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Topic:Ultrasound
Ultrasound in horses is a diagnostic imaging technique that utilizes high-frequency sound waves to produce images of the horse's internal structures. It is commonly used in veterinary medicine to evaluate soft tissues, tendons, ligaments, and organs. This non-invasive method allows for real-time visualization of physiological and pathological conditions, aiding in the diagnosis and management of various equine health issues. Ultrasound is particularly valuable for assessing musculoskeletal injuries, reproductive health, and abdominal conditions in horses. This page compiles peer-reviewed research studies and scholarly articles that explore the application, methodology, and advancements in ultrasound technology within equine veterinary practice.
Effect of intrauterine treatment with prostaglandin E2 prior to insemination of mares in the uterine horn or body. Two trials were conducted to investigate the effects of intrauterine infusion of PGE2 and uterine horn insemination on pregnancy rates in mares achieved by breeding with a suboptimal number of normal spermatozoa. Estrus was synchronized and mares were teased daily with a stallion to detect estrus. Mares in estrus were examined by transrectal palpation and ultrasonography to monitor follicular status. On the first day a 35-mm diameter follicle was present, hCG (1500 IU, iv) was administered and the mares were bred the next day. Mares (Trial 1, n = 34; Trial 2, n = 28) were inseminated with 25 m...
Sternal bone biopsy in standing horses. To develop a technique for sternal bone biopsy in standing horses. Methods: Experimental study. Methods: Five adult horses. Methods: Horses were restrained in a standing stocks and sedated. The sternal biopsy site, identified by ultrasonographic examination, was clipped and prepared for aseptic surgery and infiltrated with local anesthetic. An electric bone biopsy drill (Osteocore; Institut Straumann AG, CH-4437, Waldenburg, Switzerland)), which yielded 4-mm-diameter bone specimens, was used to obtain sternal biopsies through a small skin incision. Sections (7 microm) of the bone specimens wer...
Diagnosis and management of abnormal embryonic development characterized by formation of an embryonic vesicle without an embryo in mares. To determine the incidence, ultrasonographic characteristics, and risk factors associated with embryonic development characterized by formation of an embryonic vesicle without an embryo in mares. Methods: Prevalence survey. Methods: 159 pregnant mares. Methods: From 1994 to 1998, mares between 11 and 40 days after ovulation with normal and abnormal embryonic development were examined ultrasonographically, and characteristics of each conceptus were recorded. Results: The incidence of abnormal embryonic development in mares characterized by formation of an embryonic vesicle without an embryo was...
Twin reduction in the mare: current options. Twin pregnancy in the mare causes economic loss. Early transrectal ultrasonographic detection of twins and manual crush of one embryonic vesicle is the method of choice for managing equine twins (90% success rate). Transcutaneous and transvaginal ultrasound-guided twin reduction techniques are described for twin pregnancies that advance beyond 25 days of gestation. Reported success rates for the ultrasound-guided procedures are 50% and 20%, respectively.
Post-breeding endometritis in the mare. Post-breeding endometritis is a major cause of subfertility in the mare. Endometritis is a normal event in the immediate period after mating, but the presence of ultransonographically visible uterine fluid more than 12 h later is thought to be evidence of uterine pathology. In mares that are free of venerally transmitted endometritis, treatment is aimed at removing the intraluminal fluid. If the endometritis persists past day 5, when the embryo enters the uterine lumen, the cytotoxic environment will not be compatible with pregnancy. Reproductive anatomy, defective myometrial contractility, lo...
Techniques for evaluating selected reproductive disorders of stallions. Numerous techniques may be used for evaluation of the different reproductive disorders of the stallion. Approaches may vary from real-time ultrasonography and biopsy for evaluating testicular tumors to use of special assays for evaluating sperm or plasma for presence of antisperm antibodies. This communication addresses techniques used to evaluate five relatively uncommon, but perplexing, disorders of breeding stallions: (1) seminal vesiculitis, (2) hemospermia associated with idiopathic urethral defects, (3) acrosomal dysfunction, (4) abnormal spermatozoal chromatin, and (5) azoospermia.
[Ultrasound guided surgical reduction of twin pregnancies in the horse up to the 46th day of pregnancy]. Methods for elimination of one of two embryos in twin pregnancies of mares were studied. Transvaginal ultrasound guided punction of yolk sac or allantoic cavity with fluid aspiration was used. Punction was done in 8 mares, pregnant between 22 and 46 days. In six cases, pregnancy did continue normally with one embryo only while in two cases, both embryos died following the procedure.
