Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Peters GJ, Oosterhof A, Veerkamp JH.1. Adenosine inhibits thymidine and uridine incorporation of PHA-stimulated lymphocytes of man and horse at concentrations higher than 50 and 10 microM, respectively. Deoxyadenosine is inhibitory at concentrations higher than 100 microM. Thymidine and uridine incorporation of porcine lymphocytes are elevated 5-7-fold by 25-100 microM adenosine, deoxyadenosine, inosine and hypoxanthine. Leucine incorporation of PHA-stimulated lymphocytes was affected by adenosine and deoxyadenosine in the same way, but to a lower extent. 2. Effects of adenosine and deoxyadenosine were more pronounced at shorter...
McChesney SL, England JJ, McChesney AE.An agent lethal to embryonated chicken eggs was isolated from lung tissues of a quarter horse mare with a fatal respiratory disease. The lesions induced in embryonated chicken eggs, the tinctoral properties, the ultrastructural morphology, the resistance of the organism to sodium sulfadiazine, and the presence of a chlamydial complement fixing antigen, identify this isolate as a member of the family Chlamydiaceae and suggest the agent to be Chlamydia psittaci. Two Shetland ponies experimentally infected with the isolated agent developed subclinical infection as demonstrated by an increase in c...
Kydd J, Miller J, Antczak DF, Allen WR.The maternal immunological response to the developing equine fetus was investigated in 69 pregnancies of various genotypes. In normal intraspecies horse pregnancy (N = 16), 94% of mares produced strong cytotoxic antibody responses to paternal histocompatibility antigens which were first detectable between 44 and 70 days after ovulation. In all other types of pregnancy examined (intraspecies donkey, N = 19; interspecies mule, N = 6; interspecies hinny, N = 2; extraspecies horse-in-donkey, N = 3; and extraspecies donkey-in-horse, N = 21), antibody production was observed less frequently, and som...
Chevalier F, Palmer E.Ultrasonic echography in the mare allows pregnancy diagnosis as early as Day 14 after ovulation. In the 1980 and 1981 breeding seasons, a total of 7438 examinations of 4688 mares were performed on several farms with the same apparatus. The accuracy of positive pregnancy diagnosis was estimated to be greater than 95% and of non-pregnancy diagnosis greater than 84%. When abnormal pictures of vesicles are found, it has to be decided whether it is a conceptus or a cystic structure. Most small vesicles do not develop, whereas large ones, deformed shapes, presence of some echoes, or a division insid...
Brown MP, Stover SM, Kelly RH, Farver TB.Six adult mares were given a single dose of ampicillin trihydrate (250 mg/ml) intramuscularly at a dosage of 20 mg/kg body weight. Serum, synovial fluid, peritoneal fluid and urine ampicillin concentrations were measured serially over a 48 h period. The mean peak serum ampicillin concentration was 2.49 micrograms/ml at 6 h. Ampicillin was found in synovial fluid and peritoneal fluid, which obtained mean peak ampicillin concentrations of 1.65 micrograms/ml and 1.81 micrograms/ml at 6 h and 4 h respectively. These concentrations declined in parallel with serum concentrations and were still detec...
Zavy MT, Sharp DC, Bazer FW, Fazleabas A, Sessions F, Roberts RM.Uterine secretions were obtained on Days 4, 8, 12, 14, 16, 18 and 20 of the oestrous cycle and early pregnancy. Acid phosphatase activity was significantly affected by day of the cycle, reaching a maximum at days 12-14 during the luteal phase and then declining to almost undetectable levels, by Day 20. In pregnant animals, activity continued to increase beyond Day 14. Two-dimensional polyacrylamide gel electrophoresis showed that albumin was a major component. However, a number of unique proteins of non-serum origin appeared in mid-cycle but had disappeared by Day 20. One of these was a basic ...
Saltiel A, Calderon A, Garcia N, Hurley DP.Ovarian activity, as measured by the presence of small (10-15 mm diam.), medium (15-30 mm) and large (greater than 30 mm) follicles, corpora haemorrhagica and corpora lutea (CL), was determined in a total of 3584 ovaries during 1 year using post-mortem specimens. There were significant correlations of the incidence of ovulated follicles (ovulations), large and medium follicles (P less than 0 . 001) and of the mean number of small follicles (P less than 0 . 05) per mare with respect to season. The yearly averages of ovulated, large and medium follicles were 30 . 1, 13 . 9 and 73 . 9%, respectiv...
