by Jon VanZile
There are plenty of unanswered questions about the chytrid fungus in frogs and amphibians, but one thing seems certain: action must be taken to confront this slowly unfolding crisis. The modern epidemic of chytrid fungus first came to international attention in 1999, when biologists described a new species of chytrid fungus called Batrachochytrium dendrobatidis, or Bd for short. Within a few years, field biologists were blaming massive amphibian kills throughout the world on Bd, which flourishes in moist, cool habitats.
According to the Amphibian Ark, a nonprofit group of scientists working to protect amphibians, Bd results in the disappearance of about 50 percent of amphibian species and 80 percent of individual amphibians wherever it thrives. Worse yet, there is no way to control the disease in the wild, making Bd one of the worst mass extinction events in recorded history.
The implications for the pet trade are profound—at least in part because the pet trade probably helped spread the disease, along with zoos and research programs that move amphibians around the globe. Already, Bd has been discovered on every continent except Antartica, in both public and private collections. As these animals move from large scale breeders to pet shops to hobbists, they are almost certainly spreading the infection to new populations and even into the wild.
Recognizing a threat to their industry, breeders, hobbyists, and the Pet Industry Joint Advisory Council (PIJAC) have swung into action to address the problem. They are also working closely with zoos, conservationists, and academics to develop a comprehensive strategy to contain the worst threat most amphibian species have ever confronted.
Awareness Campaign Kicks Off
In late 2007, PIJAC sponsored an international conference entitled "Amphibian Declines and Chytridiomycosis: Translating Science into Urgent Action." The conference, which attracted 200 participants, launched the Bd Free 'Phibs education campaign designed to spread the word about Bd. "We're not just focused on the industry," said Dr. Jamie Reaser, senior advisor for the health and environmental stewardship at PILAC. "It's anybody who has amphibians in a captive context." Since the conference, however, the group has been in "fundraising mode," according to Reaser, who conducted her doctoral work on amphibians in decline.
"We have funds for a start-up and we're working on a website and campaign materials," Reaser said. "Fund-raising is important to help develop campaign materials for commercial enterprises, hobbyists and pet shop owners. The need is two-fold: to make sure the materials are helpful, and to make sure the information is disseminated as widely as possible." Whatever the final campaign looks like, Reaser is hoping it will get a positive reception in the industry. "I think there's a large percentage of the community who aren't aware this is an issue," Reaser said. "But those that understand the issue and are aware of it are very supportive. Understandably so, because a lot of these people got into the trade because they love animals."
Among the supporters is the Sandfire Dragon Ranch in Bonsall, California. Sandfire is one of the country's largest breeding facilities for pet frogs, as well as a leading voice in the industry when it comes to Bd. "I wouldn't say it's affected our business," said Michael Ready, amphibian specialist with Sandfire Dragon Ranch. "But depending on how the industry rallies and how the science plays out, it could affect the industry enormously."
The Quest for Standard Protocols
One of the main goals of the PIJAC-sponsored conference was to begin developing protocols to detect, prevent, and treat the chytrid fungus. So far, however, no standards have emerged, and multiple groups are working simultaneously on their own approaches. Phoenix – based PetSmart, which announced it was developing anti-Bd protocols after the conference, declined to comment for this story. A spokesperson said the company is still working on the issue.
Things haven't gone much further in the academic world, where a number of research groups and zoos are independently developing protocols even as new science is still emerging. Dr. Allan Pessier, a veterinary pathologist at the San Diego Zoo, hopes to change this. Pessier recently hosted a conference with some of the world's leading chytrid researchers to "bring vets in animal husbandry together, go through all the protocols and develop a disease control manual. A lot of the current protocols have common threads and are based on the same original source documents," Pessier said.
But chytrid is a wily enemy. "It's not going to be as simple as we have infected animals, so let's treat them," Pessier said. "The treatments we have often don't work in the first round. You may have residual infection, so you have to go to a second round."
Stakes Are High
While many of these issues have yet to be settled, cost is an obvious concern. Any new measures to screen for chytrid, quarantine animals, and test and treat will inevitably make it more expensive to produce and sell amphibians.
Unfortunately, detecting chytrid with the current methods is difficult and can be expensive. The current PCR test used to detect the fungus costs between $10 and $30 per test. With a population of 50,000 frogs or more, it would be prohibitive to test every animal at a large operation like Sandfire. "For people producing in this country, it would drive up their costs," said Ron Gagliardo, a training officer for the Amphibian Ark and researcher based at the Zoo Atlanta. "But it might wipe out trade for places like Peru, Suriname and other poor countries."
