Thursday morning last and it felt like the sky forgot to wake up. A thick fog lingered low and heavy over Lough Derg and its surroundings, with no intention of rising.

At 9.45am, I received a call that shocked me and reaffirmed the dangers of farm life.

“Tadhg, I was agitating the tank and I’ve weanlings dead and more falling around the place,” said the caller.

My only response was ‘stay out of the shed and I’ll be on the way’.

On arrival, the smell of slurry was particularly pungent, aided by the stillness of the day.

Through the fog, I saw the sight of six weanling heifers lying dead on the ground, while two more were in a shed staggering and blind.

The farmer had managed to open a gate to allow the rest of the animals to escape, endangering his own life.

This incident highlights the risks of dealing with slurry that are often forgotten because of the regularity of the job.

On reflection, it could have been no longer than three minutes from the time the agitator was turned on to when the animals dropped dead.

The animals at the furthest end of the shed were those that died instantly – the other two managed to clamber out.

Toxic gases

Toxic gases such as hydrogen sulphide (H2S), carbon dioxide (CO2), ammonia and methane are produced by the decomposition of slurry and can be released when the slurry is mixed.

Hydrogen sulphide is the real killer. Denser than air, it is slow to rise. The weather would have been a factor on this day.

It causes acute central respiratory failure similar to the mode of action of cyanide.

Those exposed to lower doses that survive will have hypoxic brain damage.

Children are more susceptible because of their high lung intake to weight ratio and higher lung surface area to weight ratio.

Agitating

The practices of agitating slurry on this farm had been the same for the last 30-plus years, as it is on many other Irish farms.

However, the facts are that a single breath of slurry gas can kill man and beast.

Each time it goes without incident is like winning a game of Russian roulette, but not on this day. Thankfully, no human became a statistic this time.

Tadhg Gavin MVB CertDHH, Killaloe Veterinary Clinic, Co Clare. Killaloe Veterinary Clinic is part of XLVets. XLVets is a group of progressive practices who are working together to achieve a better future for agriculture and veterinary in Ireland. For further information, go to www.xlvets.ie.

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