The vascular system in horses encompasses a network of blood vessels responsible for the circulation of blood throughout the body. This system includes arteries, veins, and capillaries, which facilitate the transport of oxygen, nutrients, and waste products to and from tissues. The vascular health of horses is vital for maintaining overall physiological function and performance. Common areas of study within equine vascular research include the examination of blood flow dynamics, vascular diseases, and the impact of exercise on vascular function. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and clinical relevance of the vascular system in equine health.
Blue MG.The objective of this study was to investigate an hypothesis that chromosome anomalies are an important cause of prenatal loss in the mare. An attempt was made to analyse, cytogenetically, a series of 26 equine abortuses. Cell cultures were prepared from a range of tissues, but failed to grow, and chromosome analysis was therefore not possible for any of these specimens. Consequently, a study was made of the metaphase chromosomes prepared from 22 equine embryos after their surgical removal from mares' uteri. The karyotypes prepared for each specimen were normal. The current findings are discus...
Robinson NE, Scott JB.The effects of a 60-minute IV infusion of histamine (0.5 mg of histamine base/minute) on the systemic, pulmonary, and digital vasculature were investigated in mature ponies. Immediately after the start of histamine infusion, there were a transient decrease in systemic pressure lasting less than 1 minute and then a brief period of systemic hypertension. Systemic pressure then returned to preinfusion levels for the remainder of the infusion period. Pulmonary arterial pressure increased transiently coincident with systemic hypotension. Histamine increased cardiac output and decreased both total p...
Allen WE, Newcombe JR.The records of 200 pairs of consecutive pregnancies in mares showed that in 82 per cent of cases the second pregnancy was initially established in the opposite uterine horn to that of the first, irrespective of the parturition to conception interval. This relationship also occurred when the first pregnancy ended in abortion after 140 days but not if it terminated before this time.
Tatarov G, Khristov S, Martinov S, Gergov P, Khristova V.Attempts were made to produce inactivated vaccines against horse Herpes virus 1, using various inactivating agents and adjuvants, Best results were obtained with vaccine No 3 (glutaraldehide inactivator and "CTC" adjuvant). Used were two strains of the virus (St. Karaja and Varna). isolated in this country in cell cultures of a sucking pig kidney. Vaccine No 3 showed good immunogenic properties. Its application resulted in the full cease of abortions and respiratory diseases on the base of infection with the horse Herpes virus 1. The vaccination protects newborn colts from rhinopneumonitis if ...
Gleeson LJ, Coggins L.Twenty-one pregnant mares were inoculated with EHV1. Nineteen became infected as evidenced by clinical signs and/or viremia but only one mare aborted a virus-infected fetus. The viremias were leukocyte-associated and appeared to be non-productive, latent infections of these cells. Infectivity, detectable by cocultivation, persisted in the circulating leukocytes for as long as 9 days without resulting in abortion. The data suggest that it is extremely difficult to evaluate the efficacy of vaccines in preventing EHV1 (Rhinopneumonitis) abortion due to the paucity of non-exposed mares, lack of te...
Greenwood RE, Simson AR.An outbreak of ataxia and paralysis on a Thoroughbred studfarm is reported. The cause of the disease was attributed to equid herpesvirus (EHV1) infection which stemmed from a single 10-month abortion on the studfarm. Stallions, mares and foals were all affected but the most serious clinical signs occurred in the mares. there were 35 out of 39 mares, 2 out of 4 stallions and 5 out of 39 foals which exhibited signs of ataxia. Nine mares became recumbent and died or were euthanased. Treatment with betamethasone and antibiotics was given. The outbreak was contained to one area of the stud apart fr...
Slone DE, Vaughan JT, Garrett PD, Vaden MF, Purohit RC.The vascular anatomy of the adrenal glands and a surgical technique for bilateral adrenalectomy in the equid are described. Bilateral adrenalectomy was performed in six ponies and one horse via bilateral transcostal retroperitoneal approaches through the 18th rib during a single anesthetic period. Complications included hemorrhage from the right side only and pneumothorax which usually occurred on the right side. One pony died as a result of the surgical technique. Maintenance of adrenal function was accomplished with desoxycorticosterone pivilate and prednisolone.
