Comparative vaginal cytology of the estrous cycle of black-footed ferrets (Mustela nigripes), Siberian polecats (M. eversmanni), and domestic ferrets (M. putorius furo).

Vaginal cytology and vulva size were used to characterize the reproductive cycle of female black-footed ferrets (Mustela nigripes), Siberian polecats (M. eversmanni), and domestic ferrets (M. putorius furo). Emphasis was on black-footed ferrets because of the need to breed these critically endangered animals and on Siberian polecats because of the close taxonomic relationship to black-footed ferrets. Vaginal cytology of the 3 species of ferret is similar. Proestrus was characterized by an increasing percentage of superficial epithelial cells and enlargement of the vulva. During estrus, superficial cells were usually greater than or equal to 90% of epithelial cells in the vaginal lavage and after several days were fully keratinized. Neutrophils were more common during all stages of the estrous cycle in domestic ferrets than they were in the other species. Following copulation, percentage of superficial calls in the vagina declined and vulva swelling subsided. Large cells, probably of uterine symplasma origin, were observed in vaginal lavages following whelping or pseudopregnancy. Vaginal cytology is extremely useful in the reproductive management of black-footed ferrets and Siberian polecats. Knowledge of normal vaginal cytology could be applied to the diagnosis of female reproductive abnormalities in all 3 species.     

Evaluation of oral and subcutaneous delivery of an experimental canarypox recombinant canine distemper vaccine in the Siberian polecat (Mustela eversmanni).

We assessed the safety and efficacy of an experimental canarypox-vectored recombinant canine distemper virus (CDV) subunit vaccine in the Siberian polecat (Mustela eversmanni), a close relative of the black-footed ferret, (M. nigripes), an endangered species that is highly susceptible to the virus. Siberian polecats were randomized into six treatment groups. Recombinant canine distemper vaccine was administered s.c. at three dose levels (10(4.5), 10(5.0), and 10(5.5) plaque-forming units [PFU] per dose) and was administered orally by spraying the vaccine into the oropharnyx at two dose levels (10(5.5), 10(8.0) PFU per dose). The sixth group of control animals was not vaccinated. For both routes of administration, two 1-ml doses of reconstituted vaccine were delivered 4 wk apart, followed by live virus challenge 3 wk after the second vaccination. During the challenge, Synder Hill test strain CDV obtained from the National Veterinary Services Laboratory in Ames, Iowa, was administered i.p. Serial blood samples for CDV serology were collected immediately before vaccination and challenge, and 10, 15, and 20 days after challenge. Clinical signs and body weights were recorded up to 32 days after challenge. The survival rate in animals receiving vaccine at the highest oral dose (10(8.0) PFU per dose) was 83.3%. Survival rate was 50.0% in the high s.c. and 60.0% in the medium s.c. groups. All animals in the low-s.c. dose, low-oral dose, and control groups died after exposure. Vaccine dose overall (oral and s.c.) and dose in response to s.c. administration when considered alone were significant predictors of survival (P = 0.006 and P = 0.04, respectively). Among the polecats challenged with virulent virus, those that died became sick sooner than those that survived. Animals that died lost significantly more weight during the 10 days after challenge than did animals that survived (P = 0.02). Survival rates did not differ by sex, founder female status, or breeding pedigree in any of the treatment groups. Survival rates were higher in animals with increasing serum neutralization titers (P = 0.027). This study demonstrates the efficacy of oral delivery of a recombinant CDV vaccine in the Siberian polecat. Further studies are needed to evaluate the safety and efficacy of vectored recombinant vaccines in highly susceptible species and especially in those species in which vaccination with modified live CDV has led to disease.     

