Lacrimal Secretion Variation and Menace Response Appearance in Healthy Standardbred Foals From Birth to Four Weeks of Age.
Authors: Nardi Samanta, Nuti Martina, Nocera Irene, Sgorbini Micaela, Marmorini Paola, Barsotti Giovanni
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Lacrimal secretion and protective reflexes develop gradually in neonatal foals, yet little was known about the normal timeline for these critical ocular defence mechanisms during the first weeks of life. Researchers measured tear production using the Schirmer Tear Test I (STT I) in 31 healthy Standardbred foals at birth and weekly for four weeks, whilst recording menace response appearance; maternal tear values served as adult comparison data. Foals presented with significantly reduced tear secretion from birth (19.11 mm/min versus maternal baseline of 23.20 mm/min) that continued declining over the study period, reaching its lowest point at three weeks (16.84 mm/min), whilst notably, no foals demonstrated a functional menace response at any assessment point. The absence of both robust lacrimation and protective blink reflexes during this critical early period may substantially elevate corneal ulcer risk in neonates, warranting heightened vigilance from equine professionals managing young foals and suggesting that environmental management—such as stall design and bedding selection—warrants particular attention to minimise corneal trauma during this vulnerable developmental window.
Read the full abstract on PubMed
Practical Takeaways
- •Neonatal Standardbred foals have physiologically lower tear production than adults for at least 4 weeks after birth—monitor corneal health closely during this vulnerable period
- •The absence of menace response in young foals is developmentally normal and does not indicate neurological deficits; assess corneal integrity independently
- •Foals aged 2-4 weeks show the lowest tear production, making this the highest-risk period for corneal ulceration; increase surveillance and consider protective measures if risk factors present
Key Findings
- •Lacrimal secretion in healthy Standardbred foals at birth (19.11 ± 2.49 mm/min) is significantly lower than in adult dams (23.20 ± 1.83 mm/min)
- •Tear secretion continues to decrease during the first month of life, reaching minimum at week 3 (16.84 ± 2.33 mm/min)
- •No foals demonstrated menace response at any observation point during the first month of life
- •Reduced lacrimation combined with absent menace response in early neonatal foals may predispose to corneal ulcer development