Squires EL, Hillman RB, Pickett BW, Nett TM.Thirty-two light-horse mares were confirmed to be pregnant and assigned to one of four treatments: (1) injected with 250 micrograms of Equimate on day 70 and again on day 77 if abortion had not occurred; (2) injected with 250 micrograms of Equimate on day 70 and every 24 hr until abortion occurred (maximum four injections); (3) injected with 250 micrograms of Equimate on day 70 and every 12 hr until abortion (maximum eight injections); and (4) injected with 250 micrograms of Equimate once only on day 35 of gestation. Mares were observed four times daily for incidence of abortion or side effect...
Ammar AM, Heitmann J, Kirchhoff H.After abortion sera were taken from 58 thoroughbred and other mares of the northwestern part of Germany and investigated by ELISA (enzyme linked immuno-sorbent assay) for antibodies against Mycoplasma equirhinis, M. subdolum, M. equigenitalium, M. pulmonis, M. felis, Acholeplasma laidlawii, A. hippikon, and A. equifetale. Reactions at serum dilutions of 1:32 and higher were considered as positive. At serum dilution 1:32 no antibodies were found in 11 sera. The remaining sera showed antibodies against one or more of the mycoplasma antigens investigated. The number of multiple reactions decrease...
Eaglesome MD, Henry JN, McKnight JD.Vaccination, in July and again in either November or December 1976, of 55 pregnant Standardbred mares with a live-virus rhinopneumonitis vaccine attenuated in cell culture failed to protect some mares from infection with equine herpesvirus 1. From 1976-12-08 to 1977-03-08, 33 mares foaled healthy foals, 16 mares foaled dead foals or live foals which died usually within 48 hours and six mares aborted. Gross and histological examinations and virus isolation studies confirmed that equine herpesvirus 1 caused 18 of the 22 neonatal deaths, stillbirths or abortions.
Holtan DW, Squires EL, Lapin DR, Ginther OJ.Pony mares were bilaterally ovariectomized at different stages of pregnancy between Days 25 and 210. Abortion or fetal resorption occurred within 2 to 6 days after operations in all 14 mares ovariectomized between Days 25 and 45 and after an interval of 10 to 15 days in 9 of 20 other ovariectomized between 50 and 70 days. All 12 mares ovariectomized on either 140 or 210 days carried their foals to normal term. The termination of early pregnancy was preceded by a loss of uterine tone and of a palpable uterine bulge. The mean length of gestation in all mares in which pregnancy was not interrupte...
Steven DH, Jeffcott LB, Mallon KA, Ricketts SW, Rossdale PD, Samuel CA.Post-partum placentae and uterine biopsy samples from mares after normal and abnormal foalings are described. After normal delivery there is little damage to fetal or maternal tissues. The villous epitheliochorial palcenta separates cleanly at the maternal-fetal interface and the afterbirth consists almost exclusively of fetal tissue. Uterine involution is well advanced by the 3rd and 4th days post partum and the changes are usually complete by the oestrus 7--10 days after parturition. Placental separation and involution of the uterus appear to proceed normally in malpresented foals and in oth...
Barnes RJ, Comline RS, Jeffcott LB, Mitchell MD, Rossdale PD, Silver M.The concentrations of 13, 14-dihydro-15-oxo-prostaglandin F(PGFM), the stable metabolite of prostaglandin F, were measured in the plasma of catheterized mares and foetuses and non-catheterized thoroughbred mares and ponies during the last months of gestation. The plasma concentration of PGFM increased gradually towards term in all groups of animals. During the operation for insertion of catheters, maternal and foetal concentrations of PGFM were high, but the values fell to basal levels 24--48 h after the operation. It was found the preoperative starvation (24 h) led to a rise in the concentrat...
