Normal Postpartum Involution of the Uterus in the Dog

Ninety-eight reproductive tracts from dogs at different postpartum time periods were used to investigate stages of normal involution. Seventy-eight reproductive tracts were obtained from the field, and 20 obtained surgically for gross and microscopic examination. Plasma progesterone was measured in 22 dogs at various times postpartum.

The uterine horns during the first week postpartum were dilated and edematous. The placental sites were 1.5-3 cm in width, rough, granular and covered with mucus and a few blood clots. By the fourth week the placental sites were thick, grayish-tan and nodular with a few blood clots within nodules. The uterine horns during the seventh week were greatly contracted and the placental sites were narrow and light in color. A few nodules were still present on the surface. By the ninth week the uterine horns were uniform in shape and contracted with a narrow lumen. The placental sites appeared as a narrow brown band.

Histologically the placental sites during the first week postpartum were covered by an eosinophilic staining necrotic mass and a few intact epithelial cells scattered on the surface as an interrupted single layer. Under the necrotic mass, large eosinophilic staining cells in moderate number were scattered throughout the lamina propria of the placental site. These cells were considered to be decidual cells. By the fourth week the placental sites were covered by a large lobulated mass of collagen fibers. The uterine glands were greatly dilated and degenerate, and mononuclear cell infiltration in the lamina propria was pronounced. By the seventh week, large masses of collagen fibers were detached from the surface, and endometrial glands were normal in size and shape. By the ninth week surface sloughing was completed. However, regeneration and replacement of the endometrial lining from the mouth of the uterine glands continued until the end of the twelfth week when the involution process was completed.

The progesterone levels were very low for eight weeks postpartum.

     

Multiple urogenital abnormalities in a Persian cat

A 1.5-year-old female Persian cat was presented for inappetence and azotemia. Ultrasonography and urography revealed multiple abnormalities involving the genitourinary tract, including agenesis of the right kidney and ureter. Gross examination of the abnormal uterus revealed segmental aplasia of right caudal uterine horn causing cranial distension with fluid, a normal left uterine horn, and both normal ovaries. Microscopically, endometrial glands of the right uterine horn were markedly decreased in number. The right uterine horn was hemorrhagic suggesting estrus. This is the first report of this combination of urinary and uterus abnormalities in the veterinary literature.     

A radiographic method for measuring the effect of exogenous hormone therapy on uterine involution in ewes.

Twenty-six pluriparous Suffolk ewes were used to monitor the effects of four hormone treatments on the rate of uterine involution, which was assessed by means of radio-opaque markers and radiography. The close correlation between measurements of the genital tract in live sheep and after slaughter indicated that this method of monitoring uterine involution was acceptably accurate. Uterine involution was complete by about 29 days after lambing. None of the hormone treatments with progesterone, oestradiol-17 beta, prostaglandin F2 alpha or an oxytocin analogue, administered shortly after lambing, had any effects on the rate of uterine involution. There was no correlation between the duration of increased plasma concentrations of 13.14 dihydro-15-keto-prostaglandin F2 (PGFM) and the rate of uterine involution.     

Leukotriene B4 in cows with normal calving, and in cows with retained fetal membranes and/or uterine subinvolution.

Two experiments were performed to study the relationship between leukotriene B4 (LTB4) synthesis and placental separation and uterine involution in the cow. In experiment I, the concentration and synthesis of LTB4 by caruncular tissue was lower in cows with retained fetal membranes (RFM cows, n = 11) than in cows that expelled the fetal membranes normally (NFM cows, n = 19). The presence of bacterial cell wall, especially of alpha-hemolytic streptococci and coagulase positive staphylococci enhanced LTB4 synthesis by allantochorion only in NFM cows. In the RFM group, Escherichia coli lipopolysaccharide decreased allantochorionic LTB4 synthesis. With caruncle, only epidermal growth factor increased LTB4 production in NFM cows. In experiment II, the caruncular and endometrial secretion of LTB4 was lower in cows with subuterine involution (SUI cows, n = 5) or cows with SUI and RFM (SUI+RFM cows, n = 4) than in cows with normal uterine involution (NUI cows, n = 8). This decrease was especially noticeable in the previously gravid horn. In the three uterine involution groups, there were no differences in LTB4 synthesis by caruncular tissue taken from the previously gravid horn. However, progesterone and a bacterial suspension of E. coli reduced the synthesis of LTB4. Estradiol had no effect on LTB4 synthesis at the end of the postpartum period. These results suggest that LTB4 may play an important role in both placental separation and uterine involution in cattle and LTB4 synthesis may be modulated by endocrine and bacterial factors.     

