The effect of metritis and subclinical hypocalcemia on uterine involution in dairy cows evaluated by sonomicrometry.

The objective of this study was to examine the effects of metritis and subclinical hypocalcemia on reduction of uterine size in dairy cows using ultrasonography and sonomicrometry. Four piezoelectric crystals were implanted via laparotomy into the myometrium of the pregnant uterine horn of 12 pluriparous Holstein Friesian cows 3 weeks before the calculated calving date. Sonometric measurements were conducted daily from 2 days before parturition (= Day 0) until Day 14 after calving and then every other day until Day 28. Distances between adjacent crystals were expressed in relation to reference values obtained before calving. The diameter of the formerly pregnant uterine horn was measured using transrectal B-Mode sonography starting on Day 10. Cows were retrospectively divided into the following groups: cows without metritis (M-; n = 7), cows with metritis (M+; n = 5), cows with normocalcemia (SH-; Ca > 2.0 mmol/l on Days 1 to 3; n = 5) and cows with subclinical hypocalcemia (SH+; Ca < 2.0 mmol/l in at least one sample between Days 1 and 3; n = 7). Metritis did not affect (P > 0.05) sonometric measurements, but the diameter of the formerly pregnant horn was larger (P ≤ 0.05) between Days 15 and 21 in M+ cows than in M‒ cows. Reduction in uterine length in hypocalcemic cows was delayed (P ≤ 0.05) between Days 8 and 21 compared with normocalcemic cows, but the uterine horn diameter was not related to calcium status. In conclusion, both diseases affected reduction of uterine size until Day 28. Cows with metritis had a larger uterine diameter, possibly attributable to accumulation of lochia, and cows with subclinical hypocalcemia had delayed reduction of uterine length, presumably related to reduction of myometrial contractility.

Retrospective study on the occurrence of porcine circovirus 2 infection and associated entities in Northern Germany.

Porcine circovirus type 2 (PCV 2) represents a widespread, globally occurring pathogen with an increasing number of associated entities. To further elucidate the origin, spread and pathogenesis of PCV2 and associated changes archived material of pigs originating from Northern Germany and submitted for necropsy between 1961 and 1998 were investigated by using in situ hybridisation and polymerase chain reaction. PCV2 was first detected in a pig from 1962. However, incidence of detectable viral DNA and occurrence of PCV2-associated lesions varied substantially in the following years. The overall incidence of PCV2 infection was low between 1961 and 1984 (0-11.7%) and increased between 1985 and 1998 (14.3-53.3%). PCV2-associated pathological changes including postweaning multisystemic wasting syndrome (PMWS) and most likely porcine dermatitis and nephropathy syndrome (PDNS) were first observed in 1985. Selected sequence analyses of PCV2 DNA segments revealed high homology with current virus strains. In summary, findings showed that PCV2 has been present in the pig population in Northern Germany since 1962. This represents worldwide the earliest report about the detection of the PCV2 genome in pigs. Associated lesions such as PMWS and PDNS were not observed before 1985, indicating that virus infection alone does not seem to be sufficient enough to trigger the development of associated entities. Limited sequence analysis revealed no changes in the viral genome thus suggesting that other factors including environmental changes or co-infections with other agents might play a contributing role in the altered virulence of this pathogen and the occurrence of PCV2-associated lesions.

Transrectal Doppler sonography of uterine blood flow during the first 12 weeks after parturition in healthy dairy cows.

The aim of this study was to determine if transrectal colour Doppler sonography of uterine arteries is a useful method to quantify uterine changes during the first 12 weeks after parturition in cows. Examinations were carried out on days 1, 7, 14, 28, 56 and 86 after parturition (day 0) in 42 Holstein-Friesian multiparous dairy cows (mean lactation number: 2.63+/-0.73). Findings obtained by transrectal manual palpation were quantified using scores for uterine size (SUS) graded from 1 to 6. The mean diameter of intrauterine fluid accumulation within the uterine body and the presence of a dominant follicle and/or a corpus luteum were examined using B-mode sonography. Blood flow was measured by determining blood flow volume (BFV) and pulsatility index (PI) of the uterine arteries. Clinical uterine involution was complete on day 28 as demonstrated by transrectal palpation and B-mode sonography. BFV declined (P<0.05) steeply between days 1 and 7 from 4312 ml/min to 1443 ml/min and moderately (P<0.05) to 230 ml/min on day 28. From this time on there were no significant changes (P>0.05) of BFV until the end of the study. The pulsatility index rose from 1.54 on day 1 reaching a peak value of 5.56 on day 28 and decreased (P<0.05) linearly to 3.13 on day 86. The results show that transrectal colour Doppler sonography is an additional tool for examining uterine changes during the first 12 weeks after parturition in cows. While uterine blood flow changes were only demonstrated during the first 4 weeks of the puerperium, the pulsatility index was also suitable to investigate alterations in uterine perfusion during the next 8 weeks after parturition.