Substrate

From UroWiki

Substrate is the material on which your uromastyx lives and walks. It can be many different materials, but there are some you should also avoid; as with anything which can potentially present a medical problem, prevention is better than cure.

Admin notice: while these are provisionally categorised as good and bad materials, there is a huge amount of debate on what should be classified as one or the other, and almost all of the materials listed, in both sections, have drawbacks as well as advantages. The current grouping is based on the majority opinion of each material, as evidenced by discussions in uromastyx-related forums. Due to current debate on this issue, this page has been locked and can only be edited by an administrator; if you have an opinion, drop it into the article's discussion page, start a thread on the Official Forum, or contact the admin directly.

Materials generally recommended

Playsand 

This is only classed as safe for an older uromastyx, as defined by being over 18cm (7") in length. Once washed (to remove dust) and sifted for larger particles, it produces no dust is easy to keep clean so long as faeces are completely removed straight away. Most keepers recommend a playsand substrate is completely changed every six months, and pool filter sand is said to be the best variety. It is important to note that there is a sizeable faction who argue that uromastyx do not actually live on sand in the wild; they live in semi-arid areas with solid sun-baked ground covered by a layer of dust, and therefore a sand substrate may look nice but isn't natural and poses an impaction hazard.

(Note: in the context of playsand, 'washing' refers to a process of filtering. This is often achieved simply by putting the sand into a fabric sack - an old pillowcase is ideal - and pouring or pumping water through until the water runs clear. This removes the finer dust-producing articles from the bulk of the playsand and leaves it safer for use in an enclosure.)

Tiles 

Either slate, which is also good for keeping claws in order, other rough ceramic tiles to prevent slipping or even linoleum tiles, which are also easy to maintain as they just wipe clean and are easily disinfected. Some keepers have used locally-available granite, and while radon buildup is a possible concern, any enclosure with good ventilation and positive pressure shouldn't be affected.

Reptile carpet (also known as Repti-carpet) 

This works well and looks nice. It's also fairly easy to clean; even easier if you have more than one piece cut to fit in the cage, in which case you can simply swap the new piece in and clean the old piece. The down side are that uromastyx normally pass a bowel movement every day, requiring the cleaning and replacement of the carpet and decorations on a daily basis; also, Repti-carpet has been known as a factor in damaged claws (they can get caught in the fabric) and, if not cleaned scrupulously, can be a good breeding-ground for bacteria.

Newspaper/paper 

This is a good idea if you're concerned about cost and ease of cleaning. Its not the prettiest set-up for your tank, but it works well. The ink in the newspaper will not harm your lizard - it's designed to be non-toxic (for regular contact with human skin) with dirty-looking feet being the worst that could happen. Butcher paper or some other, plain paper may be better in terms of avoiding ink smudges. Be aware that your lizard may hide under the newspaper.

Paper towels 

This is a good idea for very young or new uromastyx, of 18cm (7") or less. It allows you to change out the substrate as soon as they urinate or defacate, and you are more easily able to observe their defecation patterns to ensure that they're healthy and settling in well.

Materials generally not recommended

Most of the following materials are bad for one main reason - impaction. A lot of stores may try and tell you that they are suitable, they may even be using them themselves, but each of the following has proven to cause impaction and death to uromastyx, bearded dragons, and other reptiles, and should be avoided.

Corn cob 

This is not only an impaction substrate, but one that harbours fungus and bacteria.

Birdseed 

Some keepers keep their lizard on birdseed or millet, and although you can use these materials with varying degrees of success, this is generally not recommended as it tends to be harder to maintain and less hygenic. Also, make sure it does not contain sunflower seeds, which are unhealthy.

Crushed walnut shell 

To most people this looks harmless enough, but the edges are very sharp and when ingested, these sharp edges can cut your uromastyx on the inside and cause internal bleeding, infections, and other medical problems. If it does pass through when ingested, it is often trapped in the vent area.

Calcium sand (also known as Calci-sand) 

The problem with this product is twofold. First, lizards often like the taste of it and may eat it if they are lacking adequate calcium in their diet. In theory this is fine, except all tests show that it is not digestible, no matter what the product states, and it has been known to clump and form an indigestible bolus in their digestive tract. This often leads to impaction, paralysis and eventually death.

Vita-Sand 

Even though this is made by ZooMed, a well-known supplier of lizard-keeping equipment, it is inappropriate for uromastyx for the same reason as Calci-sand.

Repti Bark 

This is very fibrous and could easily end up causing impaction, and has been known to end up lodged in the vent.

Any of the wood shavings 

These should generally be avoided, particularly soft woods such as cedar or pine - both contain dangerous aromatic oils which emit fumes which are toxic to your lizard (see the article on building materials), and pine can get impacted if ingested.