Basu R, Chatterjee A.The administration of pregnant mare's serum gonadotropin (PMSG), 30 IU on day 18 of pregnancy, resulted in premature labor in rats. However, this abortifacient efficacy of PMSG was not demonstrable when a simultaneous injection of progesterone, clomiphene, or indomethacin was scheduled, thus suggesting that the action of PMSG is medicated by the estrogen-stimulated release of prostaglandin. The termination of pseudopregnancy in bilaterally hysterectomized rats by PMSG and its reversal by indomethacin revealed that the inhibition of luteal function by PMSG does not require the presence of a ute...
Anderson BG, Anderson WD.Methyl methacrylic casts were prepared and tissue was freshly collected for histologic examination to compare the vascular supply and the structure of the vessels of the iris in the adult horse with those of the dog. In the horse, ciliary blood vessels divided in the iris and formed a complete major arterial circle of the iris. In the dog, the ciliary blood vessels divided in the ciliary body and, by means of recurrent branches, formed a complete arterial circle. From this circle, radial arteries extended toward the pupillary margin. The radial vessels in the horse were nearly straight and joi...
Dutta SK, Campbell DL.Blastic transformation of peripheral blood mononuclear cells and serum neutralization antibody levels for equine herpesivurs type 1 were measured in 19 mares from three farms at the time of termination of their pregnancy by normal foaling or viral abortion. The stimulation indexes of lymphocytes obtained from the mares from two farms (Farm 1 and 2) which had virus abortions, ranged from 2.1 to 10.8. But there was no significant difference in stimulation index levels between the aborting and normal foaling mares on these two farms. Equine herpesvirus type 1 was isolated from the mononuclear cel...
Allen WE, Newcombe JR.The records of 200 pairs of consecutive pregnancies in mares showed that in 82 per cent of cases the second pregnancy was initially established in the opposite uterine horn to that of the first, irrespective of the parturition to conception interval. This relationship also occurred when the first pregnancy ended in abortion after 140 days but not if it terminated before this time.
HENNING MW.1. Two outbreaks of infectious equine abortions are reported; both
with a very high abortion incidence.
2. In the majority of the abortions studied the foetal organs were found
to be extensively invaded by S. abortus-equi but in others this organism
could not be recovered from the foetus or after-birth.
3. Both donkey and horse mares were found to be susceptible, donkeys
being on the whole more resistant than horses.
4. Abortion was successfully produced in both horse and donkey mares
by means of (a) the oral administration of minced abortus-equi infected
foetal organs (4 cas...
Singh M, Charan S.To study the immunokinetics of equine herpesvirus 1 (EHV1), donkey mares were immunised with a laboratory strain of EHV1, or with recommended doses of Pneumabort-K vaccine (EHV1 Army 183 strain, formalin-inactivated, with an oil adjuvant) and a booster was given after three months. Humoral immune responses were studied by employing a virus neutralisation (VN) test. A leucocyte migration inhibition test (LMIT) was employed for the assay of cellular immune responses. The VN antibody titre reached 1:64 or 1:128 after primary immunisation and showed a marginal increase (1:256) after secondary immu...
Shortridge EH.Extract
Recent reviews of brucellosis in horses (Stableforth and Galloway, Citation1959; Mascaro and Hoffman, Citation1963: Ritscher, Citation1963) refer to Brucella abortus associated with fistulous withers, arthritis and debility and emphasize the rarity of abortion caused by this organism. One case of abortion in a mare caused by Br. abortus was reported as having occurred in Iowa, U.S.A. (McNutt and Murray, Citation1924).
Bergentz SE.Jean Martin Charcot was the first to give a detailed description of intermittent claudication, and a correct interpretation of the mechanism behind the symptoms. He borrowed the name of the syndrome from the veterinarian literature, where it had been described to occur in horses, and caused by inflammatory changes in aorta at the origin of the large vessels to the extremities. The case presented by Charcot was a man with a traumatic pseudoaneurysm in his common iliac artery. He had in addition an arterio-enteric fistula, a condition which probably had not been described before.