Poisonings associated with herbicides are much more common in cattle and sheep than in pigs. The important ones however include arsenic. borax and pentachlorphenols (PCPs). The latter can be absorbed through intact skin or mucous membranes to which they are highly irritant.

PCP's are used widely as preservatives, insecticides, fungicides and molluscicides but generally they are inactivated in soils when used correctly. Contact with treated wood used in feeding troughs can cause salivation and severe irritation to the mouth.

Clinical signs

These include nervous changes, respiratory distress, tremors, muscle weakness, convulsions and death.

Diagnosis

This can be difficult but a careful examination of the products on the farm and their access will often assist.

Treatment

• If nervous signs are severe use a sedative such as stresnil. Give electrolytes.