A recent rise in the number of blackleg cases in cattle across the country has caused concern among vets.

The Department of Agriculture issued a statement in August stating that there has been a sharp increase in the prevalence of large blackleg outbreaks in cattle being referred to its regional veterinary laboratories for postmortem.

Although the disease is described by vets as fatal, vaccination is a cheap and extremely effective solution for prevention.

However, what is absolutely imperative when it comes to vaccination, according to Tipperary vet Damien Corcoran, is how farmers are administering the vaccine.

“We see blackleg every year – it’s probably the most probable cause of an animal being found dead suddenly. But this year we have seen a little uptick in cases - this uptick is related to the nature of how the disease persists in the environment.

“The disease survives in the environment as spores. Clostridial bacteria produce these spores and they survive in the soil for a long time and any year where soil gets disturbed – it could be where a farmer has reseeded, or where they’ve reclaimed land or carried out ditch work – that can expose soil to the surface that hasn’t been exposed for a long time. That’s then a source of blackleg disease.”

Spores

“In a year like this where a farmer may not have done any reclaiming or reseeding, the spores can come to the surface where land is getting poached around drinkers and troughs.”

“The most common thing with clostridial disease is that the farmer doesn’t see the animal sick.

“The farmer could have done their herding at 9am in the morning and at 5pm in the evening the animal is dead. It hits them like a tonne of bricks. Over the course of 12 hours, they’ll go from being perfectly fine to dead,” Corcoran explained.

Correct vaccination

There have been incidences, Corcoran added, where farmers have lost animals even though they’re vaccinating.

The probable cause is that they’re not vaccinating properly.

“All diseases are a balance between vaccination status and immunity and the disease exposure.

“When people are using vaccines, it’s important that they get correct advice. Farmers all know how to administer vaccines, but they need to look at what animals are most at risk, when are they most at risk and what is the best way that they should be vaccinated.

They also need to know what the course of immunity is; [with blackleg] you need two vaccines given a certain period apart to give you full immunity.”

So many farmers, he added, give the first vaccine and don’t give the second so it’s important to get good advice around what groups are most at risk and the manner in which they should be vaccinating.

According to MSD Animal Health, calves two months old should be vaccinated twice, four weeks apart, followed by annual boosters before the anticipated danger period which is usually spring or early summer when stock are let out.

Most cases, it said, are seen in cattle between six and 24 months old.