Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Veterinary Research
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.
Incidence, location and classification of 371 third carpal bone fractures in 313 horses. The medical records and radiographs of all horses with a third carpal bone fracture admitted to The Ohio State University Veterinary Hospital from 1979 to 1987 were reviewed. Three hundred and seventy-one fractures were found in 313 horses; 57 percent were Standardbreds, 41 per cent were Thoroughbreds, and only 1.6 per cent were Quarterhorses. All were young racehorses (average age = 3.1 years). Third carpal fractures occurred more frequently in the right limb (60 percent) than the left limb (40 percent); Thoroughbreds had a greater right-left disparity (67.5 percent R, 27.1 per cent L). Fract...
Isolation and characterization of monoclonal antibodies against an attenuated vaccine strain of equine herpesvirus type 1 (EHV-1). The production and differentiation of monoclonal antibodies (mabs) against the Rac-H strain of EHV-1 used as an attenuated live vaccine to prevent rhinopneumonitis and abortion is described. Seven different antigenic sites were detected by the 15 mabs produced. EHV-1 specific mabs as well as EHV-1 and -4 common mabs could be established, allowing easy typing of EHV isolates. One mab recognized the vaccine strain only. This reaction was used to investigate a possible involvement of the vaccine strain in cases of abortion. Common antigenic determinants with EHV-1,-3,-4 and BHV-1 could also be de...
The pattern of venous drainage of the equine ileocaecal junction. The veins draining the ileocaecal junctions of horses (n = 19), donkeys (n = 3) and a plains zebra, (Equus burchelli antiquorum) were injected with latex via the ileocolic vein, and dissected. In all specimens the ileocaecal papilla was drained by 2 major papillary veins: one cranial and one caudal to the papilla. A smaller dorsal vein drained either into the cranial or into the caudal vein. The submucosal veins seemed to increase in number in the ileocaeacal junction to form a venous plexus. This plexus, together with veins from the caecum and the distal ileum immediately bordering the ileoca...
Non-invasive measurement of bone: a review of clinical and research applications in the horse. The current methods for non-invasive measurement of bone quality are reviewed. In the horse this has traditionally involved the use of radiography, but there are now two other modalities available for the critical evaluation of cortical bone quality and strength. These utilise single photon absorptiometry and ultrasound velocity. Photon absorptiometry gives a direct measurement of bone mineral content, by using a monoenergetic radionuclide source, and transverse ultrasound velocity in bone gives a measure of bone stiffness or elasticity. They can both be used conveniently on the metacarpus of ...
Kinematic analysis of the instant centers of rotation of the equine metacarpophalangeal joint. A kinematic analysis of the instant centers of rotation analysis was performed on 21 metacarpophalangeal joints from 11 horses. Manual and computerized methods were used to locate the instant center of rotation on photocopies of transparent composite tracings of a series of radiographs of each joint. The instant centers of rotation of the proximal phalanx about the distal portion of the third metacarpal bone were located consistently on or near the eminence for attachment of the collateral ligaments. The instant centers of rotation of the sesamoids about the distal portion of the third metacar...
Application of cloned fragments of equine herpesvirus type-1 DNA for detection of virus-specific DNA in equine tissues. Tissue specimens obtained from equine herpesvirus-1 (EHV-1), subtype 1-infected aborted foetuses were analysed for the presence of virus DNA by means of Southern blot and dot blot hybridisations. The specificity of the methods was confirmed although the sensitivity was inferior to classical techniques such as virus isolation. However, the possibility of detecting the state of the virus DNA and the ability to distinguish between subtypes were important features, and the dot blot method was shown to have potential for a rapid diagnostic test. This report demonstrates some potential practical app...
Bony fragments in the tarsocrural and metacarpo- or metatarsophalangeal joints in the standardbred horse–a radiographic survey. Radiographic examination of the tarsocrural, metacarpo- or metatarsophalangeal joints was made in 139 Standardbred horses. Most were under three years old with no history of orthopaedic problems. In the tarsocrural joint, osteochondrosis was observed in 25 (18.1 percent) of the horses (n = 138) and 14 (56 percent) of these were affected bilaterally. In the metatarsophalangeal joint, the most frequent radiographic abnormality was single or multiple bony fragments or defects at the plantar proximal end of the proximal phalanx, which was noticed in 40 (28.8 percent) of the horses (n = 139). The l...
