Twenty-three virgin Holstein heifers received uterine inoculations with ureaplasma and were necropsied one to thirteen days later. Three heifers inoculated intracervically were necropsied on days 3, 5 and 11.
Granular vulvitis was produced on average by 3.6 days in fourteen of sixteen uterine inoculated heifers monitored for four or more days. Two cervically inoculated heifers monitored for over four days also developed granular vulvitis by the fourth day.
At necropsy, ureaplasma was recovered from 94% of uterine horn cultures for the first four days postinoculation and 50% during days 5 to 7. Thereafter all uterine cultures were negative. The percentage of positive ureaplasma recoveries from uterine tube flushings was lower than for uterine horns but remained positive for a longer period. By day 7, three of four uterine tube flushings were still positive. No bacterial pathogens were isolated from the uterine horns or uterine tube flushings.
On histopathology 50% of uterine inoculated heifers had endometritis up to six days postinoculation and a slightly higher percentage (58%) had salpingitis. Endometritis was not found in any heifers after day 6. Residual salpingitis was present in one heifer on day 7. Endometritis was present in cervically inoculated heifers necropsied on days 3 and 5 but not on day 11. Salpingitis was not found in any of the three cervically inoculated animals.
The study concluded that some strains of ureaplasma are pathogenic for the upper reproductive tract of the cow and should be considered significant when isolated from cases of granular vulvitis, endometritis or salpingitis.