Jeffcott LB, Kold SE.Thirty-three cases with subchondral bone cysts in the stifle are reported. The condition was most commonly seen in young Thoroughbreds and produced intermittent lameness of varying degree. Radiographically distinct areas of radiolucency were found in the distal femur or proximal tibia adjacent to the femorotibial joint. Lesions were usually unilateral but 5 horses had cysts in both stifles. The cases could be divided into 2 distinct groups. Horses in Group A (28 cases) had a large circular or dome-shaped cyst in the medial femoral condyle with a distinct communication with the femorotibial joi...
Leishman D, Miller RB, Doig PA.The density of uterine glands, height of surface epithelium, numbers of hemosiderin laden macrophages, inflammatory cells and layers of periglandular fibrosis were evaluated in uterine biopsies from 40 mares. These features were found to be highly variable in normal equine endometrium. Minor pathological changes appeared to be masked by this normal variability. Atrophy of uterine glands was recognized in mares which had been barren for more than three years. No significant differences were found between barren and normal mares in the height of epithelium, number of hemosiderin laden macrophage...
Acland HM, Allen PZ, Kenney RM.Twenty-three of 24 mares were infected experimentally with contagious equine metritis organisms by intrauterine inoculation, and killed 2-116 days later. From mares killed within 14 days after infection the organism could be recovered from many sites in the uterus, and most sites in the cervix, a few sites in the vagina and oviduct and from one clitoral sinus. At this time the endometrial folds were swollen and there were 10-20 ml of fluid in the uterus. In mares killed after 14 days, the organism was recovered from the ovarian surface (1 mare), oviduct (4 mares), uterus (2 mares) and the clit...
Alexander S, Irvine CH.Mares were bled once daily throughout a cycle, or 3 times daily from the first day of oestrus to the 2nd day after ovulation. LH was measured by heterologous radioimmunoassay and by an in-vitro bioassay based on LH-stimulated testosterone production by mouse Leydig cells. The patterns of bio- and immuno-active LH during the oestrous cycle were similar but not identical, so that in both groups of mares the ratio of biological: immunological (B:I) activity during the LH surge was significantly higher before than after ovulation (P less than 0 . 001). Considerable individual variation in cycle me...
Deegen E, Müller P, Petzoldt K.On the basis of cytological similarities in chronic obstructive disease (COPD) in human beings and in horses during 1981 a total number of 144 horses with COPD were examined. Bronchial secretions were taken under endoscopic control and stained with a modified Hansel staining procedure. Whereas 26 horses did not exhibit signs of allergic reactions cytologically and 94 horses showed low amounts of eosinocytes and/or mast cells in their secretion; only the secretions of 24 horses (16,67%) were characterized by fairly high contents of these allergy associated cells and low numbers of neutrophilic ...
Weiser MG.Erythrocyte volume distribution curves (erythrograms) were determined on a total of 300 blood samples from healthy dogs, cats, horses, and cattle (dairy cows). An index of anisocytosis was determined for these animals. Erythrograms were highly reproducible, and the mean corpuscular volumes determined from erythrograms compared well with those determined from hemograms. Bovine and equine erythrocyte volumes were found to be stable after the blood was stored at 4 C for 24 hours. Under the same conditions, canine and feline erythrocytes increased slightly in volume. After incubation of blood dilu...
Otcenásek M, Mátl J, Vítovec J, Vladík P, Wohlman J.A case of maduromycotic mycetoma (eumycetoma) in seven years old draught horse is described. The disease was localized in anal region and healed after surgical treatment. Attention is drawn to the necessity of distinguishing three types of mycosis in horses, characterized by the origin of tumor lesions - mycetomas, hyphomycosis and entomophthoromycosis - and information was gathered on their etiology and geographical occurrence. On the basis of the morphology of fungal elements traced in inflammated changed tissues and with regard to the existing findings on the origin of eumycetoma in animals...
