Four virgin heifers were experimentally inoculated intravaginally with 7 X 10(6) Tritrichomonas foetus, and 2 heifers served as uninfected controls. The durations of infection were 13, 20, 21, and 28 weeks, respectively. An ELISA that used whole T foetus antigen was used to detect anti-T foetus immunoglobulins (IgA, IgG1, IgG2, and IgM) in vaginal, cervical, and uterine secretions, and sera during the course of infection. The vaginal and cervical antibody responses were characterized by significantly increased T foetus-specific IgA and IgG1 at 7 to 9 weeks of infection, whereas uterine IgA and IgG1 responses peaked at 10 to 12 weeks. The antibody response in serum was predominantly of the IgG1 and IgG2 subclasses. In all reproductive tract regions, IgA persisted at least until the time of T foetus clearance, and usually longer. The next most persistent isotype was IgG1, lasting longest in the vagina, then cervix, and for the shortest time in the uterus. In local secretions, IgG2 was seen only transiently, increasing at weeks 13 to 15 in the vagina, and at weeks 10 to 12 in the cervix. Little IgM, relative to that present before infection, was detected in any secretion or serum, although cervical secretions had the greatest amount. Eight to 12 weeks after clearance, the 4 experimental heifers were inoculated intravaginally with 1 x 10(5) T foetus, transient infections (2 to 3 weeks' duration) were established in only 2 of 4 heifers, as determined by culturing of reproductive tract secretions. The lag times of antibody responses during this reinfection were shorter than in the initial infection, and ELISA optical densities were at least as high as during the primary infection, suggesting an anamnestic response.

Vaginal aerobic bacterial flora was studied in 5 healthy bitches before, during, and after a 10-day period of treatment with ampicillin and an equally long period of treatment with trimethoprim-sulfamethoxazole. Blood variables and antimicrobial drug susceptibility also were studied. Bacteria were isolated from all bitches before the first treatment period. Bitches from which only a sparse number of bacteria were isolated had flora that varied from day to day. In most instances when bitches were given an antibiotic to which their vaginal bacterial flora was susceptible, these bacteria were eradicated after only 1 day of treatment. This was true for pasteurellae, streptococci, and, in all but one case, Escherichia coli. Staphylococcus intermedius was more difficult to eradicate, and, although susceptible in vitro, it was unaffected by antibiotic treatment in 1 bitch and it took 7 days to eradicate in another. Eradication of aerobic bacteria in the vagina was total only in the bitch that had sparse flora from the beginning. Bacteria colonized within 0 (in 4/5 bitches) to 4 days after termination of treatment with ampicillin and within 0 (in 4/5 bitches) to 3 days for trimethoprim-sulfamethoxazole. Mycoplasmas emerged during and after both treatment periods, and E coli became apparent during treatment with trimethoprim-sulfamethoxazole. Because mycoplasmas may be genital pathogens in bitches and E coli is a common uropathogen, their appearance should be an argument against widespread use of antibiotics in healthy breeding bitches. Two bitches developed a vaginal discharge during treatment or shortly after. Blood variables did not change during the study, nor did antimicrobial drug resistance of the isolated bacteria.

The present study was carried out to investigate the estrous behavior and vaginal smear after induction of estus with exogenous hormones in the premature, metestrous and anestrous bitches. In a total of 21 bitches(Mixed breed: 16, Jindo breed: 5), from 10 months to 5 years of age and weighing 8 to 15 kg the change of vaginal smear and the estrous behavior before and after induction of estrus was studied. In the treatment A(They were given the PGF2alpha, estrone, estradiol-17beta, PMSG and HCG) proestrus commenced in 10.16+-1.44(Mean+-SEM) days after treatment. The mean duration of proestrus and estrus was 7.50+-1.44 and 13.50+-3.44 days, respectively. In the treatment B(They were given the PMSG and HCG) proestrus commenced in 5.53+-0.59 days after treatment. The mean duration of proestrus and estrus was 6.60+-0.71 and 14.60+-1.14 days, respectively. All of the 6 bitches in the treatment A showed vulval swelling and vaginal discharge. 14 of the 15 bitches in the treatment B showed vulval swelling and vaginal discharge. However, all of the treatment A and B showed male acceptance. The main change of vaginal smear in proestrus and estrus after induction of estrus was an increase in the proportion of anuclear and superficial cells associated with a decrease in small intermediate and parabasal cells. By the estrous behavior and vaginal smear the estrus was induced in all the premature, metestrous and anestrous bitches