Specialeprojekt Mette Olesen (AU), Tobias Wang (AU), Mads Bertelsen

Objective
To characterise the physiological response following surgery in ball pythons (Python regius), and to investigate the effects of 2 commonly used analgesics on this response.

Design
Prospective controlled study.

Sample Population
15 healthy ball pythons.

Procedures
Snakes were randomly assigned to 1 of 3 treatments receiving either meloxicam (0.3 mg/kg), butorphanol (5 mg/kg), or saline (control) preoperatively before a minor surgical procedure (catheterization of the vertebral artery). Catecholamine concentration, cortisol concentration, blood pressure, heart rate and blood gases were measured for 72.5 h postoperatively.

Results 
Heart rate increased significantly during the first hour after surgery, but did not correlate with increased levels of adrenaline and cortisol. The adrenaline level increased briefly at 2.5 h, whereas the cortisol level increased from 1.5 h reaching a maximum at 6.5 h. Blood pressure increased within the first hour, but returned to baseline levels at 2.5 h. After 24.5 h, blood pressure and heart rate, as well as hormone concentrations, remained stable at baseline levels. There were no significant differences in the physiological parameters between the untreated control animals and snakes receiving meloxicam or butorphanol.

Conclusion and Clinical Relevance 
Measurement of physiological parameters provides a means of assessing postoperative pain in snakes. Meloxicam and butorphanol at the dosages used do not decrease the physiological stress response and do not appear to provide analgesic effects in ball pythons.