On-farm incidents relate to poisoning or high residual chemical levels in farm animals destined for the food chain. This includes lead and copper poisoning, ragwort consumption, rodenticides and botulism. Since 2015, more than half of on-farm incidents reported to our Scottish Food Crime and Incident Unit (SFCIU) were caused by lead exposure and poisoning. These incidents can put food safety at risk if the animals are not restricted from the food chain.
These incidents commonly happen in the spring when cattle are put out to pasture and young cattle are usually affected due to their inquisitive nature.
Sources and symptoms of lead poisoning
Lead poisoning of cattle accounted for 48% of all on-farm incidents in 2016/17. Sources of lead include lead batteries, burnt out cars, bonfire ash, lead flashing, flaking lead paint, lead shot, paint tins and geochemical sources such as old mine workings.
Symptoms of lead poisoning in animals include blindness, odd behaviour including grinding teeth, bobbing head, twitching eyes/ears, frothing at mouth, muscle tremors, staggering, excitability and convulsions. Once an animal is showing symptoms of lead poisoning death usually occurs shortly afterwards.
What we have done
In response to the consistently high numbers of lead on-farm incidents, we implemented an awareness program aimed at farmers to help prevent these incidents and to mitigate the risk to consumers.
Prevention measures included:
There was a 63% decrease in lead on-farm incidents between 2016 and 2017.
Copper on-farm incidents
Copper poisoning usually affects sheep. Sources of copper poisoning on-farm include cattle minerals and feed, supplements such as boluses and drenches, pig or poultry manure, distillery by product feeds and fertilisers (from copper stills) and others such as copper sulphate foot baths and copper piping.
Symptoms of copper poisoning are sudden in onset and affected animals become increasingly weak. Some sheep may spend time wandering aimlessly or head-pressing. As the disease progresses, jaundice develops and breathing becomes shallow and rapid due in part to the development of anaemia.
Numbers of copper on-farm incidents in Scotland have remained consistent over recent years with 3 reported in 2016 and 4 in 2017.
Other on-farm incidents
Other types of on farm incidents are less common but can include rodenticides, botulism, ragwort, ergot, cadmium, arsenic or malicious contamination.
Future prevention initiatives
We will continue to focus efforts on incident prevention. For 2019, the on-farm leaflet will be updated to include information on other types of on farm incidents, not just lead.