Digestive Problems in Lizards


One of the commonest problems encountered with keeping lizards is issues with the digestive tract. It is not always realised that more problems arise in this way by keeping the lizard at the wrong temperature than feeding the wrong food. A lizard – in fact all cold blooded creatures – need warmth from their environment to help them digest their food and if the atmosphere is too cold, the lizard will be unable to digest its food properly, causing all kinds of problems from severe diarrhoea to constipation and anorexia. A meal lacking in variety – for example mealworms – can also cause constipation, partly because of lack of fibre and partly through boredom. In the wild, carnivores and insectivores catch their prey and so it is essential to try to mimic that as well as you can.

Know your Species

Lizards have a great deal of special needs when it comes to food, not only from a basic nutritional stance of having adequate vitamins, but also from the type of food which should be made available. A very tiny lizard, such as the anoles, it is very difficult to provide the appropriate live prey and they can easily become anorexic and develop nutritional deficiencies. Larger lizards such as iguanas are so difficult to feed successfully that digestive problems are almost certain to occur later in their lives as they have such special needs. Green iguanas when young tend to eat their own faeces, in an attempt to keep up their gut flora. Owners are often distressed by this, which is not a behavioural trait but a requirement which they share with some mammals, for example the rabbit.

Lizard Stomachs and their Digestive Problems

The lizard stomach is very simple; it is essentially an elongated sac, with a few refinements such as fermentation chambers depending on species. Because the stomach and gut are so simple, it is essential that the external temperature is kept at the optimum to enable this uncomplicated process to work well. If the temperature is kept too low, the natural fermentations will not take place and the symbiotic bacteria which ensure adequate digestion of the food and therefore absorption of adequate vitamins, minerals and fats to occur, will die.

Gut Flora

If this gut flora is not present, then the animal will not thrive. It will occasionally ‘self-medicate’ by eating its own faeces – this is normal in youngsters but if seen in adults is a marker that something is wrong. If this behaviour is noted, especially if it goes with other problems like skin issues or anorexia, diarrhoea or constipation, the animal should be taken to the vet. If the temperature is kept too high, the animal’s metabolism will run too fast and the food available is likely to be inadequate.

Constipation in Lizards

A constipated lizard can often be relieved by upping the water available in the environment. If the stools are too dry, they will not be easy to pass and so the lizard will tend to ‘hang on to them’, making the situation worse. This is the same in all animals, from the smallest lizard to an elephant, although the treatment that often works for lizards – a warm water soak – would presumably be more difficult for an elephant! If the animal is severely constipated it is possible in some species to introduce water under the skin to hydrate it quickly and this often does the trick.

To prevent constipation it is important to avoid very dry bedding which the lizard might eat and which will then swell up inside creating problems. It is also important to vary the diet, with fibre to bulk up the food. It is vital not to let your lizard become seriously constipated. In very bad cases the faeces can ‘mineralise’, which means that surgical removal is the only recourse and is very often not successful, with fatal results.

Diarrhoea in Lizards

Diarrhoea in lizards can be caused by bacteria or by diet. Too many green vegetables, especially the very watery ones like lettuce or the ones very high in iron like broccoli and watercress can cause watery diarrhoea. If you notice that your lizard’s stools are loose, look carefully at their diet and minimise the vegetable content for a while. If only one lizard in a group is affected and they share the same diet, it would be wise to isolate it and watch it carefully, always being ready to take it to the vet if it becomes lethargic or shows any other non-typical behaviour.

Cleanliness of the environment is key to the health of any lizard and if the diarrhoea is profuse, it would be a good interim measure to remove any small bedding and replace it with paper towels as being easier to change and keep clean.

General Tip for Digestive Health in Lizards

Because lizards as a group cover such a wide diversity of species, it is difficult to give general feeding advice, but several things apply to any lizard. The first is to keep them clean. This may seem an obvious piece of advice, but it is easy to sometimes let general good animal husbandry slip and it is all too easy, in the warmth of a lizard environment, for bacteria to breed and cause digestive problems.

If one lizard of a group becomes ill, it is vital to isolate it and carefully clean the whole environment before returning the non-affected individuals to it. Feed fresh food and remove any leftovers regularly. Make sure that feeding procedures are species specific; some lizards which are freely available to buy are very fussy eaters with very specialized nutritional needs and will not thrive unless they are adhered to. And lastly, get to know your lizard. Everyone is different, and that applies to lizards too – when you first bring it home, spend a while getting to know what it eats and when it defecates. This will probably save you an awful lot of worry in the future.


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