Tortoises (taxonomic order Testudines, formerly Chelonia) are a familiar reptile to many. Though a common pet in the 1950s and ’60s, bans on wide-scale wild imports coupled with the realisation that tortoises required more specialised care than simply wandering the back garden in summer and hibernating in a wooden crate in the shed in winter turned tortoise keeping into a specialist hobby. Today, captive-bred individuals are more commonly available and the keeping of companion tortoises has seen a resurgence. There are 40 to 50 living species currently recognised by different authorities, and in the UK the commonest tortoises kept as household pets are the “Mediterranean tortoises”, with other tropical species being available to more experienced, specialist chelonian enthusiasts. The Mediterranean tortoise complex comprises five species: the Greek (or spur-thighed) tortoise (Testudo graeca), the Hermann’s tortoise (T. hermanni), the marginated tortoise (T. marginata), the Egyptian (or Kleinmann’s) tortoise (T. kleinmanni) and the Russian (or Horsfield’s) tortoise (Agrionemys horsfieldii).
It is essential that any tortoise owned has the correct paperwork for legitimate ownership, and any breeder or seller must provide appropriate Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) paperwork for the tortoises in their care. Species such as the Greek and Hermann’s tortoises listed on Appendix 1 of CITES are afforded the highest level of protection and require a licence for sale. Many species are of conservation concern and it is important that tortoises are not illegally collected from the wild and imported for the pet trade. For example, the Egyptian tortoise is listed as critically endangered by the International Union for Conservation of Nature (IUCN) (Perälä, 2003) and even the Greek tortoise, one of the most common of pet species, is classified as vulnerable in the wild (Tortoise and Freshwater Turtle Specialist Group, 1996).
The majority of health issues in pet tortoises presented to veterinary surgeons are caused by inappropriate husbandry, diet and general care. Consideration of the tortoise’s physiology as an ectotherm, and therefore their dependence on prevailing environmental conditions (notably temperature) to regulate internal homeostasis, is essential to long-term optimum health (Figure 1). Given that tortoises are famous for their long lifespans, with numerous records of “celebrity” Greek tortoise lifespans over 160 to 175 years found in the press, correct husbandry needs careful planning to prevent individuals experiencing suboptimal health and welfare for many decades.
Temperature
Tortoises should be provided with space to roam and a thermal gradient within their enclosure to ensure correct regulation of their physiology. Digestion, growth, reproduction and immune functioning are reliant on the animal being able to use the prevailing environmental temperature to regulate physiological demands. Tortoises kept at an incorrect temperature will be unable to combat disease, and poor diet will lead to inappropriate shell growth and development of the juvenile animal into a mature adult. Heating is essential for all species. Even in the hottest of hot UK summers, the number of days that meet the preferred optimum temperature zone (POTZ) for the Mediterranean tortoises (20 to 28°C) is limited (for animals kept in outdoor enclosures).
Tropical species such as the rainforest-dwelling red-footed tortoise (Chelonoidis carbonarius)
and the savannah-dwelling leopard tortoise (Stigmochelys pardalis) require more constant higher temperature ranges and humidity and do not hibernate. A daytime hot spot of 35°C should be provided, with the coolest end of the enclosure managed at 25°C, and the background temperature of the entire enclosure should be maintained at 25°C overnight. Similar background temperatures are required for the leopard tortoise but a hotter basking spot and lower relative humidity may be provided than for rainforest species (except when juveniles). Expert advice should be sought when any tortoise is considered as a pet but especially so for these more specialised and challenging species; thorough homework before obtaining an animal will prevent future health issues and potential poor tortoise welfare.
Hibernation
For species that hibernate, the current trend of milder winters poses problems for early waking from hibernation and animals being conscious in suboptimal conditions. Hibernating tortoises need to be checked regularly to ensure that if an animal does wake up, it can be managed appropriately and brought inside into a vivarium or to a “tortoise table” where temperature and humidity can be controlled. Always ensure that a hibernating tortoise is safe and secure and, if outside, in a dry and pest-free space. It is not uncommon for veterinary surgeons to be presented with hibernating tortoises who have been chewed by rodents. Similarly, care must be taken for free-ranging tortoises in a domestic garden as predation attempts by foxes can cause severe, sometimes fatal, damage to the tortoise’s legs, carapace and/or plastron.
Diet
It is essential that tortoises are provided with the correct diet and balance of calcium to phosphorous within the foods offered to prevent metabolic bone disease (MBD) and pyramiding of the tortoise’s shell while it is growing. Tortoise diets need to be high in structural fibre, low in fat and low in protein (Figure 2). In the wild, tortoises spend a large amount of their day grazing and browsing on vegetation around them, and will move over large distances and eat a wide variety of plants; this variety should be replicated in captive diets.
Safe weeds and garden plants include: plantains (the common lawn weed, not the fruit that resembles a banana), dandelion leaves and flowers, mallow, chickweed, hibiscus flowers, nasturtiums, pansies/violas, clover, bramble leaves (avoid thorns), stinging nettles, roses and geraniums. Safe vegetables include: globe artichoke, rocket, watercress, lamb’s lettuce, carrot tops and kale.
Provide a mixture of vegetables to prevent over-dependence on one dietary ingredient and to reduce any potential anti-nutrient properties of individual vegetables.
Mediterranean tortoise species and grazing tortoise species (eg the leopard tortoise) do not need to be provided with dog food, boiled eggs, cheese, bananas or other high-protein, high-fat, high-energy foods. Avoid peas and beans, which are high in protein and phytates that inhibit calcium uptake. Plants that contain oxalates (eg spinach) also bind calcium, thus reducing uptake, and increase the chances of renal and urinary problems (such as kidney stones). The rainforest tortoises (eg red-footed tortoise) should be provided with 30 percent of their daily intake as fruits (eg papaya, mango, tomatoes) and a very small amount of animal protein (eg hard-boiled egg once a month).
Lighting
Finally, always provide a tortoise with access to UVB light from a reptile-specific lamp for at least 10 to 12 hours a day. UVB is essential in the metabolic pathway of calcium and vitamin D3 – both of which are essential to the structural integrity of the tortoise’s skeleton and carapace.
To conclude
A tortoise provided with room to roam around, with a thermal gradient and a basking hotspot, a diet of greens, forage and appropriate leafy vegetables plus a UVB lamp will lead a long and healthy life, and be a much-loved family pet.
