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For tortoise, terrapin and turtle care and conservation

FOLLICULAR STASIS AND OVARIECTOMY IN TERRESTRIAL TORTOISES

Stuart McArthur B Vet Med MRCVS (Former Veterinary Liaison Officer)
Newsletter No. 151, Jan/Feb 2003, Question and answer section.

My tortoise hasn’t eaten or passed faeces for several weeks, possibly even months! Despite this my tortoise seems reasonably well, possibly even a little overweight - but this cannot be right - can it?

It certainly sounds suspicious of a significant problem, although without examining the tortoise, listening to how it has been cared for, and possibly even taking samples of blood faeces urine or even radiographs it will be hard for a vet to give specific advice here. Possible explanations for this are many.

Some explanations for prolonged anorexia can apply to either sex. These include things like:

  • Intestinal impaction (obstruction of the gut) as a result of eating bedding/substrate
  • Incorrect lighting, humidity or heat provision (very common in the UK).
  • Blindness, possibly following too cold a hibernation.
  • Obesity as a result of a previous episode of overfeeding or inappropriate diet. In such animals there are occasionally other complications such as hepatic lipidosis (fatty liver)
  • Perhaps the keeper’s assumption that this animal is reasonably well is incorrect and this tortoise is severely dehydrated or suffering from gout our renal failure or nutritional disease. Perhaps it has retained eggs. Perhaps it has an infectious disease.
  • Many wild-caught Testudo horsfieldii have a tendency to aestivate during periods of good weather. This is particularly the case in animals which have become used to annual cycle of such behaviour in the wild, and then following their capture find it hard to lose the habit in captivity as a result of some sort of natural seasonal programming. This situation is potentially normal!

So what about gender related conditions?

This will depend upon the gender in question.

If the tortoise is male and reasonably well cared for he may have an excessive interest in breeding. This is most common in good weather when the tortoise has been well cared for. In the absence of a compatible female to mate, the male tortoise has a tendency to become nomadic. It will pace about the perimeter of any enclosure, no matter how large, in an effort to escape and seek beautiful breedable females. During this time of pacing aggression and escapology, the male tortoise generally has little interest in eating. His hormones are buzzing and it won’t be until the day length shortens and temperatures fall that his behaviour will become more reasonable and his appetite more "normal".

If the tortoise is female then a lot of things can go wrong with the reproductive cycle of mature breedable tortoises.

I am regularly presented with tortoises called Toby, Ben, Tommy etc, which are clearly female, but have been presumed by their keepers to be male for many, many years - as a result of never having laid eggs! These female tortoises are often kept on their own or at least without the company of a male. There is some evidence from this that a lack of contact with a male might have led to reduced ovulation and the lack of egg laying. These females are designed to breed yet clearly this has not happened. Things may have gone wrong with their ovaries and if such an animal has been inappetent and failing to produce faeces for many weeks then follicular stasis (deranged ovarian activity) or egg stasis (egg retention) should be considered possible causes. These animals will require investigation to determine if this is the case or not. The explanation of how this tortoise has previously been cared for and if it has ever bred will be a very useful starting point here. Often female tortoises, which have been well cared for, appear to thrive and get into good shape for breeding. Without the company of a male fertile breeding is not possible. Whilst some isolated female tortoise lay the occasional egg, especially where they have a previous history of breeding and egg laying, many female tortoise do nothing obvious with reproductive function. In many of these animals the ovaries develop large amounts of heavily yolked follicles, which are later to form eggs following ovulation. Without mating and ovulation, these follicles can be vast in number, even in excess of a hundred. They will fill the space of the coelomic cavity making it hard for the tortoise to eat. As the metabolism may be committed to making yolk, high levels of necessary proteins in the blood stream may depress the appetite. Yet such animals will look reasonably well until their metabolism and body reserves to cope with all this become exhausted. This is what we know as "Follicular Stasis"

The vet says he is worried my [female] tortoise has a problem with its ovaries. What sort of tests may he want to do and what sort of costs may be involved in all this?

The tests your vet may wish to perform on an anorexic tortoise will depend upon their level of knowledge and the facilities available to them. It will also depend upon how much the owner of the tortoise is prepared to spend on diagnostic tests to determine the cause of any illness. Blood analysis (See plate F4) is very useful as it provides a gauge of the animal’s overall health. Animals with follicular stasis may have low numbers of white blood cells, High levels of blood proteins, blood calcium, cholesterol and certain enzymes. So a general heath profile would be a good start. These may easily cost anything up to £50 depending upon what is being looked at. However they will help us understand if this is a very sick tortoise or not. What else? Well imaging techniques such as radiography, untrasonography and endoscopy all have a place in assessing the state of the reproductive system of a mature female tortoise. Personally I like ultrasound scanning where it is possible. This doesn’t need an anaesthetic and tells us much about the ovaries. Some animals do not have a shape allowing such scanning. I am aware of other vets who regularly use endoscopy to assess the reproductive tract. This can also be helpful but would involve some form of anaesthesia. It can be useful to "scope" a tortoise prior to any anticipated surgery in order to check that things are as we think internally. Finally radiography (See plate F3) is available to almost all veterinarians and tells us about some conditions. Eggs can easily been seen and so can bladder stones and the level of mineralisation of the skeleton. Pneumonia will show up if the right sort of radiograph is taken and radiography is a useful tool in all chelonians suspected of being poorly. Radiography will not tell us what the ovaries are doing and complements blood tests, ultrasound and endoscope examinations. The cost of the procedures mentioned will vary, often with the skills and experience of the veterinary practice concerned. It is best to ask your practice how much these things will cost before they are undertaken.

