The creators of the breed intended that great care be taken to prevent this undesirable trait from manifesting in the Dogo Argentino, as the breed was always intended to be a pack hunter.
Dogos can develop an aggressive or dominant temperament if not socialized with other dogs at an early age, particularly with other dogs of the same sex, but can be trained by an experienced handler.
However, some Dogos are being bred by inscrupulous people for the sole purpose of dog fighting. The Dogos of these lines (unlike the original Dogo Argentino) are extremely dog aggressive and not suited for big game hunting. Additionally, the Dogos of these bloodlines are sought after for dog fighting because they combine strength and a willingness to continue fighting despite substantive injury. These Argentine Dogos are somewhat smaller than ones used for big-game hunting (Dogos involved in dog fighting are often between 75 and 90 lb.). In some rare cases, they are cross-bred with the American Pit Bull Terrier. In the United Kingdom it is illegal to own any of these dogs without specific exemption from a court. See Dangerous Dogs Act 1991 for details.