Lab results have determined the death of 200 cattle in a grazing pasture near Shamrock, Sask., earlier this month was caused by a combination of dehydration, poor water quality and heat, according to a statement released Thursday by the province.
Sulphate levels in the water were more than three times the lethal concentration, at 24,000 milligrams per litre. Concentrations of 1,000 milligrams per litre are enough to cause neurological trauma, while levels of 7,000 milligrams or more can result in death.
"The water quality seems to be worse than many had suspected," Dr. Betty Althouse, Saskatchewan's chief veterinary officer, told media Thursday.
"There can be very few signs for a few days with animals consuming these levels of salts in water, and so they may look fine for a few days, and then there would be sudden death," Althouse explained.
"It's not like you're going to see a few die one day, and a few the next. It does tend to be a fairly sudden and catastrophic event."
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She said no one was prepared to find such a high of amount of salt in the water.
Total dissolved solids in the water were measured at 33,400 milligrams per litre.
It's recommended that pregnant or lactating cows should not consume water with more than 5,000 milligrams of total dissolved solids per litre, while water with over 7,000 milligrams of dissolved solids per litre is not recommended for any cattle.
Barry Blakley, a veterinary toxicologist at the University of Saskatchewan, said he's seen salt concentrations of this level at least twice this summer, both in the last few weeks.
He said that faced with no other source of water, cows that chose to avoid drinking the contaminated water would have become naturally dehydrated. Those that drank it, would have become dehydrated more quickly, he said.
Other water sources tested
The cattle found dead on July 7 were located within pasture operated by Shamrock Grazing Ltd.
The province's Ministry of Agriculture and the company are working together on testing other water sources in the immediate area.
The remnants of the herd, about 240 cow-calf pairs, have been moved to another pasture with a different water source. Some of the animals are still in distress and receiving veterinary care.
Producers have been reminded to frequently monitor cattle water sources, especially during hot weather.
If producers have any questions regarding livestock water requirements, they are encouraged to contact their local Ministry of Agriculture regional office or the Agricultural Knowledge Centre at 1-866-457-2377.