Mydriatic effect of topically applied rocuronium bromide in tawny owls (Strix aluco): comparison between two protocols.
OBJECTIVE
To evaluate the mydriatic efficacy of a neuromuscular blocking agent (rocuronium bromide) applied topically to only one eye of nocturnal birds of prey and to assess for any general and/or local adverse effects due to its use. Animal studied  Twelve healthy adult tawny owls (Strix aluco) were randomly divided in two groups.


METHODS
Six birds (Group 1) received a single dose of 0.35 mg of rocuronium bromide. The second group of subjects (Group 2) received two doses of 0.35 mg of rocuronium bromide (total 0.70 mg/eye). In both groups, the curariform agent was instilled topically. Pupil diameter was measured with a pupillary gauge in 10 min intervals for a total of 100 min and then every 20 min for a total of 240 min. The assessment of the pupillary light reflex was performed using a standard light source during pupillary size recording.


RESULTS
Maximal pupillary diameter was 11.5 ± 0.3 mm for Group 1 and 11.0 ± 0.6 mm for Group 2 and no statistically significant differences were detected among the two groups. The maximal pupillary diameter was achieved at T80 for Group 1, and at T60 for Group 2. A complete fundus examination was possible on all treated eyes of subjects of both groups. The drug did not cause any noticeable adverse effects in any of the examined birds.


CONCLUSIONS
Results of the present study suggest that a single topical administration of 0.35 mg of rocuronium bromide to the eyes of healthy tawny owls results in sufficient mydriasis to allow for a complete examination of the fundus.
Barsotti
Giovanni
G
Department of Veterinary Clinic, Faculty of Veterinary Medicine, University of Pisa, Pisa, Italy. gbarsott@vet.unipi.it
Briganti
Angela
A
Spratte
Johanna Roselinde
JR
Ceccherelli
Renato
R
Breghi
Gloria
G
D000287:Administration, Topical; D000732:Androstanols / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D015878:Mydriasis / Q000139:chemically induced / Q000662:veterinary*; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000077123:Rocuronium; D020305:Strigiformes
D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium