This information is aimed at the commonly encountered Testudo species (and Agrionemys horsfieldi, previously Testudo horsfieldi) kept in the United Kingdom (UK). It is strongly advised that you join your local tortoise keepers association. Those that are worthy of membership are generally charities with very reasonable membership fees. Most give substantial amounts to facilitate chelonian welfare and conservation programs across the world. 

The most common cause of illness within the captive population of tortoises is inadequate husbandry, such as unsuitable temperatures, inadequate lighting sources or spectra, humidity provision or poor nutrition. Tortoises thrive in outdoor enclosures in countries that permit this due to their climates. Sadly, the United Kingdom is not one of these countries and indoor accommodation is a necessity for most part of the year. Many tortoise owners, unlike other reptile enthusiasts are not used to the idea of environmental control through lighting, heating or humidity manipulation. High numbers of tortoises kept outdoors have "survived" for many years or decades, but owners should realise that these animals under such conditions are being maintained in conditions very different to those found in their natural habitat, i.e. Spain, Tunisia or Africa, to mention a few. The common belief that we often encounter where a tortoise can live and thrive under the UK conditions is wrong and this, coupled with long hibernation periods, frequently much longer than those experienced in their natural habitats, are often the cause of chronic diseases or conditions encountered in practice. Programs such as Blue Peter have not helped along the way and hibernating a tortoise in a loft or shed in a box full of hay has again contributed to suffering reptiles. In this article we are hoping to push awareness in tortoise keeping by optimising husbandry.

Tips on hibernation such as hibernating tortoises in a fridge - yes a fridge! - are supplied in another article, as there are differences between species, for example the Russian Tortoise (Agrionemys horsfieldi hibernates and aestivates), whereas the Tunisian Spur-Thighed Tortoise (Testudo naebulensis) does not hibernate.

Tortoises are found in a range of environments generally found in moderate biomes or Mediterranean Forest ecoregion for the species commonly encountered where they feed on high levels of fibre and experience high temperatures, very different to a temperate oceanic climate found in the UK. A patch of grass in a garden and a mixed greens diet is not an equal substitute for natural diet within the forests or shrub lands.

They tend to be intolerant to damp and a dry shelter should be provided. We must remember that although it may rain and become damp in their natural environment during the wet season, they have been exposed to high levels of ultraviolet lighting, high fibre weeds and seasonal cycles which will mean that their immune system is very different to those kept in captivity and in the United Kingdom outdoors. If left to the influence of the climate found in the UK, tortoises will hibernate for 5-6 months, twice as long as hibernation time in their natural environment. Some tortoises like the Tunisian Spur Thighed Tortoise will not hibernate at all in the wild and therefore species and subspecies recognition is very important. For these reasons, tortoise keepers should have an indoor setup that could be used when the conditions are not adequate - for example in early spring after hibernation.

Tortoises may climb or burrow and males may become very hyperactive during the breeding season, which means that they should be protected from predators such as foxes, cats or even rats. Good ventilation is essential and the use of open top tortoise tables or indoor pens are highly recommended compared to vivaria or glass tanks.

A microclimate may be created depending on the depth and type of substrate used. Commonly used substrates include newspaper, alfalfa or grass pellets, reptile carpets, peat, soil or sand mixes, astroturf or bark chippings. Cat litter, crushed corn cob, walnut shells or small wood chips are perhaps not a good idea as they may become impacted or obstructed. Russian tortoises (Agrionemys horsfieldi) and Mediterranean species (Testudo graeca, T. hermanni, T. marginata) tend to like burrowing and therefore a substrate that permits this would be a good idea. If food is presented on a tile or area with no substrate this will reduce the risk of ingestion.

Tortoises seldom thrive in groups of more than eight and therefore groups with reduced numbers are recommended. Adequate space should be provided as overcrowding will create stress and predisposition to disease. Quarantine periods are extremely important and can vary between 2 months and years depending on the source. Even those specimens quarantined for years cannot be guaranteed as free from pathogens such as viruses. 

