The UVB Varanid debate !

[mdfmonitor]

Just looking tonight & he can stand on the floor now & reach the top!! still growing an inch a week!

I had a ceramic to heat the lower level for winter, i've swop it for another basking spot flood, he now uses both basking sites at the lower & higher temps.

He goes by the skylight light levels if he's full, otherwise he waits up for me!!

[Roman]

Originally Posted by smy_749

I'm sure there are already discussions about this, and most of us agree that its not necessary for a healthy monitor. Everyone I've talked to in our US community agrees, however our european counterparts look down upon us for not using adequate lighting and keeping our animals in small boxes (frequently said on FB groups)

As I am one of these “European counterparts” I might just add some of “our” views here…

First of all, I did keep an Ackies dwarf monitor (Varanus acanthurus) for some years, but that’s my only experience with keeping any lizards at all. Having said that, I have several books about keeping monitors and have good connections to several keepers and breeders of lizards in general and monitors in particular.

I don’t know about the “European” point of view, but here in Germany it is pretty much the common opinion that you need UVB light to keep your lizard healthy. The reasoning behind this is obviously the vitamin D3 synthesis to add calcium to the bone structure. I suppose this topic is well known for most of us, so I don’t go into too much details. Basically there is no need to supplement vitamin D3 for vertebrates which feed on mammals or birds, because there is more than enough vitamin D3 in the liver of each prey, so for most snakes there is no need for any supplementation. Insectivore lizards on the other hand need an outside source for vitamin D3, because insects don’t contain enough D3 to provide an adequate source. So in order to provide enough vitamin D3 you have to either supplement the feeder insects with some multivitamin powder or provide a source of UV-B light so that the monitor can build enough D3.

In Germany we use both methods simultaneously, we provide UV-B light and supplement every second meal with a multivitamin powder (and any meal with some calcium powder). I found some statement in my literature that it might be enough to just add the supplementation without UV-B, but they also stated that it might be tricky to get the right amount without under-supplying the monitor or to poison it with an overdose. So the general recommendation is to use UV-B lighting as one light-, heat- and UV-B-source.

There is no obvious need to provide UV-B light for most snakes (with the exception of the Diamond pythons Shaun mentioned, the rough green grass snake Opheodrys aestivus as an insectivore snake might also benefit from additional UV-B light). However I use two HCI and one 70 W UV-B spot for my large Spilotes enclosure (tiger ratsnakes). I don’t know if there is any positive effect for the snakes, they do not favor or avoid the basking spot right under the UV-B spot, sometimes they use it, sometimes not. The light has a very positive effect on my plants, they grow even better right under this spot as in the rest of the enclosure, so I keep this light as an additional light and heat source.

Roman

[Mikoh4792]

Originally Posted by Roman

There is no obvious need to provide UV-B light for most snakes (with the exception of the Diamond pythons Shaun mentioned, the rough green grass snake Opheodrys aestivus as an insectivore snake might also benefit from additional UV-B light).

Roman

I was told by a keeper of a 25 year old diamond python that they do not need UVB, it's just that people were keeping them wrong until recently.

[smy_749]

Roman, I didnt mean it in a negative manner. But many times on Fb I see those statements. Anyways, its only been a day or two, already noticing twice the activity level. They switched basking spots from the one they always used to the one closest to the bulb. They also increased their appetites, but it has been warm lately and the bulb added extra heat. So too early to say.

[Roman]

Originally Posted by smy_749

Roman, I didnt mean it in a negative manner. But many times on Fb I see those statements.

Smy, don't worry, I did not think you meant it negativ.

Roman

[murrindindi]

Originally Posted by Roman

Insectivore lizards on the other hand need an outside source for vitamin D3, because insects don’t contain enough D3 to provide an adequate source. So in order to provide enough vitamin D3 you have to either supplement the feeder insects with some multivitamin powder or provide a source of UV-B light so that the monitor can build enough D3.
I found some statement in my literature that it might be enough to just add the supplementation without UV-B, but they also stated that it might be tricky to get the right amount without under-supplying the monitor or to poison it with an overdose. So the general recommendation is to use UV-B lighting as one light-, heat- and UV-B-source.

