An investigation on the presence of Chlamydiaceae in Swedish dogs.

BACKGROUND: Bacteria belonging to the family Chlamydiaceae cause a broad spectrum of diseases in a wide range of hosts, including man, other mammals, and birds. Upper respiratory and genital diseases are common clinical problems caused by Chlamydiaceae. Very little is known about chlamydial infections in dogs. Few clinical reports on natural disease in dogs describe mainly conjunctival and upper respiratory signs, and the role of Chlamydiaceae in genital disease is unclear. The present study aimed at studying the prevalence of Chlamydiaceae in healthy dogs and in dogs with genital or upper respiratory disease, including conjunctivitis. METHODS: A real-time polymerase chain reaction (PCR) for Chlamydiaceae was used to detect any chlamydial species within this family. Swab samples from the conjunctiva and the mucosal membranes of the oropharynx, rectum and genital tract were taken from 79 dogs: 27 clinically healthy dogs, 25 dogs with clinical signs from the genital tract and 28 dogs with conjunctivitis. There were 52 female and 27 male dogs. From 7 of the male dogs, additional semen samples were analysed. RESULTS: No Chlamydiaceae were detected from any dog. CONCLUSIONS: Although the number of dogs that was included is limited, the results suggest that cases of Chlamydiaceae in dogs probably are related to infection from other species, and that dogs in general do not harbour Chlamydiaceae. Bacteria belonging to the family Chlamydiaceae do not seem to be of major importance for genital or ocular disease in Swedish dogs.

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

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-17beta and progesterone concentrations. The cervix was open on the first day of standing estrus at a mean estradiol-17beta serum concentration of 87.4+/-21.8 pmol/L (range 14 to >or=180 pmol/L) and closed at an estradiol concentration of 47.1+/-12.4 pmol/L (range 4 to >or=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-17beta 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.

A short sperm-oocyte incubation time ZBA in the dog.

The fertilising capacity of a semen sample can be predicted by evaluation of spermatozoa with in vitro tests. The zona pellucida binding assay (ZBA) accounts for several parameters and interprets the interaction between the spermatozoa and the oocyte. The present study was made in two parts. The aim of the first experiment was to evaluate whether the sperm binding capacity of oocytes varies between different oocyte pools. Each zona binding was made with oocytes from different bitches, using pooled frozen-thawed semen from the same two dogs. The sperm-oocyte complexes were incubated for 1h. There was a significant difference between the six replicates in the number of sperm bound to the zona pellucida (ZP), which indicates that the sperm binding capacity of the ZP differs between oocyte pools. The aims of the second experiment were to evaluate the effects of five different treatments of the spermatozoa on the ZBA, and to evaluate two different incubation times of the sperm-oocyte complexes. ZBAs were made with: fresh semen; semen kept chilled for 1 or 2 days prior to the ZBA; and with semen that had been frozen with or without Equex. The oocytes and spermatozoa were incubated for 1 or 4h. For fresh semen and for semen frozen without Equex, incubation for 1h resulted in a higher number of bound spermatozoa per oocyte than incubation for 4h (P<0.0001). When the effect of the different sperm treatments on the number of spermatozoa bound to the ZP was evaluated, it was found that this number was higher for fresh spermatozoa than for chilled or frozen-thawed spermatozoa both after 1 and 4h of co-incubation (P<0.0001). After 1-h incubation of the sperm-oocyte complexes, spermatozoa chilled for 1 day showed better zona binding capacity than spermatozoa chilled for 2 days, and spermatozoa frozen without Equex had a better zona binding capacity than spermatozoa frozen with Equex. Sperm motility and sperm plasma membrane integrity were higher in fresh than in chilled and frozen-thawed semen. The acrosome integrity was high in all groups of treated semen. In conclusion, 1-h incubation of the sperm-oocyte complexes seems to be sufficient for fresh and chilled semen. Further studies are required to establish the optimal incubation time for sperm-oocyte complexes when frozen-thawed semen is evaluated, as a comparison between semen frozen with Equex and semen frozen without Equex gave different results depending on whether the incubation time was 1 or 4h (in the present study), or 6h [Ström Holst B, Larsson B, Linde-Forsberg C, Rodriguez-Martinez H. Evaluating chilled and frozen-thawed dog spermatozoa using a zona pellucida binding assay.