Tear Production and Intraocular Pressure in Healthy Canine Neonates

Abstract

Diseases such as keratoconjunctivitis sicca sometimes need lifelong therapy with lacrimomimetics and lacrimostimulants and several forms of uveitis and glaucoma need an aggressive approach when treating. Therefore, when a puppy is presented in a clinical situation, it is necessary to use and interpreted diagnostic tools such as STT and tonometry in a correct way. Previous veterinary research does not provide this information. The aim of this study is to measure the development of basal and total tear production and intraocular pressure in canine neonates.

Eight healthy beagle puppies were used to measure aqueous tear production using a standardized Schirmer Tear Test with (STT1) and without (STT2) the application of topical anesthesia. Also, intraocular pressure (IOP) was measured using a TonoVet® rebound tonometer. These measurements were performed once a week starting from the moment the eyes opened at the age of 2 week until the age of 12 weeks.

STT1, STT2 and IOP values at the age of 2 weeks were all lower than adult values and increased significantly until the age of 9, 10 and 6 weeks, respectively. IOP values decreased significantly between 9-10 weeks of age, increased significantly between 10-11 weeks, and decreased significantly again between 11-12 weeks. There was a significant effect of time on all parameter.