When to feed
Being grazers in the wild, Uromastyx should be fed in early to mid morning, allowing them to feed when they want throughout the day. ideally, the food should be fresh and waiting for them when they awake. The precise schedule will depend upon your individual Uromastyx. If you are unable to feed your Uromastyx in the morning, make sure you supply food as soon as you are able - for this reason, advance preparation of food is a good idea.
In the wild, Uromastyx may go weeks, even months without eating, then gain and store most of their energy during the growing season for plants (Robinson, 1995). In captivity, though food can be offered daily, this is not needed. Feeding 2 to 4 times a week (depending on time of year) is often more than enough. There is a common misconception that you cannot overfeed Uromastyx. This is not true, especially if the proper temperatures aren't reached; there are many examples of overweight/obese Uromastyx in captivity (though this cannot only be attributed to overfeeding).
In the wild, Uromastyx may go weeks, even months without eating, then gain and store most of their energy during the growing season for plants (Robinson, 1995). In captivity, though food can be offered daily, this is not needed. Feeding 2 to 4 times a week (depending on time of year) is often more than enough. There is a common misconception that you cannot overfeed Uromastyx. This is not true, especially if the proper temperatures aren't reached; there are many examples of overweight/obese Uromastyx in captivity (though this cannot only be attributed to overfeeding).
How to feed
Your Uromastyx should be fed from a bowl or on a slate tile at the cool end. The food should be cut or shredded into pieces (or ground, depending on the type of food); although Uromastyx will chew larger pieces with their powerful cutting jaws. This is most necessary when the animals are young, as it reduces the amount of leftovers, and ensures they get as much as possible. Also make sure that the food bowl and any additional seed bowls are located where the lizard cannot easily kick sand into the bowl, or drag the salad onto a sandy substrate where sand will stick to it.
List of Food
Regularity
The foodstuffs listed below are divided into three main categories - staples, rotationals and occasionals - as well as seeds, which are given their own listing. In most cases, the best guide is simply common sense: don't feed an occasional to your Uromastyx for two weeks in a row. Variety is the key. For example, feed escarole for a week and then endive the next week, both mixed together on other weeks; throw in some rotationals or an occasional to give added variety. Note that sprouts (such as alfalfa sprouts compared to alfalfa plants) are generally lacking in useful nutritional content and should be avoided.
- Staples are meant to be fed regularly, at every feeding.
- Rotationals should be fed less often; once or twice per week at most
- Occasionals should be fed once per month at most
Chemical Content
The following chemical traits are discussed in this list, so here are some brief definitions (you can find many more common definitions used when talking about Uromastyx in the list of abbreviations):
- Oxalates/Oxalic Acid (C2H2O4) binds calcium, removing it from other foods so it won't be digested.
- Goitrogens induce hypothyroidism, and depress thyroid function, by interfering with absorption of iodine. Restriction of iodine causes the thyroid to increase its size as it tries to filter more blood to get more iodine.
- Vitamin C can cause diarrhoea at high levels; low levels are said to help reptiles cope with stress and disease.
- Acidic fruits and vegetables may cause diarrhoea and toxicity
- Phosphorus can be dangerous at high levels. See below for more information on the Calcium:Phosphorus ratio.
Staples
Staple greens are greens that can be fed regularly as the basic food for the Uromastyx; you should pay attention to what combinations you feed your lizard so as to keep the nutrients well-balanced. Terms like oxalates and goitrogens are explained more in the section on what not to feed, at the bottom of this page.
Species
Notes
Link to Nutritional Info
Curly Endive (Cichorium endiva)
Low - Moderate oxalates, high calcium
Nutritional Info-Endive
-Frisée (C. endiva var. Crispum)
-Escarole (C. endiva var. Latifolia)
Dandelion (Taxacum officinale)
High in calcium and Vitamin A. Both leaves and flowers.
Nutritional Information - Dandelion
Note: although dandelions are listed as a staple, they should be considered a moderate staple - in large quantities, they function as both a diuretic and a source of potassium and other salts, possibly causing dehydration and large deposits of snalt. Also be aware of many plants which are in fact false dandelions, and should not be fed. Be cautious of pesticides in wild greens; be absolutely sure that the place you gather them from has been pesticide-free for at least two years.
Note #2: An addition to the previous note; much of the "dandelion" sold in North American grocery stores is actually Italian Dandelion (Cichorium intybus) and is closer related to Endive than it is true Taxacum spp.
Chicory (Cichorium intybus)
A great Staple! Higher than Endive/Escarole in numerous nutrients. It should be noted that "Belgian Endive" or "Witloof", although the same species, is much lower in nutrients (less than romaine lettuce), and has a negetive Ca:P ratio (0.73 in Witloof, versus 2.13 in regular Chicory). The latter cultivar should be treated as an occaisonal, or just skipped all together.
