Lacrimal Secretion Variation and Menace Response Appearance in Healthy Standardbred Foals From Birth to Four Weeks of Age.

This research examines tear secretion and response to threat in newborn Standardbred foals during their first month of life, showing a lower lacrimal secretion in foals compared to their dams, and suggests that this could increase the risk of developing corneal ulcers.

Research Methodology

• The research was conducted on 31 Standardbred foals, housed along with their dams in 4 x 4 m boxes. They were used to measure changes in lacrimal secretion and observe response to threat (menace response) after birth.
• Both dams and foals underwent an ophthalmic examination, with the dams acting as a control group for comparing lacrimal secretion with the newborns.
• The Schirmer Tear Test I (STT I) was administered to the foals within 48 hours of their birth and then weekly for a total of four times. Meanwhile, the dams had an STT I examination before delivery.
• The results from 11 out of the 31 dams were excluded from the findings based on observed signs of ocular adnexa inflammation, as such could potentially influence lacrimal secretion.

Key Findings

• After birth, the tear secretion in the foals as measured by the STT I was lower than the tear secretion in their dams.
• The average STT I in the foals decreased over the course of the study, reaching its lowest at the third measurement timepoint.
• None of the newborn foals showed a response of menace at any observed point, indicating low responsiveness to threat stimuli.

Conclusion and Implications

• Overall, the research concluded that within 48 hours after birth, healthy Standardbred foals have a lower lacrimal secretion than their dams, which does not increase in the first month of life.
• This lower tear secretion, combined with the lack of a menace response, could put the foals at a higher risk of developing corneal ulcers in their early life as these factors can predispose them to this condition.