Common Health Concerns in Crested Geckos
MBD and Calcium Deficiency (Rare)
Calcium deficiency, while rare in crested geckos that are fed a proper diet, can be a serious issue and in many cases, can be life threatening. Signs of calcium deficiency include a soft, flexible jaw, curvature of the spine and in very serious cases, the inability to walk. Sometimes in geckos with MBD you will see a wavy tail, but that is not necessarily a symptom of MBD.
Calcium disorders commonly result when a keeper's "home made" fruit or baby food concoction doesn't have the proper amounts of calcium and vitamin D3, or the geckos are being fed a poorly formulated commercial diet. Additionally, some vitamins can actually BLOCK calcium absorption, so if you over-do a supplement with vitamins and calcium in it, it could actually have the opposite effect.
If your gecko is exhibiting signs of calcium deficiency such as a soft jaw, wavy tail (maybe) or twitching and trouble moving, the first thing you need to do is get your gecko to a qualified herp veterinarian as soon as possible. I strongly recommend that you do not leave such a life-threatening condition in the hands of a general "dog & cat" veterinarian, as they will not likely have the experience and knowledge needed to address and treat the issue in time.
Wavy Tails in Young Geckos (Cosmetic Issue, Not Permanent)
Be sure not to confuse a youngster's wavy tail with MBD. A lot of "helpful experts" on forums, who mean well, but have been misinformed themselves, are telling other new gecko owners that their geckos have a calcium deficiency, or MBD, because it has a wavy tail. It's actually pretty common for hatchling geckos to have a wavy tail upon hatching, or for a tail to become wavy during adolescence, or even adulthood, under certain circumstances (too much heat, dehydration, etc.). Babies hatching with wavy tails are not as common with crested geckos, but it's seen all the time with leachianus, chahoua and to a slightly lesser extent in gargoyle geckos.
With fresh hatchlings, a wavy tail is either a sign of dehydration or it has to do with the nutritional reserves of mom when the egg was developing - sometimes they get low toward the end of the season, etc. This doesn't mean the baby gecko is going to be affected permanently. In other words, this is completely natural and should not be seen as a problem in need of a solution. :-)
Just FYI, even a lack of calcium can actually be caused by too much of a certain vitamin blocking calcium absorption, so don't automatically assume giving more calcium is always better, as this is another common misconception.
I have seen cases of all sizes of geckos with tails that became wavy after being shipped when extremely hot. This is a cosmetic issue caused by dehydration, not a genetic issue or even MBD. We have also seen this in geckos that had become dehydrated without excessive heat. In the vast majority of these cases the tails have straightened back out over time. If someone tells you it is MBD, they are mistaken.
Entamoeba Invadens (Rare)
While there are a ton of harmless Entamoeba species found in various reptiles, Entamoeba invadens is the only parasite we know of that causes a high rate of mortality in otherwise healthy crested geckos. While a lot of crested gecko people refer to it as "Entamoeba", they are referring specifically to Entamoeba invadens, which can be fatal in crested geckos. Other species of Entamoeba are harmless in low concentrations, so don't freak out if you see another Entamoeba species listed in the results of a fecal analysis.
Entamoeba invadens is a parasitic organism that does damage to the gastro-intestinal tract and other organs, such as the liver. Entamoeba can wipe out a whole collection of crested geckos in relatively short order, if not identified, contained, and properly treated. If caught early enough, though, this organism can be effectively eliminated with Flagyl (metranidazole).
A lot of times people will blame "Entamoeba" when they can't figure out why else their gecko died, but almost every time I've helped someone troubleshoot some random gecko deaths, it's not because of any species of Entamoeba, let alone an infestation of Entamoeba invadens. In fact, I can't remember hearing of a confirmed outbreak in the past 5+ years.
