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Post-hibernation problems in Mediterranean tortoises

A C Highfield

Tortoises which emerge from hibernation with health problems are in serious - and immediate - danger. For a variety of biological reasons, tortoises are at their most vulnerable at this time. In particular, the white blood cell count is very low (thus reducing their ability to fight infection), and the blood urea level is very high due to metabolic toxins accumulated over the hibernation period. This combination of low WBC and high blood urea, at a time when other body functions are also not functioning at peak effectiveness does mean that should anything go wrong, the time available to treat and correct the problem is considerably less than normal.
It is therefore extremely important that tortoises which fail to function normally as they come out of hibernation are detected quickly and given prompt, effective treatment and support.

There are several factors to consider in connection with hibernation. Each of these is critically important to the survival and well-being of the tortoise.

TEMPERATURE in hibernation.

Freezing is the biggest killer of hibernating tortoises by far. If the tortoises body temperature reaches freezing point at any time during the hibernation period, death or very serious injury will invariably occur. Do not make the mistake of believing that insulation alone will protect your tortoise - it won't. It merely slows up the rate of heat exchange. Prolonged spells of sub-zero temperatures will kill no matter how well insulated your tortoise is. The only way to offer complete protection is to use a reliable thermometer. If the temperature falls to dangerous levels, move the tortoise to a safe location at once. The ideal temperature for hibernation is circa 5oC.

DURATION of hibernation.

Tortoises in the wild typically hibernate for between 8-12 weeks. If you hibernate your tortoise for longer than this, then you are placing it as serious risk. The smaller the tortoise, the greater the risk (it's body fat reserves are less).

CONDITION of the tortoise.

Sick or underweight tortoises should never be hibernated. They will not survive. Always perform a detailed pre-hibernation heath check to ensure that the animal is a) up to a safe weight and b) is not displaying any signs of disease. Sick or underweight tortoises will need overwinter care indoors, with adequate light and heat to enable them to function - and feed - normally.
For complete details of recommended hibernation conditions and a very detailed guide to how to carry out pre-hibernation health checks, you should consult 'Safer Hibernation & your Tortoise'. An illustrated (20+ pages) booklet is available free of charge from the Tortoise Trust on request. Please send a medium sized SAE if you would like a copy. Other topics featured include: diet and feeding advice, tropical and unusual tortoises, overwintering techniques, hand and force feeding, common health problems etc.
This leaflet however concentrates upon what to do if you have noticed problems. Firstly, if your tortoise is 'late' in getting up, do not assume that all is well. Check it immediately. Often a sick or frost damaged tortoise will not get itself out of hibernation. If left without help it will simply die. Certainly, no tortoise should in our opinion ever be in hibernation later than the end of March. If your tortoise is still 'in hibernation' when ambient temperatures in early spring are much above 12oC or about 60oF then it may need help urgently. Don't delay. Act immediately.

First Steps

The first thing tortoises really need to do on emerging from their hibernation is to drink. Not only will they naturally be somewhat dehydrated, but due to the accumulation of toxins during hibernation the kidneys need a throughput of fluid in order to 'flush' these away. The main waste is uric acid. This is a white, crystaline substance which in a dehydrated animal looks a bit like thick emulsion paint or even like powdery chalk. If a tortoise is allowed to become acutely dehydrated, this substance can cause very serious damage to the kidneys and the bladder. It is very important that it is flushed out as quickly as possible. Drinking is therefore very much more important at this stage than feeding.
Many people experience problems in getting tortoises to drink - in fact almost all tortoises will drink provided water is offered in a suitable manner. We recommend placing the entire tortoise in a sink or washing-up bowl filled with about l" of very slightly warm water - less in the case of very small tortoises, a little more for giant specimens. Simply offering a small dish of water to the tortoise is not likely to stimulate a good drinking response, but actually placing it in water is usually successful.
The tortoise must also be kept reasonably warm. An ideal temperature is between 22oC - 25oC. A basking lamp such as a suspended 150W light bulb about 10" above the tortoise will definitely help if the outdoor temperatures are cool and the weather dull - it is absolutely vital that such temperatures are maintained in order to speed up activation of the tortoise's digestive system. As the tortoise awakes certain biological changes take place; one of the most important of these is the release into the bloodstream of a chemical called glycogen, which has been stored in the liver. This provides extra energy to give the tortoise an initial 'boost'. Feeding must take place before this is exhausted, or the animal will begin to decline. The glycogen level can be artificially boosted by providing water with glucose in solution daily - about 2 teaspoons per 250 ml dilution, at about l0-20 ml per day for an average sized animal. Do not continue this therapy indefinitely, or dangerously high blood-sugar levels may be attained.
All tortoises should very definitely feed within ONE WEEK of emerging from hibernation. If they do not there is either,

a) A health problem,


b) A husbandry problem.

