Successful artificial insemination in the Asian elephant (Elephas maximus) using chilled and frozen-thawed semen

BACKGROUND

Artificial insemination (AI) using frozen-thawed semen is well established and routinely used for breeding in various mammalian species. However, there is no report of the birth of elephant calves following AI with frozen-thawed semen. The objective of the present study was to investigate the fertilizing ability of chilled and frozen-thawed semen in the Asian elephant following artificial insemination (AI).

METHODS

Semen samples were collected by from 8 bulls (age range, 12-to 42-years) by manual stimulation. Semen with high quality were either cooled to 4 degrees C or frozen in liquid nitrogen (-196 degrees C) before being used for AI. Blood samples collected from ten elephant females (age range, 12-to 52-years) were assessed for estrus cycle and elephants with normal cycling were used for AI. Artificial insemination series were conducted during 2003 to 2008; 55 and 2 AI trials were conducted using frozen-thawed and chilled semen, respectively. Pregnancy was detected using transrectal ultrasonography and serum progestagen measurement.

RESULTS

One female (Khod) inseminated with chilled semen became pregnant and gave birth in 2007. The gestation length was 663 days and the sex of the elephant calf was male. One female (Sao) inseminated with frozen-thawed semen showed signs of pregnancy by increasing progestagen levels and a fetus was observed for 5 months by transrectal ultrasonography.

CONCLUSION

This is the first report showing pregnancy following AI with frozen-thawed semen in the Asian elephant. Successful AI in the Asian elephant using either chilled or frozen-thawed semen is a stepping stone towards applying this technology for genetic improvement of the elephant population.

Low-dose insemination—Why, when and how

The typical dose for insemination into the uterine body of the mare is > 300 x 10(6) progressively motile spermatozoa (PMS) and an insemination dose of > 200 x 10(6) PMS is recommended for frozen-thawed semen. Low-dose insemination techniques allow for a drastic reduction in the numbers of spermatozoa required to achieve pregnancy. Acceptable pregnancy rates can be achieved with doses ranging from 1 to 25 x 10(6) PMS in volumes ranging from 20 to 1000 microL. Two techniques have been described: hysteroscopic insemination and transrectally guided deep horn insemination using a pipette. Similar pregnancy rates can be attained by either method when 5 x 10(6) PMS are used. Hysteroscopic insemination may provide an advantage when the dose is 1-3 x 10(6) PMS. These techniques have the potential to make more efficient use of frozen-thawed or sex-sorted semen from certain stallions. The use of low-dose insemination to improve fertility of infertile stallions warrants further investigation.

Transcervical endoscope-guided emptying of a transmural uterine cyst in a mare

An 18-year-old Friesian mare with a large intrauterine cyst was examined by transrectal ultrasonography. There were several small to moderately sized intraluminal endometrial cysts, one of which connected via the myometrium to a large subserosal cyst, thereby effectively forming a 'transmural' cyst complex. During a videohysteroscopy, the intraluminal part of this transmural cyst was removed by electrocoagulation via a polypectomy snare. It was then possible to drain the large subserosal part of the cyst into the uterine lumen by transrectal massage, thereby confirming the presence of the transmural connection.

First Established Pregnancies in Mediterranean Italian Buffaloes (Bubalus bubalis) Following Deposition of Sexed Spermatozoa near the Utero Tubal Junction

At the time of AI following Ovsynch protocol, a total of 51 buffaloes were randomly divided in a first group (n = 30) subjected to conventional AI into the uterine body with 20 million non-sex sorted frozen-thawed spermatozoa, while a second group (n = 21) was inseminated near the utero-tubal junction (UTJ) ipsilateral to the ovary carrying the preovulatory follicle with 2.5 million live (4 million total) sex-sorted frozen-thawed spermatozoa. The semen used for flowcytometric sorting was collected and processed on a farm in Italy, and then shipped to a laboratory in Germany. Eleven buffaloes were inseminated with X-chromosome bearing spermatozoa and 10 with Y-chromosome bearing spermatozoa. Conception rates after conventional and UTJ inseminations were 43.3% (n = 13) and 42.8% (n = 9) respectively (p = 0.97). Eight of the nine foetuses obtained after insemination with sexed spermatozoa corresponded to the sex as predicted by the cell sorting procedure (five male and four female foetuses by ultrasound vs six male and three female foetuses by cell sorting). In conclusion, for the first time buffalo semen has been successfully subjected to procedures for flowcytometric sperm sorting and freezing. Low doses of sexed spermatozoa have been deposited near the UTJ giving conception rates similar to those of conventional AI with full dose.

