Horses > Reproduction
The condition your filly has is sometimes referred to as "witch's milk" in the older literature. This phenomenon, which is occasionally observed in most all mammalian species, is due to elevations in lactogenic, or milk producing hormones, in the mare's milk crossing over into the fetal circulation. This condition is generally not associated with any problems and should resolve over time. It is observed in all breeds and isn't unique to Clydesdales.
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