Foaling Watch Update: Lady Dyanaformer’s NI Test, Surprise’s Calcium Spike, and Udder Changes Explained
Elusive Surprise – Day 331
Surprise showed a big jump in her mammary secretion calcium levels today. Yesterday morning, her test was still under 20 ppm, but tonight’s reading came back at 125 ppm—a significant increase.
What does this mean?
📈 Rising calcium = foaling preparation is accelerating.
❌ Not quite at 200 ppm = unlikely to foal tonight.
🧪 pH still above 7.2 = no immediate drop signaling birth.
We expect her numbers to keep climbing over the next several days, and we’ll continue testing daily to monitor her progress.
Lady Dyanaformer – Day 324
Dyana was restless Friday night, and over the past 24 hours, she started accumulating mammary secretions. Since she’s only at day 324, she’s trending earlier than last year, so we decided to remove her Caslicks and run her Neonatal Isoerythrolysis (NI) test to ensure her foal can safely nurse.
Good news: Her NI test came back negative, which means:
✅ She hasn’t developed antibodies that could harm her foal.
✅ The foal can safely nurse colostrum right after birth.
✅ No extra management is needed to prevent NI—for now.
Since NI antibodies can develop late in pregnancy, this test is only good for 14 days. If she doesn’t foal within the next two weeks, we’ll need to retest to confirm nothing has changed.
Dyana’s first mammary secretion calcium test yesterday morning came back at 65 ppm—a sign she’s starting to progress, but still a ways from the 200 ppm threshold that indicates imminent foaling. Today, however, her udder has slightly reduced, which meant we couldn’t collect enough secretion to retest. This fluctuation is completely normal, as udder development can shift throughout the day based on hormonal activity, movement, and other factors. As foaling gets closer, her mammary gland changes will become more consistent.
My Audubon – Day 304
No major changes to report today. She still doesn’t have enough udder development to begin testing mammary secretions, which is completely normal for this stage. We’ll continue to keep a close eye on her.
Understanding the Chemtrics Foal Watch Test
For those unfamiliar with how we track foaling progression, we use the Chemtrics Foal Watch test kit to check calcium levels in mammary secretions. The process is simple but effective:
Collect 1.5cc of mammary secretion
Mix with 9cc of distilled water in a test vial
Add 1 drop of indicator solution
Gradually draw the mixture into the test vial, watching for a color change to blue
The color change tells us how much calcium is present:
Below 100 ppm: Unlikely to foal soon
100-200 ppm: Progressing, but likely not within 24 hours
200+ ppm:
54% chance of foaling within 24 hours
84% chance within 48 hours
98% chance within 72 hours
We also check pH using pool test strips, since a drop below 6.5 often occurs right before foaling.
Why Do We Remove Caslicks Before Foaling?
Dyana had her Caslicks removed yesterday, which is a common procedure in broodmares. A Caslicks is a surgical closure of part of the vulva to prevent infections, especially in mares with poor conformation. It’s typically removed a couple of weeks before foaling to ensure an uncomplicated delivery.
NI Test: Why It Matters
The Neonatal Isoerythrolysis (NI) test checks whether a mare has developed antibodies against certain red blood cell antigens that could harm her foal. NI occurs when a foal inherits a red blood cell type from the sire that the mare’s immune system doesn’t recognize. If the mare has developed antibodies, she’ll pass them to the foal through her colostrum, which could cause the foal’s immune system to destroy its own red blood cells—leading to life-threatening anemia.
The test screens for the most problematic antigens—Qa, Aa, Ua, and Ca—with Qa and Aa responsible for 90% of NI cases.
✅ Dyana and Surprise both tested negative, meaning her foal can safely nurse colostrum at birth.
We’ll continue monitoring all three mares closely and will update as they progress!
