RSPCA WA is investigating the death of about 25 cows in a paddock in Oakford.
A member of the public made the disturbing discovery earlier this week before alerting authorities.
According to 7News, the owner of the cattle is currently away, but their son said the livestock had contracted pneumonia.
The dead cows have reportedly been in the paddock for a number of days, but the son said due to the weather they have not been able to move them.
New floating jetty speeds up emergency response times for Marine Rescue Mandurah
Marine Rescue Mandurah volunteers are heading into the busy summer boating season with a major upgrade to their operations with the installation of a new purpose-built floating jetty.
Baldivis Police on the lookout for reckless dirt bike riders
Baldivis Police are on the lookout for reckless dirt bike riders.
WATCH: Youths captured on CCTV stealing car in Golden Bay
A group of youths have been captured on CCTV stealing a car in Golden Bay.
Fire crews battle early morning blaze in Warnbro
Firefighters have extinguished a bushfire in Warnbro.
Driver charged over alleged hit-and-run on Mandurah Terrace
A 20-year-old man has been charged over an alleged hit-and-run in Mandurah.
More paramedics, ambulances to be stationed in Dawesville, Australind
More paramedics and ambulances will be stationed in Dawesville and Australind.
Strict demersal fishing bans to come into force off WA coast to save species from extinction
Commercial fishing for demersal fish will be permanently banned off a section of WA's coast along with a raft of other changes to save the under-threat species.
Police call for witnesses to fatal Waroona crash
Police are calling for witnesses to a crash in Waroona that claimed the life of a 55-year-old woman.
WATCH: Confronting footage shows moment car ploughs into teen on Mandurah Terrace
WARNING: This story contains confronting footage.