Chytrid fungus in captive Animals

[cichlidjedi]

I have to say within the last week I have been reading and watching many things on the web about the dying of amphibians across the world and it makes me sad. The animal planet special The Vanishing Frog really got me upset and I'm so glad I was able to donate to Amphibian Ark to help out captive breeding of these critically threatened species. I thank all of those on this site who had posted in forums all the wonderful links to watch and read about this worldwide extinction. I did however want to inquire to those of you that have been long avid caudate keepers, why are the animals we keep not dying off to the same fungus? Is it that the species we keep are able to naturally fight of this fungus and the threatened species lack this defense? I would imagine in the pet trade were many of us have happened to buy some animals that these creatures are crammed together in Distribution, before they reach re-sale and live in far worse enviornments until someone saves thier lives. Almost all of these animals are captured from the wild, but yet seem to be healthly in all of our homes? Does the tap water we use have natural fungicides in it as a benefical additave to make water safer to drink? I only inquire because I have recently aquired 9 differn't species of caudates and want to make sure the best care and proper water conditions are meet for my aquatic species. I did do research on the species I purchased to make sure temps, enviornment and everyday husbanry techniques are used. I use regular tap water and add a dechlorinator to help rid water of Chlorine/Chlormine, heavy meatals and detoxify ammonia. One of the species I have had for over two years and are in great health (maybe a little to fat). I make sure all species are isolated from each other, but to be honest I don't sterilize my equipment from tank to tank. Newer species I aquire outside of local breeders I try and isolate further due to possible infection outbreaks. My background has always been in freshwater fish (central American cichlids) and the benefit is that many over the counter medications are avaliable to medicate sick fish, but with caudates I see no over the counter medications except for the occasional eye rinse medication used for turtle care. I do have a nice microscope that hooks into my work laptop for taking slide pictures and I have yet to set it up and scrape my animals to gain a little fun biology in my home. Is Chytrid something we need to look out for in the future for are animals in capativity, and also does anyone have information on safe bacterial and worming medications? Sorry to be so long winded, but I want to be safe for the sake of my slimly brothers and sisters

 

[Jennewt]

I was hoping someone more authoritative would jump in here, but I'll try to get the ball rolling...

Based on my limited reading on this subject, I believe that most caudates do not drop dead when they are infected with chytrid fungus. They can carry the disease, and it does affect their skin, but it doesn't have a huge impact on their overall health. [Apply the usual disclaimers: this may be an over-generalization.] It appears to me that the dart frogs are much more susceptible to the disease.

I have a strongly-held theory that almost every amphibian that dies in captivity (particularly those "mystery" deaths where the animal had perfect conditions and looked perfectly healthy the week before) are multi-factorial. Meaning that there is almost always more than a single factor that caused the animal to die. On the basis of this theory, I would say that, even if our sals can carry chytrid without a big impact on their health, it's still something we need to be concerned about because it could at some point be "the straw that breaks the camel's back" in the life one particular animal. We also need to be concerned because our animals could be a source for spreading the disease, both to other captive animals (for example, I send an infected newt to someone who keeps dart frogs, causing their frogs to die) and also to wild animals (for example, I dump some tank water on my garden and infect the local toads).

 

[Daniel]

I am not an expert on this topic, either, but apart from the possibility that some amphibia maybe less susceptible to chytrid or may even be immune to it to a certain degree my guess would be that the fungus has not been introduced into most captive held populations.

Most reports about chytrid are relatively new (compared to some other pathogens known for a long time) so the greatest danger to introduce it into captive populations would be by acquiring wild caught specimen from certain areas.

 

[Azhael]

I think i recall reading about some captive caudates that were tested and showed to be infected. I can´t remember much else though....
It´s been demonstrated that certain species of caudates do have a high tolerance or even inmunity if you will to the chytrid fungus. I don´t think the investigation has included all of them, and i´m inclined to thinking those might be exceptions.
I think it´s very possible that captive animals have a different response to the infection due to the different conditions, and they might be carriers without dying right away from it.
I regret to say i have no access to serious information on this topic, but i hope someone does.