Hysteroscopic or rectally guided, deep-uterine insemination of mares with spermatozoa stored 18h at either 5°C or 15°C prior to flow-cytometric sorting

Practical application of sex-selected spermatozoa in the horse industry would be greatly improved by the ability to develop simplified methods for shipping, storing, and inseminating sex-selected spermatozoa. Acceptable pregnancy rates have been achieved using fresh sex-sorted stallion sperm, however many stallion owners are reluctant to send their stallions to the sorter location for collection during the breeding season. Furthermore, the technology would be more applicable if the hysteroscopic insemination technique was not necessary for adequate pregnancy rates. Hysteroscopic insemination requires expensive equipment and specially trained personnel. In the present study, stallion sperm were sex-sorted after being stored at either 5 degrees C or 15 degrees C for 18 h. Twenty million sex-sorted sperm were then inseminated using one of two insemination techniques: the hysteroscopic method or the rectally guided, deep-uterine technique. Results were determined based on 16-day pregnancy status. A first-cycle pregnancy rate of 72% (18/25) was achieved when sperm were shipped at 15 degrees C, sex-sorted, and then inseminated using the hysteroscopic method. With these results, it can be concluded that stallions are not necessary at the sorter location to achieve acceptable fertility with sex-sorted sperm. There was a tendency for more mares to become pregnant when sperm were shipped at 15 degrees C prior to sorting, when compared to shipment at 5 degrees C. Similarly, there was a tendency for more mares to become pregnant when hysteroscopic insemination was utilized, when compared to the rectally guided, deep-uterine technique. These trends suggest that if larger group numbers were available, significant differences between the treatments may be revealed.

Improving the efficiency of sperm technologies in pigs: the value of deep intrauterine insemination

The use of AI in pigs has dramatically expanded in the last few years. New methodological advances in AI are required to serve the requirements of new sperm technologies, such as the use of low dose AI, because the use of cervical AI has a very low efficiency leading to low fertility results. One of the strategies devised to meet these requirements is the deposition of semen near the site of fertilization in the oviduct. Using deep intrauterine insemination with a specially designed catheter, a 20-fold reduction in the number of freshly and diluted inseminated spermatozoa can be achieved without decreasing farrowing rates. Moreover, an advantage of deep intrauterine insemination is the possibility of using processed, 'weaker' spermatozoa such as those that have been frozen-thawed or sex-sorted. Although deep intrauterine insemination should be of benefit to the pig industry, more investigations are needed to understand the mechanisms related to sperm colonization of the oviducts and identify the minimal sperm numbers needed to obtain maximal fertility results for processed and unprocessed boar spermatozoa.

[Thermal injury and wound healing of the endometrium subsequent to minimally invasive transendoscopic use of Nd:YAG-laser-and electrosurgery in horses]

Transendoscopic thermal preparation techniques like laser- or electrosurgery have proved to be most reliable for minimal invasive intrauterine surgery during operative hysteroscopy in mares. To determine the effect of Nd:YAG laser surgery on the endometrium and the complete uterine wall compared with electrosurgery, standard lesions were obtained by transendoscopic monopolar electrosurgery (loop electrode, cutting blade) and Nd:YAG laser surgery (contact, bare fibre, 25 Watt, exposure time four seconds, non contact, 80 Watt, exposure time four seconds) in five healthy mares on days d 0, 7, 14, 18 and 21. The gross effects were controlled endoscopically before the consecutive lesions were set. Following the last diathermic endometrial irritation, hysterectomy was performed under general anaesthesia. Recovery of the mares was uneventful. Specimens from the lesions were collected after dis-section of the uterus, fixed in formalin, routinely embedded and stained with H. E. for histological evaluation. The different energy forms caused tissue alterations of comparable quality but differing in degree. Most intensive peripheral hyperemia and tissue edema occurred on postoperative days three to seven. Non contact laser irradiation initiated maximal amount of fibrinous exudate. Lesions created with a loop electrode were superficial only and did only affect the endometrium. Preparation with an electrosurgical cutting blade or a laser bare fibre resulted in craterlike lesions lined by carbonisation and did involve deeper layers of the myometrium. The lesions caused by non contact laser irradiation affected all layers of the uterine wall. Three weeks postoperatively, reepithelization of the luminal epithelium was completed. The depth of thermal injury and coagulative necrosis, inflammatory reactions and scar formation was greater in lesions created by laser application compared with those set with a loop electrode at power densities comparable to those usually achieved at hysteroscopic surgery. The results suggest that an electrosurgical loop designed for operative hysteroscopy may be a reliable tool for diathermic resection of pathological endometrial structures like uterine cysts characterized by minimal thermal injuries and a short period of reconvalescence. Non contact laser irradiation may result in deep thermal injuries with the risk of delayed uterine perforation but may be profitable for treatment of partly intramural structures like an intramural leiomyoma.

