UV lighting - sunshine on their shoulders

by Bonnie J. Keller

Twice within a couple of weeks  I heard prospective lizard owners ask the question, " Do we really need that UV light for this little lizard? It's SOOO expensive. Can't we do without it?" My heart sinks every time I hear this, because the inevitable answer from the typical pet store employee (who doesn't want to lose the sale) will be, "Well, I have heard that they can live for years without it, I guess you don't really need it." Fortunately, in both cases, I was able to get correct information to the people to let them know how vital UVB light is to reptiles.

UVB light is what makes us suntan (yes, and sunburn). It is an invisible part of the sun's light that is essential to health. How many times do mothers tell their children, "Go out and play, you need some sun!!"?? Mothers seem to instinctively know that their children need sunlight for some reason, but they just don't know why. Here's why…

Without getting too technical, the UVB contained in sunlight interacts with pigments found in our skin, as well as that of reptiles and other animals. The chemical reaction that takes place forms vitamin D3. Now, if you look at any carton of milk, they all advertise "vitamin D fortified". Why? Because vitamin D3 is what takes the calcium that is so important in milk and turns it into usable chemicals that eventually make up bone. So, without vitamin D3, little of the calcium we take in would actually end up in our bones at all. Fortunately, we humans are able to take in vitamin D3 in our diet in place of getting sufficient sunlight to produce it (thus the milk jug bragging.)

Most reptiles, however, aren't so lucky. Dietary vitamin D3 is usually ingested when we eat meat, milk, or other animal products. (This is likely one reason why snakes don't appear to need supplemental UVB lighting.) Many reptiles don't eat other animals. Iguanas, for instance, are complete vegetarians, as are many of the popular tortoises. Anoles, while they do eat bugs, don't get enough D3 from the crickets that we humans may feed them. Some other lizards that are half-and-half veggie eaters/meat eaters may get SOME of the D3 they need, but not all of it. So, the only options we have to allow these reptiles to produce vitamin D3 naturally are:

1) let them roam around outside at least 3-4 days a week

2) give them artificial "sunlight" that will produce vitamin D3

Since option 1 is not feasible year-round in most places, nor is it a good idea to place your reptile directly in the sun without shade, option 2 is our best alternative. Also, merely placing the animal in a sunny window won't work, either: glass and most plexi-glass blocks UVB light, and even regular window screen blocks more than half of it.

Since we have domesticated these animals and/or taken them from the wild to serve as our personal entertainment/educational slaves, it is our responsibility to provide them with the best habitat we can. Sure, an anole is $5 or so. Yeah, it might only live a couple of years. But how miserable do you think it is for that animal when its bones are slowly softening in its body? Ever seen an older lady with osteoporosis??? Though the symptoms may or may not show before the animal dies, that is pretty much exactly what happens to a reptile that does not get sufficient UVB light. Yes, a UVB-producing bulb is relatively expensive: the VitaLite brand costs around $20 or so. This brand gives off minimal UVB light, and should only be used for those reptiles who are the omnivores (half-veggie/half meat). Those reptiles which are vegetarians need a higher UVB concentration, found in two other brands: Zoo-Med's Iguana-Lite or Reptile-Lite, and ESU's Desert 7% bulb. The Zoo-Med bulbs give off 5% UVB, the other bulb 7%. Natural sunlight has approximately 6-8% UVB, so any of these above bulbs would reasonably simulate the sunshine a reptile would normally receive. To ensure that they receive the correct amounts, however, it is important to place the light 12-18 inches from where the animal will be most of the time, and they need to be replaced every 6-8 months (even if they still LOOK like they are working).

One new option that has come onto the market in the last decade has been a new screw-in bulb that offers both heat and UVB. Research apparently backs up these claims, and the bulbs have been used in several zoos and breeding facilities with phenomenal results. The down side to these bulbs is that they are rather expensive, costing about $35 per bulb. But, it may well save you money in the long runcsince this can replace both the heat and light source, and will not require the special fluorescent fixture of other bulbs - and, it doesn’t have to be replaced as often as the fluorescent bulbs do.   

So, the answer to the question, "Does the lizard/turtle really have to have this UV light?" is , "Absolutely!" And get the best one you can. Your reptile's life and well-being depend on it. Though it is only part of the list of necessary supplies for a lizard or tortoise, it is one of the most important things you can do to ensure your pet's health. (And the next time you're feeling those winter-time blues from not enough sunlight, try placing a UVB bulb near where you sit - I bet it helps some!)

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