TB eradication the ‘only show in town’

Ireland’s live export trade is utterly dependent on having a TB eradication scheme and, as a result, it’s the “only show in town”, a vet in the west of Ireland has said.

Aoife Mulhern, a veterinary inspector with the Department of Agriculture, said that not having an eradication scheme is “unthinkable”.

“TB eradication is the only show in town, there’s no alternative for us,” she told an IFA meeting in Tuam, Co Galway, last week.

She warned that reactor numbers are going in the wrong direction.

“The number of reactors are way out of line with herd incidence. What we’re seeing is larger breakdowns.

“When the scheme opened in the 1950s, 80% of the herds in Ireland were infected with TB.

“The end of an eradication scheme is always the most difficult. It’s nearly easier to get from 80% to 8% than it is from 8% to 0%.

“Suddenly the graph changed around 2016 up to 2018. Between 2022 and 2024 there was an uptick [in reactors].

“This uptick is a real cause of concern, the question is how do we respond to it? How do we make things better?”

TB is an extremely difficult disease to control, she said.

“When we look at TB disease… we don’t look at it just as a regulation.

“To someone in breakdown, it’s a highly infectious respiratory disease.

“It has multiple sources, any ruminant can be a host, deer, badgers, humans and the environment. There are multiple modes of transmission. It has a carrier state.

“It’s not like having an animal with mastitis, where a few days later you can see she’s sick and you get your vet out.

“It could take two years for symptoms to show and this carrier state is really difficult to deal with in an eradication programme,” she outlined.

Noting cattle movement figures, she said that there was 3.5 million movements in 2022 excluding animals for slaughter.

“Other countries which have been successful in eradicating TB wouldn’t have as many movements as that,” she said.

Mulhern warned that the expansion of the dairy industry has “come at a price”.

“We’ve large intensive dairy herds and we’re seeing large breakdowns in dairy herds and we know why that is.

“Bacteria thrive in communities like cows where there’s high numbers, they’re close together, they’re very stressed.

“When cows calve down they go into that peak milk state, they’ve a negative energy balance and they’re very vulnerable to disease.

“It only takes one bacteria to infect a dairy cow – through either a bought-in animal or a badger, and then it spreads like wildfire. When I qualified in 1994, I was testing in Claremorris. We never heard of breakdowns of 40 to 150 reactors. That’s what we’re dealing with today in large intensive dairy herds. These large dairy farms are coming under pressure.

“TB behaves differently in a dairy herd than it does in a beef herd. It’s a real concern,” she said.

Mulhern also said that it is up to the vet to carry out the test to the best of their ability. “The worst thing that can happen you is to have infection in your herd and you’re there for a year and it’s not disclosed. It’s the responsibility of vets to carry out the test correctly.” 

“Nobody wants TB and nobody deserves TB. But there are things you can do to reduce your risk,” she advised.

“I’m not saying don’t do this but it’s something to think about; avoid purchasing in breeding stock.

“Can you rear your own? Can you avoid purchasing from multiple sources? Do you want an animal that has been in five herds? Or do you want an animal that has been in one herd.”

When asked if other animals such as birds and foxes are being tested to see if they are a source of TB, IFA animal health chair TJ Maher said that there is no evidence that birds spread TB.

“I’ll be brutally frank, we can’t stay turning the bushes upside down. Deer, cattle and badgers they’re the hosts. Don’t go chasing shadows. We have a badger problem, we need to solve it. There is no evidence that birds spread TB,” he said.

Mulhern responded by saying that any eradication scheme must be based on evidence.

“We don’t have evidence that birds and foxes are a source of TB. When investing in an eradication programme, we want to invest in the programme that has the most impact,” she said.

The vet added that it would be an “absolute dream” if there was a vaccine that would be acceptable for an eradication programme. But she warned that if Ireland started vaccinating cattle with the BCG vaccine, the same one that humans and badgers receive, then we’d be blocked from trading with other countries. However, since there is no test available to show the difference between an infected animal and a vaccinated animal, this is a non-runner.

IFA animal health chair TJ Maher told the meeting that it is important that the different levels of risk are discussed when animal movements and TB are being talked about.

“Seventy per cent of all reactors are cows, breeding animals. For the last two years farmers who are restricted with TB have been allowed to buy in stock onto their premises, particularly cattle.

“Previously if they had a restriction they weren’t allowed to buy in cattle and their business was shut down.

“That has been happening for two years and there hasn’t been an endemic explosion of TB in those herds. We have to accept that there are different levels of risk.

“This is the key issue. This is where we have a clear divergence of opinion with the Department.

“Breeding stock are a very significant risk and must be treated differently.

“We have to accept that the vast majority of cattle are killed at 26-27 months of age and their risk of getting TB is far lower because they don’t live an awful long of time. Their ability to spread it is far lower.

“When we talk about risk and trading, we have to make sure we differentiate between the two.”