The use of ultrasonography for pregnancy diagnosis in the bitch

Twenty-three Greyhound bitches housed at 3 breeding kennels were examined for pregnancy via transabdominal palpation and ultrasonography. Pregnancy was timed from the calculated day of ovulation (day of ovulation = day when first pup was whelped--63), and from a single breeding date (day 0). Starting on day 10 after ovulation, 9 bitches were monitored every 3 days by ultrasonography only, to determine gestational vesicle sizes during gestation and the time when fetal movements and heartbeats could be first detected. The other 14 bitches were examined by ultrasonography and transabdominal palpation on the same day every week, starting on postovulation day 19, to compare the effectiveness of the 2 methods of pregnancy determination. Parturition was the final determinant of pregnancy status. The earliest correct diagnosis of pregnancy was at 18 days after ovulation, but fetal movements and heartbeat could not be identified until days 28 and 35, respectively. Estimation of fetal numbers by ultrasound or palpation was not reliable when there were more than four in the litter. Pregnancy and nonpregnancy were correctly determined by both methods in an increasingly greater number of bitches as gestation progressed, but ultrasonography was more accurate at all stages; on days 19 to 22, 26 to 30, 34 to 38, and greater than 40 after ovulation, correct diagnoses were made in 33%, 42%, 50%, and 75% of the bitches by palpation and in 42%, 67%, 75%, and 83% of the bitches by ultrasonography. The most common error was failure to detect pregnancy by palpation or ultrasonography in bitches with small litters and tense abdominal muscles.(ABSTRACT TRUNCATED AT 250 WORDS)     

Monitoring pregnancy in babirusa (Babyrousa babyrussa) with transabdominal ultrasonography.

This case report documents the application of transabdominal ultrasonography for detecting pregnancy and monitoring fetal development in an unanesthetized, unrestrained babirusa (Babyrousa babyrussa). A 4-yr-old multiparous female babirusa was trained to accept monitoring via transabdominal ultrasonography on a weekly basis postcoitus. Uterine changes associated with pregnancy were first detected at 30 days gestation. Three fetuses were first visualized on day 38, and two of the three fetuses were detectable until term. One fetus failed to develop and appeared to be resorbed between days 80 and 94 of the 161-day pregnancy. The growth of the remaining two fetuses was monitored via cranial measurements taken during the weekly scans throughout the pregnancy. By monitoring a subsequent pregnancy via ultrasound in the same female it was possible to confirm her tendency towards partial resorption, with earliest detection of uterine changes on day 32 and apparent resorption of one of three fetuses at approximately the midpoint of gestation. Two rectal scans of a different female under anesthesia at 28 and 50 days gestation showed stages of development comparable to those visualized transabdominally. However, the transabdominal scans produced better images of the reproductive tract, perhaps because of the close proximity of the pregnant uterus to the abdominal wall.     

Accuracy of Trans-abdominal Ultrasound Pregnancy Diagnosis in Sows using a Linear or Sector Probe

The assessment of an early and reliable pregnancy diagnosis in sows is very important for limiting the number of non-productive days in sow herds. The aim of the present study was to investigate the accuracy of trans-abdominal ultrasound detection for early pregnancy diagnosis in sows under field conditions. Particular attention was paid to the time when a reliable diagnosis can be made, and to possible differences between two commonly used types of scanners. In total, 202 sows from two herds were tested daily with scanners A (linear transducer of 5 MHz) and B (sector transducer of 3.5 MHz) from day 16 until 25 after insemination. Ninety-three percentage of the sows were pregnant 36 days after insemination. Using ultrasound, the first pregnancy could be detected already 18 days after insemination. The sensitivity, specificity and overall accuracy were higher than 95% from day 24 (scanner A) or day 23 (scanner B) post-insemination onwards. The positive predictive values from day 19 onwards were consistently higher than 95% with both types of scanners, whereas the negative predictive values were consistently low for both scanners during the entire period. The sensitivity of testing tended to be slightly lower in sows with a litter size of <10 total born piglets, compared to sows with 10 or more piglets. In conclusion, pregnancy diagnosis in sows using trans-abdominal ultrasound testing can be assessed quickly and reliably under field conditions from day 23 of gestation onwards. Predictive values of positive test results were high in these herds, whereas those of negative test results were low. This implies that sows with a negative test result early in pregnancy should be retested later.     

