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Reptiles: how to deal with reproductive disease

by
01 June 2015, at 12:00am

JAYNE LAYCOCK reports on her ‘pick of the month’ CPD programme on The Webinar Vet, this one presented by Sean McCormack of Richmond Vets on reproductive disease issues in reptiles

REPRODUCTIVE disease in reptiles is not likely to be an issue that vets in practice encounter frequently but with an increasing trend towards keeping reptiles there is a real niche in the market for vets with a keen interest in “exotic” species.

Even for those of us who would rather steer clear of our reptilian friends it is reasonable to assume we will encounter a reptile with reproductive disease at some point in our career.

This webinar organised by The Webinar Vet is the perfect place to equip yourself with essential information for managing these cases and Sean McCormack delivered exactly what’s needed on a very practical level.

He covered the main reproductive conditions encountered in reptiles including calcium disorders, egg binding and prolapses of the cloaca, oviduct, phallus and hemipenes.

Sean explained that these conditions are seasonal and with spring being an important time for reproductive change, it is the perfect time of year to learn more about this particular topic.

Calcium disorders

With calcium being intrinsically linked to the reproductive system it should come as no surprise that calcium disorders such as metabolic bone disease and hypocalcaemia can develop as a result of the reproductive system.

The follicular phase of the reproductive cycle in female reptiles puts a huge demand on calcium along with foetal and egg production and this makes reproductive females particularly prone to calcium disorders. This must be taken into consideration with any reptile presenting with MBD or hypocalcaemia and the question must always be asked, “Is this patient a reproductively active female?”

Reptiles presenting with MBD may show a number of clinical signs including anorexia, weight loss, weakness, lameness, dystocia and pre-ovulatory stasis. Reptiles suffering from acute hypocalcaemia may present having just fallen off a branch or sitting lifeless at the bottom of their cage.

X-rays should always be performed. In the case of MBD, the transverse processes of the caudal vertebrae cannot be easily visualised, with digits and extremities also appearing more radiolucent.

X-rays are essential as they may also reveal a clutch of eggs or mature follicles. This will firstly demonstrate that this is a reproductive female and secondly indicate that hypocalcaemia or dystocia is likely to recur even after treatment, unless the issues associated with the large egg clutch are dealt with.

Treatment of calcium disorders includes the use of UV light, oral and parenteral Ca gluconate (diluted), as well as correcting any energy deficits using oral or injectable glucose and other types of recovery feeding formula. If an animal presents with acute hypocalcaemia, the owner can be reassured that the problem should be easily corrected over 24-48 hours. However, if clinical signs of MBD are advanced, treatment is likely to be prolonged and may not be successful.

Egg binding

Sean was keen to stress the differences between the two types of egg binding: pre-ovulatory (aka follicular stasis) and post-ovulatory (aka dystocia). Preovulatory egg binding is the development of mature follicles which do not progress to ovulation. Many will resorb without illness if conditions for breeding change in the early stages but in many cases in captivity follicles will persist, leading to inflammation and infection and eventually coelomitis and death.

This is one of the few diseases of captive reptiles often associated with good care and nutrition where affected individuals are often over-conditioned or obese.

Chameleons are particularly prone to follicular stasis as they are designed to produce a large number of eggs at a young age and if over-conditioned appear to be particularly at risk in their first breeding period. Stress, lack of hibernation and underlying disease leading to hormonal imbalances also play a role across reptile species. Pre-ovulatory eggbound reptiles present with anorexia, lethargy and a distended abdomen with an x-ray revealing multiple spherical masses of a soft tissue opacity (a good analogy would be a bunch of grapes).

If treated in the early phase of the disease it may be possible to manage these cases by reducing their feed, providing them with visual access to a male and a nesting site. However, if reptiles have been chronically ill due to follicular stasis, the prognosis is poor without vet intervention.

Spaying and removal of the ovaries will be necessary but great care must be taken as the ovaries lie close to both the vena cava and adrenal gland. Owners must always be warned there is a 5-10% chance of recurrence as removal of all the ovarian tissue can be difficult.

In comparison, post-ovulatory egg binding (dystocia) is the difficulty in giving birth or laying eggs which can be either obstructive or non-obstructive. Obstructive dystocia is seen with over-sized and/or abnormally shaped eggs or with abnormal pelvic structure and/or size; whereas poor nutrition, dehydration, lack of a nesting site and the feeling of insecurity are just some factors predisposing a reptile to nonobstructive disease.

Differentiating between pre- and post-ovulatory egg binding can be achieved by taking an x-ray where instead of seeing spherical masses of soft tissue opacity in pre-ovulatory disease you would see masses which are ovoid in shape and calcified in postovulatory disease.

Treatment of dystocia depends on the underlying cause. In non-obstructive dystocia reptiles need to be hydrated, given the correct nutrition and treated with calcium with or without oxytocin.

Obstructive dystocia can be determined by taking an x-ray and Sean advises taking great care if attempting to manipulate eggs in obstructive disease as often fibrinous adhesions are present and rupture of the oviduct is a real possibility. Ovocentesis via the cloaca or abdominal wall can prove useful in reptiles harbouring large eggs or it may be possible to surgically remove the eggs.

Prolapses

Prolapses of the cloaca, oviduct, hemipenes and phallus are usually caused either by straining or by increased abdominal pressure. Straining can be caused by conditions such as constipation, parasitic disease, dystocia or bladder stones and an increase in abdominal pressure could be caused by follicular stasis, abdominal masses or an increase in respiratory effort. It is also known that calcium disorders, MBD and hypocalcaemia, are intrinsically linked with prolapses.

A prolapse will be obvious to an owner and general first aid advice needs to be given over the phone. In order to minimise trauma and contamination, Sean advises placing the reptile in a small container with some damp tissue. Once presented at the practice, the prolapsed organ needs to be kept moist and the swelling can be reduced by applying a sugar solution. The prolapse can then be replaced under general anaesthesia and a purse string suture placed if required.

Summary

Sean delivered further detail on the diagnosis and management for all the above conditions including providing a number of real case examples.

The Webinar Vet organised yet another webinar which provides practical and useful information, arming us with enough knowledge to deal confidently with a species perhaps not as familiar to us as our furcovered friends.