The Australian Diseases - Old and New

The Sleeping Giant Has Been Disturbed!

Note: Waiting in the queue is a major update of this entire disease section. We have now been made aware that the myriad of problems which we have been seeing in frogs - which started suddenly in the wet season of 1997/98 - is almost certainly caused by the introduction of one chemical group in particular: the neonicotinoid insecticides. As we continue to look further into this problem, the information presented here is still useful for identifying problems in frogs elsewhere in Australia. Chemical pollution is not just here but everywhere! As soon as we have enough reliable volunteers to take some of the weight off our President/curator's shoulders, we will be able to update this section of our site.

Over recent years, there has been a lot of publicity in the media about frog declines and, in particular, the role that disease has had in causing many species to decline and even disappear entirely. However, most of the attention thus far has been focused on the relatively recently discovered "chytrid fungus" (Batrachochytrium dendrobatidis for the scientifically inclined). Chytrid (pronounced KIT-trid) fungus is indeed a serious disease and causes massive dieoffs where it occurs - but it is not the only disease which has been causing frog and cane toad deaths in Queensland.

This disease section features information about SOME of the known disease problems in amphibians but also describes the new problems that we have found in the frogs and toads that have been brought to us (found in the wild) since August 1998. By chasing researchers and labs to find out what is wrong with these animals, we have learned that there are a wide variety of new disease issues in Australia that were unknown before we turned up with our specimens. We have categorised these new problems into different syndromes or situations but the bottom line is that the chemicals are probably causing immune deficiency and the animals simply pick up whatever they are exposed to:

  • immuno-deficiency complex (primary pathogen is likely to be viral but includes a large list of secondary pathogens)
  • respiratory/nervous system disease (probably a drought-tolerant soil fungus - a species of Fusarium is our top shortlisted suspect)
  • cancer and other neoplasias (oncogenic herpes viruses are at the top of our theory list but some of the neoplasias might have other origins such as toxic pollution)
  • the "Redlynch" virus (viruses were found in the orginal specimens we sent to labs but this could page will be renamed "malfrmations and deformities" and it includes reproductive failure)
  • hyperbiliverdism (an undescribed disorder somewhat similar to jaundice in reptiles, possibly involving an adenovirus)
  • pathogen pollution from category 4 and 5 cyclones (hurricanes/typhoons)
  • the rise of environmental pathogens (especially soil bacteria as a result of man-made and climate level changes to soil quality and ph)

The pages in this section are described below. Use these links to get to specific pages or you can use the navigation at the top.

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Fungal diseases:

  • Chytrid fungus - general information (the world's most publicised amphibian disease but certainly not the only serious amphibian disease)
  • Chytrid recognition in the captive and backyard setting - including steps you can take to reduce the damage caused by chytrid on your own property
  • Chytrid treatment procedures we are using to recover frogs/toads
  • Mucor amphibiorum - a soil fungus causing mucormycosis, a fatal condition for which no cure has yet been found; this disease also affects Platypus, especially in eastern Tasmania
  • the new "respiratory/nervous system" disease - this remains unidentified in the lab but we have received well over 1,500 cases of it; the nervous system is attacked and a predictable collection of subtle symptoms results but standard histology does NOT reveal its presence (or even a cause of death) because the tissues are undamaged (all damage is to the nervous system) - this is likely to be a drought tolerant soil fungus and we have narrowed down a species of Fusarium as our top suspect (based on culture results), possibly producing a mycotoxin and it has serious implications for climate change modelling
  • Pathogen pollution from cyclones - sure, we get cyclones (hurricanes) all the time, but NOT like Larry and Yasi!

Viral diseases:

  • general information about some of the viruses causing problems for amphibians
  • the "Redlynch" virus - named after the Cairns suburb where we first learned of the disease; the virus has been found by sequencing but remains unidentified and will be given a proper name once isolated and characterised; based on what we've seen thus far, this disease could become the biggest threat to Australian frogs we've seen so far - if it is allowed to spread without control, we predict it will easily overtake the losses caused by chytrid fungus. It is worth noting that this disease is absolutely deadly to cane toads!
  • the immuno-deficiency complex - a new problem we first uncovered in the White-lipped and Common Green (White's in North America) tree frogs (Litoria infrafrenata and Litoria caerulea) in 1999; because this problem is so species-specific and appears to have a link with other virus problems, we believe the primary pathogen involved is probably a virus; once this problem 'activates' in the frog, it is overrun by a long list of simultaneous secondary problems including severe, multiple parasite infestations, skin degenerative conditions, hyperbiliverdism, neoplasias, environmental fungi and bacteria, and other independent diseases.

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Bacterial problems:

  • Aeromonas hydrophilla ("Red leg") is one of the most commonly encountered problems in captive amphibians but this can also become a widespread problem in the wild, as it did in the UK in 2004. This page also includes Pseudomonas ("dropsy").
  • Environmental bacteria and fungi - the term 'environmental' can be confusing here but these refer to bacteria and fungi which are found everywhere in the environment (including inside the guts of amphibians) but are background/incidental pathogens which are not supposed to be problematic to a healthy animal; however, these can erupt into a life threatening problem if the immune system is impaired such as when the animal is stressed, it already has other diseases or parasites, or there is a dramatic ecological change (such as drought or flood).


  • some general information about the parasites that have been identified so far in local amphibians
  • Bot fly larvae (Batrachomyia) - a temporary parasite in local frogs which can be tolerated if only one or two larvae are present but life threatening when more than three are present - we've observed that the breeding frequency of these flies varies according to climate - droughts drop their numbers significantly while they become overwhelming during La Nina periods!


  • the numbers of cancer and other tumours (neoplasias) found in local frogs is excessive on a GLOBAL scale: 31 cases from Cairns as of Oct 2019, thus making Cairns the 'frog cancer capital' of Australia - and that is not a distinction to be proud of!

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Symptoms of a sick frog/toad:

  • Disease spreads rapidly around the body in amphibians but many of these affected animals can be recovered if their conditions are recognised quickly. Even if an individual frog/toad can't be saved, it is still important to recognise the problem and tell someone (a researcher or frog conservation group, for example) so that it becomes known that a particular problem is active in an area and can be investigated. Although symptoms of illness in amphibians can sometimes be very dramatic looking, most of the time the symptoms are highly cryptic or only apparent in the animal's behaviour - here are some basic indications you can use to know if the frog or toad you have or have found is ill - REMEMBER: ALWAYS ALWAYS ALWAYS WEAR GLOVES OR A PLASTIC BAG OVER YOUR HANDS WHEN HANDLING AMPHIBIANS, even if you think they are healthy

Precautions and disinfection methods page:

  • it might not be possible to entirely stop the destruction that diseases cause but they can certainly be slowed down or prevented from establishing in some areas; everyday people, especially those who visit the forests and wetlands for any reason (camping, fishing, hiking, tourism, etc.) can make a big difference to the speed that diseases get around; taking no precautions at all can mean that you might actually be involved in the INTRODUCTION of an amphibian disease to a place it wasn't before! Please read this page if you are interested in frogs and/or visit wild places to enjoy the beauty of nature.

Special Alerts

  • mostly for Australian residents, this page presents special warnings and alerts for problems which have reached a new location or reports we're seeking of where a problem has turned up

Researcher's page

  • if you are a disease researcher, please visit this page and help us out if you have any information about the problems described on this page

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