Parâmetros oftalmológicos e ecobiométricos sob anestesia geral do graxaim-do-campo (Lycalopex gymnocercus) e do graxaim-do-mato (Cerdocyon thous) em cativeiro

Abstract

There are not many studies in the area of ophthalmology of wild animals and understanding the anatomophysiological ocular characteristics of the species is crucial to improve the diagnostic accuracy of the ocular diseases that may affect them. The objective of this study is to gather information about the physiological ophthalmic parameters of the species Lycalopex gymnocercus and Cerdocyon thous, comparing them with each other and with values already published in the literature for wild and domestic canids. Twelve graxaim, six pampa fox and six crab-eating, clinically healthy at the time of evaluation and from two different captives in the central region of the state of Rio Grande do Sul were studied. The procedures performed were: physical and chemical restraint, ophthalmic examination, and complementary tests: Schirmer I tear test (STT I), rebound tonometry (IOP), ultrasonic pachymetry (UP) and ocular ultrasonography (US). Ultrasonography evaluated: anterior chamber depth (ACD); lens thickness (LT); vitreous chamber depth (VCD); and axial globe length (AGL) of both eyes. The data obtained were statistically analyzed, compared using the t test and ANOVA (p < 0.05) in relation to the right and left eyes and animal species. The results obtained were expressed as mean values (mean ± standard deviation) found for Lycalopex gymnocercus: STT I: 3.66 ± 0.88 mm/min, IOP: 11.80 ± 3.05 mmHg, CCT: 549.33 ± 17.85 µm and echobiometric measurements: ACD: 3.30 ± 0.20 mm, LT: 6.60 ± 0.24 mm, VCD: 6.71 ± 0.47 mm and AGL 16.15 ± 0.68 mm. For Cerdocyon thous: STT I: 5.00 ± 2.59 mm/min, IOP: 11.77 ± 3.05 mmHg, CCT: 531.91 ± 58.13 µm and ecobiometric measurements: ACD: 3.45 ± 0.21 mm, LT: 6.39 ± 0.15 mm, VCD: 6.55 ± 0.30 mm and AGL 16.55 ± 0.30 mm. Statistical analyzes for all tests performed did not reveal a statistically significant difference between the eyes (right and left) or in relation to the gender of the animals. Comparison of domestic and wild canids emphasizes the need to use species-specific reference values, and the ocular characteristics of domestic canids should not be restricted to Cerdocyon thous and Lycalopex gymnocercus. The data on normal values and their variations from normality presented and discussed here are benchmarks for more accurate diagnoses of the pathological alterations that survived the visual system of graxains, equally guaranteed for other studies in the area of ophthalmology originating from wild and domestic species.