25 cows mysteriously died in a pasture area in Australia.

An investigation has been launched following the discovery of a large number of dead cattle in a semi-rural meadow in Oakford, south suburbs of Perth.

A woman made this distressing discovery as she passed by the property to feed her horses.

In a video shared on social media, the woman claimed that one of the 25 dead cows had been lying on top of a pile of firewood since Sunday.

The owner of the property was reported to be away. His son told Seven News that the cows had contracted pneumonia.

The son added that due to recent rainy weather, the dead cows could not be collected or buried.

The RSPCA (Royal Society for the Prevention of Cruelty to Animals) will conduct a comprehensive investigation to determine the exact cause of death for the animals.

RSPCA investigators were seen examining the dead animals at the scene on Tuesday.

According to Meat and Livestock Australia, pneumonia in cattle is commonly associated with respiratory diseases in cattle and is the most common disease and cause of death in beef cattle.

To treat cows with pneumonia, it is recommended to isolate affected animals in a well-ventilated area protected from extreme cold or heat.

Providing hydration, easy access to water and feed, and minimizing physical stress on the animal are also important.

Antibiotic and anti-inflammatory treatments can help with recovery.