A ninth case of equine infectious anaemia (EIA) has been confirmed.
The condition, known as swamp fever, is alleged to have been brought into the country in a batch of infected anti-serum to treat another equine illness. The anti-serum was given to six foals, who subsequently became ill. Three mares have died from the condition.
Michael Sheridan, Dept of Agriculture, deputy chief veterinary officer
According to the Department of Agriculture, the new cases involved animals that were already identified as part of a high-risk group.
"I think it's a little early to say that we have the situation under control," said Michael Sheridan, deputy chief veterinary officer of the Department of Agriculture, speaking on RTÉ Radio.
The owners of animals that have passed through or had contact with the affected premises in Meath and Kildare are being traced and the animals tested. Some 2,200 tests have already been carried out, and the Department of Agriculture is awaiting some test results.
"The main method of control is tracing the infected animals and putting them down," Mr Sheridan said.
"Unfortunately, they very often become carriers; even when they recover from the disease; they can become carriers and remain then as a source for the following year."
EIA, which has not been found in Ireland before now, attacks the immune system and can be spread by blood-sucking insects, such as the horsefly, through infected blood, or by contaminated medicine.