Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Veterinary Medicine
Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Diagnosis and approach to poisoning in the horse. Poisoning in the horse can present a highly complex case. The practitioner, owner, toxicologist, and pathologist play important roles, and all contribute information that may be important to the case. Once all the information is available, all the evidence is collected (historical, clinical, pathologic, and analytic), and proper sampling of specimens has occurred, a complete summary of the findings can be provided to the client. Based on identification of a potential toxic source and, ultimately, the diagnosis, specific treatment of affected animals and prevention of additional cases can be in...
Horses damp the spring in their step. The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle-tendon units.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes...
Metal toxicosis in horses. The ubiquity and stability of metals in the environment make them unique as a pollutant or an essential dietary component. Metals are neither created nor destroyed by chemical processes but are redistributed in the environment. In combination with other elements, metal compounds and alloys are essential materials of the contemporary world. Inappropriate use or distribution in the environment leads to adverse health effects on all biologic systems, including horses. Gastrointestinal upset is a common feature of acute toxicosis with metals in general. Among the metals discussed, arsenic and inor...
Fescue toxicosis. Most of the tall fescue pastures in the United States are infected by an endophyte, N. coenophialum. The fungus derives nutrients from the plant while supplying the plant with toxins for defense. The most detrimental toxins for animals in tall fescue are ergopeptine alkaloids, especially ergovaline. Ergovaline functions as a dopamine D2 agonist and alters prolactin and several other hormones in the body. Pregnant mares are most susceptible during their last month of gestation. Clinical signs include prolonged gestation, dystocia, retained placentas, agalactia, and dysmature foals that are eith...
Adverse drug reactions and interactions in the horse. Drugs undergo extensive evaluation before they are marketed. The occurrence of adverse reactions, however, may be so rare that thousands of patients must receive the drug before reliable data are available. It is necessary that veterinarians be informed about the drugs they use, be able to recognize drug-associated complications, know how to evaluate the patient for evidence of drug-associated toxicity, report adverse effects of drugs to the respective manufacturers, and be prepared to provide medical support and antidotal treatment (if it exists) for a patient if toxicosis occurs.
Botulism in the horse. Botulism should be considered in cases where weakness, paralysis, or intolerance to exercise might be seen in the horse. Dysphagia may also be present, although it is not a consistent finding. Potential sources include carrion in hay, moldy or otherwise rotted vegetation or forage, birds carrying material from animal burial or other similar sites, and contaminated carcasses on-site. Horses, especially foals, may also suffer from toxicoinfectious botulism, a condition where the C. botulinum might colonize and produce toxin within the gastrointestinal tract. Wounds also may harbor the organism a...
Toxic plants. What the horse practitioner needs to know. Horses poisoned by a plant may show a myriad of clinical signs. Awareness of the poisonous plants growing in a given area and those that are likely to appear in hay and their associated clinical signs can be instrumental in making diagnoses. More importantly, the information can be shared with clients to help prevent plant poisonings in horses.
Toxic feed constituents in the horse. Poisoning cases in horses associated with dietary exposures can encompass a wide variety of etiologies that can be caused by natural or man-made components. Feed mixing errors and ingestion of feed formulated for other species are the most common means by which poisonings from man-made materials occur. Ionophore feed additives and antibacterial agents are especially toxogenic to horses. Effects of ionophores in horses include clinical, clinicopathologic, and pathologic changes associated with cardiac, muscular, and neurologic tissues involvement. The acute effects of ionophores, however, can r...
Damper for bad vibrations. This research presents the hypothesis and findings that short muscle fibers in horses and other large mammals may protect bones and tendons from damaging vibrations during running, negating the previous […]
Mycotoxins. Horses consume feed grains and forages that can produce a range of mycotoxins resulting from mold invasion. Toxicosis of horses often occurs from fumonisins or aflatoxin in grains, from the tremorgenic mycotoxins in dallis grass, or from slaframine in red clover. Fumonisin toxicosis often is severe and fatal, and aflatoxin can be acute or chronic and debilitating. Other mycotoxins reported in horses may cause moderate to mild signs that regress when the contaminated feedstuff is removed. Overall, horses appear to have a relatively low prevalence of reported mycotoxicoses among domestic animals...
