The mare's udder will begin to fill 2-4 weeks before term. The teats themselves will fill by about 4-7 days before foaling. A clear thick or watery discharge is often present 4-5 days before foaling and when dried is referred to as "waxing of the teats".

The secretion will often become cloudy 1-2 days before foaling however the changes observed are often more important than the signs themselves.

The best predictor of foaling is obtained through milk calcium levels. A commercial water hardness test Softchek¬ works well and is available from many plumbing supplies or through the manufacturer:

Softchek Water Hardness Test Strip Environmental Test Systems PO Box 4659, Elhart, IN 46514