It has been suggested Bleeding Calf Syndrome is linked to Pregsure, a vaccine used to control bovine viral diarrhoea (BVD). However, both the Scottish Agricultural College and NFU Scotland this week cautioned against making this connection. The Veterinary Medicines Directorate, the UK regulator, meanwhile, has stated the benefits of the vaccine outweigh any supposed risks.
The Moredun Research Institure has also said the cause of the disease "remains unknown at this time".
"Our preliminary findings have failed to find a definite link between the disease and any of the parameters investigated," a spokesman said. Parameters included a viral cause, genetic susceptibility and an immunological basis for damage to the calves' bone marrow.
The SAC's veterinary service identified 75 cases of BCS across the UK in the past 12 months. Pregsure, a BVD vaccine produced by Pfizer Animal Health,
has been voluntarily withdrawn from the market in Germany to help progress epidemiological investigation, the SAC said.
A spokesman added: "SAC also notes that no direct causal link has been established between the use of the BVD vaccine and Bovine Neonatal Pancytopenia, formerly Bleeding Calf Syndrome."
The VMD also stressed that there was no direct link between the vaccination and the disease, saying that in the UK at the end of February this year, the incidence of suspected adverse reactions with symptoms similar to the disease was one animal for every 24,947 doses of Pregsure; figures which were considerably lower than those for Germany.
"At this stage, the benefits of the vaccine are considered to outweigh the risks. In Europe, some cases of the disease have occurred where the cow has not been vaccinated, while in the UK, a small number of cases have been reported involving vaccines other than Pregsure."
Union vice-president Nigel Miller, who is also a vet, called for a concerted effort by scientists, vets and cattle producers to find a solution.
"Beef and dairy farmers should keep an eye out for unexplained deaths in any young calves, in particular for signs of persistent bleeding. If they think they have affected animals, they should contact their local vet or their local investigation laboratory and make use of the available post-mortem services."
He asked producers to discuss herd health plans with vets.