Cats
The Feral Cat has had a substantial effect on the Australian environment. It has driven many Australian native animals to endangerment and even extinction.
Cats also carry Toxoplasmosis, a disease that is harmful and fatal particularly for the native marsupials. It causes blindness, paralysis, respiratory disorders, and loss of young due to stillbirth and spontaneous abortion, and can also effects humans.
Whilst cats do prey on rabbits, they do very little to reduce the population and rabbits just sustain the amount of feral cats in Australia. The intentional release of large numbers of cats to control rabbit plagues also furthered their spread.
28 species and subspecies, mostly marsupials, have become extinct since Europeans arrived, and many of these extinctions are linked to cats and other introduced species.It's a different story with pets, though. If you have a cat, there are easy steps you should take to minimise the impact on local wildlife. Keeping it in at night can reduce the kills it makes by half.
At Rabbitbusters we trap cats using cage traps or leg hold traps so if it is a pet it can be handed in alive to the proper authorities.