Nutritional Information - Chicory
Nutritional Information - Witloof
Alfalfa (Medicago sativa)
Plant, not sprouts
Cactus pad/leaf (Opuntia spp.)
High calcium
Cactus/Prickly pear(O. ficus-indica)
High calcium
Nutritional Information - Prickly Pear
Squash
Butternut Squash (Cucurbita moschata)
High fibre & Vitamin A
Nutritional Information - Butternut Squash
Spaghetti Squash (Cucurbita pepo)
High calcium & fibre
Nutritional Information - Spaghetti Squash
Species
Notes
Link to Nutritional Info
Curly Endive (Cichorium endiva)
Low - Moderate oxalates, high calcium
Nutritional Info-Endive
-Frisée (C. endiva var. Crispum)
-Escarole (C. endiva var. Latifolia)
Dandelion (Taxacum officinale)
High in calcium and Vitamin A. Both leaves and flowers.
Nutritional Information - Dandelion
Note: although dandelions are listed as a staple, they should be considered a moderate staple - in large quantities, they function as both a diuretic and a source of potassium and other salts, possibly causing dehydration and large deposits of snalt. Also be aware of many plants which are in fact false dandelions, and should not be fed. Be cautious of pesticides in wild greens; be absolutely sure that the place you gather them from has been pesticide-free for at least two years.
Note #2: An addition to the previous note; much of the "dandelion" sold in North American grocery stores is actually Italian Dandelion (Cichorium intybus) and is closer related to Endive than it is true Taxacum spp.
Chicory (Cichorium intybus)
A great Staple! Higher than Endive/Escarole in numerous nutrients. It should be noted that "Belgian Endive" or "Witloof", although the same species, is much lower in nutrients (less than romaine lettuce), and has a negetive Ca:P ratio (0.73 in Witloof, versus 2.13 in regular Chicory). The latter cultivar should be treated as an occaisonal, or just skipped all together.
Nutritional Information - Chicory
Nutritional Information - Witloof
Alfalfa (Medicago sativa)
Plant, not sprouts
Cactus pad/leaf (Opuntia spp.)
High calcium
Cactus/Prickly pear(O. ficus-indica)
High calcium
Nutritional Information - Prickly Pear
Squash
Butternut Squash (Cucurbita moschata)
High fibre & Vitamin A
Nutritional Information - Butternut Squash
Spaghetti Squash (Cucurbita pepo)
High calcium & fibre
Nutritional Information - Spaghetti Squash
Rotationals
Rotationals are food that is given once or twice per week or per fortnight; it is important to use your own judgement when doing so. Rotationals include the following:
Collard Green (Brassica oleracea)
High calcium, moderate oxalates
Nutritional Information - Collareds Green
Radicchio (Cichorium intybus)
Nutritional Information - Radicchio
Rucola/Rocket/Arugula (Eruca sativa)
Nutritional Information - Arugula
Watercress (Nasturtium officinale)
High vitamin C, A, and oxalates (6:1 ox:ca)
Nutritional Information - Watercress
Bok Choy/Choi/Pak Choi (Brassica rapa - See below)
High vitamin C, A, goitrogens
Nutritional Information - Pak-choi
Soaked Lentils (Lens culinaris)
Nutritional Information - Lentils
Shredded carrots (Daucas carota)
High vitamin A, moderate
Nutritional Information - Carrots
Summer Squash (Cucurbita pepo)
e.g. zucchini/courgette;
high phosphorous
Nutritional Information - Summer Squash
Hubbard squash (Cucurbita maxima)
High fibre & Vitamin A
Nutritional Information - Hubbard Squash
Scallop Squash (Cucurbita pepo)
Nutritional Information - Scallop Squash
Acorn Squash (Cucurbita pepo)
Nutritional Information - Acorn Squash
Coriander/Cilantro (Coriandrum sativum)
High vitamin A, moderate oxalates
Nutritional Information - Cilantro
Bell/Sweet Peppers (Capsicum annuum)
Green
Moderate oxalates
Nutritional Information - Green Sweet Pepper
Red
High vitamin C, A, moderate oxalates
Nutritional Information - Red Sweet Pepper
Yellow
Moderate oxalates
Nutritional Information - Yellow Sweet Pepper
Collard Green (Brassica oleracea)
High calcium, moderate oxalates
Nutritional Information - Collareds Green
Radicchio (Cichorium intybus)
Nutritional Information - Radicchio
Rucola/Rocket/Arugula (Eruca sativa)
Nutritional Information - Arugula
Watercress (Nasturtium officinale)
High vitamin C, A, and oxalates (6:1 ox:ca)
Nutritional Information - Watercress
Bok Choy/Choi/Pak Choi (Brassica rapa - See below)
High vitamin C, A, goitrogens
Nutritional Information - Pak-choi
Soaked Lentils (Lens culinaris)
Nutritional Information - Lentils
Shredded carrots (Daucas carota)
High vitamin A, moderate
Nutritional Information - Carrots
Summer Squash (Cucurbita pepo)
e.g. zucchini/courgette;
high phosphorous
Nutritional Information - Summer Squash
Hubbard squash (Cucurbita maxima)
High fibre & Vitamin A
Nutritional Information - Hubbard Squash
Scallop Squash (Cucurbita pepo)
Nutritional Information - Scallop Squash
Acorn Squash (Cucurbita pepo)
Nutritional Information - Acorn Squash
Coriander/Cilantro (Coriandrum sativum)
High vitamin A, moderate oxalates
Nutritional Information - Cilantro
Bell/Sweet Peppers (Capsicum annuum)
Green
Moderate oxalates
Nutritional Information - Green Sweet Pepper
Red
High vitamin C, A, moderate oxalates
Nutritional Information - Red Sweet Pepper
Yellow
Moderate oxalates
Nutritional Information - Yellow Sweet Pepper
Occasionals
Occasional greens that can be added to spice up your Uromastyx' diet can include the items on this page. It is recommended to give occasional items not more than once or twice a month. When feeding edible flowers, be 100% sure that the flowers are free of all pesticides and fertiliser. If you are unsure of the origin of any flowers, do not feed them to your lizard.
