Britain's horse racing body says trainers could face doping sanctions without a positive sample from a horse.
The tightening of the rules starting next month follows an investigation into the use of Sungate, which is legal in Britain but contains the banned steroid stanozolol.
The British Horseracing Authority was concerned in the Sungate investigation that no charges could be brought against trainers ''even though there was evidence that prohibited substances had been administered to horses in their care or control.''
The revised rules will allow the BHA to bring charges if it has ''sufficient evidence that certain prohibited substances have been administered to horses in the care or control of a trainer.''
The horses also will be disqualified from races they ran in after the banned substances were administered.