There is no obvious need to provide UV-B light for most snakes (with the exception of the Diamond pythons Shaun mentioned.
Roman

Hi, there are no Varanid species that are strictly insectivorous as far as I know (either in the wild or captivity), so I`m not sure which species you feel actually need supplementary UVB to remain healthy in captivity?
There is now overwhelming evidence that fully supported captive Varanids do NOT need exposure to real or artificial UVB in order to remain in good health, long lived and productive.
My own thoughts are that Varanids in the wild may benefit from UVB exposure more especially during the harsher periods when food may perhaps be in relatively short supply (so the ability to absorb the UVB rays is a sort of "back up" system).

I`m not sure that Diamond and Carpet snakes actually require UVB to remain healthy either (though there`s absolutely no harm in providing it), as they certainly do bask in unfiltered natural sunlight in the wild (personal experience).
In that respect, I don`t quite understand why the other member (Shaun) only uses a 2-0 UVB tube for this subspecies (I`m not suggesting a 2-0 is harmful at all).

[murrindindi]

Originally Posted by smy_749

Roman, I didnt mean it in a negative manner. But many times on Fb I see those statements. Anyways, its only been a day or two, already noticing twice the activity level. They switched basking spots from the one they always used to the one closest to the bulb. They also increased their appetites, but it has been warm lately and the bulb added extra heat. So too early to say.

Hi,
I`ve used MVB`s for many years here in Europe, convinced it was necessary, but for the last two years I haven't, and neither have I noticed the slightest difference in behaviour during that period.
I`m totally convinced these days that while real/artificial UVB may not be harmful, it isn`t needed in captivity so long as they are fully supported in regards to temps, humidity, a whole prey diet, suitable substrate and nesting etc, etc. Without all those parameters being met, no amount of UVB irradiation or supplementation will keep them healthy in the long term.

[Roman]

Originally Posted by murrindindi

Hi, there are no Varanid species that are strictly insectivorous as far as I know (either in the wild or captivity), so I`m not sure which species you feel actually need supplementary UVB to remain healthy in captivity?
There is now overwhelming evidence that fully supported captive Varanids do NOT need exposure to real or artificial UVB in order to remain in good health, long lived and productive.

I agree, most small or medium sized varanids feed on insects and smaller vertebrates like other lizards or snakes. But most of us can’t provide those on a regular basis, so that leaves us with an insectivore diet with some baby mice as occasional treats.

All sources I could find will tell you that insects provide no or nearly no vitamin D3, so you have to provide it from an external source, especially as baby mice are the equivalent of a big burger for a small monitor, something you may eat, but not on a regular basis.

Could you please provide your source that there is no need for an external exposure of UV-B?

How do you feed your monitors, which food-mix do you provide?

Roman

[murrindindi]

Originally Posted by Roman

I agree, most small or medium sized varanids feed on insects and smaller vertebrates like other lizards or snakes. But most of us can’t provide those on a regular basis, so that leaves us with an insectivore diet with some baby mice as occasional treats.

All sources I could find will tell you that insects provide no or nearly no vitamin D3, so you have to provide it from an external source, especially as baby mice are the equivalent of a big burger for a small monitor, something you may eat, but not on a regular basis.

Could you please provide your source that there is no need for an external exposure of UV-B?

How do you feed your monitors, which food-mix do you provide?

Roman

Hi again, my sources are many, there are some very experienced keepers and breeders of Varanids in Germany, one of those being Prof. Dr. Hans-Georg Horn, are you familiar with his work?
In America there`s Frank Retes (one of the worlds most successful keepers and breeders), also Justin Burokas and Ben Aller....
May I ask which books you have that suggest UVB is necessary for captive Varanids?
All my monitors have ALWAYS received a whole prey diet from hatchlings to adlulthood which included vertebrate and invert prey.
Edit: I cannot believe that vertebrates are not readily available in Germany (you say "most of us cannot provide them on a regular basis"), and the suggestion that baby mice "are like feeding a burger" (junk food) is complete nonsense, they are a healthy and very nutritious meal.
Please do not take anything I say as being disrespectful to you!

[formica]

I use a full spectrum CFL bulb, E28 fitting, alongside my heat lamps, doesnt add any extra heat at all; if anyone is looking for a simple solution to add alongside their heat lamps.

