Ophthalmological abnormalities in wild European hedgehogs (Erinaceus europaeus): a survey of 300 animals

The evaluation of normal ocular parameters in two breeds of hedgehogs

OBJECTIVES

The purpose of this study was to evaluate conjunctival microflora and measure normal tear production and intraocular pressure (IOP) in two breeds of hedgehogs (long-eared hedgehogs and Brandt's hedgehogs).

METHODS

Forty-eight hedgehogs from two different breeds were chosen for the study. Tear production was measured using the Schirmer tear test (STT) and phenol red thread test (PRTT) in both eyes. IOP was measured using a rebound tonometer. To perform microbiological sampling one drop of tetracaine was instilled in the eyes. Two sterile microswabs were used to collect samples for the microbial and fungal culture. All the microswab samples were transferred in phosphate-buffered saline (PBS) to the laboratory for culture. Two MacConkey and two blood agar media plates were employed for each eye. Oneplate of sabouraud dextrose agar (SDA) was used for the fungal culture for each eye. Standard biochemical tests were performed to identify the isolated organisms.

RESULTS

The mean STT and PRTT values were 1.6 ± 0.1 mm/min and 2.4 ± 0.3 mm/15 s in long-eared hedgehogs and 2.2 ± 0.1 mm/min and 2.5 ± 0.3 mm/15 s in Brandt's hedgehogs, respectively. Mean (SD) Intraocular pressure of right eyes in long-eared hedgehog and Brandt hedgehog were 19.7 ± 1.4 mmHg and 19.2 ± 2.4 mmHg, respectively. In the left eyes of long-eared hedgehog and Brandt hedgehog mean (SD) IOP were 19.8 ± 1.5 mmHg and 19.5 ± 2.1 mmHg, respectively. In long-eared hedgehogs, the most common bacteria were Staphylococcus epidermidis and Bacillus spp. In Brandt's hedgehogs, 24 out of 48 eyes had Staphylococcus epidermidis, which was the most commonly isolated bacterial species.

CONCLUSIONS

This study established reference intervals for IOP, STT and PRTT in hedgehogs and recognised and compared ocular conjunctival microflora in two breeds of hedgehogs.

Repeatability, reproducibility, and agreement of three tonometers for measuring intraocular pressure in rabbits

The aim of this study was to evaluate repeatability, reproducibility, and agreement of three commonly used tonometers in animal research (TonoLab, TonoVet, and TonoPEN AVIA) in a cohort of 24 rabbits. Additionally, the impact of sedation on IOP was investigated in 21 New Zealand White rabbits with the TonoVet tonometer. Repeatability was determined using the coefficient of variation (CoV) for two observers. For the TonoLab (6.55%) and TonoVet (6.38%) the CoV was lower than for the TonoPEN AVIA (10.88%). The reproducibility was highest for the TonoVet (0.2 ± 3.3 mmHg), followed by the TonoLab (0 ± 12.89 mmHg) and lowest for the TonoPEN AVIA (− 1.48 ± 10.3 mmHg). The TonoLab and TonoVet showed the highest agreement (r = 0.85, R² = 0.73). After sedation, a significant IOP reduction (often > 25%) was observed. Our results show that among the three tonometers tested, the TonoVet tonometer is best for use in rabbits while the TonoLab should be avoided. The impact of sedation on IOP was substantial and should be taken into account during experimentation.