Pregnancy-specific protein B (bPSPB) and progesterone monitoring of post-partum dairy cows with placental retention

The relationship between placental retention, progesterone and pregnancy-specific protein B (bPSPB) was determined in 60 calving Holstein cows. The cows were divided into two groups with placental retention (WPR, n = 16) and no placental retention (NPR, n = 44). Every 4 days, until 60 days post-partum, blood samples were taken and the uteri were checked using ultrasonographv. The puerperal characteristics of NPR and WPR were as follows: mean days of abnormal vaginal discharge: 20.2+/-5 versus 35.6+/-7 (P < 0.01); mean intervals to uterine involution: 21.4+/-3.7 versus 27.6+/-7.6 days (P < 0.01); rate of endometritis: 25 versus 100% (P < 0.01). The mean numbers of oestrus cycles per cow were 1.75+/-0.5 versus 0.85-/+0.9 (P < 0.05) and the mean durations of the first oestrus cycle were 18+/-3.5 versus 16+/-2.1 days (P > 0.05). The mean intervals to first ovulation were 21.5+/-8.4 versus 35+/-19 days (P < 0.01). bPSPB blood concentrations were higher in the WPR group at calving with 955+/-170 versus 750+/-205 ng/ml (P < 0.01) and also during the first 32 days post-partum with 173.68+/-47.3 versus 131.0+/-29.2 ng/ml (P < 0.01). The mean bPSPB half-life was similar in the two groups: 6.9+/-2.5 versus 6.5+/-2.1 days (P > 0.05). In conclusion, it was found that placental retention was associated with a higher rate of endometritis, a lower number of cycles, longer interval to first post-partum ovulation and higher concentration of bPSPB at calving and during the post-partum period. The positive relationship between bPSPB concentrations and calf birth weight and their association with post-partum pathological events may be useful in monitoring animals presenting high concentrations at calving.     

Plasma concentrations of 13,14-dihydro-15-ketoprostaglandin F2 alpha in mares during uterine involution.

Twelve mares were allowed to foal naturally, after which they were monitored to study uterine involution. Starting on day 3 after parturition, the internal genital tract was examined per rectum manually and ultrasonographically every other day for changes in uterine characteristics and ovarian activity. By day 5, gravid and nongravid uterine horns were similar in size, and by day 7, uterine fluid was absent. On day 7 after parturition, endometrial biopsy samples were obtained for histologic evaluation, and uterine swab specimens were obtained for microbiologic culture. Uterine swab specimens from 10 of 12 mares had slight bacterial growth. The uteri of 8 of the 12 mares were histologically involuted by day 7. All mares ovulated 7 to 12 days after parturition. Concentrations of 13,14-dihydro-15-keto-PGF2 alpha (PGFM) were measured in jugular plasma samples obtained daily for 21 days after parturition. Concentrations of PGFM were low by the day after parturition, and there was no significant correlation between uterine involution and PGFM concentrations in these mares. All 12 mares were bred at the first estrus after parturition, and 9 became pregnant.     

