The cattle section will be missing from both South and West Otago A&P shows this year.
Due to the nationwide attempt to eradicate the disease Mycoplasma bovis, both show committees have decided it would be too much of a risk to run cattle sections.
South Otago A&P cattle convener and chairwoman of the Royal Agriculture Society southern district, Jackie Kelly, said it was not worth putting people's livelihoods in danger.
''It would be heartbreaking if someone's herd suffered due to bringing them to our show,'' Mrs Kelly said.
Dairy companies were undertaking intensive testing of milk for signs of the disease. Results would not be available until November 15, Mrs Kelly said, just a week before the show.