[Influence of inbreeding on litter size and the proportion of stillborn puppies in dachshunds].

In the present study, factors influencing the litter size of puppies and the number and the proportion of stillborn puppies per litter were analysed in normally sized German dachshounds. Data was available for litters registered from 1987 to 2002 in the German dachshound kennel club. The records studied here contained 42,855 litters. The mean litter size was 5.22 +/- 2.01 puppies. The proportion of puppies born dead per litter was 6.6%. The age of dam, the puppy's year and month of birth, the hair type and the inbreeding coefficients of the puppies, the sire and the dam were significant on the litter size and the number and the proportion of puppies born dead. The litter size decreased and the percentage of puppies born dead increased with increasing inbreeding coefficients of the puppies, dams and sires. The increase of the inbreeding coefficient of the puppies by 1% led to a 0.06% higher percentage of puppies born dead per litter. The increase of the inbreeding coefficients of the dam and the sire by 1% resulted in 0.02% and 0.007% higher percentages of puppies born dead. Young and older dams had smaller litter size than middle-aged dams. The percentage of puppies born dead per litter increased with an increasing age of the dam. In the recent birth years, the litter size and the percentage of puppies born dead increased in German dachshounds.