Early conception factor lateral flow assays for pregnancy in the mare.

The ECF lateral flow assay test is marketed to detect non-pregnancy in mares. The objectives of the present study were to determine the accuracy of the ECF test, the accuracy of the electronic reader accompanying the ECF test, and agreement between two human readers and the electronic reader. Serum samples were collected from anestrus, cycling but not inseminated, and inseminated mares, and were evaluated with the ECF test (EDP Biotech Company, Knoxville, TN, USA) at The Ohio State University and at the EDP Biotech Laboratory. Specificity ranged from 0.07 to 0.16, the negative predictive value ranged from 0.15 to 0.33, and accuracy ranged from 0.43 to 0.52. The electronic reader did not add improve the accuracy or predictive values of the test. Based on the electronic reader, 80.0% of the serum samples collected from the anestrus mares were false positives; Readers 1 and 2 had 60.0 and 33.3% false positives, respectively. For samples collected during the estrous cycle, 83.9% were false positives by the electronic reader, whereas Readers 1 and 2 had 43.7 and 26.4% false positives. We concluded that, regardless of whether the test strips were evaluated by a human or electronic reader, this assay was not accurate for determination of the non-pregnant mare.

Evaluation of intratesticular injection of glycerol for nonsurgical sterilization of dogs.

OBJECTIVE: To determine efficacy of intratesticular injection of glycerol as a means to sterilize dogs. ANIMALS: Six 2- to 4-year-old sexually intact male dogs. PROCEDURE: Testicular volume, serum testosterone concentration, and number of sperm in ejaculate were determined before and at weekly intervals for 12 weeks following intratesticular injection of a 70% glycerol solution (1 ml/testis). Testicular tissue specimens for histologic evaluation were obtained 4, 8, and 12 weeks following injection. RESULTS: Number of sperm in ejaculate following glycerol injection was not significantly different from number before injection. Compared with preinjection values, serum testosterone concentrations were significantly less 5, 9, and 10 weeks following injection, although libido and ejaculate characteristics were unchanged. Testicular swelling was evident 24 to 48 hours following injection, and testicular volume decreased starting on week 5 following treatment. Seminiferous tubules and evidence of normal spermatogenesis were detected in testicular biopsy specimens obtained from all dogs 12 weeks following injection. CONCLUSION AND CLINICAL RELEVANCE: Intratesticular injection of a 70% glycerol solution did not result in azoospermia and sterility in dogs.

Prevalence of fetal maldispositions in equine referral hospital dystocias.

A retrospective investigation was performed to determine the population characteristics of horses presented for dystocia at 2 equine referral hospitals and the types of fetal maldispositions among these horses. The study population consisted of a similar number of Thoroughbreds (25%), Standardbreds (24%) and draft horses (22%). Most of the current literature pertaining to equine obstetrics is based on a predominately draft horse population (63%). The latter population appeared to have more transverse presentations (P = 0.06), possibly because of the higher number of draft mares. In our study, 43% (6/14) of the transverse presentations occurred in draft breeds. Furthermore, 18% of the draft mare dystocias (6/33) were transverse presentations whereas only 8% (6/73) of the 2 major light breeds (Thoroughbred n = 3; Standardbred n = 3) had transverse presentation dystocias. Despite the significant breed differences between the 2 populations (P < 0.001), the prevalence of all other fetal maldispositions was not different from those previously reported. Severe dystocia was often multifactorial, with 86% of cases involving malposture and over half (58%) of these involving more than one extremity. Head and/or neck deviation were a major reason for referral. In 30% of cases malposition was a factor, and abnormal presentation was involved in 24% of referrals.

Testicular prosthesis in a Quarterhorse stallion: a case report.

A testicular prosthesis was surgically removed from the scrotum of a Quarterhorse stallion presented for evaluation of a large, firm, unilateral scrotal mass. The prosthesis was constructed from methyl methacrylate moulded around a roll of fiberglass casting tape. The prosthesis had been surgically implanted in the scrotum approximately 4 yr prior to presentation in order to give the appearance of 2 testicles in the scrotum for showing and breeding purposes. The horse had been used to successfully breed mares prior to presentation and produced 4.046 x 10(9) progressively motile, morphologically normal spermatozoa in an ejaculate collected 4 mo after surgery to remove the prosthesis. Ethical issues raised by this case are discussed.

