Natal patterns among registered dogs in the United States
Tedor, J.B.; Reif, J.S.
Journal of the American Veterinary Medical Association 172(10): 1179-1185
1978
ISSN/ISBN: 0003-1488 PMID: 659298 Document Number: 137509
Data were analysed on 87 880 litters registered with the American Kennel Club during 1971-1973. The breeds with the largest number of registrations were, in descending order, the Poodle, Alsatian, Beagle, Irish Setter, Dachshund and Miniature Schnauzer. The Poodle and Alsatian accounted together for approx. 30% of registered births. Litter size averaged 4.73, ranging from 2.55 for Papillons to 8.43 for Foxhounds. 50.6% of pups born were males , but many breeds varied significantly from the expected 1:1 sex ratio; larger breeds tended to produce more males and smaller breeds more females . Male births were significantly less frequent in Jan. than in other months. The geographical and seasonal distribution of whelping are discussed. Overall, the greatest and smallest numbers of monthly births were in May and Feb. resp. (197 667 and 129 900). A seasonal pattern of whelping was seen in the Basenji, with 41, 23 and 13% of births occurring in Dec., Jan. and Nov. resp.; 17 breeds seemed to have a peak whelping month in autumn instead of spring.