Green beans (usually Phaseolus vulgaris)
Canned, moderate oxalates
Green beans (usually Phaseolus vulgaris)
Raw
Nutritional Information - Green Beans
Green Peas (Pisum sativum)
Raw
Nutritional Information - Green Peas
Sugar Snap Peas (Pisum sativum)
Pea & pod - moderate oxalates
Nutritional Information - Snap Pea
Mustard Greens (Brassica juncea)
High vitamin C & A, moderate oxalates, goitrogens. Feed very sparingly or not at all.
Nutritional Information - Mustard Greens
Turnips Greens (Brassica rapa)
Leaves only! High vitamin C & A, moderate oxalates. Feed very sparingly or not at all.
Nutritional Information - Turnip Greens
Romaine lettuce (Latuca sativa orlongifolia)
red and green; mainly consists of water, contains little nutritional value for uros but very good for hydration. It is relatively high in oxalates, and should only be fed when high water content/rapid rehydration is required.
Nutritional Information - Romaine Lettuce
Nutritional Information - Red Leaf
Nutritional Information - Green Leaf
Flowers
As a general rule, Uromastyx can safely eat any flowers which are also human-edible, which includes (but is by no means limited to) the following:
Pansies (Viola tricolor)
Violets (Viola spp.)
Nasturtiums (Tropaeolum)
Dahlia (Dahlia)
Dandelion (Taraxacum officinale)
Catsear/Cat's Ear/False dandelion (Hypochoeris radicata)
Rose petals (Rosa)
Hollyhock (Malva sylvestris)
Alfalfa (Medicago sativa)
Birdsfoot Trifoil (Lotus corniculatus)
Hibiscus (Hibiscus)
Roselle (Hibiscus sabdariffa)
A great treat and an excellent source of vitamins
Roselle leaves (Hibiscus sabdariffa)
Green beans (usually Phaseolus vulgaris)
Canned, moderate oxalates
Green beans (usually Phaseolus vulgaris)
Raw
Nutritional Information - Green Beans
Green Peas (Pisum sativum)
Raw
Nutritional Information - Green Peas
Sugar Snap Peas (Pisum sativum)
Pea & pod - moderate oxalates
Nutritional Information - Snap Pea
Mustard Greens (Brassica juncea)
High vitamin C & A, moderate oxalates, goitrogens. Feed very sparingly or not at all.
Nutritional Information - Mustard Greens
Turnips Greens (Brassica rapa)
Leaves only! High vitamin C & A, moderate oxalates. Feed very sparingly or not at all.
Nutritional Information - Turnip Greens
Romaine lettuce (Latuca sativa orlongifolia)
red and green; mainly consists of water, contains little nutritional value for uros but very good for hydration. It is relatively high in oxalates, and should only be fed when high water content/rapid rehydration is required.
Nutritional Information - Romaine Lettuce
Nutritional Information - Red Leaf
Nutritional Information - Green Leaf
Flowers
As a general rule, Uromastyx can safely eat any flowers which are also human-edible, which includes (but is by no means limited to) the following:
Pansies (Viola tricolor)
Violets (Viola spp.)