Resident Macrophages and Lymphocytes in the Canine Endometrium

Resident immune cells play a major role in endometrial immunity and in tissue homoeostasis. This study aimed to analyse the distribution of macrophages, B and T lymphocytes (respectively, Mø, B‐Lym and T‐Lym) in the canine endometrium throughout the oestrous cycle and in late involution (at the proestrus stage post‐parturition). An immunohistochemistry technique was used on samples from 50 post‐pubertal healthy female dogs, of which five in late post‐partum. The distribution of resident immune cells was analysed in three endometrial layers (superficial, intermediate and basal areas). Mø, B‐Lym and T‐Lym were demonstrated to reside in the endometrium in all the stages of the canine cycle; their numbers being considerably higher during late involution. T‐Lym were scattered in the stroma or amidst the glandular epithelium, constituting the predominant immune cell population in anestrus and proestrus, but decreased in number at all other stages. Endometrial B‐Lym remained fairly constant during the canine cycle, although its numbers were higher in late involution. Mø counts were higher during anestrus compared to the other stages, the cells being displaced into the superficial endometrial layer. Mø demonstrated the highest level in late involution samples, forming small aggregates below the surface epithelium. The number of immune cells was not normally distributed, suggesting the influence of individual factors, such as age or parity, not explored herein due to limited sample availability. Still, this study provides important information for the interpretation of endometrial biopsies in dogs and for the understanding of the increased susceptibility to uterine infection during dioestrus found in the bitch.     

Primary lymphoma of the uterine horn in a Lhasa Apso dog

Primary lymphomas of the canine female genital tract are uncommon tumours. A 9-year-old intact female Lhasa Apso dog presenting with a closed pyometra underwent an ovariohysterectomy (OHE), and the hyperplastic uterine horn along with multiple follicular cysts on the right ovary was examined by histological analysis. Severe infiltration of medium-sized lymphocytes with strong positive immunoreactivity for CD79a and numerous anaplastic features was detected in the unilateral uterine horn, and the dog was diagnosed as having extranodal marginal zone B-cell lymphoma (MZBCL). The present case reports an extremely rare occurrence of primary lymphoma involving the uterine horn in a dog and describes histological characteristics of the tumour for definite diagnosis.     

一例犬子宫蓄脓的诊断及手术治疗

本试验对一例患有子宫蓄脓的西施犬通过询问病史、临床检查、血常规检测、X光及B超检查进行确诊,采用手术法治疗。结果显示,血常规检查发现白细胞、中性粒细胞均增多,X光检测到明显膨大的子宫,B超影像可观察到子宫角为圆腔状的黑色暗区,子宫壁增生变厚产生无回声液性暗区。对于子宫蓄脓的诊断,血常规检查显示体内有炎症变化,X光和B超确诊病犬为开放性子宫蓄脓,对病犬采取手术疗法,彻底切除卵巢和子宫。病犬术后恢复良好。     

Genital lesions and distribution of amastigotes in bitches naturally infected with Leishmania chagasi

Recent reports indicate that Leishmania chagasi has tropism to the male canine genital system, which is associated with shedding of the organism in the semen, supporting the hypothesis of venereal transmission. The aim of this study was to describe the lesions and assess parasite load in the genital system of bitches with canine visceral leishmaniasis (CanL). Symptomatic (n=5) and asymptomatic (n=5) bitches seropositive for CanL were randomly selected at the Center for Zoonosis Control (Belo Horizonte, State of Minas Gerais, Brazil). Five serologically negative, healthy, adult bitches also from the CZC were used as controls. Samples from genital organs (vulva, vagina, cervix, uterine body, uterine horns, uterine tubes, and ovaries), liver, and spleen were histologically evaluated and processed for immunodetection of Leishmania sp., and PCR. The most significant histological change was a mild to moderate vulvar dermatitis, characterized by a histio-plasma-lymphocytic infiltrate. This change was detected in all asymptomatic, four symptomatic, and three uninfected control bitches. In one symptomatic and one asymptomatic bitch intracytoplasmic amastigotes were observed within macrophages in the inflammatory infiltrate. Samples from all the segments of the genital tract were positive in at least one infected animal, in the absence of detectable amastigotes in the tissue. These findings support the notion that L. chagasi does not have genital tropism in the bitch, which is in contrast to our previous findings in naturally infected male intact dogs.     

