Genetics Canada

Contractural Arachnodactyly

Contractural Arachnodactyly (CA) is a lethal disorder linked to a genetic condition caused by a recessive mutation that affects Angus and Angus-influenced cattle.

While CA-affected calves are born alive, and most can walk, suckle and survive, their upper limb joints (particularly hip, stifle and hock) have a reduced range of motion. Affected calves appear normal by four to six months of age, but most perform poorly and are relatively tall and slender, with compromised feet and leg conformation. Without DNA or progeny testing, carrier animals are indistinguishable from animals that are free of the condition.

For additional information, click here.

  • Testing of suspect animals is essential to avoid the negative impact of CA and to slow propagation of the defective gene.

    Samples may be submitted in one of the following forms:

    • Hair follicles: When submitting hair samples, please make sure at least 25 follicles (bulb intact) are included to ensure an adequate volume of DNA to complete the test.
    • Blood collector cards
    • Semen samples