Nasturtiums (Tropaeolum)
Dahlia (Dahlia)
Dandelion (Taraxacum officinale)
Catsear/Cat's Ear/False dandelion (Hypochoeris radicata)
Rose petals (Rosa)
Hollyhock (Malva sylvestris)
Alfalfa (Medicago sativa)
Birdsfoot Trifoil (Lotus corniculatus)
Hibiscus (Hibiscus)
Roselle (Hibiscus sabdariffa)
A great treat and an excellent source of vitamins
Roselle leaves (Hibiscus sabdariffa)
Fruits
Note: Fruit is not an essential part of the diet, and can end up being very messy (Often getting stuck to the uros face, tail and feet, along with many of the cage furnishings). If given, fruit is only for a rare occasion.
Apple peel (all varieties)
Apricot (Prunus armeniaca or Armeniaca vulgaris)
High vitamin A
Nutritional Information - Apricots
Blackberries (e.g., Rubus fruticosus)
High vitamin C, moderate oxalates, high fibre
Nutritional Information - Blackberries
Blueberries (Vaccinium spp.)
Moderate oxalates
Nutritional Information - Blueberries
Cherries (e.g., Prunus avium)
Good source of potassium
Nutritional Information - Cherries
Cranberries (Vaccinium Oxycoccos)
High fibre
Nutritional Information - Cranberries
Figs (Moraceae spp.)
High calcium & fibre, moderate oxalates
Nutritional Information - Figs
Grapes (Vitis spp.) - Red & Green
Moderate oxalates
Nutritional Information - Grapes
Guava (Psidium spp.)
High vitamin C & fibre, moderate oxalates
Nutritional Information - Common Guava
Nutritional Information - Strawberry Guava
Mango (Mangifera spp.)
High vitamin A, moderate oxalates
Nutritional Information - Mango
Nectarine (Prunus persica)
Nutritional Information - Nectarines
Peach (Prunus persica)
Low oxalates, goitrogens
Nutritional Information - Peach
Papaya (Carica papaya)
High vitamin C & calcium
Nutritional Information - Papaya
Asian Pear (Pyrus pyrifolia)
High oxalates
Nutritional Information - Asian Pear
Pear (Pyrus spp.)
High oxalates
Nutritional Information - Pear
Raisins (Vitis spp.)
Seedless, high fibre & sugar
Nutritional Information - Seedless Raisins
Strawberries (e.g., Fragaria rosaceae)
High vitamin C, moderate oxalates
Nutritional Information - Strawberries
Melon
Cantaloupe (C. melo cantalupensis & C. melo reticulatus)
High vitamin A
Nutritional Information - Cantaloupe
Honeydew melon (C. melo inodorus)
Nutritional Information - Honeydew
Watermelon (Citrullus cv.)
Nutritional Information - Watermelon
Seeds
Uromastyx are generally fond of seeds. Although some keepers use seeds as substrate, it is generally recommended for health reasons to restrict the use of seeds to food items. The following seeds can be fed to Uromastyx:
White Millet (Panicum miliaceum)
Nutritional Information - Millet
Safflower (Carthamus tinctorius)
Nutritional Information - Safflower
Clover (Trifolium spp.)
Sesame (Sesamum indicum)
Only in small amounts
Nutritional Information - Sesame
White Millet (Panicum miliaceum)
Nutritional Information - Millet
Safflower (Carthamus tinctorius)
Nutritional Information - Safflower
Clover (Trifolium spp.)
Sesame (Sesamum indicum)
Only in small amounts
Nutritional Information - Sesame
What not to feed
As a general rule, you should avoid feeding your lizard any of the following items:
- Insects (See Below)
- Sunflower seeds (Helianthus annuus) - these are high in fat and unhealthy for the lizard
Avoid foods with high levels of the following:
Oxalic acid - this binds calcium, removing it from other foods so it won't be digested. Foods high in oxalates include:
- Beets (Beta vulgaris)
- Kiwi (Actinidia deliciosa )
- Parsley (Petroselinum crispum)
- Pomegranate (Punica granatum)
- Carambola/starfruit (Averrhoa carambola)
- Chard (Beta vulgaris)
Goitrogens - this induces hypothyroidism, and depresses thyroid function, by interfering with absorption of iodine. Restriction of iodine causes the thyroid to increase its size as it tries to filter more blood to get more iodine. The worst offenders include:
- Soy beans (Glycine max)
- Broccoli (Brassica oleracea Italica)
- Kale (Brassica oleracea)
- Brussels sprouts (Brassica oleracea Gemmifera)
- Spinach (Spinacia oleracea)
- Cauliflower (variety of Brassica oleracea)
- Rutabaga/Swede (Brassica napobrassica or Brassica napus)
Vitamin C - high levels can cause diarrhoea (5000g+ per day in humans); low levels are said to help reptiles cope with stress and disease.