Uterus unicornis in two mares

Two American Paint Horses, a 3-year-old nulliparous mare and a 7-year-old primiparous mare, presented for recent infertility and a pre-breeding examination, respectively. Examination of the internal reproductive tract of both mares using transrectal palpation and ultrasonography revealed the presence of the cervix, uterine body, left uterine horn and bilateral ovaries. The right uterine horn could neither be palpated nor imaged. The clinical diagnosis of uterus unicornis in one mare was confirmed at necropsy, which revealed combined aplasia of the right uterine horn and oviduct.     

Lack of natural luteolysis associated with uterine horn aplasia in a heifer

A heifer with congenital left uterine horn aplasia had completely normal reproductive cycles when ovulation occurred from the right ovary. Subsequent to ovulation from the left ovary, however, the corpus luteum persisted for months unless prostaglandin F2 alpha was administered. The reproductive tract was examined after slaughter. The left oviduct ended blindly, resulting in fluid-filled cysts. Except for aplasia of the left uterine horn, the reproductive tract appeared to be morphologically normal. This natural model confirms that the luteolytic signal in cattle is sent from the uterine horn to the ipsilateral ovary, but not to the contralateral ovary. Diagnosis of this abnormality required careful palpation per rectum. The normal luteolysis that occurred with exogenous prostaglandin F2 alpha treatment provided misleading information that the heifer was normal.     

Site of Intrauterine Artificial Insemination in the Bitch does not Affect Sperm Distribution within the Uterus

The aim of this study was to evaluate the distribution of frozen–thawed spermatozoa within the uterine lumen and oviducts following intrauterine laparoscopic deposition at two sites. Twelve bitches of unknown reproductive history were randomly distributed into two groups. Semen (3 ml containing 300 × 10⁶ frozen–thawed spermatozoa) was infused at the uterine body (UB group) or at the cranial tip of the left uterine horn. A 22‐G catheter was used to access the uterine lumen. Sperm cell distribution was evaluated after ovariohysterectomy performed 3 h after artificial insemination (AI). There was no difference between groups in mean time to perform AI. Spermatozoa were detected in all uterine segments, including the tip of both horns, but none was detected in the oviduct. The 22‐G catheter facilitated deposition of semen in the uterine lumen, particularly at the UB site. Sperm cell distribution occurred evenly along both horns, independent of the site of semen deposition.     

Pre-breeding Ovaro–Uterine Ultrasonography and its Relationship with First Service Pregnancy Rate in Seasonal-Calving Dairy Herds

The objectives of the study were to characterize an ultrasound reproductive tract scoring (URTS) system to assess suitability for breeding in dairy cows, to describe the prevalence of these scores in commercial dairy herds and to examine their relationship with subsequent fertility. Ultrasound examinations (7797) were performed on 5751 Holstein–Friesian cows prior to breeding in 62 seasonally calving herds over 2 years. Data recorded from images of both ovaries and the uterus were combined into a six point scoring system and the prevalence of cows with cystic ovarian follicles and uterine abscesses and adhesions was recorded separately. The prevalence of ovulatory cows which had completed uterine involution (score 1), or had mild (2) or moderate endometritis (3) was 62.5%, 21.7% and 2.2%, respectively. The prevalence of anovulatory cows with moderate endometritis (4), ovulatory cows with pyometra (5) and anovulatory cows which had completed uterine involution (6) was 3.3%, 2.2% and 8.1%, respectively. The interval between calving and examination differed between cows with each of the scores 1, 2, 5 and 6 (61, 46, 53 and 50 days, respectively, p < 0.05) but not between cows with scores 3 and 4 (37 and 35 days, respectively). Ovulatory cows which had completed uterine involution (score 1) had a higher likelihood of pregnancy to first service than ovulatory or anovulatory cows which had not completed uterine involution (p ≤ 0.10). The prevalence of cows with cystic ovarian follicles or abscesses or adhesions of the reproductive tract was 3.9% and 1.2%, respectively. In conclusion, 29% and 11% of cows in seasonally calving and breeding dairy herds had not completed uterine involution or were anovulatory prior to the mating start date, respectively. Both conditions, detected using a URTS system, significantly reduced first service pregnancy rate in these pasture-based dairy herds.     