PREGNANCY DIAGNOSIS WITH ULTRASOUND IN THE DOMESTIC CAT

Ultrasonographic examinations of seven pregnant cats with known breeding dates were made on successive days to establish the identifiable characteristics of pregnancy. Subsequent serial examinations were made to sonographically characterize normal feline prenatal development before 30 gestational days. An enlarged uterus, gestational sacs, and fetal poles were recognized as the features of early feline pregnancy and were first seen at 4, 11, and 15 days, respectively. Cardiac activity was detected earliest on gestational day 16, and recognizable feline fetal morphology appeared at day 26. Fetal membranes became apparent at as early as 21 days of gestation. Generalized fetal movements were first noted at day 28. Live and dead fetuses were compared in utero and marked differences were noted, with dead fetuses rapidly losing previously recognizable morphology. Determination of litter size in each cat could not be done accurately by ultrasound examination. It was concluded that the diagnosis and accurate dating of early pregnancy in the domestic feline may be accomplished with serial ultrasound evaluation.     

Surgical resolution of an ectopic pregnancy in a captive gerenuk (Litocranius walleri walleri).

A full-term ectopic pregnancy was diagnosed in a multiparous, captive gerenuk (Litocranius walleri walleri) following prolonged gestation without parturition. Until 213 days of gestation, fetal viability was determined by transabdominal ultrasound of fetal heartbeat, physical palpation, and visual observations of fetal movements. Survey abdominal radiographs obtained at day 229 of gestation revealed a fully mineralized fetal skeleton in an inappropriate position for parturition. Surgical exploration revealed a full-term, nonviable, male calf contained within fetal membranes attached to the omentum. Histologic examination of the fetal membranes identified lesions compatible with placenta-cotyledon separation occurring prior to surgical removal. No congenital fetal abnormalities or infectious processes were identified. Visual observation of the reproductive tract at the time of surgery revealed no abnormalities or evidence of concurrent pregnancy.     

Accuracy of pregnancy diagnosis and prediction of calving date in red deer using real-time ultrasound scanning

One hundred and sixty-two 18-month-old farmed red deer were used to test the accuracy of pregnancy detection and equations for predicting gestational age. Deer ranging from 30 to 110 days gestation were examined by rectal ultrasonography using a 5 MHz transducer while they were standing. Each scan was recorded on video tape for measurements of uterine diameter, amniotic sac diameters, crown-rump length, head length, head diameter, nose length, chest depth, chest width and placentome base-apex length and width. Fetal age was calculated from the mean of the age predictions derived from each dimension measured on individual deer, for 132 deer between 44 and 110 days gestation. All the hinds diagnosed as pregnant produced offspring, and all the hinds diagnosed as not pregnant failed to produce offspring. Between one and six fetal and uterine dimensions were measurable and the number measurable increased with fetal age. The mean error of calving date prediction in 132 deer was 0.97 days. The error of prediction when measurements were made between 44 and 60 days was 0.44 days, whereas between 61 and 80 days and between 81 and 110 days the errors were +0.95 and +4.72 days, respectively. The estimates of calving date were all within 13 days of the calving date.     

应用B-超对小尾寒羊早期胚胎和胎盘发育的研究

应用B-超监测10只健康的妊娠小尾寒羊,以研究早期胚胎和胎盘的发育过程。结果表明,早期胚体发育在妊娠第6周完成;妊娠30～46d,羊膜囊的短径与胎龄之间存在线性关系(R=0.9528,P<0.01),回归方程为Y=0.565065X 18.751970(Y:妊娠天数,X:羊膜囊宽)。胎盘发育期集中在妊娠前11周,在此期间胎盘突直径也可用于预测胎龄,二者之间的方程式为:Y=4.961429X-16.655714(Y:胎盘突直径,X:妊娠周),相关系数R=0.9882(P<0.01)。     

Early pregnancy diagnosis by means of ultrasonography as a method of improving reproductive efficiency in goats

