort.

These cases are not all the same. A calf with mild flexural deformity may do well with early conservative care, while a calf with severe fixed joints or multiple birth defects may have a guarded outlook. Your vet can help sort out whether the problem is likely soft-tissue contracture, bone deformity, neurologic disease, or part of a larger congenital syndrome.

These deformities can develop for several different reasons before birth. Some are genetic or inherited, especially when similar defects appear in related calves or within a bloodline. Others happen because the fetus did not move normally in the uterus, which can lead to fixed joints and shortened soft tissues. Merck Veterinary Manual also notes that congenital contractures and related deformities may occur with fetal malformations and some inherited neuromuscular disorders in cattle.

Infectious and toxic causes are also important. In-utero viral injury can disrupt development of the nervous system and limbs. Merck notes that fetal exposure to bovine viral diarrhea virus during pregnancy can cause congenital defects, and arthrogryposis may occur with some fetal malformation syndromes. In some regions, lupine exposure during pregnancy is a classic cause of crooked calf disease. Extension sources describe the highest risk window as roughly days 40-70 of gestation, when toxic lupine alkaloids can interfere with fetal movement and lead to arthrogryposis, scoliosis, cleft palate, and jaw deformities.

Nutrition and maternal health may also play a role in some herds, although they are not the only explanation. A careful herd history matters. Your vet may ask about sire lines, previous affected calves, vaccination status, grazing areas, drought conditions, and whether pregnant cows had access to lupines or other known teratogenic plants. That history often helps narrow the likely cause more than the limb appearance alone.

Diagnosis starts with a hands-on exam. Your vet will look at which limbs are affected, whether the joints can be gently straightened, whether the calf can bear weight, and whether the problem seems to involve tendons, bones, joints, or nerves. They will also check for dehydration, nursing ability, pressure sores, and other congenital defects such as cleft palate, spinal curvature, or neurologic abnormalities.

Radiographs are often the next step when the deformity is moderate to severe, worsening, or not clearly a soft-tissue contracture. X-rays help show whether the bones and growth plates are aligned normally and whether there are fractures, rotational changes, or angular deformities that may not respond to splinting alone. In more complex cases, referral imaging or orthopedic consultation may be recommended.

History is a major part of diagnosis in cattle. Your vet may ask when during gestation the dam grazed certain pastures, whether other calves in the herd were affected, and whether there is a pattern tied to a particular bull or cow family. If a hereditary defect or infectious cause is suspected, your vet may recommend herd-level investigation, necropsy of severely affected calves that do not survive, or laboratory testing to guide future breeding and prevention decisions.

Prevention starts before breeding and continues through pregnancy. If a herd has repeated cases, work with your vet to review pedigrees, affected family lines, and sire selection. Recurrent defects in related calves raise concern for an inherited problem, and removing suspect animals from breeding plans may reduce future risk.

Pregnancy management matters too. Keep cows on a balanced nutrition program and maintain a strong herd-health plan with your vet, including vaccination and biosecurity decisions that fit your region. Review grazing areas for known teratogenic plants. In western and range-based systems, lupine exposure during the critical gestation window is a well-known risk for crooked calf disease, so pasture timing and plant control can be important prevention tools.

If one affected calf is born, document the date, dam, sire, pasture history, and any other abnormalities. If more than one calf is affected, involve your vet early for a herd investigation. Early pattern recognition can help identify whether the problem is genetic, toxic, infectious, or sporadic, which is the key to preventing the next case.