Factors influencing the ingestion of Onchocerca cervicalis microfilariae by Culicoides variipennis (Diptera: Ceratopogonidae). Culicoides variipennis were fed under controlled conditions on two ponies that exhibited seasonal changes in Onchocerca cervicalis microfilarial (mf) skin density and skin distribution. The seasonal changes did not radically affect mf ingestion. Flies were fed on the umbilicus of infected ponies by two methods: individual feeding in consecutive order at the same site, or by mass feeding. Linear regression analysis indicated that ingestion of microfilaria was independent of feeding time and engorged weight. In the individual feeding data, there was a trend toward an increased ingestion of mf as...
Evaluation of equine locomotion during different degrees of experimentally induced lameness. II: Distribution of ground reaction force patterns of the concurrently loaded limbs. Force plate and high-speed film data from a group of six walking horses were used to study the distribution of the ground reaction forces (GRF) of the concurrently loaded limbs. Three different degrees of supporting lameness were induced in a forelimb or a hindlimb using modified horse shoes. In all experiments the alterations in the distribution in the transverse horizontal GRF (Fx) were small. During unilateral forelimb lameness, the decreased longitudinal horizontal GRF (Fy) was compensated by an increase of the Fy forces of the contralateral forelimb and the ipsilateral hindlimb. The decre...
Restricted conceptus mobility results in failure of pregnancy maintenance in mares. Cycling pony mares were bred and used to test the effect of restricted conceptus mobility on luteal maintenance (i.e. maternal recognition of pregnancy). In Experiment 1, uterine horns were ligated to restrict conceptus mobility to one uterine horn, Group 1; one horn plus the uterine body, Group 2; or one horn, the body and approximately 80% of the second horn, Group 3. Pregnancies were monitored with real-time ultrasonography. Four of five mares in Group 1 and two of four mares in Group 2 returned to estrus (Day 16.0 +/- 1.9 and 14.5 +/- 0.7, respectively) and subsequently lost the embryonic ...
Equine Cushing’s disease: differential regulation of beta-endorphin processing in tumors of the intermediate pituitary. Equine Cushing's disease is caused by an adenomatous hyperplasia of the intermediate pituitary which secretes high levels of beta-endorphin, ACTH, and other peptide derivatives of POMC. In the present study we found that plasma and cerebrospinal fluid immunoreactive beta-endorphin (i beta-endorphin) levels were 60- and 120-fold higher than control values in horses with Cushing's disease. There were no significant differences in intermediate lobe i beta-endorphin concentrations, although anterior lobe i beta-endorphin was significantly reduced in Cushing's horses, presumably because high levels...
Detomidine: a preliminary analysis of its duration of action in the horse by variable interval responding. Variable interval (VI) reinforcement scheduling is a specific type of operant conditioning that is sensitive to drug effects even when overt clinical signs of the drug have diminished. Six horses were conditioned to break a light beam with a head-bobbing movement and this behaviour was reinforced with a reward of clean oats (approximately 30 mg/reinforcement). Initial training procedures included familiarisation with the behavioural equipment and fixed-ratio reinforced scheduling. To establish baseline rates of behaviour, the horses were converted to a variable interval (60 secs) reinforcement...
Fasciola in horses in the Republic of South Africa: a single natural case of Fasciola hepatica and the failure to infest ten horses either with F. hepatica or Fasciola gigantica. The faeces of 11 horses were examined for Fasciola spp. eggs. One of them was positive for Fasciola hepatica, a finding which was confirmed post-mortem. The 10 negative horses were subsequently infested with either F. hepatica or Fasciola gigantica, each animal receiving orally from 500-9,500 metacercariae. No clinical signs were observed and no fluke eggs were detected in the faeces, and neither immature nor adult Fasciola worms were recovered from the horses slaughtered 16-26 weeks post-infestation with F. hepatica and 28-34 weeks post-infestation with F. gigantica, respectively. The results...