Acids - concerns with causing diarrhoea and toxicity
- Tomatoes (Solanum lycopersicum, also Lycopersicon lycopersicum and Lycopersicon esculentum)
- Oranges (Citrus sinensis or Citrus aurantium)
- Grapefruit (Citrus × paradisi)
Phosphorus - high levels can be dangerous
- Bananas (of the genus Musa)
- Corn (Zea mays)
- Potatoes (Solanum tuberosum)
Freezing greens
When freezing green vegetables, especially leafy greens, thiamine (vitamin B1) will leach out. When Uromastyx are fed frozen greens over a long period of time with no extra thiamine added to their diet, a deficiency -hypothiaminosis- will occur. This causes tremors and twitches, which resembles the symptoms for MBD.
- Insects (See Below)
- Sunflower seeds (Helianthus annuus) - these are high in fat and unhealthy for the lizard
Avoid foods with high levels of the following:
Oxalic acid - this binds calcium, removing it from other foods so it won't be digested. Foods high in oxalates include:
- Beets (Beta vulgaris)
- Kiwi (Actinidia deliciosa )
- Parsley (Petroselinum crispum)
- Pomegranate (Punica granatum)
- Carambola/starfruit (Averrhoa carambola)
- Chard (Beta vulgaris)
Goitrogens - this induces hypothyroidism, and depresses thyroid function, by interfering with absorption of iodine. Restriction of iodine causes the thyroid to increase its size as it tries to filter more blood to get more iodine. The worst offenders include:
- Soy beans (Glycine max)
- Broccoli (Brassica oleracea Italica)
- Kale (Brassica oleracea)
- Brussels sprouts (Brassica oleracea Gemmifera)
- Spinach (Spinacia oleracea)
- Cauliflower (variety of Brassica oleracea)
- Rutabaga/Swede (Brassica napobrassica or Brassica napus)
Vitamin C - high levels can cause diarrhoea (5000g+ per day in humans); low levels are said to help reptiles cope with stress and disease.
Acids - concerns with causing diarrhoea and toxicity
- Tomatoes (Solanum lycopersicum, also Lycopersicon lycopersicum and Lycopersicon esculentum)
- Oranges (Citrus sinensis or Citrus aurantium)
- Grapefruit (Citrus × paradisi)
Phosphorus - high levels can be dangerous
- Bananas (of the genus Musa)
- Corn (Zea mays)
- Potatoes (Solanum tuberosum)
Freezing greens
When freezing green vegetables, especially leafy greens, thiamine (vitamin B1) will leach out. When Uromastyx are fed frozen greens over a long period of time with no extra thiamine added to their diet, a deficiency -hypothiaminosis- will occur. This causes tremors and twitches, which resembles the symptoms for MBD.
Bee Pollen
Bee pollen is a natural appetite stimulant. If you try feeding it to your uromastyx, you may find that the lizard may or may not be interested - it varies with the individual. Bee pollen is a good source of vitamin, but should be limited to once a week at most, as it is high in vegetable proteins. Additionally, if you feed a lot of flowers (primarily during spring/summertime), you need not use it as often.
Bee pollen as a superficial remedy
The use of bee pollen by some may be bypassing a serious underlying issue, which is why the lizard’s diet need stimulated in the first place. Lack of appetite can be due to more prosaic reasons - acclimatisation, brumation - or it can also be due to serious issues, such as impaction, parasitic infection (you should have a stool sample checked at least once a year at the vet), incorrect husbandry (temperatures, diet, UVB, and so on). If it’s been eating well before and has recently become picky, that’s usually a warning sign, if it can’t be attributed to something like acclimatisation or brumation.
It is important to remember that the uromastyx is a wild animal living indoors; if it’s hungry, it’ll eat, and if it doesn't eat (which will be in conflict with one of its most basic instincts), that’s usually a sign that something is abnormal and an indication that you should check the basic things listed above..
Bee pollen as a superficial remedy
The use of bee pollen by some may be bypassing a serious underlying issue, which is why the lizard’s diet need stimulated in the first place. Lack of appetite can be due to more prosaic reasons - acclimatisation, brumation - or it can also be due to serious issues, such as impaction, parasitic infection (you should have a stool sample checked at least once a year at the vet), incorrect husbandry (temperatures, diet, UVB, and so on). If it’s been eating well before and has recently become picky, that’s usually a warning sign, if it can’t be attributed to something like acclimatisation or brumation.
It is important to remember that the uromastyx is a wild animal living indoors; if it’s hungry, it’ll eat, and if it doesn't eat (which will be in conflict with one of its most basic instincts), that’s usually a sign that something is abnormal and an indication that you should check the basic things listed above..
Collecting wild plants for food
General warning: When picking any wild-picked plant or flower intended for human or uromastyx consumption: always make absolutely sure that it has not had weedkiller sprayed on the area where it is growing, for at least the past two years. Many weedkillers can take a long time to disperse their poisons, and any growing plants may be tainted. This applies more to gardens and urban areas than to countryside, but it is still a danger in any environment (farmers may want to kill weeds in the countryside, for example). Also make sure you are not downhill from any large factories, farms, etc. These operations can leach large amounts of chemicals into the ground, sending it downhill, into the soil below.
