shaking/tremors? in the head

Question
My four year old iguana had metabolic bone disease a few years ago, but he recovered and now has a proper diet, UVB lighting, and I give him vitamins and calcium powder. He has been eating well and has been very active, and still is. His skeletal structure, especially his shoulders and legs, still look healthy and strong. Nothing like they were when he had MBD.

However, over the last three days when I have gone into his cage, his head has been shaking like some kind of seizure. It is only his head, the rest of his body is fine and either still or moving towards me normally. I does not look like head bobbing, it is erratic and tremor like. Could this be a result of kidney disease or some lasting physical damage because of his MBD? Or some other deficency? Please help and thank you so much for your time.

Answer
Hi Katie,
What you are seeing can be normal shudder bobs..with these, their heads move in all directions and when an ig is  just "learning" the shudder bob, they can look very erratic with the movements.  When does he do it?  When you are going near him? When he sees you or someone/thing else?  If yes, then they are most likely normal and he is saying to stay away from his territory.
Generally these bobs are done when they are alert and dewlap may be out.
If he is doing this while relaxed and calm, then there may be a problem that a vet would need to check for possibly neurological problems.
How often do you give the calcium?  How much does he get?  Calcium should only be used 3 times a week or so, in a very, very small amount unless so prescribed by a vet.  Over use of calcium can cause as many, if not more problems than not enough calcium.
How old are your uvb lights?  What is the exact brand? Type?  Uvb lights generally need replaced every 6 months to a year.  There are also new studies that have proven that not all lights claiming UVB are actually giving good uvb. I will include a paragraph I wrote pertaining to UVB.
If you suspect that the shudder bobs are not normal shudder bobs, then a vet needs to run some tests..blood work will show any problems with calcium and other nutrients plus possibly kidney/liver problems.
If you do a search on GOOGLE for "Iguana shudder bobs" videos you can see what a shudder bob looks like. Something tells me that he is now feeling healthy and has become mature and testing his abilities to warn everyone that he is a healthy ig!

Supplying uvb can be done in a few ways. By special lights that come in fluorescent tubes or special screw in bulbs (mercury vapor)that are designed to produce uvb and heat. The tubes do not produce heat. UVB is needed by the Iguanas to be able to absorb the calcium in the foods they eat. With out the uvb, they will develop metabolic bone disease. There are tubes that say ''full spectrum'' but they do not produce any uvb.
With the correct tubes, they must say that they produce BOTH uvb and uva. The uvb needs to be 5% or higher. Repti Sun 10.0 and the Repti Glo 8.0's are a great source for uvb.(not compacts) The old "favorites" are the repti sun 5.0 or the Iguana light..which are the same tube, just different package. These need to be positioned 6-8 inches over the iguana for the 5% and 8% and 8-10 inches for the 10% so that they get the uvb that is needed.  The tubes need to be replaced every 6-9 months as that they stop producing UVB long before they stop producing light.Using a fixture that holds two uvb tubes of at least 3 feet in length will provide adequate uvb for your iguana. There has been new studies that have proven that compact uvb lights, both the spiral/coil type and the ones that look like long "U's" laying on their side and a few other brands are causing what basically amounts to snow blindness in reptiles.  To read more on this, you can go to http://www.uvguide.co.uk/index.htm
On the mercury vapor , they also produce heat. They also produce the uvb and uva. The best on the market now are the Mega Rays.(http://www.reptileuv.com) The distance from these are greater than the uvb tubes and the directions must be followed that are listed for the light. When using the mercury vapor lights, you don't need to have one light for uvb and one for heat. The Mercury vapor lights provide both.
For daytime heat, if using the tube uvb, regular household incandescent light bulbs produce heat, although they don't produce uva. I like the halogen bulbs as they produce a nice bright light for your ig. The wattage will depend on the size of your iguanas enclosure. and the room temperature.Of course, the best uvb is from the sun and if you are in an area that you are able to take your iguana outside in a proper enclosure, (Never a tank or enclosed, solid cage)