Questions about skin absorption.

[Phurba390]

Hey everyone,

My beardie is the first reptile I've owned, so my general overall reptile knowledge is intermediate at best. I have read from multiple sources reptiles absorb liquid through their skin. My question is, how much exactly? Are there any common things to look out for with regard to skin absorption? Could soap residue in the tub be absorbed and poison them?

The reason I'm wondering about this seems rather silly, but it's something I've been worrying about. I have very overactive sweat glands in my hands. Sometimes I will be holding my beardie on my chest watching TV and I'll wonder if the sweat on my hands could cause any problems. I know this seems really stupid, but I have an anxiety disorder and I've had 2 baby beardies die on me so I get overly worried about small things.

 

[AHBD]

Hi there....beardies and other reptiles don't actually absorb water through their skin. Their skin is actually a barrier, and repels water. There are a couple of lizards [ the Moloch thorny devil and I THINK the Texas horned lizard ] that have a channel type system that involves capillary action that draws water to the mouth of the lizard. It's really cool, you can probably see a video on youtube if you Google " thorny devil absorbing water ".

Your beardies will have no problems with your sweaty hands.

Beardies get hydrated by drinking and from the food they eat.

 

[Phurba390]

Thanks for clearing that up. I wonder, since they cannot absorb liquid why do people give them pedialyte baths and stuff when they're in poor health? They rarely drink the water you bathe them in, depending on the dragon, so how would bathing them in it help? I give my beardies electrolyte drink from a medicine dropper since that just made a lot more sense to me.

 

[AHBD]

It's believed that they absorb water through the vent [ their rectum ] because that belief has been around for a long time so some owners will put Pedialyte in the water hoping that it will be absorbed. A tiny bit of fluid can go up but not far enough to actually hydrate the animal. Here is an explanation and one of the only mentions of an actual clinical study. I copied/pasted this from the U.K.reptile forums, not something I wrote but I believe this is pretty accurate.


What happens most often when you place a lizard in a warm bath? Yep, they pass their wastes. Im not sure that I fully understand why this is, but there seems to be two things happening. First, an increase in temperature can cause the evacuation of the bowels as the animal tries to keep temperatures constant. Second, the water can cause the relaxation of the muscles surrounding the sphincter which would then lead to the evacuate the bowels. The issue as I see it is that neither of these are naturally timed processes. Regardless of whether or not the animal is too dehydrated to go on its own, these two processes are premature in the normal digestion of the lizard. They didnt go prior to being in the bath, but rather this was something that was somewhat decided for them by the parameters of the bath. What that means is that the normal processes of absorption of water and salts from the bolus were cut short or otherwise unnaturally timed. This has the potential to unbalance the electrolytes and therefore hydration in this careful system.

Beyond this, there is the lack of evidence to support that any water is taken into the cloaca and absorbed from a bath anyway. The absorption of water from the wastes is a slow process. In those lizards studied, absorption rates from wastes were about 7-8 ml per kg of animal PER HOUR. If you take into consideration that say a bearded dragon weighs around 1/4 of a kg, and the average bath lasts 1/4 of an hour or so, youre talking generously about 0.5 of a ml, or roughly eight to ten drops of water. However, this is for absorption by natural means within that careful system of osmotic pressure, which requires balanced salts and proteins. Now the question becomes does any water actually make it into the cloaca via a bath?

The answer seems to be no. The only evidence I could find of any testing done was by a great guy named Dr Wade Sherbrooke. He has tested this on a few species of desert lizards, by dying water and dousing or bathing the various areas of their bodies. He was then able to determine if any water was taken in and via which ways. He found that no water was taken in through the cloaca and entered into the bloodstream, regardless of hydration levels in the lizard (Sherbrooke, 1990: Jrnl of Herp, 24:3. 302-308 ). He basically found that if water gets in, it gets in through the mouth (and sometimes in the strangest of ways). Shoemaker and Nagy (1977, Ann Rev of Phys, 39:449-471) found the same thing.

So it seems that if your lizard drinks in the tub, and bathing does stimulate some to do so, then they would probably gain some decent hydration from it. However, it does not appear that any further hydration would be gained by other means.

 

[kingofnobbys]

That was very informative AHBD - and reflects what I thought was happening regarding when beardies sit for long periods in their water dish (if they have one) , ie it's to cool off, or it's to do a poo , no water is taken up through the rear end.

None-the-less I've seen the claim made very frequently - often by very experienced beardie breeders here (in Australia) that beardies can rehydrate via their rear end but never took the time to research the available literature to prove or disprove their claim. A lot of bad advise and just completely wrong advise given on local Australian reptile boards by a very small number of self appointed experts that many less experienced keepers seem willing to accept as "gospel" it seems.

