Induced cryptorchidism (or crimping) involves applying a rubber ring to a male animal’s scrotum so that the testes are held against the abdomen. This increases the testicular temperature which results in the animal becoming infertile while still producing the male hormone testosterone. The technique is used because it results in animals achieving higher growth rates than castrates.
The RSPCA does not support induced cryptorchidism as it offers no benefit to the animal concerned. Induced cryptorchids continue to display masculine behavioural patterns and, because of the constant risk of aggressive encounters, the animals may suffer chronic stress. Cryptorchids require closer management than castrates to ensure that their aggressive behaviour does not result in injury to other animals. Injury to the poll area as a result of aggressive interactions, for example, results in cryptorchids’ greater susceptibility to poll strike.