Electrocoagulative removal of endometrial cysts in the mare

Six mares had endometrial cysts removed by endoscopic electrocoagulative surgery. These mares exhibited poor reproductive histories and endometrial cysts were the only detectable abnormalities. In each case, at least two cysts greater than 2.5cm were present. One mare subsequently produced a live foal; two are presently in foal; one conceived but absorbed; one formed more cysts after surgery; and one has not yet been bred. Histologically, the walls of the cysts contained entire lamina propria, relatively normal endometrial glands, and small cystic spaces.     

Endometrial cysts in the mare

Endometrial cysts are a contributing factor to subfertility in the mare. This article is a review of incidence, pathogenesis, clinical significance, diagnostics, and current treatments available.     

The technique and clinical appication of endometrial biopsy in the mare.

The author describes a technique for obtaining endometrail biopsy specimens from mares. the noraml cyclincal histology of the endometrium and anarbitarry classification histology of the endometrium and an arbitarary classification of the histopathology seen in endometrial biopsy speciemens. Previous literature on the subject is cited. Results of endometrial biopsies taken by the author from 134 barren mares, with histories of subfertility are descirbed and classified. The use of the technique and the interpretationof its find ings in relation to reproductive performance is discussed.     

Endoscopic electrosurgical excision of laryngeal granulation tissue in a standing pregnant mare

An 11-year-old, eight-months pregnant mare suddenly developed severe respiratory distress. Endoscopic examination identified intralaryngeal granulation tissue obstructing the airway. In order to avoid general anaesthesia and the problems associated with a permanent tracheostomy, the mass was resected electrosurgically while the mare was standing. Patency was restored to the airway and the mare foaled without complication.     

Technique and interpretation of cervical and endometrial cytology in the mare

This paper illustrates and describes the findings obtained from cervical and uterine cytology smears in the mare. Cervical/endometrial cytology is a simple technique that provides valuable information to the clinician regarding the existence of an acute or active endometritis. The most frequent observation is the presence of neutrophils. Chronically infected/inflamed mares with some degree of inflammatory cellular infiltration can also be identified on the cytology smear by the presence of neutrophils, macrophages and lymphocytes. Microorganisms are sometimes found with either acute or chronic endometritis.

This technique is not a substitute for uterine culture and biopsy. The correct identification of bacteria should be based on the cultural characteristics of the microorganisms.     

Persistent endometrial cups in the same mare in two successive pregnancies

We report upon an ageing Thoroughbred mare which showed remarkably similar and abnormally prolonged profiles of equine Chorionic Gonadotrophin (eCG) in her bloodstream during successive pregnancies sired by the same stallion. The first pregnancy was aborted at Day 75 after ovulation in conjunction with a precipitous decline in eCG concentrations which occurred immediately after the peak level had been reached. The second pregnancy, which proceeded safely to term, also involved a similar sharp fall in eCG concentrations after attainment of the peak values. Possible causes of the extended lifespan of the eCG‐secreting endometrial cups in this animal are discussed.     

The effects of endometrial damage on placental and fetal development in a mare

A 13-year-old ex-polo pony maiden mare with an extensively damaged endometrium was initially used as an embryo donor in a research herd. Embryos recovered from the mare were of normal morphology and size. Subsequently, the mare was inseminated and left pregnant. Early conceptus development was normal and she foaled a small (22 kg) but healthy filly after a gestation of 360 days. Examination of the placenta showed that development of the microcotyledons accurately reflected the damage to the uterus. Plasma progestagen profiles throughout gestation also provided evidence for placental pathology and fetal stress.     

A tubo-ovarian cyst, paraovarian cysts and lesions of the oviduct in the mare

A tubo-ovarian cyst caused unilateral obstruction of ovum transport in a young Thoroughbred mare. Its effect was a reduction in reproductive efficiency since ovulations from the affected ovary were unproductive. No occluded oviducts were found among 24 pairs of oviducts examined at post mortem. Occlusion of the oviducts in mares is apparently extremely rare. The most common types of cysts found in association with the ovaries in mares are small paraovarian cysts. They are usually found in the fimbriated portion of the oviduct and do not interfere with fertility.     

Cyclical endometrial steroid hormone receptor expression and proliferation intensity in the mare

The aims of this study were to investigate the steroid hormone receptor expression and the proliferation intensity during the equine endometrial cycle by immunohistological methods, established for routine examination of formalin-fixed, paraplast-embedded specimens. Endometrial biopsy specimens were obtained during one cycle from 7 mares. In comparison with the blood steroid hormone levels the quantity and distribution of oestrogen (ER) and progesterone receptors (PR) and the proliferation marker Ki-67 antigen expression were investigated. Rising 17beta-oestradiol concentrations in preoestrus induce a synchronous expression of ER, PR and Ki-67 antigen in stromal cells. In the early dioestrus 17beta-oestradiol levels decrease and progesterone levels reach their maxima. This correlates with an intense proliferation activity and the highest hormone receptor expression in epithelial cells. In accordance to the morphological features of asynchronous glandular differentiation in fibrotic areas (endometrosis) their epithelial hormone receptor expression is out of phase.     

The problem mare part 2: treatment

In this article different possible treatments for problem mares are discussed. The therapeutic possibilities vary and can be classified into anatomical correction, anti-infectious therapy, and treatment to enhance the uterine defence mechanisms. Anatomical correction and treatment with antibiotics are valuable therapies and have been used for many years. In recent years, stimulation of the mechanical defence mechanism of the uterus, by flushing it with physiological solution combined with parenteral oxytocin, has been shown to increase the chance of getting problem mares in foal.     

