Wildlife authorities have moved swiftly to deal with a mix of animals trapped in mud near dried-out lakes at Menindee amid calls for more action to ease an "animal welfare crisis".

Arresting images by Herald photographer Nick Moir of a red kangaroo struggling to escape - as part of a Herald report into the cause and aftermath of massive fish kill on the Darling River - drew interest from home and abroad in the fate of animals.

This kangaroo was one of several animals, including goats and sheep, that needed to be euthanised after the Herald was able to contact NPWS and animal local rescue groups. Credit:Nick Moir

In response, NSW National Parks and Wildlife Service sent staff into the parched channel near Lake Cawndilla on Friday. They found two kangaroos, two sheep and a goat, all of which were put down, a spokesman for the Office of Environment and Heritage told the Herald.

"NPWS will monitor the situation and where possible will seek to free stuck animals," he said. "If this is not possible they will be humanely destroyed."