At least once every year, an unfortunate story of cattle loss is repeated somewhere in Oklahoma. A producer encounters sudden death loss in several young calves and the veterinary diagnosis is lead poisoning. After an internet search, several important keys to prevention can be found.
1. Very small amounts of lead can cause poisoning. Calves licking crankcase oil, grease from machinery, lead pipe plumbing and batteries can be in danger.
2. Small calves represent the greatest percentage of lead poisoning cases because they are curious eaters. Other cattle however can also be affected.
3. Junk or garbage in pastures can be a source of lead. Example sources include: some crop sprays, putty, lead-based paints and painted surfaces, roofing materials, plumbing supplies, asphalt, lead shot, leaded gasoline, and used oil filters.
Symptoms of lead poisoning are often similar to other diseases and require a veterinary diagnosis to accurately confirm. Clinical signs of poisoning normally precede death, nonetheless, in many cases animals are simply found down or dead in the pasture. Observable signs vary from sub-clinical to very dramatic and take from just a few days to as many as 21 days to develop. Initial signs include depression, loss of appetite or occasionally diarrhea. The central nervous system may be affected and cause cattle to grind their teeth, bob their head, or twitch their eyes or ears. Some animals may circle, press their head or body against objects, or become uncoordinated and stagger. Muscle tremors, excitement, mania, blindness or convulsions may also be seen.
Treatment of lead poisoning can be costly and ineffective if not started quite early after ingestion of the lead. Successful treatments are usually started before the symptoms begin to appear and are often reserved for very valuable animals.
Prevention is the key. Be aware of any old or new machinery in pastures. Avoid junk or debris that could be a source of lead. (This could really be an issue after a severe thunderstorm or tornado with wind damage which results in roofing debris spread across the pasture.) Above all, DO NOT dispose of old car batteries in pastures where cattle have access to them.
Source of information: "Lead Poisoning in Cattle" Agriculture, Food, and Rural Development. Alberta, Canada.