Insemination of mares with low numbers of either unsexed or sexed spermatozoa. Two experiments were conducted to determine pregnancy rates in mares inseminated 1) with 5, 25 and 500 x 10(6) progressively motile spermatozoa (pms), or 2) with 25 x 10(6) sex-sorted cells. In Experiment 1, mares were assigned to 1 of 3 treatments: Group 1 (n=20) was inseminated into the uterine body with 500 x 10(6) pms. Group 2 (n=21) and Group 3 (n=20) were inseminated into the tip of the uterine horn ipsilateral to the preovulatory follicle with 25 and 5 x 10(6) pms, respectively. Mares in all 3 groups were inseminated either 40 (n=32) or 34 h (n=29) after GnRH administration. More mares ...
Resection of the common digital extensor tendon in a gelding. A four-year-old gelding was lame owing to a chronic septic common digital extensor tendon and sheath. The horse had been treated by open surgical lavage but the sepsis had recurred after three months. Physical, ultrasonographic, cytological and histological examinations confirmed chronic septic tenosynovitis and tendonitis. The entire intrathecal component of the common digital extensor tendon was resected under general anaesthesia and the synovial lining of the sheath was ablated. Postoperatively the horse regained good limb function and became sound.
Measuring sphere-like structures using transrectal ultrasonography. Sphere-like structures are commonly measured for clinical or research purposes. We measured two diameters, the circumference (perimeter) and cross sectional area of 113 equine ovarian follicles in a water bath then determined the relationships between those measurements and the actual volume of fluid in the follicles. Cross-sectional area, diameter3 and area2/3 were all highly correlated with the volume of the structures and superior (p 0.05) between cross-sectional area, diameter3, and area2/3. Because of the ease of measuring diameter, we suggest that diameter3 be used to estimate the actua...
Intrafollicular concentrations of steroids and steroidogenic enzymes in relation to follicular development in the mare. The objective of the present study was to determine the changes in follicular fluid steroid concentrations and in granulosa cell steroidogenic enzyme expression during the follicular phase, in relation to follicular size and physiological status in the mare. Follicular fluid and follicular cells were recovered by ultrasound-guided follicular punctures either around the time of emergence of the dominant follicle, at the end of the dominant follicle growth, or at the preovulatory stage, after injection of gonadotropin to induce ovulation. Cellular relative amounts of steroidogenic acute regulato...
Duplex-ultrasonographic evaluation of the common carotid artery in the resting, sedated and anesthetized horse. The aim of this study was to determine the blood flow in the carotid artery during halothane anaesthesia by means of duplex-sonography. Seventeen warm blood horses were evaluated in dorsal and lateral recumbency and the results were compared with the values of the same horses resting and under sedation. The cross sectional area of the vessels, the time-averaged maximal blood velocity, time-averaged maximal blood flow and the resistance index were determined and the flow profile was evaluated. During halothane anesthesia the total blood flow shows a significant increase which is not dependent o...
Ultrasonography of the equine neonatal kidney. Ultrasonography is important in the clinical examination of the foal. The ultrasonographic appearance and size of the neonatal kidneys were defined and an imaging protocol established in 6 normal Thoroughbred foals (mean age +/- s.d. 5.0 +/- 3.2 days). Characteristically, in both the heart-shaped right kidney and bean-shaped left kidney, the renal cortex was more echogenic than the medulla. The terminal recesses, renal crest and pelvis were identified, as was the ureter, which contained anechoic urine in its lumen. The renal, interlobar and arcuate vessels were seen. For the right kidney, the ...
Variability of Doppler ultrasound measurements of hindlimb blood flow in conscious horses. Ultrasonography of the left and right femoral artery and vein was performed in 5 conscious horses. Velocity waveforms, recorded using low pulse repetition frequency, were used to calculate time-averaged mean velocity (TAV), velocity of component a (TaVa), velocity of component b (TaVb) and volumetric flow. Waveform analysis included calculation of early diastolic deceleration slope (EDDS) and pulsatility index (PI) and subjective description of the waveform. Measurements were recorded at monthly intervals for 6 months. The repeated measurements were used to determine the within-horse variation...
Echotextural changes in the follicular wall during follicle deviation in mares. The echotextural changes occurring in the follicular wall in association with deviation in diameters were studied in 8 pony mares. Echotextural changes could be useful as a reference point for future studies of the follicle-selection phenomenon. Follicles were examined daily by transrectal ultrasound from 3 d before to 3 d after the beginning of deviation (Day 0). The following echotextural end points were recorded based on a scoring or percentage system: 1) thickness of granulosa, 2) echogenicity of granulosa, 3) prominence of an anechoic layer located beneath the granulosa, and 4) extent of ...
