Ocular abnormalities, tear production, and intraocular pressure findings in Italian holstein calves during their first four weeks of life

The study evaluated ocular abnormalities, Schirmer tear test 1 (STT 1) and intraocular pressure (IOP) values in healthy Italian-Holstein calves from birth to 4 weeks old, and compared STT 1 and IOP with those in adult bovines. Fifty-four calves underwent ophthalmic examination, and STT 1 and IOP assessment were performed within 48 h from birth, then weekly for the first weeks of age. Ophthalmic examination, STT 1 and IOP were assessed in calves' dams. Results for ocular abnormalities were shown as frequency and percentage. Differences in STT 1 and IOP were evaluated according to age, gender, and weight with ANOVA test. A t-test was used to compare calves' STT 1 and IOP at each measurement time with values in the calves' dams. Ocular lesions recorded were: 50 % subconjunctival haemorrhages, 25 % retinal haemorrhages, and 25 % cataract. At birth, remnants of the hyaloid system (51/51, 100 %) and tunica vasculosa lentis (49/51, 96 %) were detected, which regressed completely by the 16th week and 6th week, respectively. No statistical differences were found related to STT 1 and IOP. Statistical differences were observed between IOP as well as STT 1 in calves' dams and calves, for all time points (p-value <0.0001), with higher values in adult bovines. Ocular haemorrhages were the main ocular lesion observed, and cataract was the only congenital ocular abnormality diagnosed. At birth, calf STT 1 and IOP did not change during the first month of life, and adult bovines showed higher IOP and STT 1 compared to neonatal calves.