Eric R. Pope

Treatment of canine oral squamous cell carcinomas with photodynamic therapy.

Eleven dogs with naturally occurring oral squamous cell carcinomas were treated with photodynamic therapy (PDT) using Photochlor (HPPH) as the photosensitizer. The largest length of the tumours measured in a two-dimensional plane ranged from 0.9 to 6.8 cm. Seven of the tumours invaded underlying bone as determined by radiograph appearance. Photochlor was injected intravenously at a dose of 0.3 mg kg–1. Forty-eight hours later the tumours were treated. Tumours with a surface to base depth of greater than 1 cm were surgically reduced to less than 1 cm. Irradiation with 665 nm light with an energy density of 100 J cm–2was administered. Eight dogs were considered cured with no tumour recurrence for at least 17 months after treatment. Local treatment of oral squamous cell carcinomas with PDT appears to give results similar to those obtained with surgical removal of large portions of the mandible or maxilla. The cosmetic results with PDT are superior to those of radical surgical removal. The new sensitizer, Photochlor, appears effective for oral squamous carcinomas with results similar to those reported for other sensitizers.

A comparison of thiopental, propofol, and diazepam-ketamine anesthesia for evaluation of laryngeal function in dogs premedicated with butorphanol-glycopyrrolate.

Thiopental, propofol, and diazepam-ketamine were compared for evaluation of laryngeal function in dogs. There was no significant difference among the three protocols in time to observation of normal function after drug administration or in the occurrence of swallowing, laryngospasm, or breathing. Jaw tone was significantly greater with diazepam-ketamine. Exposure of the larynx was excellent in five dogs and moderate in three dogs, each receiving thiopental or propofol. Exposure was excellent in one dog, moderate in six dogs, and poor in one dog receiving diazepam-ketamine. Exposure of the larynx for laryngeal function evaluation is more readily accomplished with thiopental or propofol than with diazepam-ketamine.