Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Sneezing and Yawning

©1995, 2002 Melissa Kaplan



Cyclura "snalt" (Click photo for larger image)

Many people are concerned when they first see or hear their reptile sneeze, especially iguana owners, as many iguanas sneeze more often - and more productively - than any other animal (at least it seems that way to those iguana keepers who seem to spend a significant amount of time cleaning salty deposits off of windows, walls, furniture, etc.).

Generally speaking, reptiles sneeze for the same reasons humans and other animals. Sneezing is a natural biological response to an irritant in the nose. Sneezing may also be an allergic reaction, both to airborne substances and to ingested substances.

In the case of iguanas and many other lizards, sneezing is how they rid their bodies of certain salts that are the normal by-product of their digestive processes. This does not mean that if you do not see your iguana sneezing you should be adding salt to his diet, nor does it mean that the foods you are feeding him are too high in salt.

All foods have salts of different kinds, and those not required for metabolic and other physiologic processes are voided by the body; iguanas get rid of theirs by sneezing. Animals have different ways of dealing with these by-products - in the case of green, Cyclura and other iguanas, this is their way;

Stephen Barten DVM, in his chapter Lizards, in Mader's Reptile Medicine and Surgery (p.53), states:

"Nasal salt glands are present in herbivorous iguanid lizards such as the green iguana. When the plasma osmotic concentration is high, excessive sodium is excreted by these glands. The lizard may be seen to sneeze a clear fluid that dries to a fine, white powder, which is sodium chloride. This mechanism allows water conservation and may be mistaken for an upper respiratory infection.

"The internal nares are anterior in [inside, in the back] of the mouth and are a common site for discharges to accumulate, as well as a good site for bacteriologic sampling [choanal swab] when respiratory infection is present."

That is not to suggest you feed your iguanas foods which salt has been added. If you a feeding a particular food for a while (1+ weeks) and realize that your iguana is snalting more than he used to before that food became a staple, then you might want to stop feeding that food for several weeks to see if that makes a difference. If it does, go ahead and reinstate that food item, but not as often.

Sneezing is not a result of a cold virus. Reptiles can develop lung infections, usually due to bacteria, sometimes inadvertently caused by the owner when forcing oral fluids or food which get into the lungs via the rather than down the esophagus, or when regurgitated and then aspirated (inhaled) by the reptile. The common signs of a respiratory infection in reptiles do not include sneezing.

Cleaning the Snalt
Snalt is a term some green iguana keepers use when referring to the residue that gets deposited seemingly over everything their iguana comes into contact or proximity to. Made up of the words snot +salt (as smog = smoke +fog), snalt is more than just grains of salt, as one finds out when one tries to clean it off of various surfaces.

When salt deposits collect around the nostrils, they can easily be gently wiped away with a damp cloth. You may need a razor blade to scrape the deposits off the glass of their tank, however, as well a glass cleaner with a mild degreaser, to get the windows completely free of the residue. Snalt on eyeglasses should be first rinsed with hot water, then a mild soapy water applied to remove the residues. If you rub your lenses while the salt residue is still on them, you may scratch the lenses. Snalt will corrode brass and other such metals, so if you value your lamps, headboard, or other furnishings, clean them quickly and often.


Birds do it, bees do it, even reptiles in the trees do it. Yawning, that is. Researchers don't understand completely why we yawn, or why yawns are "contagious". They do know that normal occasional yawns can be due to drowsiness that may be related to a reduction in oxygen in the brain or lungs. Excessive yawning is related to health problems that are affect the body's ability to take in or circulate oxygen (heart disease, respiratory disease, etc.). Some medications can interfere with oxygen uptake, while yawning can exacerbate some joint and pain conditions, including temporomandibular joint and neuralgias.

Besides the "low on oxygen" theory is another one, one that came out of a post- WWII hospital experiencing a high rate of patient mortality except for the patients of one particular surgeon. The only thing this surgeon did differently from the other surgeons was to squeeze the respirator bag - that was full of air - which forced the air into the lungs. The theory is that the forceful inflow of air from the bag - and from our yawns - causes a redistribution of the alveolar secretions in our lungs, secretions that help protect our lungs by improving surface tension and help prevent the buildup and retention of fluids in the lungs - the cause of death in the patients by all the surgeons in that hospital who weren't "bagging" their patients.

With reptiles, there are some other things that may elicit a yawn or yawn-like action. One that snakes keepers are familiar with is the yawn-like movement snakes make as they readjust their jaw joints and adjacent bones after the "dislocation" involved in getting large prey through their mouth. Reptiles that eat slime-coated prey, such as that coating fish, many amphibians, and the amazing slime produce by snails and slugs, may engage in yawn-like movements to help clear the slime coating the inside of their mouth. If you think about it, and aren't allergic to peanuts, this must be somewhat like our trying to clear old-fashioned peanut butter (especially pb&j sandwiches made on squishy white bread) stuck to the roof of our mouths.

Yawning is apparently "contagious" across species. I've been triggered to yawn after watching my iguanas yawn, and I've caught some of them yawning after I yawned in front of them.

When you are observing your reptiles, be prepared to make use of their yawns: yawns provide a great opportunity to closely observe the inside of their mouths, both just to check out the architecture in there, as well as to make sure everything looks healthy in there.

Sources and Related Information

Barten, Stephen L DVM. 1996. Lizards, in Reptile Medicine and Surgery, Douglas Mader DVM, editor.

Walker, Benjamin MD. 1997. What is the reason for yawning? MadSci Network.

MadSci FAQs: Hiccuping, Sneezing and Yawning.

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