Lead Poisoning in Cattle Preventable

Calves More Prone to Eat Things That Adults Would Leave Alone

Russ Quinn
By  Russ Quinn , DTN Staff Reporter
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Cattle grazing. (DTN photo by Jim Patrico)

OMAHA (DTN) -- Lead is the most common cause of poisoning with cattle. Even a small amount of lead can kill livestock if they drink crankcase oil, lick grease or chew on lead plumbing fixtures or old vehicle batteries.

Lead poisoning is difficult to identify and is most often fatal in cattle. Preventing cattle from having access to sources of lead is the best way to avoid lead poisoning, according to veterinarians.

TOP CAUSE OF POISONING

Gregg Hanzlicek, director of production animal field investigations with the Kansas State University (KSU) Veterinary Diagnostic Laboratory, located in Manhattan, Kansas, told DTN lead is the No. 1 cause of poisoning in tests the diagnostic lab runs. This spring, the lab had several cases of spring calves diagnosed with lead poisoning shortly after going to pasture, he said.

"We didn't see any more cases this year than in past," Hanzlicek said. "Lead poisoning is something we see every year."

Hanzlicek said lead poisoning is diagnosed more often in young calves. The only way a cow is poisoned from lead is if they ingest lead directly, whether that is from licking an old vehicle battery or eating flakes of old paint from paint cans improperly discarded.

Newborn calves are especially susceptible as they are curious, so they eat things that older animals probably would not eat. Hanzlicek said most of Kansas received spring rains with some areas seeing heavy rains, which may have washed away soil exposing sources of lead.

Like other poisoning, one of the most common signs is finding one or more dead animals in the pasture, he said. For those cattle that are not dead, clinical signs of lead poisoning would be changes in behavior, stumbling or staggering and convulsions.

Another sign of lead poisoning would be blindness. Within a day or two of ingestion, the signs of lead poisoning will begin to show, he said.

Richard Randle, University of Nebraska-Lincoln (UNL) Extension veterinarian, said much like lead poisoning in humans, low-dose exposure could yield no signs for a long period of time. Acute poisoning, however, kills livestock much more quickly.

"The poisoning will affect the central nervous system of the animal as well as the gastrointestinal system," Randle said. "Often times cattle will almost bellow as they are in a great deal of pain. Treatment is really not effective once symptoms appear."

Randle said he saw lead poisoning quite a bit growing up and helping his father, who was a veterinarian in Mississippi, in the 1960s. In his work at UNL Extension, he has seen some cases of lead poisoning, but it is not nearly as common as it was decades ago.

PREVENTION IS KEY

Why lead poisoning happens today is probably a result of cattlemen renting different pastures or buying pastureland in recent years. A lot of times the producer will not know the history of the land and where old dumpsites were located until problems with lead poisoning arises.

Randle said he would advise cattle producers to look for signs of old dumping grounds and either clean up these areas or fence cattle off from grazing in these areas. Lead sources can often contaminate soils even after the sources are removed, but plants won't take up lead, so grass, and thus livestock, will not be affected, he said.

Hanzlicek said often it is fairly easy for cattle producers who have issues with lead poisoning to figure out where the source of the lead is located.

"Several times we or the local veterinarian had to walk the pasture to find the source," Hanzlicek said in a KSU press release. "It is usually an easy fix if they know it is an issue."

Although prevention is the best treatment, there are things producers can do should they suspect their cattle has been in contact with lead.

Hanzlicek said one thing he would recommend would be to use smartphones and take videos of the animal and send to your local veterinarian. The local vet can then decide based on the video if more testing is needed to find the true problem.

"There are a couple of good blood tests that are definitive for lead poisoning for diagnosing it in live animals," he said. "For animals that are found dead, we typically like liver and kidney tissue sent in to determine the lead level of those tissues."

Lead poisoning can also be confused for other diseases. A neurologic disease called Polioencephalomalacia, rabies and low magnesium all have similar clinical signs to a lay person, he said.

You can't just assume lead poisoning is the problem. The best source of advice is your veterinarian as he or she has been trained to recognize a diverse number of diseases, he said.

Russ Quinn can be reached at russ.quinn@dtn.com

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(SK/BAS)

Russ Quinn