The preferred optimal temperature zone (POTZ) for most of these species is 20-32° C and their preferred body temperature (PBT) is in the upper end of their gradient (26-30° C). In order to promote natural behaviour and physiological processes, a tortoise should be able to bask in the higher end of the gradient under a radiant source like a ceramic, incandescent or infrared heat source.

Heat sources can be divided in to basking sources and background heat sources. The first include bulbs and heat panels that radiate heat creating a basking spot. The latter could include heat cables or heat mats - these are ideally positioned on the side or back of the enclosure to prevent overheating of the underside (ventrum or plastron) of the tortoise.

Light sources may emit different spectra which mainly include the infrared, visible and ultraviolet (A and B). Reptiles, like birds, can see in to the visible spectrum and also the ultraviolet A (UVA) spectrum through which they see colour. This means that our perception of the environment under a ultraviolet tube looks the same as a non ultraviolet tube when it is switched on, whereas to a reptile or bird they will see differently, more enhanced and more colour.

Heat and Light are needed for Vitamin D3 production and Calcium uptake - Ultraviolet B (UVB) is the spectrum that converts Pro-vitamin D (a cholesterol) on the skin to Pre-vitamin D3. This is transformed via warmth in to vitamin D3 - warmth is needed for this to happen at a normal rate which is enhanced by basking. This is carried to the liver where Calcidiol is formed and then Calcitriol is formed in the kidneys, the active hormone that will act in the calcium metabolism.

Ceramic, incandescent and mercury vapour bulbs are examples of heat and light sources that can be used. Low wattage bulbs that emit minimal heat and high wattages (i.e. 250W) are available and used depending on the size of enclosure and requirements. Some of these sources i.e. mercury vapour bulbs will provide visible and ultraviolet lighting, whereas others like incandescent bulbs will just emit visible light and heat with no ultraviolet spectrum. Some bulbs will emit visible light and ultraviolet A, whereas others may emit full visible and ultraviolet (A and B) spectrum. Bulb types are very different and it is extremely important to supply the correct spectra. Combinations may also be used - for example a T5 or T8 ultraviolet A and B tube across the top or at the back of the tortoise table and a basking ceramic or incandescent bulb. This way the tortoise will seek the basking spot and receive radiating heat and also UV simulating the sun. More in depth information on lighting can be found on the website and is beyond the scope of this article.

High calcium and fibre with low fat, phosphorus and protein diets are the characteristics of wild diets. In captivity, this should be reproduced as much as possible, trying to avoid over-reliance of certain dietary components like lettuce, tomato or cucumber. Edible weeds, flowers and grasses should be the aim of their diet and they will forage for themselves in their enclosure. Grocery greens and vegetables are readily available and will likely be part of their diet for at least part of the year in the UK but growing weeds at home is always a better option. 

Inappropriate diets may include poisonous plants like daffodils and other bulbs, rhubarb, potatoes, onions, buttercup and yew; pelleted diets are not recommended as a major constituent and cat or dog foods, meat, milk and cheese should never be fed. 

Calcium content in the diet is important but the ratio of calcium and phosphorus has to be taken in to account. A natural diet may have a ratio of Ca:P of 4:1. Dandelions have a ratio of 3:1, whereas the ratio in supermarket greens is much lower, with iceberg lettuce containing a ratio of 0.8:1. This means that calcium supplementation is essential. 

Supplementation with calcium is essential in herbivorous reptiles and tortoises are no exception. Unfortunately, many supplements have a low Ca:P ratio, whereas others have a much higher ratio - for example, Reptivite (Zoomed) has a 2:1 ratio, Nutrobal (Vetark) has a 46:1 and Arkvits (Vetark) 30:1, therefore the latter two may be more appropriate. Egg forming females and juveniles have a higher calcium requirement and therefore daily supplementation may be necessary. Other tortoises may require supplementation every other day and those grazing on natural forage and a varied diet with grocery greens may only require weekly supplementation. Separate calcium supplements may be given daily or every other day and separate multivitamin supplement may also be given once or twice a week. 