Ectopic endometrial tissue in mesonephric duct remnants in bitches

Common congenital embryonic remnants of the canine female genital tract are Gartner cysts originating from mesonephric duct remnants. They can increase in size and lead to adverse effects in fertility and health. In the present study, three cases of mesonephric remnants in bitches were analysed. The mesonephric remnants featured an inner lining endometrium comprising surface epithelium, glands and stroma. This ectopic endometrium was further characterized by immunohistochemistry (oestrogen and progesterone receptors, proliferation activity, cytokeratin, alpha smooth muscle actin, and vimentin) and lectin histochemistry compared with normal uterine endometrium. Furthermore, hypertrophic cells at the serosal site of the uteri were detected and analysed in the same way compared with normal serosa. The ectopic endometrium of case no. 2 mesonephric remnant was comparable with normal endometrium whereas in nos 1 and 3 uteri the ectopic endometrium was reduced in thickness. In all mesonephric remnants, surface and glandular epithelial cells of the ectopic endometrium gave positive immunoreactions for cytokeratin, oestrogen and progesterone receptors and showed lectin-binding patterns comparable with normal endometrium. Some of the stromal cells of the ectopic endometria were smooth muscle actin and vimentin positive. Mitotic activity of the ectopic endometria was comparable with normal endometria. Hypertrophic epithelial cells of the serosal side showed positive reactions to anti-oestrogen receptor and anti-cytokeratin immunohistochemistry as well as lectin binding patterns and mitotic activity comparable with the normal canine serosa. The present study is the first considerable immunohistochemical characterization of canine mesonephric remnants and discusses the appearance of ectopic endometrium in mesonephric remnants.     

Distribution of spermatozoa in the genital tract of artificially inseminated heifers

Eight heifers were artificially inseminated in the uterine body with 160×10⁶ spermatozoa frozen in French mini-straws. The heifers were slaughtered 2 (n = 4) or 12 (n = 4) h after insemination and spermatozoa were recovered by flushing defined segments of the reproductive tract. The efficiency of the method was checked in different ways. There was a slight underestimation of the number of recovered spermatozoa. This underestimation was randomly distributed among heifers and genital tract segments.The total number of spermatozoa recovered was higher at 2 than at 12 h (14.6 vs 0.6 % of the total number inseminated). Most spermatozoa were found in the vagina both at 2 and 12 h after insemination and in greater number at 2 h. In uterus there was a slight decline in the number of spermatozoa recovered at 2 versus 12 h after insemination. The number of spermatozoa recovered from the oviducts were similar at 2 (89.6 × 10³) and 12 h (71.5 × 10³) after insemination. At 2 h spermatozoa were found in all parts of the oviduct with the majority located in the utero tubal junction, whereas at 12 h the most were recovered from isthmus.More spermatozoa were recovered from the left than from the right side of the tract in 6 of the 8 heifers. Only in 1 heifer were the majority of spermatozoa found in the oviduct ipsilateral to the follicle bearing ovary.     

Effect of feeding on reproductive performance in Finnish dairy cows

The effect of 2 types of feeding on the involution of the genital tract and on the fertility was studied in 79 Finnish dairy cows on a research farm. The cows were fed twice a day with home-produced feed in accordance with the Finnish feeding standard. The cows were divided according to the type of feed into a hay-urea group and a silage group. The cows were examined clinically by rectal palpation 3 times a week during 8 weeks postpartum. The time required for the complete involution of uterus and cervix was recorded. The cows in the silage group had a significantly longer time in uterine involution, a lower fertility rate at first insemination and a longer interval from calving to conception than those in the hay-urea group. The pregnancy rate in the first insemination was in the hay-urea group 91% and in the silage group 57%. The interval between calving and the first insemination was shorter in the hay-urea group than in the silage group: 71.4 +/- 10.6 and 74.0 +/- 10.3 days, respectively. The interval between calving and conception was in the hay-urea group significantly (p less than 0.01) shorter than in the silage group; 74.8 +/- 15.1 and 89.5 +/- 24.4 days, respectively.     

