Algae suspected in S.D. cattle deaths
FREEMAN, S.D. -- Official lab reports are pending, but some recent deaths of purebred cattle in Hutchinson County were likely caused by algae poisoning, according to State Veterinarian Sam Holland.
About 21 head, part of a larger herd of Angus cattle belonging to Roth Angus of Freeman, died in mid-June while on grazing land leased from the state.
"The most probable cause of death is acute algae toxicity," said Holland. "That happens when certain (common) toxic algae that grow on ponds get concentrated on one side of a stock dam."
Narrowing the field to a single variety of algae is not likely, Holland said, adding that "it's probably not one specific algae, but a class and mixture of algae. They're all capable of producing toxins. It's when they concentrate (that) you have the problem."
Brian Humphrey, a conservation officer for Hutchinson and Turner counties with the state Department of Game, Fish & Parks, said Monday he is still awaiting the official lab results on what killed the cattle, though he agreed that algae toxicity is a strong possibility.
The cattle that died, said Humphrey, were "grazing on one of our game production areas and (owner Craig Roth) was notified by a neighbor to the south that he had a bunch of dead cows."
Humphrey said the 21 dead cattle were part of a herd of about 59 cow-calf pairs. He said the cattle were drinking water that pooled near a spring. "For the most part it was a just a little spring," said Humphrey. "I don't think it was even a permanent spring." He said there was no stock dam, a report that was at variance with that received by Holland.
"As soon as we found out (Roth) contacted me and we moved the cows off there." The pasture in question is divided in two and the cattle were moved from the east to the west side of the pasture, he said.
The remaining cattle were tested and cleared for anthrax prior to being moved, Humphrey said.
Holland's office recently announced two confirmed cases of anthrax in Hutchinson County, but those affected locations were not disclosed.
"Most of the dead cows were within maybe a 100 feet of the springs, so whatever it was killed them pretty quickly," Humphrey said.
Roth's cows died on state property, but it could not be determined immediately Monday if he could recover any losses from the state. Roth could not be reached for comment.
"We've had a graze lease and have had cows grazing that area for the past three years without any problem," Humphrey said.
"If it's an algae bloom I don't think there's any way to fix that," he said, adding that test results will be needed to determine if the problem has natural or other causes.
Algae poisoning is a situation that's difficult to prevent, Holland said, but the best way for farmers to address the problem is to keep their stock near fresh water.
"The fresher the water the better," said Holland. "Make sure they have access to more than one location for water, especially around a given dam. Don't narrow it down so there's a given (watering) area because if the algae are concentrated, the (animals will) all be forced to drink from that area."
Holland said if the Hutchinson County case is confirmed it will be the first case of algae poisoning this year. "Almost every year we see some, in some years more (cases) than others." Typically cases occur later in the year, he said.
Mere skin contact with algae is not a problem, said Holland.
"I think you'd have to consume a considerable amount of the water that's contaminated with algae in a very concentrated location. That's why rarely do you see (toxicity) in a larger body of water, usually it's in a small stock dam," he said.
The immediate solution is that until conditions change, animals should be removed from the water source, said Holland, adding "that's the first thing that was done (in the Hutchinson County case)."
Humphrey said the cattle deaths preceded a large kill of white crappies in Lake Menno at the end of June. While the two incidents are unrelated, Humphrey said algae poisoning also is being considered as a contributory cause of the fish losses.
"There were hundreds of dead fish," he said, mostly smaller sizes less than 4 inches in length, though about 25 percent were in the keeper range. The fish were transferred to South Dakota State University and an out-of-state lab for viral testing
The fish sent to SDSU were heavily infested with parasites normal to the crappie, said Humphrey.
"The (parasites are) not anything new or exotic. It was just the increased number of them in combination with maybe an algae bloom and (possible) post-spawn stress. It's probably going to be a combination of stuff that killed those fish," Humphrey said.
Other species were not affected, he said, only crappies.
"It wasn't bullheads, bass, bluegill, or catfish, so it wasn't an oxygen-related problem, probably more of a parasite, post-spawn stress condition," Humphrey said.
At this time there is no concern for human health surrounding the issue, he said.