The suitability of echotexture characteristics of the follicular wall for identifying the optimal breeding day in mares. Ultrasonically detected changes in the equine preovulatory follicle were characterized for the 3 d preceding ovulation early (n = 47) and late (n = 14) in the ovulatory season. Values for the following follicle end points increased progressively over the 3 d: diameter, incidence of nonspherical shape, echogenicity of the apparent granulosa layer, and prominence of an anechoic layer beneath the granulosa. The latter 2 echotexture end points were scored from 1 to 3 (minimal to maximal). Follicle diameter and the 2 echotexture characteristics were more prominent early than late in the ovulatory s...
Effect of PGE2 on uterine contractility and tone in mares. A technique for transvaginal, ultrasound-guided intrauterine injection was developed. After preliminary study using different approaches, the procedure was successful in 24 of 25 (96%) mares, based on detecting fluid in the uterine lumen during and after the injection. The technique was used to study the effect of PGE2, reportedly produced by the embryonic vesicle, on uterine contractility on Day 12 (Day 0 = ovulation). Uterine contractility was scored (1 = minimal, 4 = maximal) every 10 min for 1 h and every 30 min for the next hour by a continuous 1-min ultrasound examination of a longitudin...
Uterine contractility is necessary for the clearance of intrauterine fluid but not bacteria after bacterial infusion in the mare. Bacteria were infused into the uteri of 5 estrous mares resistant to persistent mating-induced endometritis, first during a control cycle, and then during treatment with clenbuterol, a beta 2 agonist. Uterine cellular response was evaluated 48 h later by transrectal ultrasonography, followed by uterine lavage. During clenbuterol treatment all mares accumulated intrauterine fluid, whereas in the control cycle none of the mares retained fluid. There was no significant difference between the 2 cycles in the cloudiness of the lavage fluid, number of cells per milliliter, percentage of neutrophils ...
Relationship between ultrasonic characteristics of the corpus luteum, plasma progesterone concentration and early pregnancy diagnosis in Friesian mares. The purpose of the present study was to evaluate the change in cross-sectional area of the early corpus luteum (CL) and progesterone production in relation to subsequent pregnancy diagnosis. The cross-sectional area of the CL of 75 Friesian brood mares was measured by ultrasonography on Day 1 or 2 and Day 8 or 9 after ovulation. The change in cross-sectional area was expressed in a volume ratio. Plasma progesterone concentrations were measured on Days 8 to 9, and ultrasonography to determine pregnancy status was carried out on Day 17. The data obtained were analyzed by using a multiple logisti...
The effects of perphenazine and bromocriptine on follicular dynamics and endocrine profiles in anestrous pony mares. Nineteen anestrous pony mares were used in a project designed to determine the effects of altered prolactin concentrations on follicular dynamics and endocrine profiles during spring transition. The dopamine antagonist, perphenazine, was administered daily to mares (0.375 mg/kg body weight) in Group A (n = 6), while Group B mares (n = 7) received 0.08 mg/kg metabolic weight (kg75) dopamine agonist, 2-bromo-ergocriptine, intramuscularly twice daily. Mares in Group C (n = 6) received 0.08 mg/kg75, i.m., saline twice daily. Treatment began January 20, 1994, and continued until ovulation occurred....
Transrectal color Doppler sonography of the A. uterina in cyclic mares. Color Doppler ultrasound was used transrectally in 6 mares to locate both the left and right Aa. uterinae and to obtain flow velocity waveforms at defined times (Days 0, 5, 10, 15 and 20) during 4 estrous cycles. Blood flow reflected by the resistance index (RI) was determined for both arteries on 120 occasions. As there was no significant difference and a high correlation in the RI values between the left and right arteries (paired Student's t-test, correlation coefficient r > 0.94; P < 0.05), the average RI value was used for subsequent analyses. There were correlations between RI valu...
Effect of passive immunization against inhibin on FSH secretion, folliculogenesis and ovulation rate during the follicular phase of the estrous cycle in mares. Physiological roles of inhibin in mares were investigated by means of passive immunization using an antiserum to inhibin that had been raised in a castrated goat. Eight mares were given an intravenous injection of either 100 mL (n = 4) or 200 mL (n = 4) of inhibin antiserum 4 d after a single intramuscular injection of PGF2 alpha on Day 8 after ovulation, 4 control mares were treated with 100 mL castrated goat serum in the same manner. Jugular vein blood samples were collected after treatment with the serum until 192 h post treatment. Follicular growth and ovulations were monitored by ultrasou...
