longhairedgit longhairedgit
  • Disease Adviser
  • Disease Adviser
  • Joined: 10/10/2007 14:03
  • From Gloucestershire
  • Group: Takin' a break...
  • Posts: 3088
  • Posted on: 8/11/2007 11:26
Feeding insectivorous/carnivorous reptiles. #1
Dietary protocols are an essential component of reptile health, they cannot be ignored, oversimplified, or only partially adhered to if you wish your reptile to stay healthy over the long term, and together with temperature ranges for all species, and UVB lighting for those species that require it(diurnal species)this is an essential part of standard reptile maintenance. If you have a reptile, you must know this information.

Supplementation to avoid everyday ailments
Basically if you own a reptile of any species, you should have as part of standard and essential kit, a good multipurpose vitamin and mineral supplement formulated not for other animals but specifically for reptiles and reptiles alone. Supplementation regimes for birds and mammals are completely different to those of reptiles, and giving reptiles vitamins intended for other animals , ourselves included, will NOT do. SA37 is for mammals, and preparations like neutrobal are not reptile specific enough IMHO.

Choose preparations like reptavite by medivet or zoo med, and if you keep multiple species also consider formulations for specific species. Certain geckos and chameleons for eaxample have different and important vitamin A requirements to other reptiles, and getting the vitamin A level wrong can mean a premature death for the reptile. Its also always a good idea to keep a ready stock of calcium sources such as cuttlebone, crushed oystershell or raw calcium carbonate for reptiles that may need adjustments to the calcium phospherous ratio. Adding extra calcium to reptile vitamins can be an easy way to achieve this. This is not to say you choose a calcium source over a good retile supplement, you have it in addition to said supplement. Most insectivorous and carnivorous reptiles get by on a calcium/phospherous ratio of 1:1, to 1.5:1 but most omnivores or vegetarian or foliverous reptiles like it closer to 2:1. Try and balance that out from the indicated contents on the supplementation containers and info by adding additional raw calcium sources if needed.

As mentioned in the avoidance of MBD section, vitamins d and d3 are exremely important in permitting calcium absorbtion to happen. Nocturnals and most snakes can synthesise most of their own from food, but they may still need additional calcium. Particularly in the insectivorous groups the diet of montypic insects can be extremely low in nutrients and some supplementation of d3 and calcium is always necessary. Not at the levels involved with diurnal lizards, but essential nontheless. Snakes on average require only one sixth of the supplementation a nocturnal lizard requires, as their rodent prey has a liver and a skeleton, and this provides much of their needs. In a nocturnal lizard however we must make up for some of the lack of diet variety and regular supplementation, (weekly boosts) of tiny daily amounts are essential.

Diurnal lizards require the most supplementation, IMHO these groups should always be provided with good standard reptile bulbs such as zoomeds reptile 5:0 bulbs and iguanalights for the herbivores and tortoises if kept indoors. Given that these bulbs are still not quite as effective as natural sunlight in production of vitamin d3, it is usually necessary to also give a small amount of supplementary d3, the amount in reptavite for example is perfectly sufficient for a reptile under UVB light, but you must be careful. D3 acts more like a hormone than a vitamin, it is extremely volatile, and liquid d3 drops are to be used only in combatting mbd in animals already stricken, NOT as part of general maintenance. Most keepers using pure d3 will massively overdose their pets, often leading to as many skeletal deformities, and deaths as those using no supplementation. besides reptiles hate having liquids poured into their mouths manually, and stressing a reptile so often is a lousy practise.

In short, for diurnals, use reptile bulbs, and trust the low level of d3 in good commercial supplements like reptavite. Occasionally letting your reptile bask outside when temps reach over 75f will also help. A few hours exposure over a few days a few times a year can bring enormous benefits over a lifetime, though because the UK's climate is so miserably cold for much of the year, you cannot rely on this as your only method of obtaining UV or d3.

Feeder insects
Feeder crickets in the uk, arrive in the keepers hands nutrient depleted. Crickets, locusts, and mealworms arrive packaged in bran. Bran is not a nutrient rich food, it contains little more than fibre, and does not constitute a suitable diet for the insects themselves, who eventually starve.

A reptile eating insects that are not fed, will in turn become as nutrient depleted as they are. 85% of a crickets nutritional content for a reptile resides in its gut, and in its digestive system. An unfed cricket or mealworm will be mostly chitin , a tiny bit of protien and not much else. Therefore you must feed insects properly for at least 24-48 hours prior to giving it to your reptile. The process is commonly known as gut loading.