If your tortoise is not feeding by itself within one week of waking up, do not delay - consult a veterinary surgeon who has particular experience of reptile husbandry, physiology and treatment. Seek the underlying cause of the problem,and do not be satisfied with non-specific 'vitamin injection' therapy. There is always a logical and very good reason for a tortoise persistently refusing to eat, and generalised vitamin deficiencies are highly unlikely to be responsible. Good diagnostic techniques, combined with an understanding of reptile metabolism and function, will invariably produce a satisfactory answer.
For more details of some common health problems, you should consult the booklet 'Safer Hibernation and your Tortoise' referred to earlier. The following information however is of special relevance to frost damaged cases.

Frozen tortoises

Most tortoises which are subjected to sub-zero conditions die as a result. Some, subject possibly to only peripheral freezing may survive however. These usually sustain at least some physical damage as a result.

The most commonly encountered problem is loss of vision due to the eyes freezing. The actual damage may involve the lenses or the retinas, and the consequences range from partial sight impairment to total blindness. A sight damaged tortoise behaves abnormally:-

  • It may not move around very much. If it does walk, it may bump into objects or fail to recognise its food.

  • It may not react normally to visual stimuli, i.e. a hand waved close to the eyes may not produce the unusual head-retraction response.

  • Sight damaged tortoises usually will not feed themselves.

  • The tortoise may move in circles or hold its head at an unusual angle.

One or more of these symptoms may be present in any combination. If you hibernated your tortoise in a garden shed for example during the extreme cold of last winter and it now displays symptoms like these, there is a very high probability that it has indeed sustained frost damage. Note that this sort of eye damage requires expert diagnosis - without a proper examination using special equipment the eyes may appear to be perfectly normal.


The prognosis is very variable. Some cases recover completely reasonably quickly, other can take years. Some never recover. It very much depends upon the severity and extent of the damage sustained.

Emergency first aid

Dehydration is the most immediate danger. We use Hartmann's solution (an I.V drip compound sodium lactate) given orally at 5% of total bodyweight daily in cases of severe dehydration, reducing as urination begins and the electrolyte balance is restored. High doses of vitamin-A have definitely been shown to assist, particularly in cases of retinal damage and (to a lesser extent) in cases of cataracts on the lenses (ABIDEC is recommended).

Long-term care & maintenance

There are times when it may become necessary to resort to either force or hand feeding; particularly so in the case of sight damage or where a tortoise for some other reason is unable to feed itself. Fortunately tortoises do not find this as distressing as mammals, and from the owner's point of view the procedure is both safe and relatively simple. We classify force-feeding in three basic stages; hand-feeding, which is really no more than an encouragement to feed normally; syringe feeding, which is less time-consuming and where alternative foods can be employed; and finally, stomach-tube feeding, where semi-liquid food matter is introduced directly into the digestive system by means of a tube passed down the animal's throat.


Ideal in animals which are not in a serious condition, and where encouragement to take food into the mouth is all that is required. It is frequently highly successful with sight-damaged animals. Suitable foods: sliced apple, pears, cucumber and melon, lightly dusted with 'VIONATE' or 'ACE-HIGH'. Technique: simply open tortoises mouth, and place food within. To open a tortoise's mouth efficiently and safely, simply grasp animal firmly behind the ear-flaps and jaw with the thumb and second finger of one hand, and firmly force down the lower jaw with the thumb and first finger of the other hand.


Obtain a 5 ml or l0 ml syringe from your veterinary surgeon. Alternatively suitable syringes are often sold in pet stores as baby bird feeders. This method can be used in conjunction with the hand-feeding (above). Suitable foods: liquidised fruits - prepared baby foods are ideal. To these can be added 'VIONATE' or other vitamin supplements. Technique: open tortoise's mouth manually (as above), and simply syringe small quantities of food onto the tongue to be swallowed naturally.


