CHAPLIN, Sask. -- About 200 cattle have been found dead on a pasture in southwest Saskatchewan.

The dead cows and calves were on Crown pasture land south of the community of Chaplin, which was operated and leased out by 31 patrons. The animals were discovered Friday.

Saskatchewan chief veterinary officer Dr. Betty Althouse says preliminary necropsy and test results show the animals died of dehydration and possibly salt toxicity.

One water source on the pasture is a dugout, which may have become unsuitable for livestock due to evaporation and increased concentration of salts in the water.

"The solutions of salt in the water get more concentrated with evaporation, so that the products that are naturally in the water just become more and more concentrated so there's a higher salt than you would expect," Althouse said Monday in Regina.

"Higher salt than in the ocean really can occur in some of these alkaline sloughs in the Prairies."

She said further testing will be done.

Althouse said RCMP have also been called, as well as animal protective services, to investigate.

She would not comment on the management of the pasture.

"We've certainly had hot weather, so that increases the demands from the animals and it does lead to more concentration. So whether they were unfamiliar with the pasture and didn't know that there were other sources of water, that might have contributed."

Southwestern Saskatchewan has been baking under the heat. Last week, Environment Canada issues a heat warning for much of the region as temperatures hovered around 30C.

An estimated 240 surviving cow-calf pairs were immediately moved to a different field in the pasture that has a safe and secure water source. They've set up shade for them too, said Althouse.

"Individuals that need it are being treated, so I think they're looking after them. They're under veterinary care."