Pregnant Horse Research Articles

Evaluation of Synthetic GnRH-Analog Peforelin with Regard to Oocyte Differentiation and Follicular Development in C57BL/6J Mice.

In biomedical research, ovulation induction is a critical step in the reproductive biology of laboratory animals. This study evaluates the efficacy of peforelin, a synthetic gonadotropin-releasing hormone (GnRH) analog, in comparison to pregnant mare serum gonadotropin (PMSG, synonym: eCG), traditionally used for ovulation induction in mice. PMSG is derived from the serum of pregnant horses, and its production is becoming increasingly problematic due to animal welfare concerns and regulatory restrictions. The aim of this study was, therefore, to evaluate an ethically acceptable and less invasive alternative to PMSG. Female C57BL/6J mice, aged 3-4 weeks, were divided into two groups to receive either peforelin at three different concentrations or PMSG, followed by an injection of human chorionic gonadotropin (hCG) to induce ovulation. Key outcomes included the number and quality of oocytes collected, fertilization rates, ovary morphology, and follicular differentiation. Although the number of oocytes was significantly lower in the peforelin cohort, the fertilization rate was high. Ovarian morphology was not significantly altered compared to the PMSG cohort. This study showed that peforelin is suitable for superovulation in mice. These results suggest that peforelin could be an ethically acceptable alternative to PMSG stimulation for inducing superovulation in mice.

Serological investigation and isolation of Salmonella abortus equi in horses in Xinjiang

BackgroundSalmonella enterica subspecies enterica serovar abortus equi (S. abortus equi) is one of the main pathogens that causes abortion in pregnant horses and donkeys, which was highly infectious and greatly restricts the healthy development of the horse industry.ObjectivesIn order to investigate the prevalence and biological characteristics of S. abortus equi in different regions and breeds of horses in Xinjiang.MethodsThis study conducted ELISA detection of S. abortus equi antibodies on serum samples of 971 horses collected from three large-scale horse farms and five free-range horse farms in Yili Prefecture and Bayingol Mongolian Autonomous Prefecture of Xinjiang from 2020 to 2023. On this basis, bacterial isolation, culture, identification, and drug sensitivity tests were conducted on 42 samples of aborted foal tissues and 23 mare vaginal swabs.ResultsThe results showed that the positive rate of S. abortus equi antibody was as high as 20.91% in 971 horse serum samples. Among them, the positive rate in the Ili region (29.09%) was significantly higher than that in the Bayingole region (11.24%), and the positive rate in mares (22.45%) was higher than that in stallions (14.05%). In terms of horse breeds, the positive rates of self-propagating thoroughbred horses, half-bred horses, Ili horses and Yanqi horses were 43.22%, 28.81%, 14.72% and 11.24% respectively. In addition, S. abortus equi was more susceptible to juvenile and elderly horses, with positive rates of 70.00%and 41.86%, respectively, both of which were significantly higher than young (10.97%) and adult (19.79%) horses. Further, 9 strains of S. abortus equi were obtained through bacterial isolation, culture and identification, which were resistant to five antibiotics (Clarithromycin, Clindamycin, penicillin, Sulfamethoxazole and Rifampicin), and sensitive to 13 antimicrobial agents (Amoxicillin, Ciprofloxacin and Gentamicin, et al.).ConclusionThere was a high infection rate of S. abortus equi in Ili Prefecture and self-propagating thoroughbred horses, and juvenile or old mares were more susceptible, which will provide scientific basis for the prevention of S. abortus equi infection in different regions and breeds of horses in Xinjiang.

Effects of pregnancy on electrocardiographic, vasovagal tonus index, and echocardiographic variables in horses.