Bader H.A total of 23 mares were inseminated once within 0-6 h after clinical detection of ovulation, 14 with fresh and 9 with deep-frozen semen containing 0.1 x 10(9) to 4.7 x 10(9) motile spermatozoa. Within these two groups, the mares were slaughtered 2, 4 or 6 h after insemination and their genital tracts removed. The utero-tubal junction, isthmus and ampulla ipsilateral to the ovary in which ovulation occurred were flushed separately for sperm recovery. In 1 or 2 mares of each group, the uterine horn and corpus uteri, the cervix and vagina were also flushed. Tissue samples were collected from the...
Oltner R, Edqvist LE.Progesterone concentrations in heparinized plasma harvested immediately after blood collection were compared with levels obtained after storage of the corresponding whole blood for 2 h, 4 h, 6 h, 1 day, 2 days and 5 days at room temperature and in a refrigerator. The blood was taken during the luteal phase from 4 dogs, 4 horses, 4 pigs and 8 cows. For 4 cows the storage time was extended to 9 and 20 days. No significant effect of whole blood storage time on plasma progesterone concentrations could be shown for dogs or pigs. For the horse a slight but significant decrease was demonstrated when ...
Blue MG, Brady AA, Davidson JN, Kenney RM.Forty uterine fluid samples were obtained during oestrus and dioestrus of successive cycles from 4 mares classified as resistant to bacterial infection of the uterus. The flushings were assayed for peroxidase activity and ability to influence phagocytosis by polymorphonuclear neutrophils. Uterine fluid volumes and protein concentrations and serum oestrogen values were similar during oestrus and dioestrus. Serum progesterone concentrations were depressed during oestrus. Equine neutrophils adherent to glass slides were exposed to a genital strain of Streptococcus zooepidemicus suspended in salin...
Pashen RL, Sheldrick EL, Allen WR, Flint AP.The gonads of the fetal horse were found to be relatively devoid of 3 beta-hydroxysteroid dehydrogenase and other enzymes which metabolize dehydroepiandrosterone (DHA). In short-term in-vitro incubation experiments fetal liver converted DHA to the potential equilin precursor, 7 alpha-hydroxy DHA. DHA was converted to oestrone when incubated with extracts of horse placenta but 7 alpha-hydroxy DHA was not converted to equilin. Levels of DHA measured in peripheral blood of mares throughout pregnancy paralleled those of equilin and oestrone, and DHA concentrations fell rapidly after fetal gonadect...
Mantovani A, Caporale V, Ciuchini F, Di Trani L, Irsara A, Prosperi S.The results of antibody titrations in different animal species vaccinated against rabies are reported. The following points are considered: (1) antibody titration may be used to detect an immunity status in dogs, (2) equines should be vaccinated in infected areas, (3) experiments in progress are comparing ERA vaccine and an inactivated vaccine in bovines, and (4) the vaccination of fallow deer (Dama dama) and moufflons (Ovis ammon musimon) produced results suggesting an extension of the experiment with the purpose of vaccinating wild ruminants whenever possible.
Roser JF, Evans JW, Mikuckis GM, Adams TE, Hughes JP.As quantified by Scatchard analysis, a 27 000 g crude luteal membrane fraction contained a single population of unoccupied LH receptors characterized by high affinity, ka = 0.647 +/- 0.158 X 10(11) M-1 and low binding capacity, Rt = 4.91 +/- 0.78 X 10(-11) M/mg membrane fraction. Acceptable hormonal specificity, reversibility, saturability, high affinity and tissue specificity indicated that the binding protein was a physiological receptor. To ensure that the methods used for Scatchard analysis were valid, hCG was characterized for specific activity and maximum bindability, non-specific bindin...
Mayhew IG.A technique for the subarachnoid perfusion-fixation of the central nervous system was developed to help identify various significant vascular accidents (SVAs) in the central nervous system (CNS) of 24 neonatal foals submitted for necropsy. SVAs, comprising subarachnoid, parenchymal and nerve root haemorrhages, and oedema and necrosis, occurred in 17 foals, more frequently in the spinal cord than the brain. They occurred as frequently in premature foals as in those born at full term, in foals born dead as in foals born alive, and in foals born following dystocia with an assisted delivery as in ...
