Foal immunodeficiency syndrome (FIS), originally known as Fell pony syndrome, mainly affects two breeds of ponies: the Fell and Dales. FIS is a recessive genetic disease. Affected foals appear normal at birth, but become weak, and either die or are euthanized by three months of age due to persistent infections caused by immunodeficiency.

foal immunodeficiency syndrome in the fell and dales pony?
yes