Pregnancy rates in mares after a single fixed time hysteroscopic insemination of low numbers of frozen-thawed spermatozoa onto the uterotubal junction

REASONS FOR PERFORMING STUDY

To compensate for the wide variation in the freezability of stallion spermatozoa, it has become common veterinary practice to carry out repeated ultrasonography of the ovaries of oestrous mares in order to be able to inseminate them within 6-12 h of ovulation with a minimum of 300-500 x 10(6) frozen-thawed spermatozoa. Furthermore, in order to achieve satisfactory fertility, this requirement for relatively high numbers of spermatozoa currently limits our ability to exploit recently available artificial breeding technologies, such as sex-sorted semen, for which only 5-20 x 10(6) spermatozoa are available for insemination.

OBJECTIVES

This study was designed to evaluate and compare the efficacy of hysteroscopic vs. conventional insemination when low numbers of spermatozoa are used at a single fixed time after administration of an ovulation-inducing agent.

METHODS

In the present study, pregnancy rates were compared in 86 mares inseminated once only with low numbers of frozen-thawed spermatozoa (3-14 x 10(6)) at 32 h after treatment with human chorionic gonadotrophin (hCG), either conventionally into the body of the uterus or hysteroscopically by depositing a small volume of the inseminate directly onto the uterotubal papilla ipsilateral to the ovary containing the pre-ovulatory follicle.

RESULTS

Pregnancy rates were similarly high in mares inseminated conventionally or hysteroscopically with 14 x 10(6) motile frozen-thawed spermatozoa (67% vs. 64%). However, when the insemination dose was reduced to 3 x 10(6) spermatozoa, the pregnancy rate was significantly higher in the mares inseminated hysteroscopically onto the uterotubal junction compared to those inseminated into the uterine body (47 vs. 15%, P < 0.05).

CONCLUSIONS

When inseminating mares with <10 x 10(6) frozen-thawed stallion spermatozoa, hysteroscopic uterotubal junction deposition of the inseminate is the preferred method.

POTENTIAL CLINICAL RELEVANCE

Satisfactory pregnancy rates are achievable after insemination of mares with frozen-thawed semen from fertile stallions 32 h after administration of human chorionic gonadotrophin (Chorulon). Furthermore, these results were obtained when mares were inseminated with 14 x 10(6) progressively motile frozen-thawed spermatozoa from 2 stallions of proven fertility.

[Development of an intrauterine distension pressure for hysteroscopy in the horse]

Diagnostic and operative hysteroscopy have offered an advance in equine fertility diagnostic and equine fertility surgery. A distension of the uterine cavity and an establishment of a continuous intrauterine pressure are basic requirements for complete visualisation of intrauterine structures and safe and efficient surgical procedures. Superelevated pressure and resorption of distension media may result in fatal complications. Intrauterine pressure was monitored in 28 healthy di- or anestrus mares during hysteroscopy via a transcervically inserted catheter. Mares were sedated with xylazine and levornethadon and fixed in a stock. The pressure which was elementary for complete visualisation Parb, the pressure with onset of transcervical efflux of distension medium Pcerv and the maximum intrauterine pressure Pmax that could be obtained were determined. Complete visualisation of intrauterine structures could be achieved with a mean pressure of 17.8 +/- 5.5 mm Hg (mean +/- s) and a range of 12.8 to 28.6 mm Hg. Spontaneous efflux of distension media was registered in mares following further insufflation at a significantly higher (p < 0.001) intracavitary pressure of 62.5 +/- 10.0 mm Hg (mean +/- s). Maximum pressure Pmax that could be obtained was found to be significantly higher (p < 0.001) than Parb but also significantly higher than Pcerv with 101.6 +/- 24.4 mm Hg (mean +/- s). Clinical or cardiological signs of discomfort or affection on the circulatory system were only registered while Pmax was applicated. The results indicate, that a safe and efficient hysteroscopy can be performed with a mean pressure of 17.8 mm Hg and an upper pressure limit of 30 mm Hg.

Diagnosis of a uterine leiomyoma using hysteroscopy and a partial ovariohysterectomy in a mare

A 14-year-old quarter horse mare had a 2-year history of infertility and the presence of a mass in the right uterine horn. Prior to surgery, the mass was determined to be invasive by using ultrasonography and hysteroscopy. A partial ovariohysterectomy was performed. The mass was diagnosed histologically as a uterine leiomyoma.

