Topic:Diagnostic Technique
Diagnostic techniques in equine medicine encompass a range of procedures and tools used to identify diseases, injuries, or other health conditions in horses. These techniques include imaging methods such as radiography, ultrasonography, and magnetic resonance imaging (MRI), as well as laboratory tests like blood work and tissue biopsies. Each diagnostic method provides specific information that can aid in the assessment and management of equine health issues. Radiography is commonly used for evaluating bone structures, while ultrasonography is useful for soft tissue examination. MRI offers detailed images of both soft and hard tissues, though its use is limited by cost and availability. Laboratory tests can detect biochemical and hematological changes indicative of disease. This page compiles peer-reviewed research studies and scholarly articles that explore the development, application, and efficacy of various diagnostic techniques in equine veterinary practice.
Pulmonary arterial wedge pressures: blood gas tensions and pH in the resting horse. Blood pressure recordings were made from right atrium, right ventricle, pulmonary trunk, and pulmonary arterial "wedge" positions in the standing, resting, adult horse. Similarly, comparisons were made of blood samples collected from these vascular positions, as well as from jugular vein and carotid artery. A consistently lower partial pressure of carbon dioxide and a greater partial pressure of oxygen and pH were found in blood samples from pulmonary arterial wedge than from carotid artery. A technique for safe and rapid collection of pulmonary trunk and pulmonary arterial wedge blood gases, ...
A surgical technique applied to the study of tubal eggs in the mare. An efficient surgical technique of collecting eggs from the oviducts of mares is described. Within 6 days after ovulation recovery was successful in 22/29 mares. The technique has been used to investigate the retention and ageing of eggs in the oviducts and to determine the origin and the nature of the accessory CL during pregnancy.
Oestrogen excretion in mares in relation to various reproductive states. The rate of urinary oestrogen excretion was studied in four ovariectomized mares. In two animals ovariectomized when urinary oestrogen concentration was high, levels fell to a minimun within 48 hr. Intramuscular injection of oestradiol-17beta produced maximum urinary oestrogen levels within 3 to 6 hr and a return to minimum detectable levels within 24 hr. The major urinary oestrogen in mares was oestrone. In nine maiden mares studied between September and June, the cycle, the durations of dioestrus and oestrus, and the time of ovulation were similar in autumn (September to December) and spring...
Comparison of the methods of rectal palpation and haemagglutination-inhibition assay for diagnosis of pregnancy in mares. The diagnostic value of rectal palpation and immunological assay of PMSG was tested at different stages of pregnancy in mares inseminated with frozen semen in three separate studies. The results were based on foaling success and particular attention was paid to the numbers of inconsistent results obtained by the two tests. Generally, the number of false positive diagnoses was lower for the immunological assay than for palpation in early pregnancy (Days 40 to 60) and the relationship became reversed later in gestation.
Aspects of respiration in anaesthetized newborn foals. The arterial oxygen tension (PaO2) in clinically normal newborn foals at 1300 m above sea-level is considerably lower (less than 60 mmHg) than in similarly aged foals at lower altitudes. This figure is further reduced to less than 50 mmHg without adverse effect in newborn foals at 1300 m maintained under pentobarbitone anaesthesia for prolonged periods. Measurement of O2 dissociation curves indicates that haemoglobin becomes saturated at a lower blood O2 tension in newborn foals than adult horses.
Follicular and luteal development in pregnant mares. Examination of the ovaries of mares at various stages of pregnancy and after hysterectomy, together with measurement of progesterone concentrations in the peripheral plasma of pregnant and hysterectomized mares and in uterine and ovarian venous plasma of pregnant mares, demonstrated that the primary CL of pregnancy remains functional until at least Day 160 of gestation. The results showed that primary and secondary CL, and the placenta or uterus, all contribute to the total progesterone pool in mares during pregnancy. Similarities and differences in ovarian function observed between pregnant a...
Plasma progestagens in the pregnant mare in the first and last 90 days of gestation. Plasma progestagens were measured in eighteen pregnant mares to establish normal levels in the first and last 90 days of gestation. Progestagens increased from 25 ng/ml at 90 days before birth to 60 ng/ml at 10 days before birth, decreased to 58 ng/ml at 5 days before, and were 3 ng/ml or less by 5 days after perturition. During the first 90 days of pregnancy, progestagens reflected luteal activity with an increase in plasma levels from Day 30 to Day 60.
Ontogeny of equine haemoglobins. Studies were made of the O2 affinities of fetal and maternal haemoglobins in the horse, and correlations were found with erythrocytic levels of 2,3-diphosphoglycerate.