Pulsatile secretion of luteinizing hormone and progesterone in mares during the estrous cycle and early pregnancy.

Existence of ultradian variation in serum progesterone concentration and the relation between progesterone and luteinizing hormone (LH) secretory patterns were investigated in nonpregnant and pregnant mares. Blood samples were taken every 15 minutes for a 24-hour period on day 8 of the estrous cycle and day 18 of pregnancy, respectively. Progesterone and LH concentrations were determined by radioimmunoassay. Progesterone was secreted in pulsatile manner in nonpregnant and pregnant mares. Luteinizing hormone also was secreted in a pulsatile manner in both groups of mares. There was little temporal relation between LH and progesterone pulses in either pregnant or nonpregnant mares.

Body temperature fluctuations in the periparturient horse mare.

The objective of this study was to determine the pattern of mare deep body temperature fluctuations associated with parturition using biotelemetry. A radio transmitter was implanted in one flank in each of six mares. Telemetered data were received by a pair of antennae placed at right angles in a 3.3 x 6.6-m stall and stored on a computer hard disk. Hourly temperature data were recorded for the period of -168 through 168 hours post partum. A decrease of 0.76 degrees C in body temperature began at 4 hours prior to parturition (P < 0.1) then decreased rapidly between the 3 hours prior to and the time of parturition (Time 0). The lowest mean body temperature recorded was at the time of parturition (36.58 +/- 0.16 degrees C; P < 0.001). A supranormal increase in mean body temperature began one hour post partum, peaked at 38.02 +/- 0.08 degrees C and remained elevated for 48 hours post partum until gradually decreasing to the level of the prepartum mean by 106 hours.

Telemetric monitoring of body temperature in the horse mare.

The objective of this study was to develop a radiotelemetric system capable of frequent monitoring of mare body temperature. A radio transmitter was implanted in the flank of each of four mares. Telemetered data were received by a pair of antennae placed at right angles in a 3.3 x 6.6-m stall and stored on a computer hard disk. The data were recorded every 5 minutes except when mares were out of the stall for a 1- to 2- hour exercise period. No effect of environmental temperature, ranging from 5 degrees C to 30 degrees C, on mare body temperature was apparent. The radiotelemetric system used in this study was effective for frequent measurement of mare body temperature.

Assessment of luteal function with progesterone enzyme immunoassays in the horse mare.

Progesterone (P(4)) concentrations in the horse mare have conventionally been measured by radioimmunoassay (RIA). A commercial quantitative, competitive enzymelinked immunoassay (CELISA) has been recently introduced to the horse breeding industry along with a qualitative CELISA. The objectives of this study were to evaluate these two assays for their ability to detect transitional, cyclic, and pregnancy stages as well as early embryonic death in horse mares. The quantitative CELISA demonstrated a significant difference in P(4) levels during estrus and at Day 24 of pregnancy. There was a significant difference in P(4) concentrations in mares at ovulation and at Days 17 to 18 of pregnancy. However, there was no significant difference between pregnant and nonpregnant P(4) values from Day 1 until Day 16 of pregnancy. There was a significant difference in P(4) concentrations at ovulation and at the peak of the luteal phase in nonpregnant mares. There was also a significant difference between mares in the transitional period and Day 16 pregnant mares. The intraassay coefficient of variation was 3.1%, while the interassay coefficient of variation was 6.2%. The qualitative CELISA provided true positive diagnoses of 76.5% of the time, true negatives 67.3% of the time, false positives 4.1% of the time, and false negatives 3.1% of the time. The test sensitivity was 89.3% and its specificity was 95.7%. The CELISA provided 93% valid positive diagnoses of pregnancy on Day 21, 99% on Day 26, and 100% on Day 30. The use of either of these assay systems will provide a useful adjunct to any breeding program that utilizes one or more of the currently accepted diagnostic techniques, including teasing, palpation, and ultrasound. These assays introduce a new, inexpensive method of confirming the reproductive status in the mare.

Uterine electromyographic activity in horse mares as measured by radiotelemetry.

