A survey was performed to determine the number of Newfoundlands that were seen at the Iowa State University College of Veterinary Medicine (ISUCVM) for cranial cruciate ligament disease (CCLD) from January, 1996 through December, 2002. Of the 163 Newfoundlands seen at the ISU-CVM, 22% were diagnosed with CCLD. Further study of Newfoundlands was performed to collect pedigrees and ascertain whether or not individuals that were affected with CCLD or not were related. This information was used to determine the level of inbreeding, and the pattern of inheritance (i.e. recessive, sex-linked) for CCLD. This study found a recessive pattern of inheritance with partial penetrance of 59%. Therefore a dog has a 59% chance of showing signs of the disease when it has the recessive genotype.