MEASUREMENT OF INTRAOCULAR PRESSURE USING REBOUND TONOMETRY IN ANESTHETIZED PERUVIAN FUR SEALS (ARCTOCEPHALUS AUSTRALIS) FROM PUNTA SAN JUAN, PERU.

Ocular disease in pinnipeds under human care is well described, and intraocular pressure (IOP) can be impacted by a variety of ophthalmic conditions. Species-specific reference parameters from clinically normal animals are instrumental for understanding how ophthalmic diseases may impact ocular pressures. IOP measurements were obtained using rebound tonometry from free-ranging Peruvian fur seals (Arctocephalus australis unnamed subspecies) at Punta San Juan, Peru, over a 6-yr period (2010-2016). Retrospective data obtained from 108 (81 adults and 27 neonates comprising 69 females and 39 males) anesthetized fur seals with normal anterior segment ophthalmic examinations was included in the analysis. Differences in IOP from each eye were compared to categorical variables (age, year, sex, restraint) using an independent-samples t test. All univariate results with a significance of P < 0.05 were included in multivariate analysis. Of the 13 general linear models evaluated, the top two for both the right and the left eye included age class when all variables were evaluated simultaneously. Neonates had significantly lower IOP values than adults in both the right eye (17.5 mm Hg; 95% confidence interval [CI]: 14.0-21.1 mm Hg compared to 33.5 mm Hg; 95% CI: 31.0-36.1 mm Hg, respectively) and the left eye (18.4 mm Hg; 95% CI: 14.4-22.5 mm Hg compared to 32.3 mm Hg; 95% CI: 29.3-35.3 mm Hg, respectively). Anesthesia method was not statistically significant (P > 0.05). This is the first report of normal IOP measurements for any fur seal species. Described data can be used to improve diagnosis and management of ocular alterations in pinnipeds.

COMPARISON OF TOTAL LEUKOCYTE QUANTIFICATION METHODS IN FREE-LIVING GALAPAGOS TORTOISES (CHELONOIDIS SPP.).

Reptile hematologic data provide important health information for conservation efforts of vulnerable wildlife species such as the Galapagos tortoise (Chelonoidis spp.). Given the reported discrepancies between manual leukocyte counts for nonmammalian species, two manual leukocyte quantification methods, the Natt and Herrick's (NH) and the Eopette (EO), were compared to white blood cell (WBC) estimates from blood films of 42 free-living, clinically healthy, adult female Galapagos tortoises. To investigate the effects of delay in sample processing, estimated WBC counts and leukocyte differentials were compared for blood films prepared at time of collection under field conditions (T0) to blood films prepared from samples that were stored for 18-23 hr at 4°C in the laboratory (T1). Passing-Bablok regression analysis revealed no constant or proportional error between the NH and WBC estimates (T0 and T1) with slopes of 1.1 and 0.9, respectively. However both constant and proportional errors were present between EO and WBC estimates (T0 and T1) with slopes of 3.1 and 2.7, respectively. Bland Altman plots also showed agreement between the NH and WBC estimates where the points fell within the confidence-interval limit lines and were evenly distributed about the mean. In contrast, the EO and WBC estimate comparisons showed numerous points above the upper limit line, especially at higher concentrations. WBC estimates obtained from T0 and T1 films were in agreement, whereas heterophil and monocyte percentages based on differentials were not. Cell morphology and preservation were superior in T0 blood films because thrombocytes exhibited swelling after storage, becoming difficult to differentiate from lymphocytes. In this study, the highest quality and most reliable hematologic data in Galapagos tortoises were obtained by combining immediate blood film preparation with the NH leukocyte quantification method and a confirmatory WBC estimate from the blood film.