Floppy Tail - Strictly Cosmetic Issue, Non-Genetic, Does Not Affect Health or Breeding Ability
Floppy-Tail or so-called "Floppy Tail Syndrome" refers to a purely cosmetic condition where the tail can "flop" over, perpendicular to the gecko's body, when a gecko is hanging from a vertical surface. I don't like the word syndrome being used here because it makes it sound like more than a cosmetic issue. The truth is, this is a cosmetic issue that sometimes occurs when geckos like to hang upside down from the walls of their cages. Unless you are breeding free range crested geckos (joking), it's going to happen with some of your geckos. It's not genetic or indicative of weak genes, it's certainly not caused by poor husbandry or nutrition, and it won't adversely affect your geckos in any way.
Floppy tail can occur in geckos with strong, diverse genetics, that have been properly cared for and fed a proper diet their entire lives. In and of itself, I've found that a floppy tail is not indicative of any kind of past or present health problem, such as a calcium deficiency, which has sometimes been suspected.
In cases of true MBD or Metabolic Bone Disease, curvature of the spine and eventually a rubbery jaw will become evident. I have never seen floppy tail develop as a direct result of this. Hypocalcemia/MBD affects the entire skeletal system, including pelvic bone, which I guess could make a gecko more prone to developing floppy-tail, but floppy-tail is not a tell-tale symptom of MBD or any other health issue, and should not be considered as such.
So what causes Floppy Tail?
I believe "Floppy Tail" is nothing more than an artifact of being kept in captivity, and I say that for two reasons. First, in the wild, these geckos rest on thin branches and twigs in an upright position with their tails pointing downward, or they hide between/under things. There aren't any 90 degree vertical walls for them to hang from in a head-down position. Crested geckos in captivity sometimes have a habit of hanging upside down from the walls of their cages, where gravity pulls on the tail, eventually causing the tail to droop.
As adults, crested geckos don't generally have tails in the wild, and they don't grow nearly as large as we've bred them to grow in captivity. The pelvis probably isn't designed to support the weight of an adult tail, much less a tail that might be 30-50% heavier than it would normally be on a wild gecko.
To help reduce the occurence of floppy-tail, I simply recommend providing the geckos with lots of tall, both vertical and horizontal, climbing surfaces, and lots of hiding spots on the ground, so that they're less prone to want to hang on the walls of their cage. Artificial vines and foliage are great, as well as simple chicken wire frames used to hold up egg cartons.
In my experience with a large sample group, I have noticed that healthy, stocky, well-built geckos actually seem to be the ones most affected by floppy tail, often from mixed-lineage pairings, so it’s certainly not an issue of “weak genes” or "inbreeding", as some breeders have cited as a culprit. A gecko’s size and resting position habits, in my experience, are what put it at risk of developing floppy tail, not genetics.
A floppy tail won’t hurt them, but the pelvis can start to twist a bit, and become unsightly on a big gecko with a big tail. In this situation, I typically just coax those geckos to drop their tails. The easiest way is by pinching the tail at the base with your thumb on one side and forefinger on the other. The gecko will drop it’s tail automatically, without you having to frighten the gecko into dropping it. I've been doing this for years, and it's a completely stress free way of getting a gecko to drop its tail, if necessary.
Loss of Tail Tip - Common
There are two common causes for crested geckos can lose the tips of their tails and it seems to be the most common issue of anything else I've talked about on this page. Fortunately, experienced crested gecko keepers/breeders don't judge geckos by a damaged tail, or even the lack of a tail entirely. A lot of us think they're cooler without a tail because it makes them unique - more like an Australian knobtail gecko (Australia is relatively close, geographically).
1. "Hunting Accidents" (Less Common)
If you're feeding crickets to your geckos, and you're housing more than one per cage - such as in a breeding group - it's inevitable that geckos will accidentally bite and then tug on each others tails. Usually this doesn't harm the other gecko, but if the one doing the biting is especially slow to recognize its mistake, a minor injury can occur. These bite wounds always heal without any special attention and should be no cause for alarm. Don't be a noob and call the vet as soon as you see a boo-boo. :-) However, sometimes the tip of the tail may become damaged to a point where it is no longer receiving sufficient bloodflow, or it may get infected. When this happens, that portion of the tail will eventually, dry up and eventually fall off.