An overview of low dose insemination in the mare

The need for relatively high numbers of spermatozoa for artificial insemination limits our application of recently available technologies such as sex-sorted semen. The fertility of two different methods of low dose insemination using fresh, frozen and sex-sorted semen are compared in this overview. Satisfactory conception rates are described using very low doses of spermatozoa inseminated by either hysteroscopic or deep uterine insemination methods, proving the stallion is fully fertile. The hysteroscopic method appears to give higher conception rates when inseminating fewer than 5 x 10(6) spermatozoa and is therefore, the preferred method of insemination for sex-sorted spermatozoa. However, hysteroscopic deposition of low numbers of spermatozoa from infertile stallions does not appear to improve their fertility.

Hysteroscopic insemination of low numbers of flow sorted fresh and frozen/thawed stallion spermatozoa

The objective of this experiment was to determine the effects of flow cytometric sorting and freezing on stallion sperm fertility. A 2 x 2 factorial design was used to delineate effects of flow sorting and freezing spermatozoa. Oestrus was synchronised (July-August) in 41 mares by administering 10 ml altrenogest (2.2 mg/ml) per os for 10 consecutive days, followed by 250 microg cloprostenol i.m. on Day 11. Ovulation was induced by administering 3,000 iu hCG i.v. either 6 h (fresh spermatozoa) or 30 h (frozen/thawed spermatozoa) prior to insemination. Mares were assigned randomly to one of 4 sperm treatment groups. Semen was collected from 2 stallions with an artificial vagina and processed for each treatment. Treatment 1 (n = 10 mare cycles) consisted of fresh, nonsorted spermatozoa and Treatment 2 (n = 16 mare cycles) of fresh, flow sorted spermatozoa. Spermatozoa to be sorted were stained with Hoechst 33342 and sorted into X- and Y-chromosome-bearing populations based on DNA content using an SX MoFlo sperm sorter. Treatment 3 (n = 16 mare cycles) consisted of frozen/thawed nonsorted spermatozoa (frozen at 33.5 x 106 sperm/ml in 0.25 ml straws) and Treatment 4 (n = 15 mare cycles) of flow sorted frozen/thawed spermatozoa (frozen at 64.4 x 10(6) sperm/ml). Concentrations of sperm in both cryopreserved treatments were adjusted, based on predetermined average post-thaw motilities, so that each insemination contained approximately 5 x 10(6) motile spermatozoa. Hysteroscopic insemination of 5 x 10(6) motile spermatozoa in a volume of 230 microd was used for all treatments. Pregnancy was determined ultrasonographically 16 days postovulation. No differences were found (P>0.1) in the pregnancy rates for mares inseminated with fresh nonsorted (4/10 = 40.0%), fresh flow sorted (6/16 = 37.5%), frozen/thawed nonsorted (6/16 = 37.5%) and flow sorted frozen/thawed spermatozoa (2/15 = 133%). Pregnancy rates tended (P = 0.12) to be lower following insemination of frozen/thawed flow sorted spermatozoa. Further studies are needed with a larger number of mares to determine if fertility of flow sorted frozen/thawed spermatozoa can be improved.

Hysteroscopic insemination of mares with low numbers of nonsorted or flow sorted spermatozoa

The objectives of this study were 1) to compare pregnancy rates resulting from 2 methods of insemination using low sperm numbers and 2) to compare pregnancy rates resulting from hysteroscopic insemination of 5 x 106 nonsorted and 5 x 106 spermatozoa sorted for X- and Y-chromosome-bearing populations (flow sorted). Semen was collected with an artificial vagina from 2 stallions of known acceptable fertility. Oestrus was synchronised (June to July) in 40 mares, age 3-10 years, by administering 10 ml altrenogest orally for 10 consecutive days, followed by 250 microg cloprostenol i.m. on Day 11. All mares were given 3000 iu hCG i.v. at the time of insemination to induce ovulation. Mares were assigned randomly to 1 of 3 treatment groups: mares in Treatment 1 (n = 10) were inseminated with 5 x 10(6) spermatozoa deposited deep into the uterine horn with the aid of ultrasonography. Mares in Treatment 2 (n = 10) were inseminated with 5 x 10(6) spermatozoa deposited onto the uterotubal junction papilla via hysteroscopic insemination. Mares in Treatment 3 (n = 20) were inseminated using the hysteroscopic technique with 5 x 10(6) flow sorted spermatozoa. Spermatozoa were stained with Hoechst 33342 and sorted into X- and Y-chromosome-bearing populations based on DNA content using an SX MoFlo sperm sorter. Pregnancy was determined ultrasonographically at 16 days postovulation. Hysteroscopic insemination resulted in more pregnancies (5/10 = 50%) than did the ultrasound-guided technique (0/10 = 0%; P<0.05) when nonsorted sperm were inseminated. Pregnancy rates were not significantly lower (P>0.05) when hysteroscopic insemination was used for sorted (5/20 = 25%) and nonsorted spermatozoa (5/10 = 50%). Therefore, hysteroscopic insemination of low numbers of flow sorted stallion spermatozoa resulted in reasonable pregnancy rates.

