Effects of induced endometritis on the life-span of corpora lutea in pseudopregnant rabbits and incidence of spontaneous uterine infections related to fertility of breeding does.

A significant percentage of rabbit does fail to become pregnant after AI. We hypothesized that uterine infections induced by the insemination procedure are related to delayed luteolysis and high progesterone concentrations noted to present at the time of AI. The rabbits, randomly assigned to 4 groups (3 animals/group), were given 0.8 microgram GnRH analogue (Day 0) just prior to infusing the uterus with sterile extender (control group) or with extender inoculated with 0.5, 1, and 2 x 10(6) Pasteurella multocida (treated groups). The effects of treatments on functional life-span of CL were assessed by evaluating plasma progesterone from Day 0 to Day 23 of pseudopregnancy. In treated rabbits, the progesterone profiles closely overlapped those found in controls until approximately Day 14. Thereafter, they varied greatly between animals, but luteolysis was delayed by at least 5-6 d and developed less rapidly than in controls. On Day 21, progesterone concentrations were higher than normal in 4 treated does. In a field survey, vaginal swabs were collected at the time of the second AI from 114 non-pregnant rabbits and those positive to bacteriological culture, were killed humanely 16 d later to collect uterine swabs. Positive uterine swabs were found only in 19 of the 34 does having a positive vaginal swabs and all of them were not pregnant. The most frequent pathogen isolated was S. aureus (50%), followed by E. coli (37.5%) and P. multocida (12.5%). We demonstrated that uterine infection increases the life-span of CL in non-pregnant does and that infections of the genital tract system are quite common among does on breeding farms, probably related to using AI.

The 1993 Italian foot-and-mouth disease epidemic: epidemiological features of the four outbreaks identified in Verona province (Veneto region).

Imported cattle gave rise to an epidemic of foot-and-mouth disease (FMD) in Italy during 1993. Four outbreaks occurred in large housed beef herds in Verona province. Investigations revealed that there were no movements of livestock out of the infected premises and meteorological analyses suggested that the airborne spread of infectious particles had been limited by the anticyclonic conditions. Surveillance was therefore concentrated on the areas immediately surrounding the outbreaks and the infection was prevented from spreading.