A worldwide study of the Tollers' registration history in 17 countries shows that about 90% of the genetic diversity present in the founding population has been lost. Tollers born between 1999–2008 have an effective founder size of 9.8, realized effective population size of 18 and an average inbreeding coefficient of 0.26. Breeders are working to prevent losing heterozygosity and to maintain sufficient genetic variations. High kinship value means the breed is not able to maintain a steady level of inbreeding in the long term.