Pregnancy affects maternal hemodynamics. The changes in autonomic nervous system activity for hemodynamics adaptation in pregnant horses are still unclear. Thus, this study aimed to examine the effect of pregnancy on electrocardiographic, vasovagal tonus index, and echocardiographic variables in horses. A total of 23 Thai native crossbred mares without any cardiac abnormalities were included in this study. The animals were assigned into two groups, a non-pregnant mare group (n =12) and a pregnant mare group (n = 11). Electrocardiogram recordings (paper speed = 25 mm/s and calibration = 10 mm/mV) were performed to obtain six limb leads (leads I, II, III, aVR, aVL, and aVF). The vasovagal tonus index (VVTI) was calculated to assess variability in heart rate over short periods using just 20 consecutive beats. Cardiac structure and function were evaluated by echocardiography. Heart rate, P wave duration, PR interval, QRS duration, QT interval, and T wave duration were significantly different between non-pregnant and pregnant horses (p < 0.05). Pregnant horses had significantly lower VVTI than non-pregnant (p < 0.05). There were no significant differences in cardiac structures including % interventricular septum (IVS), % left ventricular posterior wall (LVPW), IVS in diastole, left ventricular internal diameter at end-diastole, LVPW thickness at end-diastole, IVS in systole, left ventricular internal diameter at end-systole, LVPW thickness at end-systole, and left atrium/aortic roots ratio between the two groups. However, the pregnant horses had a significantly higher cardiac output and % ejection fraction than non-pregnant horses (p < 0.05). This study provided the first evidence that hemodynamic adaptations during pregnancy modified cardiac conduction, vasovagal tonus index, and echocardiographic variables in horses.

Low-Dose Sodium Salicylate Promotes Ovulation by Regulating Steroids via CYP17A1.

To meet the current demand of assisted reproduction and animal breeding via superovulation and reduce the impact of hormone drugs, it is necessary to develop new superovulation drugs. This study examined the role of inflammation and steroids in ovulation. Sodium salicylate can regulate inflammation and steroids. However, the effect of sodium salicylate on ovulation has not been studied. In this study, mice were intraperitoneally injected with different concentrations of sodium salicylate for four consecutive days. The effects of sodium salicylate on oocyte quality and on the number of ovulations were examined, and these effects were compared with those of pregnant horse serum gonadotropin (PMSG)/follicle-stimulating hormone (FSH) treatment. We found that low-dose sodium salicylate increased the levels of ovulation hormones and inflammation by promoting the expression of CYP17A1. Sodium salicylate had the same effect as the commonly used superovulation drug PMSG/FSH and reduced the histone methylation level. Sodium salicylate can promote ovulation in mice and Awang sheep. It can greatly decrease the use of hormone drugs, reduce breeding costs and physical impacts, and can thus be used for livestock breeding.

Low plasma progesterone concentration during the early luteal phase delays endometrial development and the beginning of placentation in mares

While detrimental effects of reduced plasma progesterone concentration in the early luteal phase on conceptus development in horses have recently been demonstrated, there is no information on associated effects on the endometrium, allantochorion (AC), and chorionic girdle (CG) in this species. We hypothesised that reduced early postovulatory progesterone concentration in pregnant horses is detrimental to endometrial function and development of the embryonic membranes and is an underlying cause of delayed conceptus development. After insemination and ovulation, mares (n = 11) were assigned to treatment (TREAT) or control (CON) during two pregnancies. In TREAT pregnancies, mares received a PGF2α analogue for four consecutive days starting on the day of ovulation with the aim to reduce progesterone secretion. Mares were left untreated in CON pregnancies and thus served as their own controls. Endometrial biopsies for analysis of histomorphology, epidermal growth factor (EGF) and EGF receptor (EGFR) mRNA and protein expression in the endometrium, AC, and CG as well as abundance of regulatory T lymphocytes (Tregs) were collected on day 34 of pregnancy. Histomorphometric analysis revealed a higher luminal endometrium and a higher CG epithelium in CON compared to TREAT pregnancies. Abundance of mRNA for EGF and EGFR was large in the endometrium, AC and CG but did not differ between TREAT and CON pregnancies. The number of endometrial regulatory T lymphocytes was reduced in TREAT compared to CON pregnancies, adding further aspects to the potentially detrimental effects of reduced progesterone concentrations on equine pregnancy.