Unless you also have food for them within the reptiles cage, feeder animals become nutrient depleted again in around 24 hours, especially at high temperatures. Thusly only give your reptile what it can eat in a few hours to maintain nutritional quality. Chucking a whole box of crickets in a reptile cage and letting the reptile feed ad libitum seems like a good idea, but is in fact extremely bad practice.

It is better to have a small plastic crittter container or a spacious bucket, perhaps even an old bin in which to feed crickets, mealworms and locusts, then you feed them up with various greens, squashes, cabbages, oranges, bits of potato etc without them succumbing to humidity and dying in droves. For those that cant be bothered with prepping vegetables for them you can purchase commercial gut loading formulas that you simply mix with water, and a whole spectrum of vitamins minerals and protiens will go into the insects and consequently end up in the reptile.

Certain vitamins however may or may not survive the digestion of a cricket or mealworm, so even when gut loading it is preferable to dust them with vitamins occassionally before offerring them to your reptile.
It covers all bases, but it would be prudent to reduce the amount of dusting that goes on a little.

Those feeding crickets on natural foods like vegetables and fruits will need to dust crickets with powdered supplements as normal. In that context I include the feeding of feeder insects and the dusting of them as something you do as well as, not instead of. Do both. Vegetables from tesco dont equate to the range of foods a cricket would eat in nature, and even if they did, the cricket has to stand in for many hundreds of species of insect a reptile will not have access to in the UK, and therfore has to have its nutritional quality boosted as much as possible.

Waxworm feeding is a pain in the butt, the honey, oat and yeast mixture they feed in is very hard to manufacture in the home and goes mouldy very easily, so I would recommend that since they are very fatty, you buy them only as a treat once in a while or for pre breeding conditioning, and keep them refridgerated until you need to use them, usually within 4 days of purchase. Waxworms should be no more than 5% of a reptiles diet anyway.

To conclude this section I will add that most liquid supplements for reptiles are a bit of a joke, hard to use, and only really appropriate for insectivores like anoles and day geckos who will also take nectar, and in those circumstances its easier to buy reptile nectar, lorinectar, or just mix a weak solution of honey and water and throw a little of the usual vitamin supplements in , and mix them up.

Mammalian food items, poultry and eggs.

As many snake keepers will tell you, for those that take them, whole mammals and poultry are much more nutritionally complete than your average insect. However while it may be fine to feed a snake of primarily mammalian food for the entirety of its life, it is not so for most predatory lizards, who are generally primarily insectivorous throughout their lives.

Even huge monitor lizards, thai and bearded dragons, big skinks,black iguanas etc will still be taking huge numbers of varied foods, of which insects and invertabretes make up the primary. The unrealistic expectation of owners of these reptiles often leads to serious health problems. Just chucking rats at a monitor lizard does not constitute a good diet. Many become morbidly obese on animal fats, many get long term problems with digesting fur and feathers, and vomiting and diorrhea becomes more frequent.

Mammalian foods should still be dipped in vitamin supplements occassionally, and give your carnivores a choice, use poultry occasionally, its often less fatty, choose whole foods over meat portions, choose fertilised organic eggs over unfertilised ones, and whenever possible use fresh prekilled over frozen.

Dogfoods too are to be used only in emergencies. few reptiles will take them anyway, and long term use of dogfoods is problematic in regard to dietary fat, not to mention, put it in an 86f viv, and it stinks, dries and attracts predatory and parasitic flies from miles around. Many reptiles can get flystrike, especially chelonia, so be careful.Dog foods too, will need to be lightly dusted. Most recommendations with dog food are to do with shifting constipation, vets will recommend it for use with many reptiles even tortoises, but it should never be a regular or significant part of the diet. Just a top up for skinny carnivores or purge feeds for herbivores and omnivores.

Eggs too are an excellent source of protien, but their use should be limited (for anything other than the egg-eating snake obviously!). They are both fatty, and unfertilised eggs (a la supermarket) can cause nutritional issues.

You can buy tinned snails believe it or not, and those who are into multiple species can breed giant african land snails and madagascan giant and deaths head cockroaches, all of which make excellent low fat food for larger lizards. They are easy to keep and multiple in some numbers so you should always have plenty to give to the lizards.

Dietary deficiencies and counterproductive practises

Ok I assume you chaps and chapettes are solid enough on the environmental and supplementary issues if youve read the other stickies, but theres a few others little surprises you have to watch for. Particularly foods that are deficient in B vitamins and can block b complex vitamins from getting to the reptile, and in extreme cases, actually drain the reptiles systems of them. This results in problems with breathing, particularly amongst the monitor lizard, skink, and garter snake species who are by complicity of dietary preference, very likely to fall foul of them.