Suitability of sonographic evaluation of ovarian dynamics and uterine involution for prediction of postpartum fertility in the cow

To investigate the suitability of sonography for prediction of puerperal fertility, we used 34 cows with normal puerperium. For this purpose, the animals were examined gynecologically and by transrectal sonography at 10-day intervals between day 15 and day 45 p.p. as well as at oestrus, when they were inseminated. We judged uterine involution by diameter and sonographic structure of the uterine cross-section and ovarian activity by the presence of follicles and corpora lutea. Cows, which became pregnant after first insemination p.p., were assigned to group G1 (n = 16) and animals, which failed to conceive, to group G2 (n = 18). The cows of G1 obtained significantly better results concerning both uterine involution and ovarian activity than cows of G2. Thus, diameter of the uterine horn decreased faster and sonographic structure of the uterine cross section returned markedly earlier to the nonpregnant appearance in G1 than in G2. Group G1 also showed a significantly higher percentage of dominant follicles at all examinations. The results of the study show a distinct relationship between uterine involution and ovarian activity and puerperal fertility. But it has also to be resumed that the prediction of fertility for individuals will always be restricted by other reasons causing failure of conception.     

Ultrasonic assessment of puerperal uterine involution in Balady goats

Twenty-six postpartum Balady goats (primiparous, n=13; pluriparous, n=13) were used in this study. One animal of each group was slaughtered on postpartum days 1, 2, 4, 7, 10, 13, 19 and 25; in addition, three control nulliparous goats were slaughtered, and the genital tracts collected. Progress of uterine involution was monitored by repeated ultrasonographic measurements in live animals (primiparous n=6; pluriparous n=6) and measurement of the outer circumference of the uterine horns of slaughtered animals (primiparous n=8; pluriparous n=8). A consistent and progressive decrease in ultrasonographic and outer circumference measurements was found, although faster during the first 7 days postpartum than between days 7 and 19 postpartum. Uterine involution, assessed by the upper limit of the measurements in the nulliparous goats, followed a quadratic pattern and was completed by day 19 postpartum. Ultrasonographically, two elliptical-circular echogenic areas separated by an anechoic line of the stratum vascularis were depicted. Regressing caruncles and fluid in uterine lumen were recognized during the first week postpartum. Further analysis revealed a highly positive correlation between the outer circumference and ultrasonographic measurements. In conclusion, uterine involution in Balady goats was completed by day 19 postpartum and was unrelated to parity. The close association between ultrasound findings and macroscopic involution indicated that ultrasonography can dependably be used to monitor uterine involution under field conditions and can be a suitable alternative to animal slaughter for the study of uterine involution.     

Unilateral optic nerve hypoplasia and hydrocephalus in a Pekingese

A 3-year-old, castrated male Pekingese was examined 2 days after automobile-induced trauma. Multiple pelvic injuries and visual deficits in the right eye were identified. During a subsequent postmortem examination, multiple pelvic fractures were confirmed; however, there was no evidence of head injury. Both globes were bilaterally symmetrical and grossly normal. The intraorbital and intracranial portions of the right optic nerve were threadlike and rudimentary in appearance, while the left optic nerve was grossly normal. Moderate dilatation of the left lateral ventricle was noted. Microscopically the right optic nerve and left nerve tract contained few identifiable nerve fibers. The right optic disc was depressed, and there was thinning of the optic nerve fiber and ganglion cell layers of the retina. No microscopic abnormalities were evident in the left optic nerve, optic disc, retina and right optic tract. The histologic changes in the right eye are consistent with optic nerve hypoplasia. The relationship between the optic nerve/optic tract lesions and the hydrocephalus is unknown.