Small size and a specific inherited condition

The American Dexter Cattle Association’s 2025 chondrodysplasia guide distinguishes animals without the tested variant, carriers with one copy and animals inheriting two relevant copies. The two-copy condition causes severe fetal abnormalities; a carrier’s shorter limbs are a different genetic outcome.

For a mating of two carriers, the guide gives an expected one-in-four probability of an affected conception. These are probabilities for each conception, not a guarantee that every group of four calves will contain exactly one affected animal.

Appearance does not reliably identify every carrier. Testing supplies information that visual evaluation cannot always provide, allowing breeders to avoid carrier-to-carrier matings for this condition. The guide’s explanation concerns particular dwarfism variants, rather than every possible cause of small stature or every health condition in Dexter cattle. Genetic knowledge supports preservation without treating extreme shortness as the sole measure of breed identity.