Professor Zdenek Knotek (Sid) graduated from Veterinary University Brno in 1982 (with honours). He is head of the Avian and Exotic Animal Clinic, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic. Sid is a founding member and diplomate of the European College of Zoological Medicine, member of ARAV, past-president of EAZWV, president of CAZWV. Sid had teaching activities in Budapest, Copenhagen, Kosice, Ljubljana, Utrecht, Vienna, Warsaw, Purdue (USA), Denpasar (Indonesia). As a founder of reptile medicine specialty he headed the Unit for Birds and Reptiles at Vetmeduni Vienna (2010–2013). Sid supervises courses: Summer School for Exotic Medicine and Surgery (since 2004) and ESAVS courses - Exotic Pets Medicine and Surgery I, II, III (since 2005). His current focus involves medicine and surgery in reptiles, small mammals and birds.

Many conditions can lead to dystocia in snakes.¹ Dystocia (egg binding) can occur under a number of circumstances.² It can be caused by obstructive anatomical or non-obstructive physiological abnormalities.³ Anatomical abnormalities leading to obstructive dystocia in snakes include abnormally shaped eggs, necrotic masses, oviductal stricture, granulomas and neoplasia. Non-obstructive conditions leading to dystocia in snakes may result from obesity, disease of the endocrine system, infection of the oviduct, and inappropriate husbandry conditions.¹ Eggs become adherent to the walls of oviducts if they are not passed at the appropriate time. Clinical signs of dystocia can be very varied and snakes may remain in a reasonable state for weeks or months after the end of the gestation period before becoming ill.²

The problem of effective treatment the non-obstructive dystocia in snakes (which is the most common type of dystocia in these reptiles) is that conservative treatment with oxytocin and some other methods of conservative therapy^2,3 are rarely effective in snakes. It is not common that gentle manipulation of eggs caudally with the coelomic and cloacal palpation is effective in removing retained eggs from snakes, and the method of percutaneous aspiration of yolk (ovocentesis) that would help to collapse the egg proved to be danger for the female snake in clinical practice. Therefore, surgical intervention (e.g., salpingotomy, salpingectomy, or salpingectomy with ovariectomy) is usually required for causes of dystocia in snakes.^4-6 Two classical cases of the effective treatment the dystocia in snakes are presented.

A four-year-old, captive-bred, female Burmese python (Python molurus bivittatus) was presented due to a distension of the caudal part of the body and anorexia. According to the owner the visible swelling of the body developed within last four weeks. On physical examination, the snake was active and in a good condition, weighing 15 kg with a total length of 280 cm. No signs of any of depression were noticeable. The body swelling was soft, and localised in the caudal third of the snake´s body. The rest of the physical exam was unremarkable. Radiographs confirmed a massive enlargement of soft tissue and presence of oval shaped structures in the expected region of the oviducts. Blood was collected from the ventral coccygeal vein (vena coccygea ventralis) for a complete blood count and plasma biochemical analysis. An exploratory coeliotomy was elected to obtain a definitive diagnosis and to perform the effective treatment. After premedication with butorphanol (2 mg/kg IM, Butomidor, Richter Pharma, Austria), anaesthesia of the python was introduced with propofol (5 mg/kg IV, Propofol 1%, Fresenius, Germany). The patient was intubated with an endotracheal tube and kept under inhalant anaesthesia with isoflurane (5-2%, Isofluran Rhodia, Torex Pharma) and oxygen (3 l/min). No local anaesthesia was used. The snake was positioned in right lateral recumbency and fixed to a sterile drape. After skin disinfection with a 70% ethanol solution celiotomy was performed by a left lateral approach where the scutes and scales are in apposition. The incision was made between the second and third row of lateral skin scales. A blind perforation of the muscle layer and the peritoneum was made. Once entrance to the coelomic cavity was attained an extremely distended part of the left oviduct with numerous eggs was observed. The part of oviduct was gently elevated out of the coelomic cavity in order to visualize the dimension of the pathological changes. Two absorbable fixation sutures (Vicryl 4-0, Johnson and Johnson) were made in the wall of the oviduct and the central part of the oviduct wall was incised. The incision was made over eggs. To decrease the distance between the eggs they were be brought very near to the incision from the proximal and distal parts of the oviduct by very gentle massage. Ligatures were situated around supportive veins. Eggs were gently withdrawn from the lumen of oviduct and the mucosa was then washed with body warm sterile saline. The wall of the oviduct was sutured with a single simple continuous pattern of non-traumatising absorbable 4-0 polyglactin 910 (Vicryl® Ethicon, Germany) and the space of pleuro-peritoneal cavity was then evaluated and controlled for any local complications. At the end of the surgical procedure the pleuro-peritoneum and the muscle layer were closed with a single simple continuous pattern of absorbable 4-0 and 3-0 polyglactin (Vicryl® Ethicon, Germany), respectively. Thereafter, the non-absorbable material 3-0 Ethiol (Johnson and Johnson, UK) was used for closing the skin in a continuous everting pattern. The snake tolerated the procedure well and recovered rapidly from surgery. The postoperative treatment included seven administrations of marbofloxacin (10 mg/kg, q 24 h Marbocyl FD, Vétoquinol S.A., France) intramuscularly; five administrations of meloxicam (1 mg/kg IM, q 24 h, Metacam 5 mg/ml inj., Boehringer Ingelheim, Germany) intramuscularly; and five administrations of ringer-lactate (30 ml/kg, SC q 24 h, Riger-Lösung, Fresenius, Germany) and amino acids, vitamins, minerals and glucose (20 ml/kg SC, q 24 h, Amynin, Merial, Germany) subcutaneously. The snake started to be as active as before the salpingotomy within two days and after eight days of hospitalization the patient was released back to the owner. Three months after surgery, according to the owner, the python was healthy, in excellent condition, with a good appetite and without any complications during moulting. The diagnosis was defined as the egg binding - dystocia.

Acknowledgements

This project was partially supported by the Grant of the Faculty of Veterinary Medicine VFU Brno (Specificky vyzkum, FVL 2014). The study was performed together with colleagues Zora Knotkova DVM, PhD; Eva Cermakova Ing. DVM; Silvia Brazorda Romero DVM; and Anna Musilova DVM.

References

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2.  Zwart P. Urogenital system. In: Beynon PH, Lawton MPC, Cooper JE, eds. BSAVA Manual of Reptiles. 1st ed. Cheltenham, UK: BSAVA; 1992:117–127.

3.  Johnson JD. Urogenital system. In: Girling SJ, Raiti P, eds. BSAVA Manual of Reptiles. 2nd ed. Quedgeley, UK: BSAVA; 2004:261–272.

4.  Stahl SJ. Reptile obstetrics. In: Proceedings from the 14th Annual North American Veterinary Conference; 2000: 971–974; Orlando, FL.

5.  Hernandez-Divers SJ. Surgery: principles and techniques. In: Girling SJ, Raiti P, eds. BSAVA Manual of Reptiles. 2nd ed. Quedgeley, UK: BSAVA; 2004:147–167.

6.  Mader DR, Bennett RA, Funk RS, Fitzgerald KT, Vera R, Hernandez-Divers SJ. Surgery. In: Mader DR, ed. Reptile Medicine and Surgery. St. Louis, MO: WB Saunders; 2006:581–630.