Immunoassay detection of drugs in racing horses. VII. Detection of acepromazine in equine urine and blood by ELISA and PCFIA. We have developed and evaluated a one step enzyme-linked immunosorbent assay (ELISA) test and a particle concentration fluorescence immunoassay (PCFIA) test for acepromazine as part of a panel of pre- and post-race tests for illegal medications in racing horses. These tests are rapid, sensitive and economical and development of the tests occurred in less than seven months. The ELISA test detects acepromazine with an I-50 of about 150 pg/ml. In vivo, it readily detects the presence of acepromazine or its metabolites in equine blood and urine from 8 to 72 hours or longer, respectively, after adm...
Enumeration of anaerobic bacterial microflora of the equine gastrointestinal tract. Samples from the duodenum, jejunum, and ileum, as well as from the cecum and colon, were obtained from 11 mature grass-fed horses. Viable counts of total culturable and proteolytic bacteria were made on habitat-simulating media containing 40% clarified ruminal fluid. The mean pHs in the duodenum, jejunum, and ileum were 6.32, 7.10, and 7.47, respectively; the mean pH decreased to 6.7 in the hindgut. The acetate concentration increased along the length of the small intestine and was the only volatile fatty acid present in this gut segment. Molar proportions of acetate, propionate, and butyrate ...
cis- and trans-acting regulation of gene expression of equine infectious anemia virus. Deletion analysis of the equine infectious anemia virus long terminal repeat revealed that sequences responsive to virus-specific transactivation are located within the region spanning the transcriptional start site (-31 to +22). In addition, an active exon of a trans-acting factor (tat) was identified downstream of pol and overlapping env (nucleotides 5264 to 5461). Activation by tat is accompanied by an increase in the steady-state levels of mRNA directed by the equine infectious anemia virus long terminal repeat.
Immunohistochemical study of the local humoral immune system of the equine respiratory mucosa. An indirect immunoperoxidase technique was used to demonstrate both free immunoglobulin and immunoglobulin-containing plasma cells of IgG, IgA, and IgM classes in the mucosa of the equine respiratory tract. IgA-producing plasma cells predominated in the upper airways, whereas IgG-producing cells predominated in the lower respiratory tract. IgM-secreting cells were uncommon, but present in their highest numbers in the nasopharynx. Plasma cells specific for all of the immunoglobulin classes were identified in the surface epithelium, lamina propria connective tissue, glandular tissue and organise...
Characterisation of IgE-mediated histamine release from equine basophils in vitro. In vitro IgE-mediated histamine release by equine blood basophils was characterised as the basis for a screening test for immediate hypersensitivity responses in horses. The responses are initiated by inducing agents that are capable of crosslinking or bridging the membrane-bound IgE molecules. The release process is complete within 40 mins. In vitro histamine release is dose-dependent, with a submaximal response at less or greater than the optimal dose of inducing agent. Exogenous calcium is required but not magnesium; the optimal release calcium concentration is 1.0 to 1.5 mM. If an IgE-medi...
Evaluation of equine locomotion during different degrees of experimentally induced lameness. I: Lameness model and quantification of ground reaction force patterns of the limbs. Force plate data from walking horses were used to evaluate the locomotion of a group of six horses during experimentally induced lameness in a forelimb or a hindlimb. By tightening or loosening screws in modified horseshoes the resulting pressure pain on the sole enabled induction and release of three different degrees of supporting lameness within a period of 2 h. The ground reaction force (GRF) patterns of the different recording sessions were compared with control data of the same horse as well as with the 'standard' horse data using a quantitative evaluation procedure involving 93 GRF para...
In vitro evaluation of a sustained-release veterinary peroral pellet preparation. In a preceding in vivo study in horses, wide interindividual variation was found in the extent of bioavailability and time to reach peak concentration after peroral administration of one specific theophylline sustained-release dosage form. The purpose of the present study was to investigate the factors of potency, the pH of dissolution medium, the enzymes in the dissolution medium, and the crushing of the pellets on in vitro performance. The results show a wide variation in potency for the individual units, an increase in release rate with increasing pH, and an increase in release rate if the ...
