Why to not handle amphibians

[Hydro033]

I have read in so many places that you should never handle amphibians, but I have never come across any reference that shows empirical evidence why. Can somehow please post a link to a study that looked at why handling amphibians is bad for their health?

 

[FrogEyes]

Not without digging, but it would also not be hard to find studies which show that heat, dryness, and salts [all of which are provided by human hands] ARE bad for the skin of many amphibians [whose permeable and absorptive skin is inherintly vulnerable to dessicants like salt and heat].

 

[Sean90]

Writing assignments we have to references for minimal handling and to wear gloves. There is loads on google scholar to minimise spread of Chytrid and other zoonosis diseases.
Stress and so on.
Also with Tylototriton the risk of triggering there anti predator response reason not to handle.
Also if you go some husbandry guidelines they talk about minimal handling.

 

[Mark]

In addition to the excellent points Frog Eyes makes it's also worth mentioning that handling inevitably causes stress to amphibians. Regular stress is certainly a cause of sickness. I think in many cases the stress induced by handling will be similar to the stress levels of being caught by a predator.

 

[Hydro033]

Hm. So no tests?

 

[FrogEyes]

If you can demonstrate that the root causes are harmful, showing that a carrier of multiple causes is harmful, is somewhat pointless. It's just a logical extrapolation:

heat: harmful
dessication: harmful
salts: harmful

therefore source of heat, dessication, and salts: harmful

Look for references on the aforementioned substances [they certainly exist] and you'll have your evidence. With salt, the issue will be too many references and finding the ones which are relevant. Ditto for dessication.

This paper:
JSTOR: An Error Occurred Setting Your User Cookie
references a number of others which specifically address dessication susceptibility of various species.

This one may provide a good start for heat tolerance:
JSTOR: An Error Occurred Setting Your User Cookie

As but one of many examples, torrent salamanders have a critical thermal maximum of about 17C. We have a body temperature of about 37C. Holding a torrent salamander can cook it. There's no shortage of other amphibians which also have low CtMax.

 

[Azhael]

Just to complete the list of solid reasons why not to manipulate caudates, the oily substances in our hands as well as possible traces of creams or soaps, can also be a problem.

 

[Jennewt]

Here is one study of handling methods and amphibians:
Latex laboratory-gloves: an unexpe... [Environ Toxicol Pharmacol. 2001] - PubMed - NCBI

I can't find links to the articles, but here are 2 other references:

Cashins SD, Alford RA, Skerrratt LF (2008) Lethal effects of Latex, nitrile and vinyl gloves on tadpoles Herpetological Review 39(3) p 298-301.

Sobotka JM, Rahwan RG (1994) Lethal Effect of latex gloves on Xenopus laevis tadpoles (J. Pharmacol Toxicol Methods 32(1) p 59

If amphibians can be killed by trace substances from gloves, it's not such a stretch of the imagination to think that they can be harmed by substances on our own hands. Think of all the amphibian-toxic things that we touch all the time (metals, soaps, etc.).

I do handle my amphibians, but I make sure my hands are well-rinsed and only pick them up when truly necessary. I think hands may be safer than most gloves, but no handling is even better.

 

[Hydro033]

If you can demonstrate that the root causes are harmful, showing that a carrier of multiple causes is harmful, is somewhat pointless. It's just a logical extrapolation:

heat: harmful
dessication: harmful
salts: harmful

therefore source of heat, dessication, and salts: harmful

Look for references on the aforementioned substances [they certainly exist] and you'll have your evidence. With salt, the issue will be too many references and finding the ones which are relevant. Ditto for dessication.

This paper:
JSTOR: An Error Occurred Setting Your User Cookie
references a number of others which specifically address dessication susceptibility of various species.

This one may provide a good start for heat tolerance:
JSTOR: An Error Occurred Setting Your User Cookie

As but one of many examples, torrent salamanders have a critical thermal maximum of about 17C. We have a body temperature of about 37C. Holding a torrent salamander can cook it. There's no shortage of other amphibians which also have low CtMax.

Do you think clean, washed hands can actually elevate their heat/salt levels and decrease their hydration to such an extent? It seems far-fetched.

 

[FrogEyes]

It's a matter of degree.

What species? How long? How often? How thoroughly are hands washed? How thoroughly are they rinsed? How reliably are these procedures followed?

First, the point above is that it's hard to be sure that all people properly follow all the procedures all of the time, and that those procedures are suited for the species involved.

Second, you spoke of handling, without ever specifying any kind of conditions imposed on that handling. That's "moving the goalposts". Without specifying all these things to begin with [precisely, I should add], we can only assume that you are refering to average ordinary handling with average ordinary hands, which are salty, oily, warm, dry, and often coated in oils and chemicals.

 

[Azhael]

But it isn´t. Prolonged manipulation can indeed be lethal (i´ve personally experienced this when i was a child and an idiot). Human body temperature is much more than the typical caudate can possibly tolerate, as FrogEyes has already said.
Aquatic newts dessecate fast when you handle them. I´ve seen this many times, which is why i use a net and a small glass tank when i go herping so that contact with the animals is either non-existent or as minimal as possible.

IF you have to handle a caudate, use cold water to chill your hands and only manipulate with wet hands and for as short a time as possible. There is no need for testing, this stuff has been confirmed many times.

 

[Hydro033]

It's a matter of degree.

What species? How long? How often? How thoroughly are hands washed? How thoroughly are they rinsed? How reliably are these procedures followed?

First, the point above is that it's hard to be sure that all people properly follow all the procedures all of the time, and that those procedures are suited for the species involved.

Second, you spoke of handling, without ever specifying any kind of conditions imposed on that handling. That's "moving the goalposts". Without specifying all these things to begin with [precisely, I should add], we can only assume that you are refering to average ordinary handling with average ordinary hands, which are salty, oily, warm, dry, and often coated in oils and chemicals.

Well of course it is a matter of degree. That is why I asked if there were any publications on the topic.

I had a gray tree frog, which I left with my girlfriend when I went away to grad school. Her mother became obsessed with it. She often takes him out and lets him sit on her palm and they "watch TV together." This is not a joke...

She holds her hand flat, palm up and fingers pointing straight (think waitress holding a tray). He just sits there and doesn't jump off for periods in excess of an hour sometimes. She has been doing this for almost a year now and he is still doing just fine.

I told her to clean her hands before touching him, but she never listened to any of my advice concerning this frog (despite me studying the damn things in grad school....sigh).