Hysteroscopy in bitches

The aim of this study was to determine whether the canine endometrium could be examined by hysteroscopy. Eight German shepherd bitches were used. Two bitches were in dioestrus, five were in anoestrus and one was about 8 weeks post partum. The uterus was exposed through a ventral celiotomy. A 3 mm straight laparoscope or a 4 mm laparoscope with a 30 degrees angle, and a catheter for inflation of the uterus were used. After hysteroscopy the bitches were spayed and the uterus of each bitch was examined macroscopically and histologically. Endometrium and uterotubal junctions were visible in all bitches. The cervix and caudal uterine body could not be visualized in three bitches as two bitches had uterine discharge and air escaped through the cervix in the other bitch. In the post-partum bitch, dark-brown sites of implantation were observed. Four bitches (aged 9, 22, 25 and 31 months) had endometrial cysts (0.5-2.0 mm in diameter). Hysteroscopy caused petechiae and ecchymosis in the endometrium of four bitches. Traumatization of the endometrium affected only the epithelium and the most superficial part of the lamina propria. In conclusion, hysteroscopy appears to be a very sensitive tool for evaluation of the canine endometrium. Further research is necessary to determine the effects of hysteroscopy on subsequent fertility.

Successful non-surgical deep intrauterine insemination with small numbers of spermatozoa in sows

A 100-fold reduction of the standard dose for artificial insemination in pigs (3 x 10(9) spermatozoa in 80-100 ml fluid) can be used when spermatozoa are deposited surgically next to the uterotubal junction. The present study was performed to develop a technique for non-surgical deep intrauterine insemination in pigs without sedation of the animal. In Expt 1, sows were weaned, treated to induce oestrus and used to evaluate the difficulties involved in the insertion of a flexible fibre optic endoscope through the cervix and along the uterine horn. Deep uterine catheterizations were performed on each sow at 30-40 h after hCG treatment in the crate in which the animal was housed. The endoscope was inserted through an artificial insemination spirette, moved through the cervical canal and propelled forward along one uterine horn until the entire endoscope was inserted. In 30 sows (90.9%) no or minor difficulties were observed during insertion and in these animals the procedure was completed in 4.1 +/- 0.26 min. Insertion of the endoscope through the cervical canal was not possible in only one sow (3.03%). In Expt 2, endoscopic deep intrauterine insemination at 36 h after hCG treatment was performed in 15, 18 and 13 sows with 100, 20 or 5 x 10(7) spermatozoa, respectively, resulting in farrowing rates of 86.6%, 88.9% and 92.3%, respectively; there were no significant differences among groups. Farrowing rates after deep intrauterine inseminations were also not different from those achieved after standard intracervical insemination with 3 x 10(9) spermatozoa (control group: n = 48; 87.5%). Mean litter size (9.41 +/- 0.38 to 10.02 +/- 0.25) was also similar among the different experimental and control groups. In conclusion, endoscopic non-surgical deep intrauterine inseminations can be performed quickly in sows, and normal farrowing rates and litter sizes can be obtained after insemination with a small number of spermatozoa.

Neodymium:yttrium-aluminum-garnet laser ablation of a urethral web to relieve urinary outflow obstruction in a horse

An 8-year-old Hanoverian gelding was examined because of urine dribbling and urethral obstruction. Mild proprioceptive deficits of the left hind limb were evident during neurologic examination. Ultrasonography per rectum revealed dilatation of the pelvic portion of the urethra. Endoscopy of the urethra revealed 2 webs of tissue: 1 was located 10 cm proximal to the external urethral opening; the other was located 65 cm proximal to the external urethral opening and prevented passage of the endoscope into the urinary bladder. The mass was ablated with a neodymium:yttrium-aluminum-garnet laser, using a transendoscopic noncontact technique. On follow-up examination 6 months after laser surgery, an endoscope could easily be passed into the bladder, and no urethral web was seen. The horse was able to void a stream of urine but continued to dribble urine intermittently. The proximal location of the urethral lesion in this horse would have made use of traditional surgical methods problematic, whereas transendoscopic laser photoablation was easy and effective.