Biochemical and toxigenic characteristics of Aeromonas spp. isolated from diseased mammals, moribund and healthy fish. In this study we describe biochemical, toxigenic and surface characteristics of 33 motile Aeromonas isolated from diseased mammals, 3 from moribund marine mammals, 24 from healthy fish and 4 from moribund fish. Aeromonas hydrophila, A. caviae and A. sobria were isolated from both mammals and fish but at a different incidence. Aeromonas hydrophila was the predominant species isolated from clinical specimens; it was isolated from pneumonia, wound infections, septicemia and abortion in horses, cattle and pigs. Aeromonas sobria was isolated from one mammal and 11 healthy fish. Aeromonas caviae was...
Chemotactic response of equine polymorphonuclear leucocytes to Streptococcus equi. Streptococcus equi infection in horses is characterised by intense infiltration of lymph nodes by polymorphonuclear leucocytes (PMNs) suggesting a potent chemotactic response to the organism or its products. Equine PMNs were separated using Ficoll-Hypaque medium and used in an assay of chemotaxis under agarose to study the components of S equi involved in this response. Results showed that complement-derived chemotactic factors generated by activation of the alternative complement pathway were important in chemotactic responses to S equi. Both whole bacteria and peptidoglycan preparations were...
The effect of detomidine (Domosedan) on the maintenance of equine pregnancy and foetal development: ten cases. Detomidine was administered throughout 10 pregnancies in eight mares. An intravenous injection of 20 micrograms/kg body weight was given weekly from Day 14 to Day 60 of gestation and thereafter every four weeks until parturition. One mare suffered torsion of the large colon and was destroyed on Day 86; the foetus was normally developed. A further mare aborted at 167 days. The remaining eight pregnancies continued to full term. One foal was delivered by caesarean section because of torticollis and, of the seven foals born spontaneously, one had bilateral upward patellar fixation at one month ol...
A clinical perspective on lameness originating in the carpus. Clinical experience continues to expand our understanding of the pathophysiology of pain and injury within the carpal joints. The anatomical and physiological capacity of the equine carpus to neutralise loading stress plays a significant role in the prevention of carpal injury. The ability of joint surfaces to dissipate axial force by transfer to the interosseous ligaments is the principal means by which carpal injury is avoided. In the medial aspect of the intercarpal joint and the dorsal aspect of the radial carpal joint, however, the effects of chronic maximal stress and isolated acute supr...
Pre-chemotactic and chemotactic properties of uterine fluid from mares with experimentally induced endometritis. Streptococcal endometritis was induced experimentally in pony mares during oestrus. Uterine fluid was collected 30, 60, 120 or 240 minutes later and tested for its effect on the in vitro morphology and chemotaxis of equine neutrophils by two independent methods. The maximal response occurred between 30 and 60 minutes after infection and persisted until 240 minutes. The chemo-attractant contained both heat labile and heat stable components and the latter appeared to be active at low concentrations.
Molecular mechanics calculation of geometries of NAD+ derivatives, modified in the nicotinamide group, in a ternary complex with horse liver alcohol dehydrogenase. The geometry of seven NAD+ analogues bound to horse liver alcohol dehydrogenase (LADH) modified only in their nicotinamide group, have been studied using AMBER molecular mechanics energy-minimization procedures. Starting geometries were taken from X-ray crystallographic data for NAD+/Me2SO/LADH reported by Eklund and co-workers. In this study the NAD+ analogues were encaged by the constituent amino acids of the enzyme within a range of 0.6 nm from the initial NAD+/Me2SO/Zn2+ complex. The calculational method used is able to rationalize individual substituent effects and to evaluate the essenti...
Uterine defense mechanisms in the mare. Uterine defense against infection in the mare has been actively investigated over the past decade. Mechanisms of defense, including the role of immunoglobulins, polymorphonuclear neutrophils, and the physical ability of mares to eliminate bacteria from the uterus, are discussed.