I agree with Daniel, the biggest concern would be with WC animals. Simply because you have no clue whatsoever what they might be carrying, and the typical pet-trade wild caught has been in crowded conditions with no food, and with it´s inmune system being torn apart by the conditions, making it an easy target for any illness.
Also some species, like dendrobatids and Xenopus laevis, should probably be considered to be a bigger risk.
Even if the animals are CB, quarantine is always a must.

 

[freves]

I seem to remember Ed K mentioning that the Bolitoglossa species that are imported in some numbers from time to time frequently carry chytrid. Also, if I seem to remember reading somewhere that chytrid has been found in some of the WC Salamandra as well as tiger salamanders, which seem to have some resistance to it's effects. Please do not quote me on any of this however. If I am unsure of an answer I usually like to do a bit of research before posting however I do not have time at the moment.
Chip

 

[Jennewt]

The Treewalker Amphibian Steward program is working on a systematic study of chytrid in dart frogs in private collections. They will be testing the frog collections of many people and then publishing the results. This study will not include amphibian collections that have no dart frogs, but it will include some collections that include both caudates and frogs. I'm looking forward to the results.

 

[cichlidjedi]

I live in Illinois and wanted to find out more about Chytrid in my state. I talked to head Illinois Department of Natural Resources Biologist today out of Carbondale, IL. He explained there are many native amphibians in Illinois that are showing chytrid fungus. It seems to be isolated in southern Illinois do to the colder climate in the Chicago area and the populations up by me haven't shown too many signs. They are however doing a state wide test of amphibians this spring and summer to get more data affecting Illinois native amphibians. The biologist informed me Chytrid doesnt seem to affect adult caudates as it does frogs and toads, but it does affect caudate tadpole development. Even though they have not tested domestic animals kept by residents or sold at retail he speculates many of the amphibians we buy from animal distribution are probably going to have chtrid fungus. Now I wanted to find out how to kill the fungus and the biologist said some Zoo's have used over 90C water temps to kill the fungus, but a lot of oxygen must be provided for the safety of the amphibans treated. I was hoping thier would be a safe fungicide out there we could use safely on our own animals, but when I asked the biologist he was not familiar with one.

 

[benw]

Hi

Interesting topic this, and one, quite rightly. we should be taking notice of. I am worried about the effects this disease will and is having on wild populations of amphibians and the entrance of it into the captive part of the hobby.

As you all can see in my profile, i keep many salamanders, and others not listed, and i was worried that this fungus may make its way into my collection.

I did a little digging around, and i cant remember where---sorry!!!--, but i found that a product for Athlete's foot and Dhobie itch called Lamisil AT spray, and i spray this on my new stock when i quarantine them.
Now im not saying this spray will cure Chytrid fungus, but it may well help, i have had no ill effects from the salamanders, although if you went berserk with the stuff it may harm them.

All i am saying in short is this stuff works for me, along with good hygiene and quarantine procedures and it last for a good time and is only about £5.

Feel free to PM me for more details:happy::happy:

Ben

 

[caleb]

I wanted to find out how to kill the fungus and the biologist said some Zoo's have used over 90C water temps to kill the fungus, but a lot of oxygen must be provided for the safety of the amphibans treated.

Did they mean 90F? This paper describes successfully treating frogs by heating to 37C (=99F) for 16 hours:

http://www.int-res.com/articles/dao2003/55/d055p065.pdf

They were a subtropical species, not sure how well temperate newts or salamanders would cope with this sort of treatment.

Chloramphenicol has also been used successfully to treat chytrid infection:

http://www.nzfrogs.org/site/nzfrog/files/Treatment Protocol.pdf

It's not the kind of thing you'd use in a home treatment, though. As far as I know, you need a prescription to get it in the UK.

Drying and/or high temperatures are apparently effective for killing chytrid on tanks, equipment, etc.

 

[cichlidjedi]

Sorry Caleb you are correct it's 90F not Celcius. High Temps are what the Saint Louis Zoo has been treating Hellbenders with to kill Chytrid.