My vet says my tortoise needs to be spayed? Can this be right?

Yes. If a diagnosis of follicular stasis has been made, the current treatment of choice appears to be for the tortoise to be spayed (See Plates F1 and F2). Some hormonal and medical treatments have been tried in tortoises with ovarian problems, but none appears to be reliably consistent in their benefits. Surgical spaying appears the quickest and simplest way to restoring the health of female tortoises with deranged ovarian activity.

Are there potential complications associated with spaying a tortoise?

The surgery in most tortoises involves cutting through the shell and removing the ovaries and possibly the oviducts. There will be risks involved in the anaesthetic procedure and in the surgery. Mostly these risks can be reduced, as clinicians familiar with the surgery and anaesthesia will have special tools such as burrs and ventilators to make the procedure simpler. However, The tortoise is having an operation because it is poorly and the operation will ultimately save her life. Therefore once this is understood the risk of surgery is generally acceptable. Most tortoises tolerate their spaying very well unless they have been poorly for some considerable time and have become much weakened by their disease. In such animals, other problems such as gout and kidney disease or upper respiratory tract disease (runny nose) may be apparent. Here the individual risks will need to be assessed by a vet. In the past 40 or so tortoises spayed by this vet less than five have had any serious complications associated with the surgery.

If my tortoise is spayed, what sort of recovery should I expect?

Again this will depend upon how poorly the tortoise has become before it is spayed. It may be that the vet advises to build up the tortoise and resolve any problems such as dehydration or energy deficiency prior to an anaesthetic. Such animals may have a feeding (oesophagostomy) tube inserted and may be hospitalised at the vet’s or in the keeper’s home before the surgery. Whilst a small number of tortoises being spayed will have a prolonged recovery, many will return to eating and normal activity within a small number of weeks. The earlier the condition is treated the truer this is. Animals that are spayed because of horribly degenerate ovaries may have a very degenerate liver. Such animals have obviously been suffering for follicular stasis for several seasons. These animals may take several months to start to rally round and eat and are a greater challenge than early treated cases (See Plates F1 and F2).

What may have made my tortoise have such serious problems with its ovaries? And how could I prevent my tortoise from having problems with its ovaries?

The cause of follicular stasis is still not fully understood, so hard and fast advice cannot yet be given. It may be that some of these tortoises, which have not been bred from, have become very old and are suffering from a geriatric degeneration of their ovaries. Here it may just be an age related thing. However, There are several things which seem to possibly trigger off reproductive activity in animals which have previously been inactive. These include improving the nutrition and care of a previously badly maintained isolated female. As she feels better she gets ready to breed. It may be that a female is temporarily exposed to a male tortoise and something about his presence, be it his behaviour, his pheromones or his amorous advances switches inactive ovaries on. If tortoises mainly require mating to ovulate and produce eggs, it may be that a lack of mating is the cause. Breedable females may not be best kept on their own away from males but should perhaps be mated by a compatible disease free male at regular intervals in order to maintain normal reproductive function… after all this is what generally happens in the wild!

Plate 4:
Here blood is taken from the jugular vein of a tortoise to help assess its overall health. The vacuum on the syringe is exaggerated for demonstration of the technique. Excessive vacuum may damage blood cells.
[Courtesy of Blackwell Publications and Stuart McArthur]
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Plate 3:
Radiography provides an excellent method of determining if shelled eggs are present. Here an abnormal gas filled egg is seen to have crushed and collapsed a second egg, whilst a third egg appears stuck in the cloaca. This tortoise has egg retention, not follicular stasis, and the radiograph allows a veterinarian to develop a suitable treatment plan. This tortoise was successfully treated without surgery.
[Courtesy of Blackwell Publications and Stuart McArthur]
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Plate 1:
This is a relatively advanced case of follicular stasis being spayed. The ovaries show follicles at various stages of degeneration and creation. Many of the follicles are becoming devitalised. These cases may take longer to recover than the example given in Plate 2.
[Courtesy of Blackwell Publications and Stuart McArthur]
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Plate 2:
This is an early case being spayed. Here the ovary shows an inordinately large number of relatively uniform and healthy looking follicles. Such cases generally recover quickly following surgery.
[Courtesy of Blackwell Publications and Stuart McArthur]
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