False dandelions
There are many small, yellow-flowering plants that look rather like dandelions. They are not, however, and many of them are not even in the same genus of plant. Common lookalike plants to watch out for include:
- Hypochoeris radicata or Catsear, which actually bears the common name "false dandelion" - note that this one is known to be safely edible
- members of the Tragopogon family
- members of the Asteraceae family
- a common example is Tussilago farfara, better known as Coltsfoot.
As a point of fact, there are literally hundreds of small yellow-flowered plants, many of which look similar to or almost identical to the common dandelion (Taraxicum officinale). Some of these are human-edible and therefore probably also okay for your uromastyx, but unless you are absolutely, completely, one hundred percent sure that you know which is which, then the best advice is not to feed them at all. You can find some websites detailing lists of dandelion lookalikes; a search for false dandelion is a good place to start. Any other foods should be compared against the list of food above.
Vitamin supplements
There is much discussion in the lizard-keeping community about the benefits of using vitamin supplements. If a proper, balanced diet is given (along with correct husbandry) then there should be no need to dust your Uromastyx food. Although it likely won't hurt to dust every or every-other feeding, keep in mind that there is a thing as too much supplementation, resulting in an overdose.
Calcium:Phosphorus ratio
The calcium:phosphorus ratio represents the amount of calcium as compared to the amount of phosphorus in your lizard's diet. While both are needed, you should aim to have a ratio of at least 2:1 (twice as much calcium as phosphorus), because each gram of phosphorus requires at least one matching gram of calcium in order for phosphorus to be absorbed by the lizard's intestinal wall. If your lizard is not provided with enough corresponding calcium, it will begin to lose calcium content from its bones, ultimately resulting in metabolic bone disease.
Adding calcium powder
As long as a good varied diet is provided for your uromastyx, they should get plenty of calcium without relying on supplements. You can also add supplements to their diet to provide sufficient calcium if there is not enough coming strictly from food. Products such as MinerALL provide additional calcium for uromastyx, but should not be used on a daily basis. It has been recommended by some long-time keepers/breeders that a small sprinkle once a week is sufficient for healthy adult uromastyx, and twice week for captive-bred hatchlings up to one year old. A sickly uromastyx may also benefit from other vitamin supplements.
UVB light source vs. vitamin D3
Every uromastyx owner will agree that the more natural the source, the better. This applies to food (fresh vegetables compared to dried foods from a pet store) as well as to light: natural sunlight is of course the best, while a recommended UVB-emitting bulb such as the Mega Ray does a credible imitation. A vitamin supplement should be considered a last resort for a lizard which isn't getting enough D3 through other sources. There are of course other beneficial effects of full-spectrum lighting, such as fine control over the photoperiod, which supplements can't even approach.
Vitamin D2 vs. vitamin D3
It is a common belief in veterinarian circles that one should not use vitamin D2 supplements with reptiles of this type. Although delicate language is employed (using phrases such as "it is believed" and "until further research is done"), it does seem that a number of researchers are of the opinion that vitamin D2 is all but useless for lizards. Some scholarly works include the following:
"D3 (cholecalciferol) is essential to calcium metabolism, and is made in the iguana (and human, for that matter) skin by contact with sufficient UVB wavelengths. Plants contain another type of vitamin D, called D2 (ergocalciferol). D2 is not nearly as efficient, close, in fact to being worthless, at metabolizing calcium, hence the need for D3."
--Melissa Kaplan
"Herbivorous species can obtain vitamin D2 from sun cured forage (Ullrey and Bernard 1999) but this is reported to have negligible impact on calcium metabolism in reptiles. It is believed that reptiles utilise vitamin D3 rather than vitamin D2."
—Boyer, T. H. (1996) Metabolic bone disease in: Reptile Medicine and surgery, Ed D. R. Mader. W. B. Saunders company, London. pp 385 - 392
"Do not assume that the term vitamin D in the label ingredient list is actually D3 because it may be D2 and unusable by reptiles."
—Susan Donoghue in Mader DR (ed): Reptile medicine and surgery, 2nd edition. Saunders Elsevier, St. Louis, MO: Chapter 18: Nutrition
However, there remains some doubt, mostly cast by comments such as this:
"Most mammals can use both forms of the vitamins. Whether reptiles are able to use vitamin D2 is not known, and some researchers believe that certain reptiles are not able to use oral vitamin D3 [sic - which seems a bit odd] at all. Therefore, until further research is done, only the vitamin D3 form should be used as a dietary supplement."
