Cashi,If your mare has been dripping milk for a while it would be useful to test the milk for colostrum. And when the foal has been born have an IGG test.
Mares first milk produced is full of antibodies and in the first 24 hours the foal has the best chance of absorbing the colostrum and thus protecting itself from disease and infection. if our mare has been losing milk her colostrum may be compromised.
If a foal does not get good colostrum in the first 24 hours it leave them open to infection.
Possibly you already know this but just hught I would mention it toyou!
Good luck.
Horses are Made to be Horses