Eighteen cyclic Shiba goats were used in this study. Estrus was synchronized with a single injection of 125 microg of a synthetic analogue of prostaglandin F(2)alpha (PGF(2)alpha) after detection of at least one corpus luteum by B-mode ultrasonography. Blood samples were collected from each animal on days 0, 7 and 21 post-mating for progesterone assay. Animals in estrus were either allowed to be mated by fertile bucks twice during estrus (group I; n=12) or not at all (group II; n=6). Ultrasonographic examinations were performed transrectally or transabdominally using a real-time B-mode scanner equipped with a 7.5 or 5 MHz transducer. All animals exhibited estrus 56.0 +/- 2.7 h after injection of PGF2alpha. The results show that the accuracy of the progesterone assay in diagnosing pregnancy on day 21 after mating was 80% for pregnancy and 100% for non-pregnancy, retrospectively. Ultrasonographic examinations showed that gestational sac and embryos heartbeats were detected on days 20.2 +/- 0.6 and 24.3 +/- 0.7 of gestation, respectively. Placentomes were detected on day 35.4 +/- 1.0 of gestation as small nodules (0.7 +/- 0.2 cm in size). At two months pregnancy, skeletal structures like skull, thorax and long bones were clear. Biparietal diameter of the skull and length of long bones could be used as an estimate of gestational age. The accuracy of detection of fetal number using real-time B-mode ultrasonography was 91.7% on day 60 of gestation. In conclusion, progesterone assay at day 21 post-mating (cut-off value, 1 ng/ml) can be used for pregnancy diagnosis in goats. However, B-mode transrectal ultrasonography was more efficient due to detection of embryo and confirmation of its viability by heartbeats. In addition, fetal number and gestational age could be determined only by ultrasonography.     

Intercellular junctions in the developing mammalian thymus.

Lymphopoiesis in fetal thymuses of mice and rabbits was studied to try to correlate heterogeneity of lymphocytes with heterogeneity of embryonic origin. The thymuses of fetal mice of 11 to 14 days gestation and of fetal rabbits of 18 and 19 days gestation were examined by electron microscopy. At the time of earliest appearance of lymphoid cells in both species desmosomes were seen on both epithelial and lymphoid cells. These desmosomes persisted for several days, then disappeared from completely differentiated lymphocytes in both species. The similarity between epithelial and lymphoid cells in their earliest developmental stages suggests a common precursor cell for both.     

Ultrasonography of the reproductive tract and early pregnancy in red deer

Thirty-five farmed red deer hinds two years of age or older were observed during mating in April and May and the dates of oestrus and, or, matings were recorded. From immediately before the breeding season and at approximately weekly intervals from the start of mating until all deer were 42 days pregnant, rectal ultrasonographic scans were taken using a 5 MHz linear transducer while deer were held standing in a restraining device. Scans were recorded on video. The vagina and cervix were visible with the lumen appearing as a continuous or intermittent white line, respectively. The non-pregnant uterus was observed in most cases and was immediately anterior to the bladder. Structures resembling ovaries were seen only occasionally. By seven days gestation a 5 mm vesicle could be observed in a few deer, and by day 14, oedema of uterine horns was apparent in some cases. A comma-shaped fetal mass 6 mm long, fetal membranes and placentomes could be observed on day 24. The heart beat was observed on day 28 when the fetus was 10 mm long. Limb buds were observed on day 31 and by day 37 the head with nose and eyes was distinguishable. Fetal movements were first observed on day 42. The accuracy of pregnancy detection before day 20 was 35 per cent, between 21 and 30 days gestation 71 per cent and from 31 to 42 days 98 per cent.     

Practical uses of ultrasound in early pregnancy in cattle

Using a 'real-time' ultrasound scanner with a 3.5 MHz rectal transducer, a herd of 80 Friesian cows were scanned at weekly intervals during early pregnancy to assess the accuracy of pregnancy diagnosis, and the accuracy of twin detection. The growing fetuses were also measured to determine the relationship between crown-rump length and age. The accuracy of detection of pregnancy was inversely proportional to the age of the cow (r -0.967), the accuracy of detection of twinning was 100 per cent and there was strong correlation between fetal crown-rump length and age (r 0.98).     

