A Toodyay farmer has been fined $50,000 and copped a four-year conditional prohibition order over the disturbing state of his live stock after dead and decaying sheep were found at his property in March 2014.

Clinton Charles Wheatley was sentenced in Perth's Magistrates Court on Monday after pleading guilty to animal cruelty on his farm.

Inspectors visited his property after a member of the public complained about a large number of dead and dying sheep. 

They were disturbed by the scenes of death and decay around the property and worked to rescue a number of sheep who appeared to be clinging to life.

A vet also rushed to the farm but he found the condition of some of the animals was so bad they cold not be saved.

"The sheep's bodies were so starved they had started to break down muscle tissue in order to supply energy, indicating deprivation of adequate food for a prolonged period," an RSPCA statement said.

The surviving sheep were determined to be in such poor health that they were not able to be moved. RSPCA Inspectors arranged with a local farmer to provide feed and water for the surviving flock, which was fed slowly and regularly on site to regain condition.

It was found the harm suffered by the sheep could have been prevented by giving them sufficient feed and water.

The conditional prohibition order the farmer received in court requires him to immediately reduce his stock levels and undergo monthly assessments.

RSPCA WA Chief Inspector Amanda Swift said, the fine imposed was reflective of the severity of the offences and suffering of the sheep.

"The conditional prohibition order imposed by the Magistrate requires Mr Wheatley to work with an independent husbandry expert to learn how to better manage his livestock in the future to prevent this happening again.

"It's thanks to members of the public who were concerned enough to report this case to the Cruelty Hotline – without them, many more sheep could have perished from neglect."