Effect of insemination dose on pregnancy rate in mares. Different insemination doses have been used for artificial insemination(AI) in horses. Since the insemination dose can affect the pregnancy rate, it is important to ensure that an adequate dose be used regardless of the type of inseminationprotocol used. The aim of this study was to find out if it is possible to decrease the insemination dose from 500 x 10(6) progressively motile spermatozoa to 300 x 10(6) progressively motile spermatozoa and still maintain an acceptable pregnancy rate when using extended fresh semen. Thirteen stallions of known fertility and a well-defined group of 64 mares w...
Effect of oxytocin, prostaglandin F2 alpha, and clenbuterol on uterine dynamics in mares. The effects of oxytocin, prostaglandin F2 alpha (PGF2 alpha), and clenbuterol on uterine contractility and tone during anestrus and diestrus, and during mobility and postfixation of the embryonic vesicle were studied in 51 pony mares. Contractility was assessed by scoring real-time ultrasound images, and tone was assessed by transrectal digital compression. Scoring was done by an operator who had no knowledge of treatment assignments. In anovulatory mares primed with progesterone for 16 d, oxytocin did not significantly alter contractility but did stimulate an increase in tone, whereas clenbut...
Administration of oxytocin immediately after insemination does not improve pregnancy rates in mares bred by fertile or subfertile stallions. It is probable that reduced pregnancy rates in mares bred to subfertile stallions is attributable, in part, to the reduced number of normal spermatozoa that colonize the oviduct. Administration of oxytocin stimulates both uterine and oviductal contractility. The hypothesis that oxytocin may enhance sperm transport to/into the oviducts, and thereby increase pregnancy rates, was tested in 2 trials. For both trials, fertile estrous mares with follicles > or = 35 mm in diameter were inseminated once at 24 h after administration of 1500 to 2000 U hCG. The inseminate dose was limited to 100 milli...
Hepatic abscesses in three horses. Hepatic abscesses were diagnosed in 3 adult horses. Two were < 4 years old and had evidence of concurrent immune-mediated conditions, including aseptic arthritis, immune-mediated thrombocytopenia, and immune-mediated anemia. Predisposing factors for hepatic abscess formation in these horses included prior abdominal surgery, proximal duodenitis/jejunitis, inflammatory bowel disease, and a penetrating foreign body in the large colon. Serum hepatic enzyme activities were within or slightly greater then reference limits in all 3 horses. The most pronounced and consistent abnormalities on CBC an...
Measurements of hindlimb blood flow recorded using Doppler ultrasound during administration of vasoactive agents in halothane-anesthetized horses. The purpose of the study was to determine the ability of Doppler ultrasound to detect changes in femoral blood flow during pharmacologic manipulation of arterial blood pressure. Doppler ultrasonography was performed in the femoral vessels of six halothane-anesthetized horses before and during administration of phenylephrine HCI and sodium nitroprusside. The time-averaged mean velocity and volumetric flow were calculated. The contour of the velocity waveform was assessed, and the early diastolic deceleration slope (EDDS) and pulsatility index (PI) were calculated. Administration of phenylephrin...
Structure-related echoes in ultrasonographic images of equine superficial digital flexor tendons. To develop a method to discriminate between structure-related echoes and echoes resulting from interference, as observed in transverse ultrasonographic images of equine superficial digital flexor (SDF) tendons. Methods: 2 normal (injury-free) SDF tendons obtained from a 3-year-old Thoroughbred and a 9-year-old Dutch Warmblood horse. Methods: Tendons were mounted in a custom-made device that permitted exact transverse and perpendicular sequential scanning with precise steps of 0.5 mm along the long axis of the tendon. Photographs of transverse tendon sections at the exact scanning locations wer...
Ultrasonographic tissue characterization of equine superficial digital flexor tendons by means of gray level statistics. To correlate quantitative analysis of ultrasonographic images of normal (injury-free) equine superficial digital flexor (SDF) tendons and equine SFD tendons that have pathologic changes with corresponding histologic sections. Methods: 4 SDF tendons, 2 of which had various stages of tissue integrity. The 2 ipsilateral tendons were used as points of reference. Methods: Tendons were mounted in a custom-made device that permitted sequential scanning, transversely and perpendicular to the tendon long axis. At precise steps of 0.5 mm, transverse ultrasonographic images were collected. Subsequently, ...
