1Bernard G Steinetz. Serum relaxin and progesterone concentrations in pregnant pserdopregnant,and ovariectomized, progestin-treated pregnant bitch -es:Detection of relaxin as a marker of pregnancy[J]. American Journal Veterinary Research, 1989,50(1) :68--71.
2Dumon C. The suppression of lactation during canine pseudopregnancy using cabergoline[J]. Pratique Med-icale & chlrurgicale de 1' Animal de comlagnie,1993,28(5) :573-577.
3Weng BC. Beta - Carotene uptake and changes in ovarian steroids and uterine proteins during the estroua cycle in the canine[J]. Journal Animal Science, 2000,78(5) :1284- 1290.
4Brittain D. Use of surgical intrauterine insemination to manage infertility in a colony of research German Shepherd dogs[J].Laboratory Animal Science,1995,45(4) :404-407.