Angry French farmers are calling for more protests over the government-backed slaughter of cattle herds affected by so-called Lumpy Skin Disease (LSD). On Thursday there were clashes between riot police and demonstrators in the southern Ariège department, after vets were called in to destroy potentially contaminated cattle at a farm. Elsewhere in the south, farmers have dumped manure outside government buildings and blocked roads. The offices of several environmentalist groups were ransacked in the Charente-Maritime department. LSD is a highly contagious bovine disease which is transmitted mainly by fly-bites. The symptoms are fever, mucal discharge and nodules on the skin. Though mainly non-fatal, it can badly affect milk production and the cows are unsaleable. The disease arrived in Europe from Africa about ten years ago. France's first outbreak was in the Alps in June, when an infected herd forced the Tour de France cycle race to cut short one of its stages. The government's policy of slaughtering entire herds where a single animal has been infected has run up against bitter opposition from two of the three main farmers' unions. Confédération Rurale and Confédération Paysanne say the policy is being brutally applied and is unnecessary as a combination of selective culling and vaccination would suffice. But most vets disagree, emphasizing the difficulty in identifying asymptomatic carriers of the virus. Since June, around 110 outbreaks of LSD have occurred in France, leading to the slaughter of about 3,000 animals. The French government is apprehensive that these protests could escalate into a broader uprising among the farming community, which feels increasingly threatened by EU regulations and foreign competition. A significant protest is planned in Brussels next week during a summit of EU leaders, as farmers also object to an impending free-trade agreement with South American countries.