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Summary A 9-year-old female diamond python (Morelia spilota) was presented with a submandibular swelling. The cytological, macroscopic and histological features of this lesion indicated a diagnosis of branchial (pharyngeal) cyst. Branchial cysts are benign lesions caused by anomalous development of the branchial apparatus and are described rarely in veterinary medicine. We suggest that possible persistence of branchial remnants should be included in the consideration of differential diagnoses for neck masses in adult snakes.

Case report A 5-year-old captive male diamond python (Morelia spilota spilota) was presented with a 1-month history of regurgitation and anorexia and discrete coelomic distention. Physical examination revealed a firm, immobile mass at approximately two-thirds of the snout–vent length from the front of the head. Ultrasound-guided fine needle aspirate biopsy of the mass in the region of the stomach showed necrosis with bacterial infiltration and possibly neoplastic changes. A gastroscopy was conducted, but showed grossly normal gastric mucosa, confirmed by biopsy. On exploratory coeliotomy, it was confirmed the mass involved most of the stomach wall and occluded the gastric lumen. The mass was completely excised and based on histopathology, a diagnosis of gastric adenocarcinoma was made. The snake was found dead 12 h postoperatively, but no specific cause of death was found on postmortem examination. Conclusion Most cases of adenocarcinoma in snakes go undiagnosed. This case report illustrates that the architecture of gastric masses may lead to false-negative gastric biopsy results in snakes with neoplasia.

A 4-yr-old male diamond python (Morelia spilota spilota) was evaluated for multiple black papillated exophytic skin proliferations and signs of pneumonia. The histopathologic structure of the skin biopsy specimens led to the diagnosis of a benign papilloma-like neoplasia. In this case, papillomavirus DNA could be amplified from a biopsy sample with a broad range polymerase chain reaction. Nested pan-herpes polymerase chain reaction was negative, and herpesvirus inclusion bodies were not found. Because of the histologically benign nature of the papilloma, the skin proliferations were left untreated. Ten mo after the first presentation, the skin lesions had regressed almost completely; 34 mo later, only scars from the biopsies were left.

Two captive Australian pythons, one carpet and one diamond python, presented with signs of central nervous system dysfunction. The carpet python was agitated. Its head was tilting and it was incoordinated and had convulsions. It was treated with antibiotics and anthelmintics but was eventually euthanased after failing to respond to therapy. The diamond python had flaccid paralysis of the caudal half. It was not treated and became disoriented and died. Hepatocytes from both pythons contained irregular 2 to 10 micron eosinophilic intracytoplasmic inclusion bodies. The brain of the diamond python was not available for examination. Occasional neurones in the carpet python brain contained similar inclusion bodies and other changes suggestive of viral infection. The clinical signs and histopathological findings in both pythons were consistent with boid inclusion body disease.

Studies of pulsatile systemic arterial hemodynamics were conducted in 10 diamond python snakes to test the hypothesis that body shape--through spatial dispersion of peripheral reflecting sites--is an important determinant of impedance patterns and of pulse wave contour. Findings support the hypothesis. Flow patterns in the aortic roots were similar to those in humans, sheep, dogs, rabbits, and guinea pigs, but in contrast to larger animals, little change in flow contour was seen in other arteries. Pressure wave contour was similar in all systemic arteries from which records were taken with no secondary diastolic wave under any circumstances. Impedance patterns at different sites showed none of the fluctuations that in other animals are attributable to discrete wave reflection. Discrete proximal wave reflection at the confluence of aortic arches was minimal. Data are explicable on the basis of widely distributed peripheral reflecting sites--a consequence of the snake's long and tapered body.

Pulse-wave velocity (PWV) and pulse-wave amplification (PWA) were measured over a proximal [51 +/- 3 (SE) cm] and distal segment (60 +/- 6 cm) of the common descending aorta of 10 anesthetized diamond python snakes (Morelia spilotes). For proximal and distal segments, PWV values were 551 +/- 66 and 921 +/- 116 cm/s and PWA were 0.91 +/- 0.05 and 0.91 +/- 0.06, respectively. PWV for proximal and distal segments were significantly different (P less than 0.02), but PWA were not. PWA for separate harmonics of heart frequency showed no significant increase above unity. Increase of PWV between distal and proximal aorta indicates a reduction in arterial distensibility, a phenomenon that in other species is associated with amplification of the pressure pulse; this was not observed in snakes. Using a simple elastic tube model 56 cm in length and 3 mm in diameter it was found that the amplification produced by the measured PWV changes is offset by attenuation due to viscous damping. Thus similarity of pulse-wave contour throughout the snake's aorta is attributable to the opposing effects of elastic nonuniformity and viscous damping.