Reproductive disease is commonly seen in captive tortoises. In reptiles sexual maturity is governed by size not by age and once a female tortoise has achieved this size she may be stimulated into trying to breed. This means some ‘young’ tortoises can become reproductively active and this means that their owners may be poorly prepared. Females initially start by producing follicles on their ovaries that can become very large. Because they are of a set volume due to the shell this compressed the intestinal tract and anorexia is a typical sign seen in these females. It is currently believed that exposure to a male is required to stimulate the female to ovulate these follicles and produce eggs within the oviducts. This can be due to pheromones or the action of butting, biting or mounting. A brief exposure to a male may stimulate a female to try to breed for a number of years. Thus females with this condition are typically animals isolated from males for a number of years.
This means females can have problems either before they ovulate which is known as pre-ovulatory ova or follicular stasis (POOS) or after ovulation and suffer from egg binding or post-ovulatory egg stasis (POES).
Clinical signs can include anorexia, not passing faeces, straining and collapse. It is important to realise that these animals may well be at a good weight and ratios such as the Jackson Ratio should not be relied upon.
These however are not specific for this condition and veterinary advice should be sought. Radiography should be performed to check for eggs. If none are present a blood sample is likely to be taken next. Females that are reproductively active tend to have elevations in blood calcium and proteins. If this is the case then ultrasound or endoscopy are required to confirm if large numbers of follicles are present. Of course it is possible that other conditions may be identified as a cause for the tortoise’s ailment.
Treatment includes a thorough review of husbandry to make appropriate for a reproductively active female. Animals in follicular stasis may resorb their follicles and medical management can help with this. However if this fails then surgery via the plastron will be required to remove the ovaries.
Animals that have ovulated may respond to medical management. There are a number of causes for egg binding. This may be due to obstruction (for example a bladder stone), mis-shaped eggs or pelvis, a lack of a nesting site or low calcium levels. The vet may wish to run a number of tests to rule these out. Medical management includes the use of hormones to stimulate the tortoise to pass the eggs. This works well in selected cases. It is also possible under sedation or anaesthesia to decompress an egg via the cloaca so it can be passed. An endoscope can also be passed up into the cloaca to check for any further problems.
If these options to do not lead to a resolution of the problem then surgery is indicated. This is typically performed via the plastron. If you wish to breed with the tortoise then a caesarean can be performed leaving the reproductive tract intact. However if you do not wish to breed with the tortoise then both the ovaries and the oviducts can be removed, preventing future problems. There are risks associated with surgery but in good hands these are minimised and if presented early the tortoises recover well. It is likely the vet will wish to place an oesophagostomy feeding tube to provide medications, fluids and nutritional support during her recovery at home. Once she is feeding the tube is removed.
It takes about 12 weeks for initial healing of the surgical wounds and about two years for the shell to completely re-grow.