Copper deposition in Wilson's disease causes male fertility decline by impairing reproductive hormone release through inducing apoptosis and inhibiting ERK signal in hypothalamic-pituitary of mice.

Wilson’s disease (WD) is an autosomal recessive disorder of copper metabolism characterized by liver and central nervous system dysfunction. Considerable evidence suggests that infertility is also very common in male patients with WD, but the exact molecular mechanisms involved remain unknown. In order to further investigate the pathological changes in the hypothalamic-pituitary-testicular (HPT) axis and its mechanisms, mice were divided into the normal control group (NC), WD model TX mice group (WD), dimercaptosuccinic acid–treated TX mice group (DMSA), and pregnant horse serum gonadotropin–treated TX mice group (PMSG). The copper content and morphology of hypothalamus and pituitary tissues, the ultrastructure and apoptosis of hypothalamus neurons and pituitary gonadotropin cells, the serum levels of reproductive hormones, and the pregnancy rate and litter size of the female mice were studied. The expression of apoptosis-related proteins and the phosphorylation of extracellular regulatory protein kinase (ERK) 1/2 in the hypothalamus and pituitary were detected. The results showed that the copper content was significantly increased in the WD group, and the histopathological morphology and ultrastructure of the hypothalamus and pituitary were damaged. The levels of the gonadotropin-releasing hormone, the follicle-stimulating hormone, the luteinizing hormone, and testosterone were significantly decreased. The apoptosis rate in the hypothalamus and pituitary was significantly increased. The expressions of proapoptotic proteins Bax and Caspase-3 were significantly increased, the expression of the anti-apoptotic protein Bcl-2 was significantly decreased, and the phosphorylation level of ERK1/2 was significantly decreased. Fertility is significantly reduced. After DMSA intervention, the hypothalamus tissue copper content decreased, the hypothalamus and pituitary tissue morphology and ultrastructure were improved, cell apoptosis was alleviated, the expression of Bax and Caspase-3 was significantly decreased, the expression of Bcl-2 was significantly increased, and the reproductive hormone level, phosphorylation level, and fertility were increased. Fertility was preserved after treatment with PMSG in male TX mice. These results suggest that copper deposition in WD causes male fertility decline by impairing reproductive neuroendocrine hormone release through inducing apoptosis and inhibiting the ERK signal in the hypothalamic–pituitary region. This study can also provide reference for the damage of copper pollution to the male reproductive system.

Ultrasonographic examination of equine fetal growth parameters throughout gestation in pony for Equine-Assisted Therapy.

Equine-Assisted Therapy (EAT) is gaining popularity. Ultrasound examination is used to decrease the abortion rate in horses. In this study, to monitor fetal well-being throughout the gestation for EAT, we measured fetal heart rate (FHR), fetal eye orbit (FEO), fetal gonad length (FGL), fetal kidney length (FKL), and the combined thickness of the uterus and placenta (CTUP) by ultrasonography in pony mares. Additionally, we measured the plasma progesterone (P4) and estradiol (E2) concentrations in pregnant horses using enzyme immunoassay. The FGL peaked at week 32 and then decreased to term, and a strong correlation (r=0.72, P<0.001) between the FGL and E2 concentration was observed. A strong correlation with gestational age was detected among the FEO (r=0.96, P<0.001), FKL (r=0.85, P<0.001), and CTUP (r=0.96, P<0.001). The P4 concentration peaked at week 10, decreased to low levels (below 5 ng/ml), and peaked before parturition. In conclusion, this study provides information on fetal growth throughout gestation in pony mares for EAT. In addition, it revealed the relationship between ultrasonographic profile and plasma hormone concentrations during gestation.

