A ridgling (also spelled ridgeling), or rig, is a cryptorchid; a male animal with one or both testicles undescended, usually describing a ram, bull, or male horse, but cryptorchidism also can be an issue in dogs and cats.

What is a ridgling in horse racing?

(A cryptorchid (ridgling) is defined as a colt which does not have both testes palpable in the entirety below the external inguinal ring, and includes a colt that has had one testicle removed.

How do I know if my horse is cryptorchid?

Signs and Symptoms: Cryptorchid horses usually exhibit standard stallion behavior, but visibly/palpably lack one or both scrotal testicles. Immature horses may be undetected until they are examined just prior to routine castration.