Schmidt GM, Krehbiel JD, Coley SC, Leid RW.Nuchal ligaments from midwestern U.S. horses infected with adult Onchocerca sp. were studied. The prevalence of Onchocerca sp. infection in horses increased with age. Ten percent of horses less than one year old were infected, 28% of horses one to five years old, 48% of horses six to 15 years old, and 90% of horses over 16 years old. Lesions in Onchocerca sp.-infected nuchal ligaments varied with age of the horse. Horses less than five years old had few or no lesions, whereas most horses six to 15 years old had focal mineralization and granuloma formation around adult worms. In infected nuchal...
Sugiura T, Nakajima H.An indirect hemagglutination was developed for the diagnosis of equine infectious anemia using sheep red blood cells coated with group specific virus antigen which had been highly purified by affinity chromatography. The presence of indirect hemagglutination antibodies was demonstrated in horses with equine infectious anemia since the cells were specifically agglutinated by all the serum samples obtained from experimentally infected horses. Antibodies appeared within 35 days after inoculation, and development of which coincided well with that of precipitating and complement fixing antibodies. ...
Glade MJ, Krook L.Changes in the developing femoral epiphysis, especially those concerning the osteocytes, were examined in pony foals systemically treated with daily intramuscular injections of either 0.5 or 5.0 mg of dexamethasone per 100 kg bodyweight for either 3, 8 or 11 months. Midsagittal sections of proximal femur from animals treated for 3 months contained significantly more bone tissue subchondrally and epiphyseally than did sections from untreated ponies. Large portions of the bone tissue appeared necrotic, although osteoblasts and patent capillaries were abundant. After 8 months the bone sections re...
Ganjam VK, McLeod C, Klesius PH, Washburn SM, Kwapien R, Brown B, Fazeli MH.The reaction between ovarian hormones and experimental uterine infection (Streptococcus zooepidemicus) was investigated in 3 groups, each containing 6 ovariectomized mares. Group 1 served as controls ('anoestrus'), Group 2 mares were injected with oestrogen ('oestrus') and Group 3 with progesterone ('dioestrus') over a period of 5 weeks. All mares received an intrauterine inoculation of the bacteria 1 week after the start of hormonal treatment, and the results of the challenge were examined by endometrial biopsy and swabs once weekly. At the end of Week 1 no bacteria were recovered from the ma...
Britton BA.Cervical and endometrial swabs were taken from 7 mares at various stages of the oestrous cycle. There was no consistent pattern of cell change throughout the cycle. The dominant cell in smears from normal mares was the columnar epithelial cell, especially in smears obtained during oestrus. A ciliated columnar epithelial cell was found much less frequently but appeared more often in smears before oestrus. Endometrial biopsies were also collected from 7 mares at intervals 2-3 weeks over an 8-month period from the beginning of spring to the end of autumn. There was no obvious change in the endome...
Melrose PA, Douglas RH.Scanning electron microscopy showed that cells in the infundibular recess of prepubertal female horses were devoid of cilia and sparsely covered with stubby microvilli and small blebs, whereas superior ventricular areas were covered with cilia. Ciliated ependymal cells in supraoptic-suprachiasmatic areas were associated with extensive blebbing, and folded tissue adjacent to the inferior borders of the mamillary body displayed distinct bands of cilia regularly interrupted by areas of sparsely ciliated cells which appeared to be undergoing ciliogenesis. Arcuate ependymal areas had well developed...
Zink MC, Johnson JA, Prescot JF, Pascoe PJ.The in-vitro interaction of Corynebacterium equi and foal alveolar macrophages was examined qualitatively and quantitatively using cells collected by sequential bronchoalveolar lavage at 2-week intervals from birth until 14 weeks of age. Total and differential counts were performed on the recovered cells. Macrophages were identified using the non-specific esterase strain. Cultures of the alveolar macrophages were challenged with C. equi suspensions and the process and extent of ingestion was examined by light and electron microscopy. Few macrophages were recovered from the lungs of foals less ...
