Investigations into the discovery of the fourth BSE-infected animal born here since 1997 are now focused on the quality of the meat and bonemeal which was legally available for pig and poultry food in 1997-2000.
The animals should not have had access to feed containing meat and bonemeal, which was banned from the cattle food chain as far back as August 1989.
But the fact that three of the animals, all born within the same general area, not only consumed meat and bonemeal, but also meat and bonemeal which was infected, is causing great concern.
This would seem to indicate that despite all the controls, meat and bonemeal, which was legally available for pig and poultry food, was still being contaminated right up to the year 2000.
The regulations in place during the past decade demanded that all the organs in cattle which Bovine Spongiform Encephalopathy can infect, be removed and sent for rendering into meat and bonemeal which was then exported for incineration.
The rest of the animal carcass, minus the organs which are called Specified Risk Material, was allowed to be rendered down into meat and bonemeal which could be fed to pigs and poultry.
However, EU laws required this process be carried out at high temperatures and pressures, to kill any infection which may have remained in the animal.
Department of Agriculture and Food investigators are now looking at the possibility that some of the plants manufacturing meat and bonemeal were not operating their equipment at the required temperatures or pressures.
One veterinary expert working in the Limerick/Kerry area, said he feared there may be more cases of the disease.
"These young animals seem to have had access to infected feed and if they did then so had other animals in the area," he said.
"However, we also have to look at the possibility that the disease may be spread by either poultry or pig slurry which may have contaminated pastures," he said.
"If that is the case we are into a different scenario altogether, but I still believe that in some way the young bull in Limerick and the cow in Kerry were somehow exposed to feed containing contaminated meat and bonemeal," he concluded.
Other theories, including the possibility that the infected meat and bonemeal may have been imported in compounded cattle feed at that period, are also under investigation.