Effects of blue monochromatic light directed at one eye of pregnant horse mares on gestation, parturition and foal maturity

Blue light directed at 1 eye advances the equine ovulatory season but may also advance foaling. In this study, effects of blue LED light on pregnancy outcome were assessed. A total of 20 mares with singleton pregnancies were studied over 2 consecutive years in a cross-over design. In 1 year, mares received an extended photoperiod using 50 lux of blue LED light (468 nm) directed at a single eye from 08:00 until 23:00 daily via head-worn light masks starting mid-December and in the other year remained untreated as controls. Gestation was shorter in blue LED light-treated than in control pregnancies (median 333.0 vs 338.5 days, P = 0.036). Foals born to blue LED light-treated mares had lower wither heights (median 103.0 vs 104.5 cm, P = 0.023), similar weights (median 55.8 vs 54.8 kg, P = 0.732) and took less time to stand after birth than control foals (median 35.0 vs 53.5 min, P = 0.036). Foals born to blue LED light-treated mares had reduced hair length compared to controls (median 12.0 vs 20.0 mm, P = 0.009) and hair regrowth in treated mares was reduced (P = 0.036). In conclusion, blue LED light directed at 1 eye advanced foaling and influenced height and hair coat but not weight in foals.

Renal failure in a pregnant mare

Renal failure in a pregnant mare

Influence of Metabolic Status and Diet on Early Pregnant Equine Histotroph Proteome: Preliminary Findings

Insulin resistance (IR) is characterized by an increase in biomarkers of systemic inflammation and susceptibility to laminitis in horses. Impacts on reproduction include a lengthened interovulatory period in horses. Dietary omega-3 (docosahexaenoic acid [DHA]) promotes anti-inflammatory processes, has been implicated in health benefits, and can reduce cytokine secretion. This preliminary study investigated the impact of IR as well as the influence of dietary supplementation (DHA) on the uterine fluid proteome in early pregnant horses. Mares were artificially inseminated; uterine fluid and embryos were collected on d 12.5 after ovulation. Uterine fluid was pooled for metabolic and diet categories (n = 8; n = 2 per metabolic and dietary status) and concentrated, and the proteome was analyzed using tandem mass spectrometry (iTRAQ). Five proteins met differential abundance criteria (±1.5-fold change, P < .05) in all comparisons (Control C, IS vs. C, IR; C, IS vs. DHA, IS; C, IR vs. DHA, IR). Serum amyloid A, afamin, and serotransferrin were upregulated in C, IR mares but downregulated in DHA, IR mares when compared to C, IS and C, IR, respectively. Quantitative PCR supported mass spectrometry results. The presence of serum amyloid A and serotransferrin in histotroph of IR mares potentially indicates an inflammatory response not seen in IS counterparts. These preliminary findings provide novel evidence on the potential impact of insulin resistance and DHA supplementation on the secreted equine uterine proteome during early pregnancy.

Corticosterone Injection Impairs Follicular Development, Ovulation and Steroidogenesis Capacity in Mice Ovary.

Simple SummaryResearchers have hitherto established hundreds of animal stress models. However, these models have some limitations due to the complexity in operation and large differences between individual animals. In particular, there are few stress models that are specifically applied in mammalian ovaries. In this study, using intraperitoneal injection of cortisol/corticosterone (CORT), we successfully established a stress model that acts on the ovarian function. Our data showed that CORT inhibits ovarian and follicular development and blocks ovulation. The establishment of this model might provide a living platform for studying ovarian stress in future research.The aim of this study is to establish an ovarian stress model, and to investigate the effects of stress on follicular development. Our data showed that continuous intraperitoneal injection of CORT successfully created a stressful environment in the ovary. To assess the effects of CORT on ovarian functions, 80 three-week-old ICR (Institute of Cancer Research) female mice were randomly divided into control group and treatment group. All mice were injected intraperitoneally with pregnant horse serum gonadotropin (PMSG). At the same time, the treatment group were injected with CORT (1 mg/mouse) at intervals of 8 h; while the control group was injected with same volume of methyl sulfoxide (DMSO). Blood, ovaries, or ovarian granulosa cell samples were collected at 24 h, 48 h, and 55 h after PMSG injection. The results showed that, compared with the control group, CORT-injected mice revealed a significant decrease in ovulation rates, ovarian weight, ovarian index, the number of secondary follicles and mature follicles, levels of estrogen and progesterone, and mRNA expression of steroid synthase-related genes. Collectively, our findings clearly demonstrated that CORT injection could represent an effective practice to simulate stresses that inhibit ovarian functions by reducing follicular development and ovulation.