Association between gestational age and bovine fetal characteristics measured by transcutaneous ultrasound over the right flank of the dairy cow

Objective   To determine bovine fetal characteristics significantly associated with increasing gestational age as measured via transcutaneous ultrasonography over the right flank.
Methods   The length of gestation at date of pregnancy diagnosis via transcutaneous and transrectal ultrasonography was determined for 224 dairy cattle by estimation from subsequent calving dates. A separate dataset was created for each measurable fetal characteristic (i.e. thoracic diameter, abdominal diameter, umbilical diameter, placentome length and placentome height) and risk factors significantly associated with gestational age at pregnancy diagnosis within each dataset, including the fetal characteristic, were identified.
Results   Abdominal diameter was the most frequently observed fetal characteristic and thoracic diameter was the least. Gestational age at pregnancy diagnosis (d) was significantly associated with fetal thoracic diameter (P < 0.01), abdominal diameter (P < 0.01) and umbilical diameter (P = 0.02) when measured via transcutaneous ultrasound. Within each model, sire breed, dam breed, dam age and/or calf sex were also significantly associated with gestational age. Gestational age at pregnancy diagnosis was not significantly associated with either placentome height or length (P > 0.05).
Conclusion   Fetal thoracic diameter, abdominal diameter and umbilical diameter were found to be significantly associated with gestational age between approximate days 73 to 190 of gestation. Transcutaneous ultrasonography may prove a useful method of estimating gestational age in the absence of accurate breeding records.     

Turnover of Dominant Follicles prior to First Ovulation and Subsequent Fertility in Postpartum Dairy Cows

Contents: The ovaries of 64 multiparous Holstein cows were scanned twice weekly by ultrasonographyfrom Day 6 postpartum until 60 days or return to normal estrous cycle, and turnover of dominant follicles in relation to subsequent fertility were determined. The mean (SD) number of days from parturition to detection of the first postpartum dominant follicle (10 mm) was 9.0 0.5, which was predominantly located in the ovary contralateral to previous pregnancy in 54/64 cows. The first postpartum dominant follicle ovulated in 34 cows, failed to ovulate in 18, became cystic in 10, and only 2 were diagnosed as ovarian quiescent which delayed the detection of dominant follicles until days 25 and 30 postpartum. Number of dominant follicles in cows with anovulated first dominant follicle was 2.8. 1.1 prior to first ovulation (range 2–5). Growth and regression of cystic follicles were observed 24 times in 6110 cows, and a total of 20 cystic follicles persisted 32.7 9.0 days (range 18–58 days) except one which persisted for 124 days. Conception rate was 89.5% and postpartum interval to conception within 180 d after calving was 96.7 days in cows detected with less than 3 dominant follicles before first ovulation compared with those of 42.9% and 141 days in cows detected with more than 4 dominant follicles. It is concluded that the number of dominant follicles detected prior to first ovulation varied from I to 5, which positively correlated with ovulation intervals, while only those cows which first ovulated less than 3 dominant follicles resulted in reasonable reproductive performance.     

A COMPARISON OF REAL-TIME ULTRASOUND, PALPATION AND RADIOGRAPHY IN PREGNANCY DETECTION AND LITTER SIZE DETERMINATION IN THE BITCH

Fifty-five bitches were examined once, at different intervals for pregnancy. Manual Papation, B-mode real-time ultrasoungraphy, and radiography were used to confirm pregnancy and to count the number of fetuses present. Predicted numbers were compared to whelping data obtained from owners. Radiography was confined to the last trimester of pregnancy and had an overall accuracy of 100% in pregnancy detection and 93% in correct litter size determination. A proor qualtiy radiograph contributed to the one incorrect count estimate. Ultrasound and palpation were used in all three trimester phases starting 3 weeks post coitus. For pregnancy detection ultrasound was 94% accurate (no false positives) and palpation was 88% accurate (one false positive). For fetal counting, ultrasound was 36% accurate and palpation was 12% accurate. Recommendations for the use of ultrasound and radiography in pregnancy evaluation are reviewed.     

