The question of the day is always "why won't my gecko eat?" There are many possible causes, but rest assured, surprisingly few are due to illness, parasites, or contagions. Reptiles are finicky things, so before you jump to conclusions about your gecko's absent appetite, troubleshoot down this list first.
Stress First and foremost, make an assessment. Is there something that could possibly be stressing your gecko? Stress will make many reptiles go off food, and it is the most common cause.
A new gecko may take one to two weeks, sometimes longer, to adjust to its new environment before beginning to eat food. This is normal. Your gecko's life has just completely changed - new home, new sounds, new sights, new enclosure, new routine, and new people. Please do not handle or play with your gecko while it is settling in, or mess around in its enclosure other than to place food, water, and mist if needed. Unnecessarily handling a new gecko and/or constantly rearranging its setup can be stressful, and can cause your gecko to take even longer to begin eating.
Geckos* don't need friends, and in fact, they don't even like friends. They are incapable of complex emotions, and are happiest when living alone. (DO NOT make the mistake of anthopomorphizing your pet. They are not people and don't feel how we do!) Please separate your geckos if you have them housed together and notice one is not eating. Geckos can bully each other, or, one could eat all the food, and the unlucky one can end up losing weight or starving. Males can even fight or kill each other. In any case, it's easier to monitor them when each gecko has its own space, as there's no guessing games between which-gecko-did-what.
Some gecko species will only thrive on a particular substrate. While I always recommend paper towels for most geckos, there are some that should NEVER be kept that way. Cave Geckos need a moist coco-husk/fiber mixture, and some moss. Knob-Tail Geckos absolutely need sand. Eublepharis hardwickii does best on a mixture of coco husk, coco fiber, and sand.
Insufficient hiding spots, inappropriate decor and/or substrate, and disruptive outside stimulus can also stress out a gecko. Keep their environment very regular and safe, so your gecko can have a stress-free life.
Diet & Feeding Methods Like many other animals, sometimes changing the feeding routine can cause disrupted eating habits.
For a new gecko, always find out EXACTLY what it was eating at the pet store/breeding facility before you got it. Often the best way to get a new gecko to eat is by simply mimicking how it was fed in its old home. Try using the same feeder insect or gecko diet that was offered to it there.
Feeding method is also very important. Are you using tongs or a bowl? Is the food placed up high or on the ground? Are you letting the prey run free? Try to use the same method that the pet store/breeding facility was using.
Crickets.Yes, crickets! Try using crickets if you haven't yet, and all else has failed. The constant movement of crickets, and their range of travel throughout the enclosure, is likely to stir up a feeding response in even stubborn geckos.
DO NOT EVER USE WAXWORMS TO END A HUNGER STRIKE. They are too high in fat content, and can be addicting. They cause more harm than good in the long run!
Temperatures Yes, I know you 'know' the temperatures in the enclosure, but check again. This is a super common and easy error for keepers of all experience levels to make.
Use an Infrared Heat Gun to measure the floor temperatures for heated terrestrial species like Leopard Geckos, African Fat-Tail Geckos, and Knob-Tail Geckos. You can purchase a heat gun online, or at any hardware store, and they are very inexpensive and easy to use. Do NOT just go off of what your thermostat reads - many thermostats are not precise, especially the common commercial ones. You want to know the exact temperature of the floor, right over their heat source, because these geckos gather body heat through contact with their bellies. I keep all of my Leopards, AFT, and Knob-Tails at a hot spot of 88-92F.
Have a thermometer in the room placed near your gecko's enclosure, where you can see it daily. A simple digital thermometer will do - it doesn't have to be a "special" reptile one. You can find these at any supermarket or hardware store. Ambient (air) temperatures are important for all species of geckos. If it's too cool, your gecko may think it's winter and decide not to eat as much/at all. Acceptable ambient temperatures for Leopard Geckos, African Fat-Tail Geckos, and Knob-Tail geckos are 65-80F. New Caledonian gecko species like Cresteds and Gargoyles are most active with ambient temperatures of 70-80.
Geckos will slow down their metabolisms in preparation for fasting in colder temperatures. If your temps are too low, your geckos won't have a feeding response or feel hungry, and may not eat! On the contrary if your temperatures are too high, you could risk over-heating, dehydrating, or even cooking your gecko. Always use a thermostat to regulate your gecko's heat source (if one is present), and always manually check the temperatures regularly to keep your gecko happy and healthy.
Ovulation & Breeding When they've got one thing on their mind, they're probably not thinking about food!
Females can go off feed when they are ovulating or producing eggs. They can also go off feed if they are being bothered too much by a male.
Males can go off feed occasionally when they are too distracted by the smell of females nearby. More commonly, they can go off feed from being over-bred during the season.
Touching back to the point I made in the beginning of this blog, I don't recommend housing geckos together permanently - ESPECIALLY a male and female. They can pester each other, in this case for mating, and the added stress can cause them not to eat.
