Reproductive Disorders of the Female Reptile
This article forms the basis of the talk given at the Reptile Index, Coventry on 30th November 1997.
An important aim of the captive husbandry of reptile species must be successful reproduction. Reproductive disorders in reptiles are relatively uncommon when compared to other clinical conditions. Although reptiles show various signs of ageing depending upon species, reproductive senility has not been demonstrated conclusively in reptiles; that is, many species keep breeding until they die of old age.
A full history and clinical examination should always be obtained even when the animal presents with what seems to be an ‘obvious’ reproductive disorder to ensure that no other disease is also present. Most reptile disorders, including reproductive ones, are due to poor husbandry practices in some way and so even the most minor detail may be important. It makes the vets job so much easier if the owner keeps an accurate record of all these things on a daily basis. A full clinical examination should follow even in the obvious reproductive problems.
History particularly relevant to reproductive disorders (and associated diseases)
History of stress (dystocia)
poor husbandry (dystocia, salpingitis, abnormal ovarian function)
change in behaviour (dystocia, pseudopregnancy)
poor handling technique (aseptic ovarian inflammation, follicular rupture, egg fracture)
trauma/fighting/ repeated mating (egg rupture/peritonitis, paraphymosis)
sexing with probe (lacerated hemipenes)
Concurrent diseases important in reproductive disorders
metabolic bone disease
The following diagnostic techniques may be usefully employed in the investigation of a reproductive disorder, and in determining the extent to which supportive therapy may be required. It is vital to the health of the patient that concurrent diseases are also diagnosed and treated, especially where these are life-threatening or form part of the aetiology of the reproductive disorder.
a) Blood Analysis
Dehydration must be corrected to stabilise the patient. A low blood glucose indicates starvation or septicaemia. Female reptiles can produce a marked increase in blood calcium when ovulating which serves as a useful marker of that stage of the reproductive cycle. A high white cell count and their level of toxic degeneration provides a measure of the severity of infection. Blood biochemistry enables the elucidation of various organ involvement in the disease.
Culture of infected parts of the reproductive tract allows identification of the disease causing organisms and sensitivity testing allows the selection of appropriate antibiotic therapy.
c) Diagnostic Imaging
The two most common methods are radiography and ultrasonography.
It has been shown that diagnostic (as used by the vet) doses of radiation do not affect reptiles in any way. It has even been shown that they can withstand huge doses of radiation, therefore owners should not be worried about normal radiographs (X rays) harming their reptile even if is carrying young. The radiograph will show the size, shape, position of the eggs or foetuses. Broken eggs can be seen and measurements taken of the pelvis to ensure that the eggs have room to pass out of the pelvis.
The use of radiography only allows visualisation of shelled eggs and laparoscopy does not facilitate the counting and measuring of enlarged follicles and oviductal eggs. Ultrasonographic examination usually requires no anaesthesia and is associated with less risk of trauma and infections that are associated with laparoscopy.
Dystocia is a delay in the normal deposition of the young or eggs. This is perhaps the most common reproductive disorder of reptiles with the highest incidence reported in chelonia.
Predisposing factors include;
a) Lack of suitable nesting place and substrate
Many terrestrial species dig holes for the deposition of their eggs. Aquatic species e.g. terrapins, turtles and crocodilians should be provided with a suitable area of dry land for egg laying. The dry area should be maintained at the correct incubation temperature or the female will not be stimulated to lay there, and the eggs may be produced in the (warmer) water or dystocia may develop. Pyschogenic dystocia may occur, where one dominant female of a group may lay eggs and inhibits the subordinates from laying.
b) Poor husbandry Overfeeding and lack of exercise, resulting in poor muscular condition, a low temperature, lack of hiding place, improper diet, unclean cage, abnormal photoperiod, movement stress or change in environment towards the end of gestation may all cause this problem.
c) Infections of the oviducts caused by retained eggs, or infection spreading from another area.
d) Abnormalities of the eggshell include two or more eggs joined at the shell and very large/misshapen eggs unable to pass through the pelvis
e) Infertile eggs may be resorbed or passed without difficulty, but they may on occasion cause dystocia.
Signs of dystocia
These include anorexia (not eating), regurgitation, straining (this may stop after a period of time), weakness of the hind legs, respiratory distress, oedema of the cranial extremities and cloacal discharge (often foul smelling).
a) Snakes These species may appear normal and healthy until weeks or even months after the end of the gestation period. In some cases, anorexia may be the only sign of illness. The animal may have laid fewer eggs than expected/ predicted from tests, or was seen contracting and then stopped.
b) Lizards/Crocodilians These species may become restless or increase their hiding behaviour. Anorexia, lethargy and weight loss are common.
c) Chelonia/Crocodilia Aquatic species appear restless, swimming in circles, repeatedly stretching out the hind limbs and may swim leaning to one side. Blood from the vent may be noted. After an extended period of dystocia, these symptoms may be replaced by lethargy and weight loss.
If the size and shape of the egg will allow normal passage through the pelvis, it is preferable to encourage the eggs to be passed via the cloaca. Calcium and oxytocin (a hormone) are recommended and should be administered by a vet to induce contractions. After medical therapy, the reptile should be confined to a warm and secluded cage and provided with the species specific environmental requirements for the deposition of young. Warm water baths may induce gravid reptiles to deliver the offspring. If medical treatment does not work then surgery is required.
Egg Yolk Peritonitis
Egg yolk is extremely irritating to the coelomic cavity and produces a severe inflammation which will kill the reptile if not treated quickly. If the reptile becomes ill whilst laying eggs or after laying a few, immediate veterinary attention should be sought. In tortoises, turtles and terrapins this condition has been associated with the animal being turned on its back whilst laying the eggs. The treatment is the surgical removal of the yolk material and copious flushing of the coelomic cavity with warm sterile saline. This treatment is carried out as an emergency procedure and the prognosis is grave.
Irritation or inflammation of the mucosal lining of the oviducts can lead to the production of egg albumin. This material may be passed unaided out of the cloaca as yellow-brown plugs looking like baked beans or may form hard masses within the tract. Surgery is required to remove these masses. A delay in treatment may result in a fatal infection.
Pre-Ovulatory Egg Binding in Iguanas
This is a common problem in green iguanas. The female develops eggs on her ovaries but then, for some reason, does not ovulate. The eggs (or follicles) take up a great deal of room in the abdomen so the female eats less and will eventually starve to death. The iguana presents with lethargy, anorexia, weight loss. On examination and palpation the animal may be thin with an enlarged (often huge) abdomen. Radiography (X-rays) will show many round small masses in the abdomen. Ultrasonography is particularly useful in those cases where the follicles are small in size and difficult to see on radiography. Medical treatment in the form of supportive therapy has been successful. However, many animals are operated on to remove the ovaries to ‘cure’ this condition and prevent this life threatening condition happening again.
As with many reptile diseases, it is important to take the animal to the vet as soon as you suspect illness. Treatment will take much longer (and cost more) the sicker the reptile is. Signs of ill-health include; decreased appetite/ not eating at all, lethargy/ less movement, change in droppings, improper sloughing or not sloughing for a prolonged period.