Factors Influencing the Frequency of Pregnancy Loss among Thoroughbred Mares in Hidaka,Japan

Pregnancy loss in mares is thought to be a main problem associated with reproductive efficiency. To clarify the situation of pregnancy loss in Thoroughbred mares in Japan, the occurrence of pregnancy loss before and after 35 days of gestation was investigated with 1,476 Thoroughbred mares in Hidaka, Japan, from 2007 to 2009. Pregnancy loss on days 17-35 was determined by ultrasound examination between 17 and 35 days after the last mating. Follow-up surveys were conducted between 35 days and foaling to determine pregnancy loss on day 35 until foaling in 843 of these mares. Using multiple logistic regression analysis, we assessed the influence of mare age, reproductive status, twin pregnancy reduction, body condition score (BCS), estrus type in foaling mares (foal heat or not), progesterone therapy, and endometrial cysts on pregnancy loss rates on days 17-35 and on day 35 until foaling in this population of mares. The pregnancy loss rates on days 17-35 and on day 35 until foaling were 5.8% and 8.7%, respectively. The overall pregnancy loss rate (day 17 until foaling, including parturient losses) was 14.7%. Risk factors for pregnancy loss included decrease in BCS between 17 and 35 days, <5 BCS at day 35, mating during foal heat, and endometrial cysts. In all, 14.7% of pregnancies were lost between day 17 and birth, contributing significantly to reduced reproductive efficiency in Thoroughbred mares in Japan. These observations indicate that mares should be maintained at high BCS and should be prevented from mating in foal heat to decrease the pregnancy loss rates.     

Comparison of transcutaneous ultrasound over the right flank with transrectal ultrasound for pregnancy diagnosis in the dairy cow

Objective   Evaluate the sensitivity and specificity of transrectal ultrasound and transcutaneous ultrasonography across the right flank between days 31 and 196 of pregnancy in the dairy cow.
Procedure   Pregnancy status and stage of gestation at date of pregnancy diagnosis by transcutaneous and transrectal ultrasonography were determined for 1570 dairy cattle. Sensitivity and specificity values and probabilities of a correct diagnosis for both techniques were determined and compared. Possible effects of gestational age, herd, method of transcutaneous ultrasound diagnosis, cow age, cow and bull breed, and calf sex on the determination of a correct diagnosis of pregnancy status were evaluated for both techniques.
Results   The overall sensitivity and probability of a correct diagnosis of pregnancy status from days 31 to 196 of gestation were significantly higher when using transrectal ultrasound relative to transcutaneous ultrasound over the right flank. However, the sensitivity of transcutaneous ultrasound changed over the course of pregnancy: it was low (7–8%) before day 84, increased to 89% between days 141 and 154, and was close to 100% thereafter. The specificity of both methods did not differ significantly. Herd and gestational age at date of pregnancy diagnosis were significantly associated with making a correct test result using transcutaneous ultrasound, although only the latter predictor was significantly associated with making a correct test result using transrectal ultrasound.
Conclusion   Transcutaneous ultrasound can not be recommended as an accurate method for early pregnancy diagnosis in the dairy cow, particularly on a whole-herd basis. However, if pregnancy testing is undertaken in mid to late gestation, this technique could provide an accurate and rapid alternative to transrectal ultrasound or manual palpation per rectum.     

Relationship of fetal age at conjunctival exposure of pregnant heifers and Brucella abortus isolation

Pregnant heifers were exposed by a conjunctival inoculation with 1 X 10(7) colony-forming units of Brucella abortus strain 2308. At parturition, milk and uterine samples from dams plus samples from dead calves were cultured bacteriologically for Brucella. The logistic regression probability of B abortus isolation increased from 0.22 to 0.90, as fetal age at exposure of heifers increased from 60 to 150 gestation days. Strain 2308 was recovered at parturition from 14 (64%) of 22, 17 (71%) of 24, and all 28 (100%) heifers that were at gestation days less than 127, 127 to 157, and greater than 157, respectively, at time of exposure. The number of infected heifers and the number of samples positive for B abortus were significantly increased as fetal age at exposure of heifers increased from gestation days less than 127 to greater than 157 (chi 2 greater than 10, P less than 0.005).     

Detection of Aleutian disease antibodies in feral American mink in southern England.

Fourteen of 27 American mink (Mustela vison) trapped in the upper Thames region were positive for anti-Aleutian disease antibodies. This demonstration of the occurrence of this viral disease in a feral American mink population suggests that it could threaten populations of at least two protected mustelids, the otter (Lutra lutra) and the polecat (Mustela putorius), and may also play a role in the apparent decline of local mink populations in Britain.