A varied diet including as many weeds and grasses as possible, with grocery greens added when necessary and regular supplementation with a product such as Nutrobal seems to be a sensible approach. These may include dandelions, clover, rape, dock, chickweed, dead nettles, hibiscus, wild pansy, bramble, mulberry, roses. Grocery greens may include broccoli, parsley, turnip, cabbage, beet tops, mustard greens, brussel sprouts, romaine lettuce, spring and collard greens, kale, spinach, endive, watercress, pak choi and mint. Oxalates found in cabbage, spinach and beet greens may be an issue if fed in large quantities as they bind calcium. However, it is thought that tortoises can deal with high levels of oxalates and therefore these are unlikely to cause issues. 

Vegetables such as swedes, carrots, parsnip, cauliflower, sweet potato and turnip can be given as up to 10% of the total diet. Peas and beans are not recommended due to their protein levels. Fruits including pineapple, mango, strawberries, cucumber, grapes, apples, pears, peppers should make up no more than 5% of their diet. 

Subject to availability, wild foods are ideal components of the captive tortoise diet. Dandelions are suitable as a healthy core food.

Caution should be taken to ensure poisonous plants listed later are not mistakenly offered.

•Dandelion (Taraxacum officianale)

•Clovers (Trifolium spp.)

•Hawkbits (Leontodon spp.) 

•Sowthistles (Sonchus spp.) 

•Hawkweeds (Pictus spp.) 

•Mallows (Malva spp.) 

•Bindweeds (Calystegia spp.)

•Sedum (Sedum spp.) 

•Ivy-leaved Toadflax (Cymbalaria muralis) 

•Honeysuckle (Lonicera periclymenum)

•Cats Ears (Hypocheris spp.)

•Vetches (Vicinia spp.) 

•Trefoils (Lotus spp) 

•Bramble (Rubus fruiticosus)

•Chickweed (Stelaria media) 

•Dock (Rumex crispus) 

•Plantain (Plantago spp.) 

•Nettles (Lamium spp.) 

•Hedge Mustard (Sisymbrium officionale) 

Green-leaf base should comprise around 75% of the normal diet of Mediterranean tortoises such as Testudo hermanni and Testudo graeca.

•Dandelion: leaves and flowers

•Alfalfa: Fresh, Sun-cured hay, dried leaves, pellets 

•Mixed grasses: Fresh, Sun- cured hay, dried leaves, pellets

•Cabbage (mixed varieties) 

•Rocket

•Clover shoots

•Kale

•Rape 

•Parsley 

•Watercress 

•Spring greens 

•Carrot tops 

•Beet tops 

•Sowthistle 

•Turnip tops 

•Chickweed

15% of the diet of Mediterranean tortoises should be grated or chopped vegetable matter

•Beans (leaves and pods) •Broccoli

•Brussel sprouts •Cauliflower

•Beetroot 

•Carrot 

•Parsnips 

•Turnip 

•Marrow 

•Pumpkin

Fruits should be fed very cautiously. High sugar levels can encourage bacterial, mycotic and protozoal overgrowth. This is particularly likely following antibiotic treatments. No more than 10% of the normal diet of Mediterranean tortoises and not feeding at all may even be safer so that we are not feeding too much.

It is essential to remove any potentially toxic plants from the garden and to avoid the use of any chemicals such as pesticides and slug pellets. It is also important to retrieve tortoises before mowing the lawn.

•Hibiscus

•Mint

•Nasturtium

•Lilac

•Rose

•Bramble

•Flowers and their leaves 

Royal Veterinary College (RVC). Diet Recommendations lead by Jo Hedley (European and RCVS specialist in Herpetology)

Holly House Veterinary Hospital (The Tortoise Hospital). Care sheet written by vets trained and lead by Stuart McArthur (MRCVS)