Oral lactose tolerance test in foals: technique and normal values

Area of Science:

• Veterinary Medicine
• Equine Physiology
• Gastroenterology

Background:

• Lactose digestion and absorption are critical for foal health.
• Understanding glucose metabolism following lactose intake is essential for assessing digestive function in young horses.

Purpose of the Study:

• To evaluate oral lactose tolerance in foals of varying ages.
• To determine the impact of age on plasma glucose response after lactose administration.

Main Methods:

• Twenty-five healthy foals aged 1 week to 12 weeks underwent oral lactose tolerance testing.
• Lactose monohydrate was administered via nasogastric tube after a 4-hour fast.
• Plasma glucose concentrations were monitored for 300 minutes post-administration.

Main Results:

• Mean plasma glucose increased from baseline (99.76 mg/dl) to a peak of 176.80 mg/dl by 90 minutes after lactose administration.
• Peak glucose concentrations were observed at 60 minutes in most foals (76%).
• A significant difference in peak glucose was found between 1-week-old and 12-week-old foals, with older foals showing higher concentrations.

Conclusions:

• Foals demonstrate a significant plasma glucose increase following oral lactose tolerance tests.
• Age influences the glycemic response to lactose, with 12-week-old foals exhibiting a more pronounced increase than 1-week-old foals.
• These findings contribute to understanding lactose digestion and glucose metabolism in developing foals.