Unfertilised eggs are loaded with avidin. This blocks b vitamins and leads animals like monitor lizards and tegus to be plagued with respiritory issues, bad co2 exchange in the lungs, and low immune system. Fertilized eggs or reptile eggs are no problem.

Frozen fish can cause similar issues with thiaminase, and this causes breathing issues with garters and piscivore reptiles, and some neurological problems. Obviously the way around the problem is with fresh fish, and likewise with the monitors, sometimes adding bits of yeast tablet stuffed into the prey helps combat previous deficiencies.

Foods rich in oxylates cause calcium blocking and even under supplementation may lead a reptile into MBD. Its not usually a problem with insectivores because the insects are coping with that kind of poisoning and alleviating the reptile of having to, but in omnivorous species, like iguanids, water dragons , beardies, and turtles, it would be foolish to overlook the potential damage, particularly having spent so much effort on getting the insect component or the diet right.

Foods to fit behaviour.

I mention this because there are many commercial products
are out there that are not suitable for most lizards (sausages and dried insects and tinned foods etc) Most omnivores and herbivores, and the lizards that go primarily on scent will take them, but those whos vision is based on movement, an dthis includes the smaller iguanids, most of the nocturnal geckos and all the line of sight predators wont take them without training, and only a tiny percentage can be trianed. If feeding live foods is not your thing avoid keeping insectivorous lizards, and dont assume all lizards will take dead foods. Most don't, and with the best will in the world, you cant make them.

Nutritionally speaking , dried insects for lizards are a joke, it might do for fish, but they are completely inappropriate for reptiles. Cant think for the life of me why its legal to sell them for that usage.

Tortoise specific

Avoid high protein meats. No matter what a vet or a reptile idiot might tell you, beyond saving the life of a constipated or severely protien depleted specimen, dog foods, regular meats, etc have no place in a tortoises diet, certain tropical species can take more protien than your average mediterranean tortoise, but lets face it , most people have the ned tortoises, hermans, russians and greeks, and protien excess leads to deformity. A little well boiled chicken moistened with olive oil would be much better if there was ever a rare need to give your tortoise a protien boost. Giving tortoises dog food is archaic herpetology and really quite stupid. Dont do it.

Green iguana specific

While many green iguanas are problem feeders, and initially to get them off to a feeding start tit can be helpful to give them insects, you should be phasing them out as soon as possible. Iguanas are primarily herbivorous at whatever age in nature, and while im not a vehement fanaticist as some are about iguanas only getting veggies , I believe at 1 year of age insects should make no more that 30% of the diet, and after that, cut it down to 10% -5%. An iguana fed too much animal protien will probably die young with hepatic lipidosis and probably get MBD. Beardies and thai dragons are not in the same league and you can give them a 50/50 split of animal and veggie matter quite happily for most of their lives.

Snake specific

Snake keeping and lizard keeping are not the same disciplines. Lizard keepers must be much more aware of nutritional deficiencies, and the accuracy of temperature gradients and avilable basking spots. Snake keeping knowledge does NOT translate into lizard keeping knowledge. There are parrallels, but the level is completely different. Most snakes can get by on the almost all rodent diet apart from specialist reptile and bird feeders, but even then you should make an attempt to try different species of rodents and supplement them occassionally, though granted, at nothing like the level of a diurnal lizard. Piscivorous lizards must be supplemented well if not getting the usual range of additional amphibian prey, and they will need some compensatory supplementation if given frozen fish. Very few snakes need UVB to help with the dietary efficiency and nutrient uptake, and they need minimal supplemetation, though granted if you happen to own a 20 foot reticulated python a supplementation is actually quite a large dose.

Nocturnal reptile specific
Basically care and vitamin supplementation is the same as for diurnal reptiles, except you cut the vitamin supplementation roughly in half. Most, especially leopard geckos and african fat tails do not do well on the same doses of vitamin A as diurnals, and you should make sure that it is present, but low. Check reptile vitamins carefully for levels, and look for gecko specific supplementation if you can find it.

Food sizing

Snakes can obviously take huge meals compared to lizards, by virtue or elastic jaw ligaments and flexible hinges, but this does not mean you should overload them. Its better to keep feeds relatiively small in proportion to the animal and have a few small items rather than one big one. You only need to see a snake with a swallowed jaw, a rupture, or lethal constipation and vomiting to know its never a good idea to push the issue on size, no matter how entertaining you think it may be, or how much you like to 2big up2 your reptiles abilities. A major swallowing problem and its game over.Please take food sizes seriously.

