Skip to main content
SLU publication database (SLUpub)

Research article2006Peer reviewed

Cervical patency during non-ovulatory and ovulatory estrus cycles in domestic cats

Chatdarong K, Lohachit C, Kiartmanakul S, Axner E, Forsberg CL


The cervix functions as a barrier to spermatozoa. Vaginal artificial insemination in cats is, therefore, likely to be successful only at the period of estrus when the cervix is open. This study aimed to define the period of cervical patency in cats in both non-ovulatory and ovulatory estrus cycles. A total of 15 reproductive cycles were studied in six cats during the estrous stage. Cervical patency was monitored with the cats under sedation, by infusing 2 mL of Iohexol contrast medium via a 3.5 French tomcat catheter into the cranial vagina during estrus. Day one of estrus was defined as the first day the cats showed estrous behavior. Non-ovulatory cycles were characterized by a serum progesterone concentration on days 11-15 that was below 5 nmol/L and a normal interestrus interval of 7-14 days. Ovulatory cycles were characterized by a serum progesterone concentration on days 11-15 that was above 5 nmol/L and an interestrus interval that exceeded 30 days. The cervix was considered to be open when the contrast medium was seen to enter the uterus, and to be closed when the contrast medium remained in the vagina. Blood samples were collected at each examination and were assayed for estradiol-17 beta and progesterone concentrations. The cervix was open on the first day of standing estrus at a mean estradiol-17 beta serum concentration of 87.4 +/- 21.8 pmol/L (range 14 to >= 180 pmol/L) and closed at an estradiol concentration of 47.1 +/- 12.4 pmol/L (range 4 to > 180 pmol/L). In the ovulatory cycles the cervix was closed at a progesterone concentration of 9.8 +/- 4.4 nmol/L (range 0.6-28.4 nmol/L). There was no difference in the duration of cervical patency in non-ovulatory and ovulatory cycles (5.5 +/- 1.2 days and 5.2 +/- 0.5 days, respectively) (p > 0.05). The higher overall mean concentrations of estradiol-17 beta seen in the ovulatory cycles than in the non-ovulatory cycles, indicate that a high level of estradiol is necessary for induction of ovulation. Ovulation in 60% of unmated females in this study indicates that the techniques used for evaluation of cyclus stage and cervical opening have the potential to induce ovulation in the cat. This study demonstrates that cervical patency is not influenced by the occurrence of ovulation, but is due to individual variations between cats. (c) 2006 Elsevier Inc. All rights reserved



Published in

2006, Volume: 66, number: 4, pages: 804-810

    UKÄ Subject classification

    Animal and Dairy Science
    Veterinary Science

    Publication identifier


    Permanent link to this page (URI)