04/25/2026
IgG testing is one of the most critical steps in ensuring a newborn foal gets the strong start it needs.
When a foal is born, it does not have a developed immune system. Instead, it relies entirely on the antibodies found in the mare’s colostrum (first milk) to protect it from infection. This transfer of immunity happens within the first 12–24 hours of life. If the foal does not receive enough high-quality colostrum, it can result in what’s called Failure of Passive Transfer (FPT), a leading cause of illness and even death in young foals.
That’s where IgG testing comes in.
An IgG test measures the level of antibodies in the foal’s blood, typically around 12–24 hours after birth. This simple test gives us a clear picture of whether the foal has received adequate immunity. If levels are low, early intervention such as plasma transfusion can be life-saving and dramatically improve the foal’s chances of staying healthy.
Why it matters:
• Early detection prevents serious illness
• Protects against infections like pneumonia, diarrhea, and septicemia
• Allows for immediate treatment when needed
• Gives peace of mind that your foal is on the right track
At Star Mountain Equine Reproduction, we strongly recommend IgG testing for every foal. It’s a small step that makes a huge difference in their future.
Healthy foals start with strong immunity 💪🏼🐴
Don’t skip this vital check.