Isolation and identification of an isoflavone reducing bacterium from feces from a pregnant horse.

The aim of this research was to isolate bacteria capable of biotransforming daidzein from fresh feces from pregnant horses. A Hungate anaerobic roller tube was used for anaerobic culture. Single colonies were picked at random and incubated with daidzein. High performance liquid chromatography was used to detect whether the isolated bacteria were able to biotransform the substrate. A strain capable of reducing daidzein was selected and characterized using sequence analysis of 16S rDNA, and a phylogenetic tree was constructed. The morphological physiological and biochemical characteristics of the strain were investigated. A facultative anaerobic, Gram-positive bacterium capable of converting daidzein to dihydrodaidzein was isolated and named HXBM408 (MF992210). A BLAST search of HXBM408's 16S rDNA sequence against the GenBank database suggested that the strain has 99% similarity with Pediococcus acidilactici strain DSM (NR042057). The morphological, physiological, and biochemical characteristics of HXBM408 are very similar to those of Pediococcus. Based on these characteristics, the strain was identified as Pediococcus acidilactici. The bacterial strain HXBM408 isolated from the feces of pregnant horses was able to reduce the isoflavone daidzein to dihydrodaidzein.

Circulatory [food] systems: Icelandic bloodmaring, reproductive technologies, and the porosity of female agricultural bodies

The integration of bloodmaring, the industry of harvesting blood from pregnant horses for the synthesis of equine chorionic gonadotropin (eCG), into Icelandic agricultural forms exposes tenuous interconnections of agrarian life, supply chains, and market interests. Corporealities and biotechnology are intertwined intimately, creating strange bedfellows spanning species, lifeways, nations, and economies within the bucolic landscape of rural Iceland. Governed by biopharmaceutical supply chains, raw resources are obscured from the final medicalized product; a quagmire of interspecies sub-contractors flow through sterilized vials, condensing in the reproductive systems of livestock in North America. Within these networks, female bodies are commoditized and technologized, fused together, and manipulated to exploit their reproductive capacities on an international scale. This paper travels international agricultural networks by tracing the veins on a mare’s neck to the circuits through which blood is reformulated into a biopharmeceutical product biologically recycled in the bodies of other livestock. Engaging feminist theory on new materialisms, science studies, and human and nonhuman animal relationships, this paper provides a multispecies ethnography of bloodmaring by exploring female agricultural bodies ensnared and enlivened via food production supply chains.

PERBANDINGAN MORFOMETRIK KUDA DI KECAMATAN TOMPASO BARAT DAN DI NUSANTARA POLO CLUB BOGOR JAWA BARAT

This study was done to evaluate the phenotypic comparison of the body measurements for genetic improvement of running horses at West Tompaso district and those at Nusantara Polo Club Bogor West Java.. Total of forty four running horses consisted of twenty two horses from Nusantara Polo Club Bogor and twenty two horses from West Tompaso district were used in this study. Observation was conducted on November 2016 - January 2017 using purposive sampling method to measure body size of horses. The pregnant horses were excluded in this. The variables measured in this study were including chest girth, chest wide, chest depth, shoulder height, hip height, hip wide, body length, neck length, head wide, and head length. Results showed that body measurements of horses at West Tompaso district tended bigger in the sizes of hip wide, head wide and head length compared with those of horses at Nusantara Polo Club Bogor West Java. While, the body measurements of horses at Nusantara Polo Club Bogor West Java tended bigger in the sizes of chest girth, shoulder height, body length and neck length compared with those at West Tompaso district.Key words: Morfometrik, horse

