Safety and efficacy of unilateral topical application of rocuronium bromide in healthy scops owls (Otus scops)

Mydriasis in eastern box turtles (Terrapene carolina carolina) following topical administration of proparacaine, 10% phenylephrine, and rocuronium bromide

OBJECTIVE

To determine the mydriatic effect of topical 10% phenylephrine with 10 mg/mL rocuronium bromide and compare this protocol with and without pretreatment with proparacaine.

ANIMALS STUDIED

Ten client-owned pet adult eastern box turtles (Terrapene carolina carolina).

PROCEDURES

All turtles were sedated with 8 mg/kg alfaxalone intramuscularly. One group of four turtles received four 20 μL drops of 10% phenylephrine and four 20 μL drops of rocuronium bromide in the right eye. Another group of four turtles received one standard drop of proparacaine followed by four 20 μL drops of 10% phenylephrine and four 20 μL drops of rocuronium bromide in the right eye. Two control group turtles received four 20 μL drops of saline in the right eye. The left eye was untreated in all turtles. Drops of the same type were separated by 2 min while drops of different types were separated by 5 min. Pupil size was recorded at 0, 15, 30, 60, 90, 120, 180, 240, and 360 min after administration of the final drop.

RESULTS

Treatment with 10% phenylephrine and rocuronium bromide resulted in pupil diameter changes from baseline that were statistically significant from zero at 60, 90, and 120 min in the non-proparacaine group and 90 min in the proparacaine group. The time to peak effect was 90 min in the proparacaine group and 75 min in the non-proparacaine group. Saline-treated pupils in the control group decreased in diameter over the study period. Overall, the treated eyes of the proparacaine group and non-proparacaine group were not different from each other, but both dilated more than the control group.

CONCLUSIONS

Rocuronium bromide and 10% phenylephrine can produce effective and safe mydriasis in eastern box turtles, but there was wide interindividual variation in effectiveness. Proparacaine did not improve the mydriatic effect.

Ophthalmic findings and parameters in Western tiger salamanders (Ambystoma mavortium) from northern Colorado

OBJECTIVE

The aim of this study was to document ophthalmic examination findings and provide reference values for ocular examinations and diagnostics in clinically normal Western tiger salamanders (Ambystoma mavortium) and to evaluate the mydriatic effect of a topical rocuronium bromide and identify any adverse effects.

ANIMALS STUDIED

Sixteen Western tiger salamanders.

PROCEDURE

A complete ophthalmic examination, including intraocular pressure via rebound tonometry [iCare® TonoVet (dog-setting) or iCare® TonoVet Plus (dog-setting)], and fluorescein and Rose Bengal stains, was performed. Ocular surface flora culture swabs were collected for microbiology in four salamanders. Rocuronium bromide (50 μL; 0.01 mg) was administered into each eye in three salamanders. Pupil size and constriction ability were evaluated up to 60 min following administration of rocuronium bromide. Distant visual examination and Doppler heart rate were used to monitor for potential adverse effects of rocuronium bromide.

RESULTS

Observed ocular abnormalities included lipid keratopathy/keratitis (19%; 3/16), parasitic ophthalmitis (19%; 3/16), and cataracts (6.3%; 1/16). A significant difference was found between tonometry with iCare® TonoVet (11.5 ± 2.7 mmHg) versus TonoVet Plus (15.4 ± 3.7 mmHg) (p = .025). Fluorescein and Rose Bengal stains were negative in all salamanders. Ocular surface microbiology revealed a high incidence of contamination from environmental flora, with the most common isolate being unidentified as Gram-negative nonfermenters (75%; 3/4). No significant change in pupil size or constriction ability was observed with rocuronium bromide.

CONCLUSION

This is the first study to document ocular examination findings and diagnostics in captive and wild urodeles and may serve as a reference for clinical assessment and future studies of the Western tiger salamander.

Application of topical rocuronium bromide dosing by ocular size in four species of wild birds

BACKGROUND

Rocuronium bromide has been evaluated as a mydriatic agent in birds, but the species applied were limited and the dose and effect were variable.

OBJECTIVE

This study aims to evaluate the efficacy of topical rocuronium bromide as mydriatics in 4 species according to horizontal palpebral fissure length: Feral pigeon (Columba livia), Common kestrel (Falco tinnunculus), Northern boobook (Ninox japonica), and Eurasian eagle owl (Bubo bubo).

METHODS

A total of 32 birds (8 for each species) were included as pre-releasing examination. Rocuronium bromide was instilled in one randomly selected eye of each bird based on palpebral fissure length criteria (0.5 mg/50 µL for pigeons, 1 mg/100 µL for kestrels and boobook owls, and 2 mg/200 µL for eagle owls). The contralateral eye was used as control and treated with normal saline. After instillation of the drug, pupil diameter, pupillary light reflex, intraocular pressure, heart rate, and respiratory rate were evaluated at 10 min intervals up to 180 min and at 30 min intervals up to 360 min.

RESULTS

Statistically significant mydriasis was obtained in all birds (p < 0.001). However, in boobook and eagle owls, marked mydriasis persisted until 360 min. Side effects including corneal erosion and lower eyelid paralysis were common, which was observed in 26/32 birds. Blepharospasm was also noted during this study. No systemic adverse signs were observed.

CONCLUSIONS

Rocuronium bromide could be a good mydriatics option for 4 species of birds, however, further studies are needed to find lowest effective dose to reduce drug-related side effects.

Use of a Smartphone-Based Device for Fundus Examination in Birds: A Pilot Study

Simple Summary

Eye examination is crucial for therapeutic plans and rehabilitation of birds in wildlife rehabilitation centers. However, fundus examination using classical direct or indirect ophthalmoscopy techniques can be challenging in those species. The aim of the study was to assess the use of a smartphone-based retinal imaging system in birds. Fundus examination was feasible in most bird species examined in this study. The difficulties of carrying out the examination seem to be related to the form of the globe, the color of the iris, and the quality of pupil dilation. Further investigations are necessary to confirm these findings.

Abstract

Ophthalmic examination is essential in the avian triage process in order to apply prompt therapeutic plans and evaluate rehabilitation potential. Fundoscopy is traditionally performed by direct or indirect ophthalmoscopy. Recent technological developments have enabled the design of a small-sized and affordable retinal imaging system to examine the fundus. We investigate the use of a smartphone-based device to realize fundus examination through a prospective cross-sectional observational study. Seventy-seven eyes of 39 birds of 15 different species were evaluated using the smartphone-based device in a rescue wildlife center. Pupil dilation was achieved prior to examination via rocuronium topical application. Assessment of fundus by the smartphone was classified as satisfactory, moderately satisfactory, and unsatisfactory. Fundus examination was also performed with a 20D, 30D, or 78D lens for comparison. Pupillary dilation was satisfactory, moderately satisfactory, or absent in 17, 32, and 28 eyes, respectively. Fundus examination with the smartphone-based device was satisfactory, moderately satisfactory, or unsatisfactory in 44, 15, and 18 eyes, respectively. The feasibility of the fundus examination was affected by the form of the globe; by the quality of pupil dilation; by the color of the iris (images could not be obtained from species with an orange, bright iris); and by the species, with owls (Strigiformes) being the easiest to observe. Based on these findings, fundus examination was feasible in most bird species examined in this study.