The objective of this study was to determine if radiotelemetry could be used to measure myometrial electromyographic (EMG) activity. A radio transmitter with one pair of biopotential leads was implanted in the flank ipsilateral to the pregnant uterine horn at least five weeks prior to the expected date of parturition in two mares. The biopotential leads were implanted in the base of the pregnant uterine horn. Telemetered data were received by a pair of antennae placed at right angles in a 3.3 by 6.6-m stall. Data were recorded on VHS format videocassette tapes continuously for the 24h prior to and following parturition. Simultaneous physiograph recordings were made as a hard copy reference. In addition, 10 mg of prostaglandin F(2 alpha) was administered to two mares in the luteal phase of the estrous cycle. Myometrial EMG during parturition was increased similarly to that of previously published reports that used myometrial electrodes wired directly to a physiograph. Prostaglandin F(2 alpha) also caused an increase in myometrial EMG activity within 8 min of administration. This study demonstrated that radiotelemetry can be used for measuring myometrial EMG activity.

Effect of xylazine on interovulatory interval and serum progesterone concentrations in the horse mare.

The objective of this study was to determine the effect of the alpha2-adrenergic agonist, xylazine, on interovulatory interval and progesterone concentrations in the horse mare. Mares were assigned to one of four treatments: Group 1 (controls) received an intramuscular injection (i.m.) of 5 cc saline (n=6), Group 2 received 10 mg prostaglandin F2alpha (PGF2alpha) i.m. (n=5), Group 3 received 500 mg xylazine i.m. (n=6) and group 4 received an intravenous injection (i.v) of 350 mg xylazine (n=6). Treatment was administered on Day 10 of the estrous cycle (Day 0=Day of detected ovulation). There was no difference in length of interovulatory interval between PGF2alpha-treated mares and control mares (mean+/-SEM; 18.8+/-1.0 versus 21.7+/-1.6 d). When compared with either xylazine-treated group, PGF2alpha-treated mares had a shorter interovulatory interval (18.3+/-1.0 d versus 22.2+/-0.6 and 22.8+/-1.3 d, respectively; P<0.05). There was no difference in the length of interovulatory interval between control mares and either xylazine-treated group. At the time of treatment all mares had progesterone concentrations>10 ng/ml, therefore the onset of luteolysis was defined as the day of the estrous cycle when progesterone concentrations decreased below 10 ng/ml. In PGF2alpha-treated mares, this event occurred earlier than in any other group (Day 11.2+/-0.2 of the estrous cycle versus 16.0+/-1.3 for control, Day 15.7+/-0.2 for Group 3 and Day 15.2+/-0.6 for Group 4; P<0.002). It was concluded that a single treatment with xylazine, either by an intramuscular or intravenous route, had no significant effect on interovulatory interval or progesterone concentrations in horse mares.

The influence of serum and gonadotropins on in vitro maturation and fertilization of bovine oocytes.

The influence of estrous cow serum (ECS) or fetal calf serum (FCS) and their interaction with gonadotropins on in vitro bovine maturation and fertilization was evaluated. The addition of ECS or FCS to the medium significantly increased the percentage of oocyte maturation over that of Ham's F-10 medium alone (P<0.05). The addition of follicle stimulating hormone (FSH), human chorionic gonadotropin (hCG) or of FSH plus hCG to the medium provided no advantage in maturation over serum alone. However, FSH plus HCG added to the maturation medium significantly improved the frequency of pronucleus formation in both groups compared with a medium to which no gonadotropins were added (P<0.05). Both ECS and FCS (as medium supplements) promoted oocyte maturation. Although the addition of a combination of FSH plus hCG to the medium did not increase the rate of oocyte maturation, it did contribute to the high incidence of subsequent pronucleus formation.

Recurrent torsion of the spermatic cord and scrotal testis in a stallion.

A stallion was twice referred for evaluation of scrotal swelling and signs of pain. The first admission followed a 3-year period of recurrent signs of left-sided scrotal pain and swelling. After the removal of the left testis because of testicular torsion, the stallion was returned to service. The conception rate was 82% for the next breeding season. Two years after initial surgery, the stallion again was evaluated because of acute signs of right-sided scrotal pain and swelling. Right-sided testicular torsion was detected and corrected, and the testis was sutured in place. The stallion's conception rate for the following breeding season was greater than 90%.

Histopathologic and gross effects of testicular biopsy in the dog.