The site of ovulation in the mare. Serial photography of the ovary of a mare by periodic surgical exteriorization of the ovary and peritonescopy in situ revealed that the ovulatory fossa is the site of ovulation in this species.
Plasma progestagens in pregnant mares. Peripheral plasma progestagens were quantified by a competitive protein-binding assay throughout pregnancy. The level of progesterone increased significantly between Days 0 and 8 (P less than 0-05) and again between Days 28 and 44 and reached a maximum on Day 64. Subsequently, it fell slowly until about Day 300 and then rose again during the last 30 days before reaching a minimum on the day after foaling. Very low concentrations of 17alpha-hydroxyprogesterone were found except between Days 40 and 120 and during the last 30 days before birth. Two unidentified compounds, one eluting slightly bef...
Serum concentrations of FSH, LH and progesterone during the oestrous cycle and early pregnancy in the mare. Heterologous radioimmunoassays were developed for equine FSH and LH. Serum concentrations were measured in twenty-three mares throughout the oestrous cycle and early pregnancy. FSH concentrations were raised fivefold by 'surges' rather than 'spiked', occurring at 10- to 11-day intervals during the oestrous cycle and early pregnancy. The late oestrous/early dioestrous surge of FSH appeared to initiate development of up to twenty follicles. The mid-dioestrous surge may be important for the further development of follicles destined to ovulate 10 to 13 days later. Levels of LH were increasing by t...
The effect of rectal palpation on the fertility of cyclic mares. The effect of rectal palpation of fertility of non-lactating, normal cyclic mares was studied over 3 years. During the first year (1971), the conception rates in mares after daily paplaption during oestrus only, and during oestrus and the first 50 days of pregnancy, were not significantly lower (P greater than 0-05) than the conception rates recorded in mares not palpated. No abortions could be attributed to palpation. Oestrus lasted longer (P less than 0-05) in non-palpated than palpated mares. During the second year (1972), first-cycle pregnancy rates in two groups of mares palpated daily du...
The use of intravascular catheters for long-term studies on the mare and fetus. Methods developed for the insertion of catheters into the umbilical artery and vein and the uterine vein of the pregnancy mare are described. The technique requires careful anaesthesia and the maintenance of normal blood gas tensions, pH and arterial blood pressure. Fetal survival was variable: three mares delivered live foals and six fetuses survived more than 15 days with a maximal period of 41 days. The erythrocytes sedimentation rate (ESR) of the fetal foal was always very low at operation but subsequently increased slightly; a sudden large rise in ESR usually indicated imminent fetal deat...
Plasma progestagens in cyclic, pregnant and post-partum mares. The pattern of plasma progestagen levels during the oestrous cycle was similar to that previously reported except for lower peak levels. The lack of significant difference (p less than 0-01) between CPBA and RIA values suggests that progesterone itself is the major component during the oestrous cycle. Progesterone levels during the first and second post-parturient oestrous cycles were similar to those observed during the cycle of the non-pregnant mare. During pregnancy there were two peaks of plasma progestagens. The first, which occurred during the 3rd month, coincided with high levels of PMS...
[Production of antirickettsial sera by immunizing horses. II. Obtaining and testing an immune serum to D. sibericus]. The authors present the results of immunization of horses-producers with a commercial antigen and the yolk culture of the living R. sibericus (strain K1) for the purpose of obtaining specific immune sera for many purposes. It was shown that the original combined scheme of immunization and reimmunization of horses, successfully approved in the preparation of immune sera to Rickettsia prowazeki also proved to be highly effective for obtaining the antisera to R. sibericus. Sera obtained after the primary immunization of horses could be successfully used as diagnostic sera, but they were of no use...
Identification of multiple equine infectious anemia antigens by immunodiffusion reactions. Equine infectious anemia (EIA) cell antigens prepared from infected equine spleen, equine leukocyte cultures or a persistently infected equine dermis cell line contained at least two serologically reacting components. For convenience one component was designated as soluble antigen (SA) and the other as cell-associated antigen (CAA). The SA appeared as a single component when it was prepared from EIA virus precipitated from infectious tissue culture fluid with polyethylene glycol and ether treated but it was mixed with CAA when the source was infected cells. Cytolytic or mechanical disruption o...
Morphology and histochemistry of the endometrial cup. The luminal and cut surface of endometrial cups were examined by scanning electron microscopy. The distribution of PAS-positive and lipid materials in cup tissue was studied and most of the lipid material was localized in the large polyhedral cup cells. The lipid droplets gave positive reactions for DNPH in the cholesterol test of Schultz. They also exhibited autofluorescence and were therefore considered to be steroidal in nature. The significance of this possibility, particularly with regard to maintenance of early pregnancy in the mare, is discussed.
