A new virus linked to climate change threatens French cattle farming

It was a little after 5 p.m. when Frédéric Carrère picked up his phone. A cattle breeder in the Pyrénées-Atlantiques for twenty-six years, he has just brought back a cow that gave birth. Frédéric is reassured, the latter did not lose her calf during the process; unlike two of his Aquitaine blondes last week. Since the beginning of September, a new pathology – epizootic hemorrhagic disease (EHD) – has affected cattle, sheep and deer in the south-west of France, causing concern among breeders. To date, 2,019 outbreaks have been recorded. Although it does not affect humans, this virus is transmitted by biting midges from warm countries and causes significant hemorrhages in the affected animal. Enough to prompt the visit of the Minister of Agriculture and Food Sovereignty, Marc Fesneau, on November 2, who came to observe the damage and assure that “the State will be there”.

Symptoms ? “The cow has some aches and pains,” Frédéric simplifies. She travels less to eat and drink. And therefore becomes more and more dehydrated… This spiral can lead to death. » In the absence of a vaccine, the protocol followed after detection of a contaminated animal is extremely strict. “First, we disinsected the entire herd,” explains the farmer, “before isolating the most affected cows in order to be able to better monitor them and forcefully rehydrate them. For others, antibiotics and anti-inflammatories were enough. And for animals intended for export, a negative PCR test must be provided. » In total, nearly 10% of his herd contracted this disease, causing significant veterinary costs – sometimes 300 euros per cow.

Poor farmers

Although no new cases have been observed since, the situation has exhausted Frédéric. Both physically and mentally. “We find ourselves completely helpless in the face of the arrival of these diseases,” he laments. Viruses mutate. We know there will be others. » Stéphan Zientara, director of the animal health laboratory of the National Health Safety Agency (ANSES), can only agree with him. According to the veterinarian and virologist, global warming favors the emergence of diseases from hot countries. “Originally, MHE, a tropical disease, was rampant in Indonesia, the West Indies and even Guyana. Insects proliferate in these regions due to the climate. These pathogens are now found in the northern hemisphere due to increasingly favorable climatic conditions which allow mosquitoes and midges to be active over a longer period of time. » In March 2023, the phenomenon was the subject of a study by the Ministry of Agriculture. The analysis highlighted the link between climate change and the spread of vector-borne diseases, noting in passing that “in high-income countries, the trend is towards control”. The observation does not really satisfy farmers who, like Frédéric, would like a little more anticipation from the public authorities.