40 sick cats dumped in Qld forest

The RSPCA says it's shocked by the discovery of 40 sick cats dumped in a state forest north of Brisbane.

Most of the cats are suffering from cat flu and two had already died when the RSPCA was alerted about the find in the Beerburrum State Forest this week.

"This large number of cats ... dumped there is virtually unprecedented. This is why we have a feral cat problem, because people dump cats and their litters in the bush. It's extremely disturbing," RSPCA spokesman Michael Beatty told ABC radio.

He did not say how the dumping incident was discovered.