If hunting accidents are common in your collection and you're worried about tails, you may want to cut down on the number of geckos you keep in an enclosure or simply increase the size of the enclosure. When given sufficient room, these accidents seem to occur with far less frequency.
2. Retained Shed (Most Common Cause)
Sometimes a gecko will have a hard time shedding the skin around the tip of the tail and if not caught in time, the unshed skin can constrict and cut off bloodflow, effectively killing the tip of the tail. If you do catch it early enough, simply peel away the unshed skin and the tail should return to normal. That said, if the tail is already damaged, you can wait to see if it heals, but it may become infected. If it becomes infected, you'll need to get the gecko to drop its tail.
To prevent or correct this, be sure to correct any humidity issues and add a humid hide if necessary. Warm temperatures can also be an issue.
Another issue with retained shed is that, even if it's not constricting bloodflow to the tail, it can cause a skin infection (this goes for anywhere, not just on the tail tip), if not removed in time. If this happens, we recommend getting the gecko to drop it's tail.
Here's how to get a crested gecko to drop its tail if it becomes infected...
Apply gentle pressure at the base of the tail (on the right and left sides) with your thumb and forefinger. You may have to roll the tips of your finger/thumb to find the spot, but it will release quickly when you do. This way works 100% of the time, once you know what you're doing, and it does so without any physical or psychological trauma to the gecko. Instead of having to frighten the gecko, you just put pressure on the nerves and the tail releases automatically. The gecko will often sit on your finger seemingly undisturbed as the tail releases.
Poor Husbandry & Poor Advice
The most common issue threatening the health of crested geckos, in my personal opinion, is bad/outdated husbandry information handed out and passed on as gospel - usually on Facebook these days. Inaccurate information is often spread around the internet by breeder/keepers who mean well, but don't really have enough experience with a large enough sample size to be making definitive statements like they do. Social media, and even a number of breeder websites, are full of less-than-sound husbandry advice, and some of these people are even considered knowledgeable in certain groups on Facebook.
Even though I generally don't get involved, I do see the advice posted out there, and I stand by the advice I give. No one, myself included, wants to correct misinformation that's posted on Facebook because we know we'll be subjected to a 20 page long argument, and most likely some pretty defensive replies from a number of people who also hand out that same bad advice - many times it devolves to adult internet bullying. If you're new to the hobby, you might think someone would say something, but the truth is it's not worth calling those people out, as they often respond defensively, as if you're challenging their expertise.
Just be mindful of who you listen to, and be especially critical of caresheets. A lot of them contain regurgitated or re-written information that is sometimes outdated, or contains information that has been taken out of context.
Inexperienced Veterinarians - Unnecessary Treatments, Drugs and Procedures
Dog and cat veterinarians who overstep the scope of their expertise in treating reptiles can actually be dangerous to your gecko's health. I know people will hate hearing this, but there are a lot of veterinarians who are awesome with traditional pets, but they simply have no business treating reptiles.
I've heard about all kinds of unnecessarily dramatic procedures (like amputations), and dosages of harsh, dehydrating drugs that have been prescribed by veterinarians who simply don't have the experience with crested geckos to know what requires intervention and what will heal or correct itself on its own. In these cases, the geckos would have literally been better off if their owners just let them heal on their own. These are tough, resilient geckos - I've bred many species and I've never seen a more robust, hardy reptile species.
I've been doing this professionally since 2004, I have yet to walk through the door of a veterinarian with a gecko, and losses are statistically very rare in my collection. If your husbandry is solid, you buy only from breeders you trust, and you heed the advice of the right breeders, you will likely never need to take a gecko to the vet. We're always glad to help troubleshoot if you send us an email.