The influence of a mineral-vitamin premix on the metabolism of pregnant horses with microelemetosis

The article presents data on research into the influence of a mineral-vitamin premix on the clinical condition, erythropoiesis and the metabolism (macro- and micro-elemental, vitaminic, proteinaceous, enzymic) of Hucul breed mares in the last trimester of pregnancy. The Marmix premix contains: vitamins – А, D3, Е, В1, В2, В12, pantothenic and ascorbic acids, niacin, biotin; nonorganic compounds of microelements – sulphate of cobalt, copper, zinc, iron, manganese; potassium iodide, sodium selenite; amino acids – lysine, threonine, methionine.The usage of the mineral-vitaminic premix Marmix on pregnant mares during 60 days causes recovery of clinical status, erythropoiesis, raises the level of the cobalt (by 45.9%) and copper (by 2.15 times), normalizes the calcium-phosphorus ratio, raises the phosphorus level in the blood (by 17.7%), raises vitamin А (by 2.5 times) and tocopherol (by 2.02 times), total protein (by 27.7%), decreases the level of urea (by 42.2%), activity of AspAT [aspartate transaminase or aspartate aminotransferase] (by 42.9%) and AlAT [alanine transaminase] (by 44.9%) and alkaline phosphatase (by 43.7%). The research conducted contributes to improvements in the study of the pathogenesis of microelementosis of mares and develops an efficient way of treating and preventing the development of microelementosis among these animals.

Clinical comparison of two regimens of lidocaine infusion in horses undergoing laparotomy for colic

ObjectiveTo compare, in horses undergoing laparotomy for colic, the effects of administering or not administering a loading intravenous (IV) bolus of lidocaine prior to its constant rate infusion (CRI). Effects investigated during isoflurane anaesthesia were end-tidal isoflurane concentration (Fe’ISO), cardiovascular function, anaesthetic stability and the quality of recovery. Study designProspective, randomized clinical study. AnimalsThirty-six client-owned horses. MethodsHorses were assigned randomly to receive lidocaine as a CRI (50 μg kg−1 minute−1) either preceded (LB) or not preceded (L) by a loading dose (1.5 mg kg−1 IV over 15 minutes). Lidocaine infusion (LInf) was started (T0) within 20 minutes after induction of general anaesthesia and discontinued approximately 30 minutes before the end of surgery. Anaesthetic depth, Fe’ISO, intra-operative physiological parameters and quality of recovery were assessed or measured. Data were analysed using one-way anova, t-test, Fisher test, Wilcoxon and Kruskal–Wallis tests as appropriate (p < 0.05). ResultsMean ± SD Fe’ISO was 1.21 ± 0.08% in group LB and 1.23 ± 0.06% in group L. Heart rate was significantly higher in group L than in group LB at times T5-T15, T25, T35 and T95. No difference was found between groups in other measured physiological values, nor in any measure taken to improve these parameters. Recovery phase was comparable and satisfactory in all but one full term pregnant horse in group L which fractured a femur during recovery. ConclusionPreloading with a lidocaine bolus prior to a CRI of lidocaine did not influence isoflurane requirements, cardiopulmonary effects (other than a reduction in heart rate at some time points) or recovery compared to no preloading bolus. Clinical relevanceA loading dose of lidocaine prior to CRI does not confer any advantage in horses undergoing laparotomy for colic.

Histological study of the licorice extract as Phytoestrogens, compared with pregnant mare serum gonadotrophyin hormone (PMSG) in the female Reproductive system of Awassi ewes