Eighty-one mixed breed intact male dogs were divided into three groups: Group 1 = left testicle biopsied by Trucut needle method (n=36); Group 2 = left testicle biopsied by Incisional method (n = 39); Group 3 = not biopsied (n = 6). The dogs were castrated 1 to 36 d following biopsy. The biopsy specimens and both testicles were examined for gross and histologic lesions. There was no effect of biopsy on testicle circumference. There was a positive correlation (r(2) = 0.93) between testicular circumference and occurrence of lesions. Incisional biopsies induced more gross lesions (67 vs 33%), and more histologic lesions (135 vs 43). The histologic lesions included hypospermatogenesis, coagulation necrosis, tubular degeneration, interstitial fibrosis and inflammation. In addition, the lesions observed in Incisional biopsy specimens were of greater severity and incidence than Trucut biopsy specimens (87 vs 35%). It was concluded that Incisional biopsy induced an increase in frequency and severity of lesions compared with Trucut biopsy of the canine testicle.

Equine body temperature and progesterone fluctuations during estrus and near parturition.

Body temperature and serum progesterone concentrations were measured in mares to determine if a change in either could be useful in predicting estrus, ovulation or parturition. There was no significant correlation (P > 0.1) between rectal temperature and the environmental temperature or progesterone concentration. Progesterone concentration did correlate with stage of estrous cycle and the stage of pregnancy. Significant differences (P < 0.05) in temperature were noted at different times throughout the day. No change in temperature occurred that could be utilized to predict estrus, ovulation or parturition. The changes in serum progesterone concentration were only useful in detecting estrus.

The effects of estrous cow serum on the in vitro maturation and fertilization of the bovine follicular oocyte.

The effect of serum obtained from a cow at the time of standing estrus (serum A), at ovulation (serum B), and at 24 h after ovulation (serum C) on the in vitro maturation and fertilization of bovine oocytes was examined. Of 144 (Group A), 159 (Group B), and 158 (Group C) oocytes, 77 (53.4%), 82 (51.6%) and 82 (51.9%) oocytes were characterized by expansion of cumulus cells, respectively. There was no significant difference in the effect of the three types of cow serum on the cumulus expansion (P < 0.05). Of 461 oocytes, 316 oocytes were cultured with sperm for fertilization, and 145 oocytes were cultured without sperm for evidence of parthenogenetic development. Of 56 (Group A), 56 (Group B), and 62 (Group C) oocytes with expanded cumulus cells, 19 (33.9%), 7 (12.5%), and 11 (17.7%) oocytes were cleaved, respectively, after exposed to the sperm for 24 h. There was a significant difference in the effect of the three types of cow serum on the fertilization rate (P < 0.05). A total of 145 oocytes was cultured in the absence of sperm and no evidence of parthenogenetic division was observed. The effect of the three types of serum obtained from the cow on the maturation of oocytes was not significant, but a significant difference did exist in the fertilization rate of oocytes. Cow serum obtained at the time of standing estrus had a beneficial effect on the fertilization rate of oocytes in vitro.

Equine lymphocyte antigens and reproduction in the Standardbred mare.

Equine lymphocyte antigen (ELA) gene frequencies were estimated for pacing and trotting Standardbred mares residing on a breeding farm in central Ohio. The ELA gene frequencies for Ohio Standardbreds did not differ significantly from the ELA gene frequencies of Kentucky Standardbreds, determined by Bailey (1983). No significant differences were found in the distribution of ELA class I antigens in horses with lower overall fertility or a history of abortion on the investigated breeding farm. Likewise, no significant association was observed when the ELA types of both the mare and the stallion to which she was mated were compared with the reproductive efficiency of the mare.

Retained fetal membranes in the mare: A retrospective study.

A retrospective study of 3456 deliveries was conducted from the records of four Standardbred broodmare farms where mares were bred by artificial insemination and maintained under close veterinary supervision. Retained fetal membranes (RFM) were observed in 10.6% of the deliveries. Retained fetal membranes occurred more frequently (p < 0.05) after dystocia and in mares which had RFM the previous year. Retained fetal membranes after normal foaling had no significant effect on the reproductive performance (pregnancy rate, pregnancy loss rate, or foaling rate), nor on the general health of the mares, regardless of the duration of RFM (3 to 144 hours). Postfoaling laminitis was not observed. Oxytocin therapy of mares with RFM starting at two hours postpartum significantly reduced the incidence of RFM >/= 8 hours. Mares with RFM which had received intrauterine antimicrobials between foaling and first breeding had a foaling rate similar to mares with RFM which had not received intrauterine therapy.