This sounds more drastic and difficult than it actually is. However, care must be taken a) not to cause physical damage, and b) not to spread infection. To avoid the former proceed slowly and gently, to avoid the second sterilise all implements thoroughly in 'MILTON' or 'BETADINE'.
The method is invaluable with very debilitated or sick tortoises who are unable to swallow, or who need food by the quickest possible route. Special diets can be given using this method, and the precise quantity of food taken can be carefully controlled. It is also possible to deliver vitamins, drugs or other substances in exact quantities where required.
Suitable foods: liquids such as plain water, water containing vitamin preparations such as 'VIONATE', 'ABIDEC' or 'ACE-HIGH' in dilution. Semi-solid foods such as plain fruit baby foods, again with added vitamins as required. We are opposed to the use of 'COMPLAN' or similar milk-based high protein food preparations , even in severe cases of undernourishment. We have often noted serious side-effects where these are employed, possibly due to lactose intolerance in some animals, and in other cases we suspect that the high protein input is causing liver and kidney damage. We have, in any case, rehabilitated so many extremely underweight and undernourished tortoises without such materials that we can honestly see no need for them. Our general policy with ALL feeding is LOW protein,HIGH vitamin and mineral content, LOW fat and HIGH fibre. This most closely approximates the diet of a wild tortoise, and we are becoming increasingly convinced that excessive force feeding on unnatural substances is one reason why so many people experience high rates of mortality in such cases whereas our own experience is that such tortoises usually make a very rapid recovery. Technique: it is best if you see this actually demonstrated before attempting to apply it. For the record, however, the technique is as follows:

Obtain a 5 ml or l0 ml syringe, also a dog catheter. Cut to size and fix to end of syringe (length of tube = just over length of tortoise). Lubricate lightly with vegetable oil. Place tortoise in an almost vertical position, extend neck and head fully in a straight line. Gently and slowly pass tube down throat, carefully avoiding the trachea, which is located just behind the tongue. Gently and slowly empty the contents of the syringe into the tortoise.

The amount of food which should be introduced in this fashion has been the subject of some confusion. Our general recommendations are as follows. These figures have been extracted from our case records based upon several hundred animals and we believe them to be highly accurate. Sometimes figures are quoted which are many times in excess of these,but we believe that such over-feeding can prove extremely hazardous, especially to a sick or relatively inactive animal.

  • VERY SMALL TORTOISES Between 75-l20 mm long - 2 ml twice per day semi-solid food.

  • SMALL TORTOISES Between l50-l80 mm long - 3-4 ml twice per day semi-solid food.

  • MEDIUM TORTOISES Between l80-220 mm long - 4-5 ml twice per day semi-solid food.

  • LARGE TORTOISES Between 220-260 mm long - up to l0 ml twice per day. Very large tortoises will require more. Monitor weight daily.

  • Alternatively, 10ml per Kg total bodyweight maximum per 24 hours plus fluids.

Remember, these are approximate guidelines only. If the tortoise has been starved for a long time prior to beginning tube feeding reduce the quantity initially. Liquids should be provided in addition, preferably by inducing the tortoise to drink voluntarily. In cases of severe dehydration, begin hydrating with fluid at a rate of 4-5% of total bodyweight daily. If oedema (puffiness, or swelling) is noted, and urination is not present, reduce level and seek expert advice; a diuretic may be necessary, as kidney function may be impaired. The most common cause of renal distress is due to solid deposits of uric acid literally blocking the kidneys; a combination of diuretic and oral Hartmann's solution is the most effective therapy, assisted by daily lukewarm baths and physiotherapy of the back legs.

IMPORTANT: Note that dog and cat (meat-based) foods must under NO CIRCUMSTANCES be given to mediterranean tortoises which are natural herbivores. In the wild these animals eat herbs, grasses and 'weeds'; the protein and fat content of these is low. Tortoises kidneys are not able to deal with the very much higher blood urea levels produced by digesting high protein foods. The liver of tortoises is similarly unable to cope well with high fat diets.

The products 'VIONATE', 'ACE-HIGH' and 'NUTROBAL' are special mineral supplements which are available from some veterinary surgeons, or in cases of difficulty, by mail-order from the Tortoise Trust. The product 'ABIDEC' is a high potency vitamin-A supplement available from most High Street chemists.

1994 The Tortoise Trust