Yilma T, McGuire TC, Perryman LE.Equine dermal cells induced with poly I:C + DEAE-dextran produced low levels of interferon tentatively classified as equine interferon beta (EqIFN-beta). In contrast, dermal cells initially primed with EqIFN-beta and then superinduced with poly I:C + DEAE-dextran in the presence of cycloheximide and actinomycin D produced greater than 100-fold EqIFN-beta. Equine blood mononuclear cells induced with Newcastle disease virus and phytohemagglutinin produced high levels of interferons tentatively classified as equine interferon alpha (EqIFN-alpha) and equine interferon gamma (EqIFN-gamma), respecti...
Webb PD.The pituitary glands of 4 horse embryos (41-55 days of gestation) were examined by light microscopy, and the pars distalis from 10 fetal foals (75-300 days) was examined by electron microscopy. At Day 41 the development of Rathke's pouch and the saccus infundibuli was advanced; the former had almost lost its connection with the stomodaeum and the latter had started to differentiate into infundibular process and infundibular stalk. By Day 43 Rathke's pouch was completely dissociated from the stomodaeum and its walls were beginning to show uneven growth. The ventral wall of the pouch, the future...
Parker WG, Sullivan JJ, Larson LL.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.
Pazdera J, Hruban V, Pichrtová J, Müller Z, Jílek F.Using a multilocus DNA probe, individual - specific hybridization patterns, the so-called DNA fingerprints (TAB) were determined in six horse families by the DNA fingerprinting method. The probe with evolutionally preserved nucleotide sequence from bacteriophage M13 determines hypervariable regions placed in genomic minisatellite DNA. The use of this probe permits an identification of an individual and execution of paternity relationships with a probability over 99.99 per cent.
Marcos R, Ribeiro T, Santos M, Correia-Gomes C, Macedo S, Guimarães T, Blielbernicht M, Caniatti M, Rocha A.Uterine lavage (UL) is a routine diagnostic procedure for endometritis. In UL the fluid is centrifuged and the sediment smeared. Samples prepared in cytocentrifuges, the so-called "cytospins", are useful for evaluating cells in fluids, but never been used in UL. The aim of this study was to assess the usefulness of cytospins after UL, comparing automatic versus manual cytocentrifuges, and to determine their value for the diagnosis of endometritis. The study was divided in two parts. Firstly, UL was performed in 16 mares and a small part of the retrieved fluid was cytocentrifuged in an automati...
Pycock J.Jonathan Pycock is one of three equine claims consultants with the Veterinary Defence Society. His career in equine reproduction, and lecturing on the same topic, has given him the opportunity to work and travel widely, and ensure his work/life balance stays in sync.
Chacon-Arellano JT, Woolley DM.Smooth muscle cells are present in the tunica albuginea testis of the horse, pig and sheep. typical fusiform muscle cells constitute a distinct layer up to 0.3 micrometer thick in the horse; there are fewer muscle cells, mainly of the branched form, in the pig; whereas in the sheep the muscle component is least well developed, with some cells intermediate in form between smooth muscle cells and fibroblasts (myofibroblasts). Attention is drawn to the continuity of this capsular muscle with the smooth muscle associated with the vasculature of the spermatic cord in the horse. This association sug...
Holden-Douilly L, Pourcelot P, Chateau H, Falala S, Crevier-Denoix N.This article describes a method that allows estimating, with the 2D version of the direct linear transformation (DLT), the actual 2D coordinates of a point when the latter is not strictly in the calibration plane. Markers placed in vertical line, above, below and in the centre of a horizontal calibration plane were filmed by a moving camera. Without correction, strong errors (up to 64.5%) were noticed for markers out of the calibration plane. After correction, calculated coordinates were consistent with actual values (error < 0.55%). The method was then applied to slip distance measuremen...
Roth TL, White KL, Thompson DL, Rahmanian S, Horohov DW.The mechanism by which a horse conceptus-derived immunosuppressive factor (HCS) of M(r) > 100,000 inhibits lymphocyte proliferation was investigated. The factor was obtained from the culture supernatants of 20-day-old horse conceptuses; activity, identified by reduced uptake of [3H]thymidine by mitogen-stimulated lymphocytes, was greatest (P < 0.01) in cultures stimulated by mitogen from pokeweed. HCS also suppressed cell proliferation stimulated by phytohaemagglutinin (P 0.05). Data from a fluorescence-activated cell sorter indicated that supplementation with HCS reduced the number of ...