While U.S. producers might not be wiped out, the prospect of increased costs is not a welcome one. As owner of The Frog Ranch in Granite Bay, California, Kim Thomas is a long-time amphibian breeder and wholesaler. Thomas says his collection consists almost entirely of captive-bred animals, and multiple tests have shown no Bd in his facility. "We've always practiced pretty tight biosecurity," he said. "Since we don't deal in wild-caught animals, it's not an issue for us." To Kim, one of the biggest threats comes not from the disease, but from our reaction to it. "I'd be inclined to go along with any new protocols," he said. "But my fear is that people will overreact. I hope it doesn't get tied up in legislation with restrictions and permits and become a revenue-producing tool for the government.”
Nevertheless, Kim's willingness to go along with new protocols—despite having a stable population of Bd-free animals—speaks to a deeper truth that everyone is painfully aware of: the cost inactivity might be hard to comprehend. "What could this cost in the loss of animals?" Reaser said. "Because if you get Bd in your collection and you have susceptible animals, you'll probably lose those animals." In even starker terms, Pessier said, "This disease has been moved around by people. I think it's a moral obligation."
Where did Bd Come From?
One of the maddening aspects to the Bd epidemic is how poorly understood the disease really is. It was first identified in 1999, but biologists suspect it has been around for much longer than that. In hindsight, some of the mass amphibian die-offs from previous generations bear the hallmarks of chytrid infection. However, the current epidemic is so dangerous because it's been so widespread. Many biologists believe that Bd was first carried from South Africa on the African clawed frog. These frogs are asymptomatic carriers of Bd and they were widely used in biomedical research. In many cases, biologists say that the original researchers weren't using proper biosecurity. Waste water was dumped into public water supplies, extra animals were released, and discharge wasn't handled properly. But even this explanation has come under fire.
"You could say the exact same thing about the American bullfrog," said Jamie Reaser, PhD, senior advisor for health and environmental stewardship for the Pet Industry Joint Advisory Council (PIJAC). "They are resistant and have been moved around the world for frog farming for longer than African clawed frogs." Today, Bd is turning up even in isolated, pristine pockets of wilderness.
"We may never know where it came from," Reaser said. "But that shouldn't prohibit us from doing everything we can do. I don't think it's going to be completely eradicated. My hope is that it can be significantly impacted."
Prevention and Treatment of Bd
There is no consensus on the best way to deal with chytrid, but a few broad guidelines have emerged. This list of precautionary measures is condensed from guidelines produced by the Amphibian Ark and researchers involved in fighting the epidemic:
• Quarantine ALL new amphibians for 2–3 months. During quarantine, never share water, utensils or enclosures between populations. Ideally, animals should be tested at least twice, six weeks apart, during quarantine using a PCR test. In the United States, PCR testing is available through Pisces Molecular in Boulder, Colorado, at (303) 546-9400.
• Consider water that has come into contact with amphibians to be considered contaminated for at least 7 weeks. All water, moist soil, and objects used to handle amphibians should also be considered infected. Before disposal, everything should be disinfected with a 1% bleach solution or heated to 120 degrees Fahrenheit for 30 minutes to kill the fungus.
• Consumers and hobbyists should be made aware of chytrid and educated about proper husbandry techniques.
• Amphibians should never be released into the wild, nor should dead animals be disposed of in the wild.
• The main symptoms of chytrid in frogs is excessive shedding of skin, but this is not a definitive diagnosis. Infected animals can be treated with a weak itraconazole solution. Itraconazole is a powerful antifungicide. Treatment regimens vary, but a five-minute bath in a .01% itraconazole solution for 11 consecutive days has been shown to eradicate the disease.
Mike Ready, a scientist at Sandfire Dragon Ranch in Bonsall Calf., reports that some hobbyists are using the over-the-counter fungicide spray Lamisil at about 1 mL per 200 mL of clean water (1 mL equals about 10 squirts from the spray bottle). The frogs are bathed for five minutes for 11 consecutive days. There is no published research on this treatment, but Ready says that hobbyists are reporting anecdotal success.
For more specific recommendations regarding prevention, testing and treatment, visit:
Reprinted by permission from PET AGE, May 2009