Some cardiopulmonary effects of midazolam premedication in clenbuterol-treated bitches during surgical endoscopic examination of the uterus and ovariohysterectomy

Midazolam was administered intravenously to 8 bitches in a randomised, placebo-controlled clinical trial before propofol induction of surgical anaesthesia. Anaesthesia was maintained with isoflurane-in-oxygen during surgical endoscopic examination of the uterus and ovariohysterectomy. Clenbuterol was administered at the start of surgery to improve uterine muscle relaxation, and to facilitate endoscopic examination of the uterus. Ventilation was controlled. Induction of anaesthesia with propofol to obtain loss of the pedal reflex resulted in a statistically significant (P < 0.05) decrease in minute volume and arterial oxygen partial pressure in the midazolam group. Apnoea also occurred in 50% of dogs in the midazolam group. The dose for propofol in the midazolam group was 7.4 mg/kg compared to 9.5 mg/kg in the control. Minute volume was significantly (P < 0.05) higher in both groups during isoflurane maintenance, compared to the value after incremental propofol to obtain loss of the pedal reflex. Propofol induction resulted in a 25-26% reduction in the mean arterial blood pressure in both groups, and the administration of clenbuterol at the start of surgery resulted in a transient, but statistically significant (P < 0.05), decrease in mean arterial blood pressure in the midazolam group during isoflurane anaesthesia. It is concluded that intravenous midazolam premedication did not adversely affect cardiovascular function during propofol induction, but intra-operative clenbuterol during isoflurane maintenance of anaesthesia may result in transient hypotension. Midazolam premedication may increase adverse respiratory effects when administered before propofol induction of anaesthesia.

T-cell distribution in two different segments of the equine endometrium 6 and 48 hours after insemination

The T-cell response after the introduction of semen into the uterine cavity in the mare was studied by examining, immunohistochemically, the distribution of helper T-cells (CD4+) and cytotoxic T-cells (CD8+) in endometrial biopsy specimens. Endometrial tissue samples were obtained from twenty-five gynecologically healthy mares during estrus before and 6 or 48 h after deposition of a single dose of stallion semen. An increase (P=0.04) in the number of helper T-cells (CD4+) compared to pre-insemination values was observed in the uterine body in both groups, 6 and 48 h, after insemination. No significant variations in numbers of CD8+ cells were recorded either 6 or 48 h after insemination. There seems to be an early (6 h) recruitment of helper T-cells to the equine endometrium after semen deposition, which might be related to the activation of the endometritis-like reaction seen as part of the equine uterine immune defense during estrus.

Fetal maceration and retention of fetal bones in a mare

A 19-year-old Quarter Horse mare was evaluated because of bloody vaginal discharge that was apparent immediately following breeding. On transrectal ultrasonography, it was evident that the uterus was filled with fluid containing echogenic particles; linear hyperechoic structures were also visible. Endoscopy was performed, which revealed a number of bones adhered to the cranial wall and floor of the right uterine horn as well as purulent fluid in both uterine horns. Bacterial endometritis and fetal maceration were diagnosed. The mare was treated with antibiotics, and the fetal bones were manually removed from the uterus. Fetal maceration with intrauterine retention of bones is rare in mares. Use of hysteroscopy supplements ultrasonography in the diagnosis of uncommon conditions of the uterus. Macerated bones may be adhered to the endometrium, thereby requiring manual removal.

[The problem mare part 1: pathogenesis and clinical investigation]

A review is given of treatment for 'problem' mares that do not become pregnant. To determine the best therapy, it is necessary to understand the defence mechanisms of the uterus and the pathogenesis of not getting in foal. A thorough clinical examination is absolutely necessary to come to a correct diagnosis. This examination will be explained in a practical way. In the second article the different therapies for treating problem mares are discussed. The therapeutic possibilities vary widely. They can be classified in: anatomical corrections, anti-infectious therapy, and treatment to enhance the uterine defence mechanism.

Standing laparoscopic-guided uterine biopsy in a southern white rhinoceros (Ceratotherium simum simum)

Transrectal ultrasonography of a 35-yr-old captive female southern white rhinoceros (Ceratotherium simum simum) with a history of chronic mucohemorrhagic vulvar discharge revealed right transmural uterine horn enlargement. Abdominal laparoscopic surgery, although extremely difficult because of inadequate instrumentation, permitted uterine visualization and biopsy. Standing anesthesia, incorporating butorphanol and azaperone together with local anesthetic infiltration, facilitated the laparoscopy. A leiomyoma was suspected on the basis of history, physical examination, ultrasonographic appearance, and histopathology. Prior rhinoceros laparoscopies have failed, primarily from limitations imposed by recumbency.