Plasma immunoreactive calcitonin levels in pregnant mares and newborn foals. Plasma calcium and calcitonin levels were measured periodically during the two last months of pregnancy and at the time of parturition in 9 pregnant mares and their foals. In pregnant animals, there was an increase in plasma calcitonin levels in the days before parturition, which was not due to any change in plasma calcium. This result indicates that in the mare, as in the cow, in the days before parturition CT secretion escapes from its control by plasma calcium. In 0-day and 7-day-old foals plasma calcium levels were significantly higher than in their mothers, but plasma calcitonin levels we...
Collection of bone grafts from the tuber coxae of the horse. Autogenous bone grafts were obtained from the tuber coxae of 9 horses. The method used involved an oblique incision to expose the lateral aspect of the tuber coxae. The periosteum was incised and reflected in order to make a 5- by 2.5-cm opening in the lateral cortex for graft retrieval. The method provided good visualization, ample grafting material, and freedom from postsurgical complications.
Bile acid kinetics and bile secretion in the pony. Bile acid pool size and synthesis rate were determined by both isotope-dilution and washout methods in ponies with chronic external biliary fistulas. Bile acid pool size (10.9 mumol/kg) and synthesis rate (11.2 mumol/day per kg) estimated by the isotope-dilution method did not differ significantly from pool size (9.4 mumol/kg) and synthesis rate (9.5 mumol/day per kg) estimated by washout method. Bile acid-dependent and -independent fractions of bile flow, determined by a method that circumvents any inevitable correlation of flow to bile acid secretion due to common factors in both parameters,...
Nerve distribution in the metacarpus and front digit of the horse. The nerve distribution to the digit of the horse was studied with the compound microscope in serial transverse sections of fetal limbs and plotted on life-size outlines of the horse's foot. It was learned that there is much variation in the topography of the branches of the principal nerves. There is no mirror-image nerve distribution on the 2 sides of the foot. The dorsal branch of the ulnar nerve does not extend below the fetlock. The communication between the palmar metacarpal nerves and branches of the dorsal branch of the digital nerves is only a crossing of nerves without exchange of fib...
Studies on the epidemiology of Strongylus vulgaris infection of the horse. Studies on the epidemiology of Strongylus vulgaris infection of the
horse. International Journalfor Parasitology 5: 423426. Observations are reported on the size and age
structure of Stronglyus vulguris populations recovered from the anterior mesenteric artery and its
main branches of horses slaughtered at regular intervals throughout a year. Marked seasonal variations were found in the mean monthly numbers of worms present. During spring/early summer the
numbers were relatively low and a large proportion of the arteries had no worms in them at all.
Thereafter, the arterial worm burdens q...
Papers and articles measurement of central venous pressure in horses. Central venous pressure measurements were made in 74 horses and ponies free from clinical evidence of cardiopulmonary disease. Using the sternal manubrium as the zero reference point, the mean value obtained was 12 cm H2O (S.D. +/- 6). There was a significant correlation with body weight (r=0.6, p less than 0.001) but there was none with age, sex, breed or type. During halothane anaesthesia, using the same reference point, the mean value was 24.5 cm H2O (S.D. +/- 6) in 28 animals in right lateral recumbency, 29 cm H2O (S.D. +/- 8) in 17 animals in left lateral recumbency and -6 cm H20 (S.D. +/...
Auto-immune hemolytic anemia in two horses. Two cases of Auto-immune hemolytic anemia (AHA) in the horse are described. The pathogenesis of AHA in man is related to the findings in the horses. Besides from routine hematological and biochemical investigations specific data were obtained from the erythrocyte osmotic fragility test, the Coombs test, the serum haptoglobulin level and the cold agglutinin test. The first patient, a six month old Dutch standardbred colt, probably suffered from an acute attack of cold-induced hemoglobinuria with severe anemia and acronecrosis of the tops of both ears and of several parts of the skin that had be...
[Dry erythrocytic diagnostic agent for the determination of antiglobulins]. Dry erythrocytic diagnostic agents were obtained under experimental conditions for determination of antiglobulins forming in the organism of man and animals under the effect of serum preparations from the blood of horses and homologoum immunoglobulins. A study was made of the sera of 100 patients with tick-borne encephalitis treated with heterologous and homologous immunoglobulins of directed action; in response to the administration of horse gamma-globulin antiglobulins (in titres below 1 : 10000) appeared in the serum; they circulated in the blood for long periods and inhibited the accumulat...