Feral cats are a triple threat to our wildlife through predation, competition and diseases such as toxoplasmosis. Eddie Van 3000/Wikimedia Commons, CC BY-SA
Feral cats are a huge threat to our native wildlife, hunting and killing an estimated 75 million animals across Australia each and every night. But the killing spree doesn’t end there. There’s a parasite lurking in kitty’s litter that continues to kill wildlife long after the perpetrator has left the scene of the crime.
The killer is toxoplasmosis, a disease caused by the parasite Toxoplasma gondii. The parasite is spread by cats but it can infect any bird or mammal. Around one-third of humans worldwide are infected with the parasite. But the deadly effects on our wildlife are often overlooked.
What does toxoplasmosis do?
In many animals, Toxoplasma infection causes nothing more than a mild case of the sniffles. If the animal is healthy, the immune system usually produces antibodies that keep the parasite under control. The parasite then goes into a relatively dormant state, forming invisibly tiny cysts mainly in the heart, lungs, brain, eyes, and spinal cord. While the cysts stay with the animal for life, they rarely cause any direct harm.
Toxoplasma gondii tissue cyst in mouse brain. Jitinder P. Dubey/Wikimedia Commons
But for some animals, infection can be deadly. If an animal’s immune system isn’t quite up to the task, either through illness or stress, the initial infection can lead to toxoplasmosis. The disease has a range of debilitating symptoms, including anorexia, lethargy, reduced coordination, apparent blindness, enlarged lymph nodes, disorientation, breathing difficulties, jaundice, fever, abortion, and death.
Some of these side-effects may kill the host directly, while for others, they will make the host an easier target for predators. For example, blinded wildlife cannot see predators, while lethargic or badly coordinated animals might be too slow to escape.
Another threat to our wildlife …
Read more, The Conversation, here, where you will find full hyperlinks
• Background Briefing Sunday: Feral cats rewrite the Australian story
• ABC: Feral cats tear through last wild bilby population in Queensland’s Astrebla Downs National Park