This study was carried out at the Iraqi ministry of science &amp; Technology as well as the Vet. Collage- Baghdad. This research aimed to study the effects of macroscopic and histological licorice extract in the genital tract of ewes as well as to study the effect of the extract on reproductive efficiency to be compared with serum hormone PMSG( pregnant horse) used for this purpose. The study used (36) local ewes which are divided into three equal groups (T 1, T 2, T 3) (Licorice extract 300, PMSG 500 and zero respectively), The first group( T1) of ewes was given licorice extract a single dose of 300 mg / kg body weight weekly for a period of ( 6) weeks, The second group (T 2), they were treated with hormone PMSG with a dose of 500 unit by intramuscular injection on the day of the raising of the vaginal sponges. As for the third group (T 3) which was given normal saline only it was used as a control group .The study results that the use of licorice extract as (Phytoestrogens) leads to a lack of awareness of the pathological changes on tissue of the genital tract of treated ewes or reduction of fertility and reproductive efficiency. As the study showed that the fertility rate increased ( 1,5%) in the Group of licorice extract which is similar to the group PMSG compared with control group which had a 1.0 fertility rate and a proportion of 88,8% of fertility. In conclusion, the licorice extract could be used to raise the rates of certain reproductive efficiency in sheep without causing any satisfactory damage in the canal genital ewes or reduction to the reproductive efficiency

The molecular phylogeny of uterine serpins and its relationship to evolution of placentation

Uterine serpins (USs), designated as SERPINA14, are expressed in the endometrium in response to progesterone. All species identified as having USs exhibit epitheliochorial placentation and are in the Ruminantia and Suidae orders of the Laurasiatheria superorder. The objective was to identify US genes in species within and outside Laurasiatheria and evaluate whether evolution of the US gene was associated with development of the epitheliochorial placenta. Through queries of nucleotide and genomic databases, known US genes were identified (caprine, bovine, porcine, water buffalo), and new US coding sequences were found in dolphins, horses, dogs, and cats. The cat sequence contained several stop codons. No sequence was found in completed genomic sequences for primates, rodents, rabbits, opossums, or duck-billed platypuses. Reverse transcription-polymerase chain reaction confirmed expression of the US gene in the uterus of pregnant horses and dogs. The ratio of nonsynonymous/synonymous substitutions suggests that the US gene evolved under positive selection. In conclusion, the US gene evolved within the Laurasiatheria superorder to play a role in pregnancy for species with epitheliochorial placentation and some but not all Laurasiatheria species that have a different form of placentation. The positive selection taking place in the gene suggests development of species-specific functions.

Gabapentin for the treatment of neuropathic pain in a pregnant horse

A 24-year-old 732-kg (1,610-lb) pregnant Belgian draft horse mare developed neuropathy and signs of intractable pain following colic surgery. Following recovery from colic surgery to treat compression of the small and large intestines because of a large fetus, the mare was noticed to have signs of femoral neuropathy involving the left hind limb. Within 36 hours after recovery, the mare developed signs of severe pain that were unresponsive to conventional treatment. No gastrointestinal tract or muscular abnormalities were found, and the discomfort was attributed to neuropathic pain. The mare was treated with gabapentin (2.5 mg/kg [1.1 mg/lb], PO, q 12 h). Shortly after this treatment was initiated, the mare appeared comfortable and no longer had signs of pain. Treatment was continued for 6 days, during which the dosage was progressively decreased, and the mare was discharged. The mare subsequently delivered a healthy foal. Gabapentin appeared to be a safe, effective, and economical treatment for neuropathic pain in this horse.

CYTOTOXICITY OF ESTRADIOL, EQUILIN, EQUILENIN, AND THEIR DERIVATIVES ON CHINESE HAMSTER V79 CELLS

Recently, we investigated the inhibitory effects of 17β-estradiol and diethylstilbestrol on microtubule assembly, cytotoxicity, and aneuploidy in V79 cells. The present study analyzes the effects of equilin and equilenin (amongst the natural estrogens originally isolated from the urine of pregnant horses) and their related compounds, on the relative plating efficiency of Chinese hamster V79 cells. The results showed that a hydroxyl group on 17-C and a methoxyl group on 3-C of the estrogen skeleton were important for cytotoxicity. Of the various compounds analyzed, 2-methoxyestradiol had the strongest cytotoxicity, suggesting also the importance of a methoxyl group on 2-C.