DO NOT BREED YOUR GECKOS OR PUT THEM TOGETHER IF YOU HAVE NOT DONE YOUR DUE RESEARCH, AND UNDERSTAND THE WORK AND RISK INVOLVED.
Parasites & Illnesses Once all of the above possible causes are ruled out, proceed with your investigation into this topic. NEVER jump to this conclusion straight away - 99% of the time, it is one of the above sections that will help you, and you needn't worry yourself unnecessarily.
MBD is an overarching problem in captive reptiles. Metabolic Bone Disease is a deterioration of bone due to insufficient calcium absorption. The gecko's bones will break and bend when it gets bad, and it can inhibit mobility and the ability to consume food. This is absolutely preventable, by always supplementing your gecko's diet with Calcium + Vitamin D3. NO, your gecko cannot overdose on D3 - That is a MYTH!! They cannot physically ingest enough calcium + D3 supplement for it to be possible. D3 is absolutely necessary to process Calcium. Your gecko either needs to receive D3 in their Calcium supplement, or via a UVB lamp. I do not recommend UVB lamps to my customers at all, as using an improper lamp for a species can potentially damage their eyesight over time, or even cause burns. I always recommend just using a Calcium + D3 supplement, which is what I provide for my own geckos.
Mouth Rot is a term that applies to oral infection in reptiles. There are many causes, and it can vary in its appearance. Generally an indentation or nook at the lip can indicate mouth rot, or a pocket of pus. In severe cases mouth rot can move to infect the eyes, and even eat away at the bone in a gecko's face. The best way to avoid mouth rot is to keep your gecko's enclosure clean regularly.
Pinworms are the most common parasite in insectivorous geckos. Only in severe cases will you see them in the gecko's feces, as they, like most parasites, are microscopic and must be viewed with a microscope. Most of the time a pinworm infestation will not be apparent, other than your gecko losing its appetite, and possibly losing weight. There are many more types of parasites of course, and they can come from your gecko ingesting the feces of another reptile (which can include tiny particles on any surface!) or secondhand by consuming feeder insects that have ingested the feces of an infected reptile. If you suspect parasites at all, you should collect a fecal sample and present it to your veterinarian for testing.
Cryptosporidium is a parasite found mainly in Leopard Geckos and African Fat-Tail Geckos. It is not as common as forums and threads make it out to be, which is why I always suggest that keepers troubleshoot from the beginning of this list first and then work their way down. Starting your investigation from this section is often an unnecessary and scary ordeal. Crypto ranges in its effects, from no symptoms, to full lethargy and starvation. Testing requires several different fecal samples to rule out Crypto, as it only occasionally sheds its Oocysts into the feces, which are needed to produce a positive test. Most veterinarians do not test in-house for this, and will need to send the samples out to a lab. There are also some online services and labs that you can mail out your gecko's samples to for tests. Crypto travels from gecko to gecko from feces to oral ingestion, as most internal parasites do. Simply put - if you quarantine new arrivals (as you ALWAYS should), and keep your geckos solitary, this is a very avoidable illness.
Insects do not come to you with reptile parasites if they are from a reputable source.I always hear people say "Crickets are bad!" or "My feeders gave my gecko parasites!" and the fact is, that is extremely unlikely. Most insects are raised on actual insect farms, far from pets, reptiles, and other animals, and are sent to you (or the distributor you purchase from) after they are born & grown there. Most parasitic infections and infestations are actually due to obtaining an infected reptile, and by infecting other reptiles in your collection through improper quarantine procedures.
If one of your new reptiles has tested positive for parasites and you are quarantining them properly after purchase - great job!! Inform the person you acquired the reptile from (with a veterinary report and fecal report) so they can test their stock too. However, if your reptile tested positive and is NOT in quarantine, it would be best to revise your quarantine procedures, and test the rest of your reptiles too as that is likely where they caught it from.
Other issues that can affect appetite can include but are not limited to: injury, neurological disorder, pre-disposed illness/conditions, infections, and organ failure.
PLEASE MAKE AN APPOINTMENT WITH YOUR LOCAL REPTILE/EXOTICS VETERINARIAN IF YOU SUSPECT PARASITES OR ILLNESS. The folks on your reptile forums or Facebook threads don't have degrees in veterinary science, and neither do breeders like myself. ONLY YOUR VET can give you a proper diagnosis and treatment options.
Force Feeding JUST DON'T DO IT!!
There is a reason your gecko is not eating, and you should find that and fix it, instead of force feeding it. If your troubleshooting is not working, please ask your gecko's breeder or a vet for help! Force feeding can cause a gecko to inhale food, and it can also cause injury to its jaw. Mostly, it causes GREAT AMOUNTS OF STRESS to your gecko. Force feeding, more often than not, can cause your gecko to stay OFF food. It is traumatizing, and many geckos will never eat again and end up dying. Just don't do it!!!