I'm not a fan of tubes tbh, I wouldnt trust my Sav not to try and climb one (ie rip it off the wall, break it and breath in lots of mercury and phosphorus!), he doesnt pay any attention to the CFL, i think because it is next to the heat lamps, which are very hot, and he knows it

Considering a monitor's resilience, I think the fact that they can survive into old age without UV, is something which should be considered with caution, given that there hasnt been a proper scientific study into the topic - however, there has been a study which has shown that UV does affect positively, the level of D3, in Varanids with a (controlled) deficiency of the vitamin...i posted the link up some time ago in another thread, will find it again if anyones interested or cant find it in search.

I dont think we should we consider all varanids to react in the same way to UV either, given their wide habitat distribution and evolutionary age, there is no reason to think they havent each evolved their own adaptions to it

[murrindindi]

Originally Posted by formica

Considering a monitor's resilience, I think the fact that they can survive into old age without UV, is something which should be considered with caution, given that there hasnt been a proper scientific study into the topic - however, there has been a study which has shown that UV does affect positively, the level of D3, in Varanids with a (controlled) deficiency of the vitamin...i posted the link up some time ago in another thread, will find it again if anyones interested or cant find it in search.

I dont think we should we consider all varanids to react in the same way to UV either, given their wide habitat distribution and evolutionary age, there is no reason to think they havent each evolved their own adaptions to it

Hi, I`d like to see the article you mention (thanks).
As far as studies being carried on captive Varanids kept under "optimum" conditions for extended periods as we now understand those to be, I don`t think there are any?

[formica]

i think this is it: http://varanidae.org/1_2-Current_Research.pdf ...its only the preliminary, i dont know what they found by the end of the study, cant find anything further

Originally Posted by Preliminary Results

Deprivation of all sources of vitamin D3
resulted in an average of 30% depletion of circulating calcidiol
in approximately two months.

A single dose of dietary vitamin D3
or UVB resulted in a significant peak of increase in calcidiol at an
average of seven days with return to baseline in an average of 14 days.

(error in my previous post, wasnt D3 that was directly measured, a metabolite of D3 was measured, calicidiol)

[murrindindi]

I did have an article but I think I sent it to someone, the title was something like "Update on vitamin D3 in basking Lizards", I`m not sure it`s available to view online, it concerned a Komodo dragon (or several) which had not had access to real or artificial UVB for some time, they found after exposure to an MVB (I think?) for around 3 months the D3 levels compared to those of wild komodoensis (they were in single figures prior to exposure). The "problem" with this study (possibly others at that time) is that this was well before current practices re temps, humidity, etc were in place, that would undoubtably effect the results, because the monitor`s didn`t have sufficient basking temps and perhaps an "inferior" diet.
Edit: This is the article, it HAS been published, as I say I used to have a copy...

1) Allen, M.E., M.F. Hoilck, M. Bush, O.T. Oftedal, R. Rosscoe, and
T. Walsh.
An update on vitamin D and ultraviolet light in basking lizards.
Unpublished data. 4 pp

[formica]

Yeah I saw that one while searching, havent had a chance to read thru it yet, i did notice it was only a few animals, the topic really needs a wider data set (as has been done for bearded dragons with clear conclusions)

insectivores are generally known to be much more efficient at using UV, than carnivores, and therefore it is generally a more important componant; monitors eating both, does throw up interesting questions, livers are full of nutriants including Vit D3 - would be good to find out what happened with the study as it progressed, they asked some interesting questions which really do need answers, considering how polarized the topic is

[mdfmonitor]

Not keen on cfl bulbs, had a day light one set high in the roof of an old cage & the heat damaged the casing!! fell apart, also i've had at least 3 mercury vapours go ping because they couldn't hack the humidity.

There's some heat generated when you start putting a number of bulbs together, that's why you need a sealed viv it creates it's own exchange of air from hot to cooler temps, which reduces you humidity around the basking bulbs.

As for vitd, i was always told give them 130f plus (depending on size) & this will allow them to digest the food & process the vit d, you can control the vitd using uvb light but you still need high basking spot floods to digest the food.

When the monitor starts getting larger you need some bulbs & wattage to cover snout to vent, ad in other lights your just upping the burn off of humidity.

160f is a good basking spot flood to aim for & if Krusty & Frank & other long term keepers say you don't need it but use it if you want to,that will do me!!