Wild Island

Devil Facial Tumour Disease (DFTD)

A cancer reshaping devil survival

First discovered in 1996, Devil Facial Tumour Disease (DFTD) is a rare and aggressive form of transmissible cancer that spreads through biting, a common behaviour among Tasmanian devils. The disease presents as large facial tumours that interfere with feeding, leading to starvation and death. Since its emergence, DFTD has caused dramatic population declines — an estimated 77 per cent overall, with localised losses of over 90 per cent in the hardest-hit regions. Fewer than 17,000 wild devils are thought to remain in Tasmania’s wild today [1][2][3].

Two distinct strains of the disease are now known: DFT1, the original strain, and DFT2, which emerged later but has also spread widely. Both continue to circulate in wild populations and contribute to the ongoing vulnerability of the species across most of the island [4][5]. Their existence poses a unique conservation challenge, as few other cancers in nature are contagious in this way.

Despite the severity of the disease, recent research offers some hope. Tumours are showing signs of genetic diversification, and some devils appear to be mounting partial immune responses — hinting at a potential shift toward long-term coexistence [6]. Conservation efforts led by the Save the Tasmanian Devil Program include captive breeding, managed wild releases and disease-free insurance populations [7]. New technologies, including artificial intelligence, are being used to analyse tumour development in real time, giving scientists more tools than ever to track and respond to changes in the disease [8].

You can learn more about the species’ biology, behaviour and conservation context in our Tasmanian Devil profile, which provides a detailed overview of their ecology, current population status and the challenges they face in the wild.

Toxoplasmosis

A Silent Parasite with Deadly Consequences

Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii, a microscopic organism that completes its reproductive cycle in the intestines of cats. The parasite is shed through cat faeces and can survive in soil, water and vegetation for extended periods. Once it enters the environment, it poses a serious threat to native wildlife. Marsupials are particularly susceptible, as they have not evolved with this pathogen and lack natural resistance. Infection can cause a range of severe symptoms, including blindness, neurological impairment, miscarriage and often death [10].

Species such as bandicoots, wallabies and pademelons are especially vulnerable. Infected individuals may appear disoriented, lethargic or uncoordinated, increasing their risk of predation or starvation. There is growing concern about both feral and domestic cats acting as widespread carriers of the disease. These cats can contaminate natural areas not just near towns but also deep within national parks and other seemingly protected habitats [11].

Reducing the spread of toxoplasmosis requires a combination of proactive strategies. Preventing cat access to wild environments, promoting responsible pet ownership, and improving the management of cat waste are all critical steps. Continued public awareness and effective policy will be essential in protecting Tasmania’s native species from this largely preventable but devastating disease.

Read More → /responsible-cat-ownership

Mange

A Cruel and Contagious Skin Disease

Mange is a debilitating skin condition caused by the parasitic mite Sarcoptes scabiei. This microscopic mite burrows into the skin of its host, triggering an intense immune response. In wombats, mange causes severe itching, open wounds, hair loss, thickened skin, and secondary infections. Over time, the condition can impair the animal’s ability to move, forage, and regulate body temperature. Without intervention, mange often leads to a slow and painful death [12].

The disease is highly contagious and can spread quickly through direct contact between wombats or via shared burrows and scratching posts. Contaminated environments can remain infectious for extended periods, making transmission especially difficult to contain. The visible suffering caused by mange has also had a profound emotional impact on many communities and wildlife carers who regularly encounter affected animals.

Treatment efforts across Tasmania and mainland Australia often rely on topical applications of Moxidectin, delivered either through direct contact or pole-and-scoop methods. While these community-based programs have provided relief to individual wombats, eradicating mange entirely remains challenging. Experts agree that without widespread, long-term wildlife health surveillance and coordinated management strategies, the disease is unlikely to be eliminated at scale [13].

Chytrid Fungus

A deadly fungus threatening Tasmania’s native frogs

Chytridiomycosis is a serious and often fatal disease in amphibians, caused by the chytrid fungus Batrachochytrium dendrobatidis. This pathogen infects the outer layers of the skin, which are essential for amphibians to absorb water, breathe and regulate electrolytes. Once infected, frogs and toads may experience skin thickening, lethargy, loss of coordination and eventual cardiac arrest. The disease has been responsible for population crashes and even extinctions of amphibian species across the globe. In Tasmania, species such as the Tasmanian tree frog (Litoria burrowsae) are considered vulnerable to infection [14].