Same goes for lizards, they too will often try to take food bigger than they can reasonable handle,and when I watch people giving basilisks, water dragons and iguanas outsized meals like whole mice, frankly it irritates me, its a galactically stupid practise. A lizard isnt a snake, and they can and do choke, become exhausted and suffocate. If the meal is too large it can take so long to digest that it rots in the gut. Remember these are ectothermic creatures, their digestion is temperature dependant, and maldigestion can be a fatal experience. Just because you can eat half a turkey at christmas doesnt mean your lizard can perform the same trick.

Overfeeding and cool temperatures can be lethal, and exceeding the mass a prey item can reasobale be expected to be to be digested can be lethal to a reptile. This isnt watching a snake or a monitor neck something huge on national geographic that took 5 years to track down and film, most reptiles do not do this every day, this is a pet in a viv , in your lounge. Treat it properly.

Theres nothing wrong with giving your reptile a chunky meal, but if its trying to neck down meals bigger than its own head, things have got way out of control. Is always better to downside and use multiple items than use big ones. Generally food pieces for most lizards should be no wider than the mouth and no longer than half the length of the head, so size feeder insects and meat chunks or mice appropriately.

You wouldnt for example give a gecko or anole inder 7 inches long a pinky mouse, you wouldnt give insist a tiny house gecko eat locusts at full size, but a full size bearded dragon, monitor,black iguana, tegu or tokay gecko at over 1 feet to 6 feet can handle pretty much any insect you throw at it. An adult savannah monitor can handle an adult mouse, but a baby will be on crickets.An adult nile monitor can handle whole adult rats and trout, maybe even a rabbit, but a newborn baby anole of gecko will need pinhead crickets and tiny mealworms.Be sensible about it.


Have happy herps, and enjoy reptile keeping.

Resized Image
  • Just popping in
  • Just popping in
  • Joined: 9/11/2007 2:52
  • From Canada
  • Group: Registered Users Basic Membership
  • Posts: 7
  • Posted on: 9/11/2007 3:02
Re: Feeding insectivorous/carnivorous reptiles. #2
i have three fire belly newts, with plants in and surrounding the tank. the plants surrounding the tank have a bit of a problem with fungus gnats, but no worries because when the gnats get trapped in the tank, the newts snatch them right up! yum!
longhairedgit longhairedgit
  • Disease Adviser
  • Disease Adviser
  • Joined: 10/10/2007 14:03
  • From Gloucestershire
  • Group: Takin' a break...
  • Posts: 3088
  • Posted on: 9/11/2007 14:10
Re: Feeding insectivorous/carnivorous reptiles. #3
Certainly there are herpetiles who will make advantage of natural foods, and in th UK you can buy drosophilia fruitflies which small reptiles and frogs will enjoy, and they can be a useful tool for adding variety to the diet, as will the odd visiting moth or mosquito, it should be pointed out though, that while an excellent occassional treat, flies are nothing like as nutritionally complete as a gut loaded cricket or cockroach, so you do have to limit the use of them sensibly.

Newts, salamanders, toads and frogs are a good deal less likely to suffer nutritional deficiencies than lizards, having a much lesser need for dietary calcium, though other trace minerals are important. Amphibians will be able to handle a much greater proportion of various flies in the diet. As fallon stated though, many herptiles are extremely stimulated by foods that fly and move, and using them is a good trick to get difficult feeders started. You need only keep waxworms until pupation and offer a group of arboreal geckos or anolis a waxmoth or two to see the incredibly intense predatory reaction they get.

In fact I would say that such feedings, though only occassionally permittable becuase of nutrition issues are very much worth the bother because of the enhancement it brings to the psychological part of an animals life quality.

Be careful about collecting wild bugs though, because many of them will have been exposed to pyrethrin pesticides, and eventually high level exposures can cause deleterious liver conditions and systemic poisoning.
Resized Image
Sparky Sparky
  • Home away from home
  • Home away from home
  • Joined: 13/11/2005 18:03
  • From Wiltshire
  • Group: Registered Users Basic Membership
  • Posts: 291
  • Posted on: 6/5/2008 18:07
Re: Feeding insectivorous/carnivorous reptiles. #4
wow, i no i will find this useful in the future.i curently keep fire belly toads and a whites tree frog. (dont worry there in differnt vivs )