Cattle producers should be on the lookout a fungus in grasses that causes circulatory problems in livestock that consume them.

The fungus, ergot, has been confirmed in several surrounding states, including Missouri and Iowa, said Richard Randle, a University of Nebraska-Lincoln beef veterinarian. He and colleagues are aware of at least a couple of unconfirmed reports in Nebraska.

Climatic conditions are key to ergot's presence, and they were ideal in some parts of the state this year. Early moisture followed by heat causes certain grasses – especially rye, but also brome, wheatgrass and others – to grow quickly and develop seed heads faster than cattle can consume them. Ergot then can move in and infect the seed heads.

Producers should watch their animals for tips of ears and tails falling off as the fungus can shut off the blood flow to extremities, Randle said. As it progresses, it can affect cattle's feet, causing them to become lame, or cause swelling in the tops of hooves. Rear legs are typically most affected.

Ergot poisoning is unlikely to be fatal but because it can make cattle less tolerant of heat, they can be more susceptible to death from excessive heat. If they are removed from the source of the fungus, they are likely to recover.

Ergot shows up larger than typical seedheads, usually dark brown, purple to black.

Ergot poisoning does not affect meat from cattle.