Ovum pick up in swine: the influence of aspiration vacuum pressure on oocyte recovery from preovulatory follicles

Endoscopical ovum pick up (OPU) in swine is a minimal invasive and reliable technique to aspirate oocytes from preovulatory follicles for studying intrafollicular development and oocyte maturation as well as for IVM/IVF-programs. The aim of the present study was to determine the effect of different aspiration vacuum pressures on oocyte recovery and on the morphology of cumulus oocyte complexes (COCs). Oestrus of crossbred Landrace gilts (n = 33) was synchronized by feeding altrenogest and follicular growth was stimulated with 1,000 IU PMSG 24 h after the last altrenogest application. On day 4 after PMSG application preovulatory healthy follicles of > 5 mm diameter were aspirated laparoscopically. Aspiration was carried out using a two-way cannula and an electronic aspiration pump. Five different vacuum pressures were used: 10, 17, 32, 47 and 66 ml water/min, corresponding to 30, 60, 125, 250 and 375 mm Hg, respectively. Fluids from different follicles were pooled per ovary and the morphology of cumulus oocyte complexes (COCs) was determined microscopically immediately after aspiration. COCs were classified into oocytes with intact cumulus (i.e. compact or slightly expanded COC), oocytes with corona radiata and denuded oocytes. A total of 695 follicles were aspirated and 501 COCs recovered. Increasing the aspiration pressure stepwise from 10 ml water/min up to 66 ml water/min resulted in a decrease in oocyte recovery rate. A significant higher (P < 0.05) rate of oocyte recovery (77.4% v.s. 59.8%) was achieved using a vacuum pressure of 17 ml water/min compared to 66 ml water/min, respectively. There was a tendency to reduce the portion of COCs with intact cumulus from 82 to 88% to 77% if the vacuum pressure increased to more than 47 ml water/min. A higher aspiration pressure provoked an increase (P < 0.05) in the number of denuded oocytes: 0 to 3% at 10 to 32 ml water/min, respectively, compared to 10% at 47 ml water/min to 17% at 66 ml water/min. These results demonstrate that variation in aspiration pressure affects oocyte recovery rate and COC quality. Aspiration vacuum pressure of 17 to 32 ml water/min was found to be optimal in swine both for oocyte recovery and COC quality.

Investigating uterine disease in the bitch: uterine cannulation for cytology, microbiology and hysteroscopy

A technique for transcervical cannulation of the uterus of the bitch for the collection of samples for cytology and microbiology was developed. This technique involved passing a cannula into the uterus with the aid of an endoscope. The uterus was cannulated successfully in mature bitches (over 10 kg) 110 times in 144 attempts. Success of cannulation was influenced by the experience of the operator and ease of cannulation by the stage of the reproductive cycle, the size of the bitch and the type of cannula. Complications associated with the procedure were endometritis, vaginitis and vaginal tears. Uterine cannulation was generally possible in all bitches studied at all stages of the reproductive cycle. Techniques for the collection of samples from the uterus for cytology and microbiology and for the processing of samples for uterine cytology are outlined. Hysteroscopy was performed on seven occasions in post partum bitches and was found to be possible at least until day 17 after whelping.

[Hysteroscopy as a diagnostic aid for uterine diseases of cattle]

A method for hysteroscopy in cattle, using a rigid tube for passage through the cervical canal, is described. Using this method, passage through the cervical canal is possible independent of the stage of the gynaecological cycles. The hysteroscopic findings of 105 examinations in cows are described and discussed.

Videoendoscopic evaluation of the mare's uterus: I. Findings in normal fertile mares

The new generation of videoendoscopes uses an electronic, instead of an optical, system for image transmission. Advantages over conventional fibre-optic endoscopes include increased image quality, handling robustness and direct display of the image on a TV monitor for multiple simultaneous viewing. In the present study, hysteroscopy was performed on 14 normal fertile Welsh Pony and Thoroughbred mares at various times during the annual and ovarian breeding cycles. Oestrus was characterised by an oedematous, relaxed cervix lying on the floor of the vagina, diffuse oedema of the endometrium and the occasional accumulation of small amounts of clear secretions in the uterine lumen. In dioestrus, the cervix appeared tight and pale and was located in the centre of the vaginal fornix. The endometrium appeared thinner due to the reduction in interstitial fluid, which allowed the underlying blood vessels to become visible, but it still had a glistening surface as a result of endometrial gland secretions. The appearance of the uterotubal papillae reflected the changes in the cervix, being relaxed, pinkish and oedematous during oestrus but remaining pale, tight and erect in dioestrus (between Days 7 and 12 after ovulation). A flexible polythene cannula was passed into the uterine lumen through the working channel of the endoscope for directed collection of uterine fluid for cytological and bacteriological examinations. Site-directed biopsies of the endometrium were taken, with flexible forceps inserted through the working channel of the endoscope, or with rigid forceps passed through the cervix alongside the endoscope. Both methods enabled accurate visual selection of the sampling area but the rigid forceps were preferred due to the larger size of the piece of endometrium recovered.