—Mader DR in Mader DR (ed): Reptile medicine and surgery, 2nd edition. Saunders Elsevier, St. Louis, MO: Chapter 61: Metabolic Bone Diseases p842
Differences between mammals and lizardsThe differences between vitamin D2 and D3 metabolism are explained in The case against ergocalciferol (vitamin D2) as a vitamin supplement -- Houghton, L. A., and Vieth, R. (2006) Am. J.Clin. Nutr. 84, 694–697. Although the metabolic pathway is known to be similar, it could well be very different in the fine details. However, the following serves to clarify:
"1. The affinities of the specific vitamin D plasma transport proteins for 25-hydroxyergocalciferol and 25-hydroxycholecalciferol were studied in sixty three vertebrate species.
2. Fish, reptile, bird and monotreme plasma proteins bound 25-hydroxyergocalciferol considerably less efficiently than 25-hydroxycholecalciferol.
3. Vitamin D transport proteins from twenty-two placental mammals bound 25-hydroxyergocalciferol and 25-hydroxycholecalciferol with equal efficiency.
4. Proteins from nine mammals bound 25-hydroxycholecalciferol 10-30% more efficiently than 25-hydroxyergocalciferol."
--Hay AW, Watson G. (1977) Vitamin D2 in vertebrate evolution. Comp Biochem Physiol B. 1977;56(4):375-80
Conclusion
It seems to be that mammals can transport both types of vitamin equally well in plasma, but reptiles transport it "considerably less efficiently" - and humans, who are mammals, don't use vitamin D2 as efficiently as D3. Although relatively unfounded, it might be valid to presume that reptiles will utilise D2 even less efficiently than humans.
Calcium:Phosphorus ratio
The calcium:phosphorus ratio represents the amount of calcium as compared to the amount of phosphorus in your lizard's diet. While both are needed, you should aim to have a ratio of at least 2:1 (twice as much calcium as phosphorus), because each gram of phosphorus requires at least one matching gram of calcium in order for phosphorus to be absorbed by the lizard's intestinal wall. If your lizard is not provided with enough corresponding calcium, it will begin to lose calcium content from its bones, ultimately resulting in metabolic bone disease.
Adding calcium powder
As long as a good varied diet is provided for your uromastyx, they should get plenty of calcium without relying on supplements. You can also add supplements to their diet to provide sufficient calcium if there is not enough coming strictly from food. Products such as MinerALL provide additional calcium for uromastyx, but should not be used on a daily basis. It has been recommended by some long-time keepers/breeders that a small sprinkle once a week is sufficient for healthy adult uromastyx, and twice week for captive-bred hatchlings up to one year old. A sickly uromastyx may also benefit from other vitamin supplements.
UVB light source vs. vitamin D3
Every uromastyx owner will agree that the more natural the source, the better. This applies to food (fresh vegetables compared to dried foods from a pet store) as well as to light: natural sunlight is of course the best, while a recommended UVB-emitting bulb such as the Mega Ray does a credible imitation. A vitamin supplement should be considered a last resort for a lizard which isn't getting enough D3 through other sources. There are of course other beneficial effects of full-spectrum lighting, such as fine control over the photoperiod, which supplements can't even approach.
Vitamin D2 vs. vitamin D3
It is a common belief in veterinarian circles that one should not use vitamin D2 supplements with reptiles of this type. Although delicate language is employed (using phrases such as "it is believed" and "until further research is done"), it does seem that a number of researchers are of the opinion that vitamin D2 is all but useless for lizards. Some scholarly works include the following:
"D3 (cholecalciferol) is essential to calcium metabolism, and is made in the iguana (and human, for that matter) skin by contact with sufficient UVB wavelengths. Plants contain another type of vitamin D, called D2 (ergocalciferol). D2 is not nearly as efficient, close, in fact to being worthless, at metabolizing calcium, hence the need for D3."
--Melissa Kaplan
"Herbivorous species can obtain vitamin D2 from sun cured forage (Ullrey and Bernard 1999) but this is reported to have negligible impact on calcium metabolism in reptiles. It is believed that reptiles utilise vitamin D3 rather than vitamin D2."
—Boyer, T. H. (1996) Metabolic bone disease in: Reptile Medicine and surgery, Ed D. R. Mader. W. B. Saunders company, London. pp 385 - 392
"Do not assume that the term vitamin D in the label ingredient list is actually D3 because it may be D2 and unusable by reptiles."
—Susan Donoghue in Mader DR (ed): Reptile medicine and surgery, 2nd edition. Saunders Elsevier, St. Louis, MO: Chapter 18: Nutrition
However, there remains some doubt, mostly cast by comments such as this:
"Most mammals can use both forms of the vitamins. Whether reptiles are able to use vitamin D2 is not known, and some researchers believe that certain reptiles are not able to use oral vitamin D3 [sic - which seems a bit odd] at all. Therefore, until further research is done, only the vitamin D3 form should be used as a dietary supplement."