Laser ablation of endometrial and lymphatic cysts

This article discusses uterine cysts (endometrial and lymphatic), their diagnosis, and therapeutic management using neodynium: yttrium-aluminum-garnet laser ablation as directed by hysteroscopic visualization. The technique used in our clinical setting is described along with a discussion of the follow-up results in mares treated by the Sarkey's Surgical Laser Laboratory at Oklahoma State University, Stillwater, OK, over the past 7 years.     

Intercellular communication in mare endometrial epithelium isolated during estrus and diestrus

A primary culture system of equine uterine epithelial cells was developed to study interactions between these cells in vitro. Cultures were prepared by combined mechanical and collagenase separation of cells from endometrial biopsies taken from mares during estrus and diestrus. Cells were maintained in DME/F12 medium containing 10% fetal bovine serum. The purity of the epithelial cell population was estimated to be greater than 95% based upon the cobblestone morphology of cells and a uniform indirect immunofluorescence labelling of cells with an antibody directed against cytokeratin intermediate filament proteins. Radiating cytoplasmic cytokeratin filaments were characteristic of cells labelled after 3 days in culture. Preliminary analysis of the incidence and rate of cell-to-cell communication between epithelial cell populations was conducted using a fluorescence recovery after photobleaching assay. Recovery of carboxyfluorescein fluorescence in cells which were laser photobleached and in contact with other cells was monitored at one-minute intervals over 5 minutes. The incidence of communication among cells isolated during estrus and diestrus was 100%. The mean rates of fluorescence recovery at one minute (8.25% ± SEM 0.91 and 10.94% ± SEM 1.20 for cells obtained from estrous and diestrous mares, respectively) were not significantly different. These studies indicate that cells isolated from the endometrium of the mare are capable of intercellular diffusion of regulatory and informational molecules between cells in contact.     

Influence of breed and oestrous cycle on endometrial gland surface density in the mare

REASON FOR PERFORMING STUDY: The diffuse noninvasive epitheliochorial equine placenta develops an intimate and complex interdigitation with the maternal endometrium throughout gestation to maximise surface contact and, consequently, optimise nutritional and gaseous maternofetal exchanges. A significant reduction occurs in the surface density of microcotyledons on the placentae of Welsh Pony vs. Thoroughbred mares that may relate to a difference in either the number or density of endometrial glands between these breeds. OBJECTIVES: To examine this hypothesis and to determine the influence of the oestrous cycle upon the development and surface density of endometrial glands. METHODS: Endometrial biopsies were taken under videoendoscopic visual control from the base of a uterine horn from young, fertile, Welsh Pony and Thoroughbred mares at defined stages of the oestrous cycle. Computer-assisted morphometric analysis then permitted the surface density of endometrial glands within the stratum spongiosum to be assessed. CONCLUSIONS: There was a statistically significant reduction in endometrial gland surface density in the Welsh Pony vs. Thoroughbred mares during both oestrus and dioestrus. POTENTIAL RELEVANCE: A substantial upregulation of epidermal growth factor (EGF) mRNA in the epithelial cells lining the apical portions of endometrial glands has been demonstrated in pregnant mares between Days 35 and 40 after ovulation, coincident with the onset of interdigitation between the allantochorion and endometrium to form the microcotyledonary placenta. The increased surface density of endometrial glands noted in the uteri of Thoroughbred mares might account for the greater surface density of placental microcotyledons in this breed.     

Surgical enucleation of unilateral mandibular radicular cysts in an 11-year-old Thoroughbred mare

An 11-year-old Thoroughbred broodmare was diagnosed with extensive radicular cysts that affected the left horizontal mandibular ramus. A left mandibular swelling was present clinically, and mandibular lesions appearing cystic in nature were identified with successive radiographic and ultrasonographic examinations. Surgical enucleation of the cysts was performed under a standing sedation protocol and the excised cystic structures submitted for histopathological analysis. Histological examination of the cystic structures confirmed a diagnosis of multiple radicular cysts.     

Diagnosis and treatment of vesicovaginal reflux in the mare

Infertility in the mare associated with VVR must be managed as a complex problem. A complete reproductive evaluation of the mare is required to establish the cause of VVR in order for proper therapy to be recommended. Establishing a prognosis for the mare's future breeding soundness is important to the horse owner and breeding manager. VVR is almost always associated with other reproductive problems and must be dealt with in view of this.     

Methods for the treatment of twin pregnancy in the mare

Within a group of 130 mares which, in the event, carried twin pregnancies, 29 (22.3 per cent) produced their twins following diagnosis of a single palpable follicle at service and a single pregnancy 42 days later. The whole group of 130 twin-pregnant mares gave birth to only 17 live foals (13 per cent). Breeding results for the following season were available for 102 of these mares, when 38 (37 per cent) produced live foals. Thus over the two seasons an average 23 per cent of this group produced live foals. In a second group, comprising 70 mares, twin pregnancy had been diagnosed in all of them by rectal palpation. Five methods of treatment were then applied to five subgroups of mares and 20 (28 per cent) of the 70 mares produced live foals that season. Breeding results for the following season were available for 53 of these mares; 33 (61 per cent) then produced live foals. Thus over the two seasons an average 46 per cent of the treated group produced live foals. The administration of a prostaglandin analogue at less than 35 days of gestation was outstandingly successful as a method of treatment.