Wildlife authorities say they are concerned about the growing number of tree frogs being diagnosed with deadly cancers in Far North Queensland.
Deborah Pergolotti, who runs Australia's only frog hospital, based at Mission Beach, south of Cairns, said the facility had treated more than 40 frogs for five different types of cancer over the years.
The most recent, a white-lipped tree frog from Ingham, was diagnosed with a spindle-cell soft-tissue sarcoma.
"It's a different type [of cancer] than we've had before," she said.
"As far as verification goes, it is the fifth type of cancer that's been isolated in cases we've had."
The malignant tumour was removed by Cairns veterinarian Paul Matthews.
"Frogs generally are pretty resilient creatures, but their immune system, like all animals, can be compromised by external factors," he said.
"I haven't seen these sort of things in frogs before — soft-tissue sarcoma is a pretty nasty thing.
"It's locally invasive and it may reoccur, even though I've removed as much of it as I could."
Experts unsure what is causing cancer in frogs
Dr Matthews said there was little to no research into what environmental factors might be causing cancerous tumours in frogs.
"We're always concerned about insecticides and herbicides that are used in the sugar cane industry that might precipitate this sort of thing, but we really have no proof," he said.
"It comes down to money, unfortunately — there's very little money around for frog research, and the vets who do this type of thing do it out of interest more than anything."
Ms Pergolotti said the majority of cancers she had seen had occurred in white-lipped tree frogs, with two unverified tumours discovered in the common tree frog.
"We see spindle-cell soft-tissue sarcoma pretty regularly in dogs [and rarely in cats], and if we can cut them out the dogs usually survive, but that's because we can remove a sizeable margin of the sarcoma [unlike frogs]," Dr Matthews said.
He said it was unlikely the frogs would survive because the cancer would likely return.
Ms Pergolotti has urged anyone who sees strange lumps on frogs to contact them.
"Any disturbances, any lumps, we want to know about it," she said.
