Genetic testing on OCD and Hydrochephalus is possible by similar labs worldwide. Have a closer look at genetic testing.
(Supplement by Marleen Binder)
Friesians are at risk of spreading dwarfism to other horses. The popularity of friesian crosses, 'warmbloods' and/or 'sporthorses' has widened the spread of the breed's dwarfism gene across other areas of the equine gene pool. These friesian crosses are being bred together or back to full-blooded friesians. Dwarf offspring can and are occurring from these combinations. There are multiple cases of mix-breed dwarfs with friesian blood on both sides.