Videoendoscopic evaluation of the mare's uterus: II. Findings in subfertile mares

Videoendoscopy of the reproductive tract was performed in 87 Thoroughbred mares with histories of reduced fertility. During hysteroscopy samples for cytological, microbiological and histological examinations were obtained under visual control. Common findings in these broodmares included: (a) endometrial degeneration, as assessed by an uneven distribution or atrophy of endometrial folds and/or a scarred appearance of the endometrium (49 mares, 56%); (b) endometrial cysts of various sizes and locations within the uterus with the most common location being at the base of the uterine horns (48 mares, 55%); (c) fluid accumulation in the uterine lumen (28 mares, 32%). A few mares had transluminal adhesions (7 mares, 8%) and in 2 mares the adhesions appeared to obstruct one uterine horn completely. A solitary discrete lump was detected in the wall of the uterine body in one mare and the suspicion of it being a leiomyoma was confirmed histologically with the aid of a visually directed biopsy sample. Free intraluminal structures were present in the uterine lumen in 3 mares, including one inspissated blood clot and two suspected remnants of resorbing pregnancies. Flexible biopsy forceps and scissors passed through the working channel of the endoscope were used to sever small thin adhesions, but this method proved inadequate for multiple adhesions or cysts. Solitary endometrial cysts were removed by means of conventional rigid biopsy forceps passed alongside the endoscope, although bleeding from the operation site usually limited this type of intervention.

Videoendoscopic evaluation of the mare's uterus: III. Findings in the pregnant mare

During a 5-year period 65 Pony and 20 Thoroughbred pregnant mares were subjected to videoendoscopic hysteroscopy from 10 to 266 days of gestation. The aims of these examinations were to 1) observe foetal and placental development in vivo (60 Pony and 10 Thoroughbred mares); 2) eliminate one of unicornuate twin conceptuses (9 Thoroughbred mares); 3) recover embryonic foetal and placental tissues non-surgically for experimental purposes (47 Pony mares); 4) induce focal separation of the placenta in late gestation as an experimental model of placentitis (5 pony mares and 1 Thoroughbred mare). It was possible to view the embryo and all constituent extra-embryonic membranes of the conceptus between Days 10 and 87 of gestation without having to perforate the allantochorion. This allowed study of physiological processes such as the coordinated uterine contractions responsible for conceptus motility between Days 7 and 17, active foetal movements, which began as early as Day 34, and invasion of chorionic girdle cells into the endometrium, which occurred between Days 34 and 38. From Day 90, vision of the foetus was reduced or prevented by the increased thickness of the allantochorion. Transendoscopic recovery of the conceptus was successful in all of 10 mares under 30 days of gestation, whereas only 10 of 18 attempts between Days 30 and 45 produced the conceptus without resorting to uterine lavage after initial rupture of the allantochorion. All 9 attempts to eliminate one of unilateral twin conceptuses were unsuccessful and the technique was abandoned as clinically unsuitable. Nevertheless, 9 of 22 (41%) single conceptuses remained viable after one or more hysteroscopic examinations.(ABSTRACT TRUNCATED AT 250 WORDS)

Uterine and fetal dynamics during early pregnancy in mares

Fetal activity and mobility and changes in diameter of the allantoic fluid compartment in the uterine horns were studied in mares between days 69 and 81 of pregnancy by use of transrectal ultrasonography (n = 12) and transcervical videoendoscopy (n = 8). The insertion tube of the videoendoscope was positioned within the allantoic sac to permit viewing of the fetus and entrance to each uterine horn. Each uterine horn was divided ultrasonographically into 3 segments of equal length, and the horns were designated on the basis of side of umbilical attachment (cord vs noncord horns). The diameter of the allantoic fluid compartment in the cornual segments increased (P less than 0.05) over the cranial (18.6 +/- 1.9 mm), middle (35.6 +/- 2.9 mm), and caudal (51.7 +/- 4.4 mm) segments, but differences between cord and noncord horns were not evident. Dynamic changes in diameter of the allantoic fluid compartment in cornual segments (ultrasonography) and at the entrance to each uterine horn (videoendoscopy) were detected (no significant difference between methods). During continuous videoendoscopic viewing (17 to 60 min/mare), extreme changes in allantoic fluid compartment diameter (76 to 100% of maximum to 0 to 25% of maximum or vice-versa) occurred an equivalent of 2.6 times/h/horn entrance; changes had an average duration of 3.4 minutes. A change from 100% (maximal diameter) to 0% (no visible lumen) or vice-versa occurred an equivalent of 1.3 times/h/horn entrance. Sometimes the uterine wall was so closely constricted++ around the fetal-amniotic unit that no intervening allantoic fluid was ultrasonographically detectable whereas at other times the uterus in the same location was widely dilated.(ABSTRACT TRUNCATED AT 250 WORDS)