A Southland veterinarian says the disease several dogs became ill with after attending a national sheepdog event is not contagious.
Organisers alerted competitors after a dog that had been at the national sheepdog trial championships in Masterton in June died.
Two others needed intensive treatment, but are expected to recover.
Vetco veterinarian Justin Muschamp has diagnosed the disease as salmonella typhimurium, which he says is likely to have come from infected food eaten by the dogs. The symptoms are generally nausea, vomiting, diarrhoea and sometimes skin lesions.
Mr Muschamp says salmonella is not common in dogs, so competitors whose dogs have shown no symptoms by now don't need to be concerned.