In Finland pancreatic degenerative atrophy (PDA) is most commonly diagnosed in two breeds of dogs: the German Shepherd and the rough coated Collie. The incidence of PDA in the Collie breed in Finland is close to 1%. Of the 51 cases diagnosed in the Collie breed 44 could be placed in one composite pedigree. An affected dog in that pedigree had, on average, 17 affected relatives distributed in 11 different litters. This clustering strongly suggests that PDA is a hereditary disease. The pedigree data indicate that PDA could be an autosomal recessive trait, although the estimated proportion of affected offspring within litters (0.13) was lower than the expected Mendelian frequency (0.25).