—Mader DR in Mader DR (ed): Reptile medicine and surgery, 2nd edition. Saunders Elsevier, St. Louis, MO: Chapter 61: Metabolic Bone Diseases p842
Differences between mammals and lizardsThe differences between vitamin D2 and D3 metabolism are explained in The case against ergocalciferol (vitamin D2) as a vitamin supplement -- Houghton, L. A., and Vieth, R. (2006) Am. J.Clin. Nutr. 84, 694–697. Although the metabolic pathway is known to be similar, it could well be very different in the fine details. However, the following serves to clarify:
"1. The affinities of the specific vitamin D plasma transport proteins for 25-hydroxyergocalciferol and 25-hydroxycholecalciferol were studied in sixty three vertebrate species.
2. Fish, reptile, bird and monotreme plasma proteins bound 25-hydroxyergocalciferol considerably less efficiently than 25-hydroxycholecalciferol.
3. Vitamin D transport proteins from twenty-two placental mammals bound 25-hydroxyergocalciferol and 25-hydroxycholecalciferol with equal efficiency.
4. Proteins from nine mammals bound 25-hydroxycholecalciferol 10-30% more efficiently than 25-hydroxyergocalciferol."
--Hay AW, Watson G. (1977) Vitamin D2 in vertebrate evolution. Comp Biochem Physiol B. 1977;56(4):375-80
Conclusion
It seems to be that mammals can transport both types of vitamin equally well in plasma, but reptiles transport it "considerably less efficiently" - and humans, who are mammals, don't use vitamin D2 as efficiently as D3. Although relatively unfounded, it might be valid to presume that reptiles will utilise D2 even less efficiently than humans.
Diet in the Wild
In the wild, Uromastyx eat a variety of plants, as well as the occasional invertebrate† or carrion (see below). Below is a list of plants eaten by various species.
Insects
Feeding insects
This is a tricky issue in uromastyx husbandry. Although many caresheets indicate the feeding of crickets and mealworms, particularly to young uromastyx for additional protein intake, it is the considered opinion of experienced uromastyx owners that these are not good food items and that the uromastyx should be treated as a strict herbivore. An uromastyx' digestive track is geared towards the vegetables in its diet and may not be able to sufficiently digest the high protein levels present when eating insects.
Consumption of insects in the wild
Although a topic of hot debate among uromastyx keepers and breeders, there seems to be a mounting body of evidence to suggest that uromastyx do not, in fact, eat many insects in the wild. Troy Jones has corresponded with Danny Molco, co-author of Ornate Spiny-tail Lizards and Study of wild populations of Uromastyx along with Ben David Osnat, and has been kind enough to share the details of his correspondence with the UroWiki. in this conversation, Danny states that insects make up less than 1% of their diet, and it's likely the result of accidental consumption (such as eating an Acacia flower and accidentally ingesting the ants on the flower).
A recent paper has noted that a population of Uromastyx aegyptia microlepis in Kuwait forages on insects and carrion when food is very scarce (Castilla et al., 2010). There is also video evidence of female Saara hardwickii feeding on insects during the breeding season. This does NOT mean that all Uromastyx spp. or Saara spp. feed on insects or carrion in the wild! Just because one or two populations are known to, does not mean all species should be treated the same, nor should they be fed insects in captivity. Varanus olivaceus and V. mabitang feeds almost exclusively on fruit; would you feed all monitors a high fruit diet? of course not!
This is a tricky issue in uromastyx husbandry. Although many caresheets indicate the feeding of crickets and mealworms, particularly to young uromastyx for additional protein intake, it is the considered opinion of experienced uromastyx owners that these are not good food items and that the uromastyx should be treated as a strict herbivore. An uromastyx' digestive track is geared towards the vegetables in its diet and may not be able to sufficiently digest the high protein levels present when eating insects.
Consumption of insects in the wild
Although a topic of hot debate among uromastyx keepers and breeders, there seems to be a mounting body of evidence to suggest that uromastyx do not, in fact, eat many insects in the wild. Troy Jones has corresponded with Danny Molco, co-author of Ornate Spiny-tail Lizards and Study of wild populations of Uromastyx along with Ben David Osnat, and has been kind enough to share the details of his correspondence with the UroWiki. in this conversation, Danny states that insects make up less than 1% of their diet, and it's likely the result of accidental consumption (such as eating an Acacia flower and accidentally ingesting the ants on the flower).
A recent paper has noted that a population of Uromastyx aegyptia microlepis in Kuwait forages on insects and carrion when food is very scarce (Castilla et al., 2010). There is also video evidence of female Saara hardwickii feeding on insects during the breeding season. This does NOT mean that all Uromastyx spp. or Saara spp. feed on insects or carrion in the wild! Just because one or two populations are known to, does not mean all species should be treated the same, nor should they be fed insects in captivity. Varanus olivaceus and V. mabitang feeds almost exclusively on fruit; would you feed all monitors a high fruit diet? of course not!