 

[Lucy1988]

Thank you AHBD! I've read this so many times in passing I didn't think to question it. It seems to me as a newbie owner quite hard to find information about beardies that isnt anecdotal. (Not that this hasn't been of imense help). Have any organised studies been done on beardies?
Lucy and Lovebug.

 

[AHBD]

You're welcome. I'm not aware of any other documented studies aside from the ones mentioned there.

 

[Lucy1988]

Was just browsing and found the study I remember being mentioned here. http://www.beilstein-journals.org/bjnano/single/articleFullText.htm?publicId=2190-4286-2-24

 

[Taterbug]

I'd have to go back and dig it up but there was a paper I have somewhere about permeability (how easy it is for water to pass through something) and lizard skin is crazy low, much much lower than human skin for example. Amphibians on the other hand have much different skin and are very sensitive to water quality, skin oils and such. Sometimes people get confused because reptiles and amphibians are usually thought to be similar.

Unfortunately, there are not many studies specifically about bearded dragons, (I have papers on other topics but not this one) so it must be extrapolated from other lizards. You'll, find many "facts" about dragons are extrapolations like this or things that are totally fabricated by the community (breeders, keepers, pet stores etc) like the pedialite/gatoraid baths which could even do more harm than good.

 

[Xazzak]

I had the same inquiry as the original poster. If the answers/studies that followed hold true, then what is the point of misting and bath soaks for beardies if they're not drinking during those times? My dragon will not drink from either, but I'm assuming it's common practice by the masses because some beardies actually drink during those times, this hydrate?

 

[AHBD]

Some people might mistakenly think that misting should be done like it is for tropical lizards. But if the humidity is very low in your beardie's tank and/or they have trouble shedding, the tank can be lightly misted. Some owners, including me, spray lightly on the dragons snout, not a mist/shower but a direct gentle stream. All my dragons have drank that way for over 20 years including all the babies I hatched. Baths are also given to aid in shedding, but they aren't always necessary but there are dragons that may drink when bathed . Here's a video of babies on youtube drinking via the spray bottle.
viewtopic.php?f=6&t=224666

 

[kingofnobbys]

Hi there....beardies and other reptiles don't actually absorb water through their skin. Their skin is actually a barrier, and repels water. There are a couple of lizards [ the Moloch thorny devil and I THINK the Texas horned lizard ] that have a channel type system that involves capillary action that draws water to the mouth of the lizard. It's really cool, you can probably see a video on youtube if you Google " thorny devil absorbing water ".

Your beardies will have no problems with your sweaty hands.

Beardies get hydrated by drinking and from the food they eat.

Bearded dragons have a similar scale channeling arrangement in their snout that draws droplets of water to the lips through capillary action.

ONLY WAY to get water into a bearded dragon is by the mouth.

In the wild water condensing in dews and mists is usually the only source of water other than insects, smaller reptiles, small mammals and bird hatchlings , green leafy herbs and fruit they have , usually for their entire lives. (Very little standing water , and running water is extremely rare in central Australia.)

 

[AHBD]

Here is an incredible video of visible capillary action of a thorny devil lizard....you can see this is totally different than other lizards. Beardies have scalation that allows water to funnel from their heads down in to their mouth, that is what many lizards do but is not the same as this. I linked the youtube video [ dubbed in Russian over English ] that was the shortest in length to just show the lizard in the water as the water visibly travels through the entire body. If you've never seen it, it is amazing.
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjmp4_z0O3MAhXDmx4KHeFqCmgQtwIIIjAB&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D1rgl4hxDh_E&usg=AFQjCNG3JPdz-745HPSAFXWEGpCVlg-sHA&sig2=QYJAFFWi3yQoPCJOwnKUVg

 

[kingofnobbys]

Here is an incredible video of visible capillary action of a thorny devil lizard....you can see this is totally different than other lizards. Beardies have scalation that allows water to funnel from their heads down in to their mouth, that is what many lizards do but is not the same as this. I linked the youtube video [ dubbed in Russian over English ] that was the shortest in length to just show the lizard in the water as the water visibly travels through the entire body. If you've never seen it, it is amazing.
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjmp4_z0O3MAhXDmx4KHeFqCmgQtwIIIjAB&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D1rgl4hxDh_E&usg=AFQjCNG3JPdz-745HPSAFXWEGpCVlg-sHA&sig2=QYJAFFWi3yQoPCJOwnKUVg

That one is blocked ,so here's another https://www.youtube.com/watch?v=JoduGti4G_k

BTW I know of only 2 amateurs who keep thorny Devils , very difficult to keep apparently because they only eat ants and you have to provide inhouse at least 3 ant nests to feed one or two.
Seen them in the wild are they are amazing little lizards .... https://www.youtube.com/watch?v=ZUsARF-CBcI (about 4 mins in .... amazing to see)