The chytrid fungus thrives in cool, moist environments, making Tasmania’s alpine regions, rainforests and wetlands ideal habitats for its spread. These conditions are common in many of the island’s protected and remote ecosystems. The fungus can persist in water, soil and on surfaces, allowing it to move between locations and affect populations even in relatively pristine environments.

Monitoring programs are in place to track chytrid presence and impact in Tasmania. However, the true scale of the threat may be under-reported. Frogs and toads are notoriously difficult to detect and survey, especially in dense vegetation or during colder months. As a result, chytridiomycosis remains a silent but significant risk to Tasmania’s amphibian biodiversity.

Psittacine Beak and Feather Disease (PBFD)

A Viral Threat to Parrots

Psittacine Beak and Feather Disease (PBFD) is a serious and often fatal viral condition that affects parrots and cockatoos. It is caused by a circovirus that targets rapidly dividing cells, particularly in the beak, feathers and immune system. Infected birds may develop feather deformities, progressive feather loss, brittle or overgrown beaks and suppressed immune function. Over time, this can leave birds unable to feed, preen or fight off secondary infections, eventually resulting in death [15].

The disease is highly contagious, spreading through feather dust, faeces, regurgitated food and contaminated nesting material. Once introduced into a population, it can be difficult to contain. PBFD poses a particular threat to endangered parrots with small and fragmented populations. In Tasmania, both orange-bellied parrots and swift parrots are considered at risk, especially during breeding and fledgling seasons when close contact is common.

There is currently no cure for PBFD, making early detection and long-term population monitoring essential. Wildlife health teams and researchers focus on surveillance during key life stages and breeding migrations, aiming to reduce transmission and protect vulnerable flocks. Continued funding, public awareness and biosecurity measures will play a vital role in preventing further spread of this devastating disease.

Aquatic Threats

The impact of disease in Tasmanian waters

Tasmania’s marine and freshwater ecosystems face a growing list of disease threats. One of the most notable is Piscirickettsia salmonis, a bacterial pathogen that caused large-scale die-offs in Tasmanian salmon farms [16]. These outbreaks sparked serious concern about the potential for pathogens to spread beyond aquaculture operations and into wild waterways, where they could affect native species already under pressure from habitat change and pollution.

The risks are not confined to farmed fish alone. Waterborne diseases can travel through interconnected systems, meaning any breach in containment can have far-reaching consequences. Polluted runoff, nutrient build-up and waste from aquaculture facilities may reduce water quality, making native fish and invertebrates more vulnerable to infection and less able to recover from environmental stressors [17].

Protecting Tasmania’s aquatic biodiversity will require stronger biosecurity protocols, better monitoring of water health, and continued research into how introduced pathogens behave in native systems. These efforts must go hand in hand with sustainable practices in aquaculture, agriculture and urban development to reduce downstream impacts.

Strengthening these protections also means understanding how aquaculture responds when outbreaks occur, and how those responses interact with surrounding waterways. In some cases this includes the targeted use of antibiotics during disease events, which carries its own biosecurity and environmental considerations. For more detail, our Florfenicol Under the Microscope blog post outlines how florfenicol is used in farmed fish and what this means for water quality and ecosystem health.

Wider Biosecurity Concerns

Emerging threats to land and wildlife

Land-based ecosystems are also under threat from a range of pathogens and invasive species. One of the most damaging is Phytophthora cinnamomi, the cause of root rot in native plants across Tasmania. This soil-borne fungus has devastated plant communities, particularly in heathland and dry forest habitats, leading to the loss of key food and shelter resources for wildlife [18].

Other biosecurity threats have emerged in recent years. Myrtle rust, a fungal disease affecting the Myrtaceae family, has been detected in Tasmania and could severely impact native trees such as myrtle beech and paperbark. In parallel, avian influenza (HPAI) outbreaks and invasive mosquito-borne diseases have drawn increasing concern, especially as global wildlife trade, tourism and climate change reshape disease risk profiles [19][20].

Climate change is acting as a multiplier. Warmer temperatures, changing rainfall and shifting seasons are altering the range and activity of disease vectors like mosquitoes, as well as the resilience of native species. Protecting Tasmania’s biodiversity in this changing context will depend on early detection, rapid response and strong cross-border collaboration to prevent incursions before they take hold.