Handling forensic necropsy cases. Immediately record the findings. A tape recorder would be excellent for this. If none is available, findings should be written down as soon as possible before memory of the examination fades. It is important to record comments on every organ that you examined. Three years from now in a court deposition, it may be difficult for the practitioner to remember if he looked at the adrenal glands or if there was no gross evidence of hyperplasia. When writing a report, it is a good idea to describe the tissue changes rather than just to give an interpretation. An example of the latter would be, "The h...
Subchondral bone thickness, hardness and remodelling are influenced by short-term exercise in a site-specific manner. It was hypothesised that subchondral bone thickness, hardness and remodelling are influenced by exercise intensity, and by location within a joint. Dorsal carpal osteochondral injury is a major cause of lameness in horses undergoing high intensity training. This project aimed to determine the subchondral bone thickness, formation, resorption and hardness at sites with high and low incidence of pathology in 2 year-old horses undergoing 19 weeks high intensity treadmill training or low intensity exercise, and to compare these factors between exercise groups. Dorsal and palmar test sites were ide...
Seasonal transmission of gastrointestinal parasites of equids in southern Louisiana. Parasite-naive pony foals were used as sentinels to monitor transmission of gastrointestinal parasites of equids in Louisiana during 4 seasons of the year. Two annual periods were studied, 1988-1989 and 1992-1993. Two or 3 foals each season were turned out to graze a contaminated pasture along with resident parasitized mares and their foals. After a grazing period of 8 wk, sentinel ponies were held in a parasite-free box stall for a period of 6 wk to allow parasites to develop, thus enhancing the evaluation of hypobiotic stages. Following this holding period, necropsies were performed for comp...
Epidemiology for the equine practitioner. In this article, I have discussed the principles and methods of outbreak investigation, reinforcing important concepts with examples from the veterinary literature. The approach presented is applicable to outbreaks caused by any agent whether it is infectious versus noninfectious or contagious versus noncontagious. The solutions vary. The experience of others presented with similar situations may be especially helpful. Because of their nature, outbreaks are difficult to prepare for. When faced with a potential outbreak, the best strategy is to approach it scientifically, systematically, and wi...
Residues and considerations for use of pharmaceutics in the performance horse. Analytic chemistry laboratories responding to the concerns of the industry over drug use and abuse in performance horses should continue to develop more sensitive methods of drug detection. The unwanted result of this increase in sensitivity is the detection of therapeutic medications days to weeks after administration. The adoption of decision or threshold concentrations for residues of nonpermitted medications should allow laboratories to focus their efforts on drugs of abuse in the performance horse industries and permit veterinarians to provide appropriate medical care to these equine athl...
Industrial chemicals and the horse. Poisoning resulting from exposure to a wide variety of industrial chemicals is not a common occurrence in horses, but it does happen on occasion. A wide range of toxicosis can occur from a wide range of industrial pollutants, such as dioxin, carbon tetrachloride, and tetrachloroethylene, to heavy metals, such as cadmium and zinc. The equine practitioner must consider industrial chemical toxicosis in differential diagnoses and work with a reputable veterinary diagnostic laboratory to confirm or rule out industrial chemical poisoning.
Mice lacking the gene for inducible or endothelial nitric oxide are resistant to sporocyst induced Sarcocystis neurona infections. Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome in horses from the Americas and is usually caused by infection with the apicomplexan parasite, Sarcocystis neurona. Little is known about the role of immunobiological mediators to this parasite. Nitric oxide (NO) is important in resistance to many intracellular parasites. We, therefore, investigated the role of inducible and endothelial NO in resistance to clinical disease caused by S. neurona in mice. Groups of interferon-gamma gene knockout (IFN-gamma-KO) mice, inducible nitric oxide synthase gene knockout (iNOS-KO) mice, endo...
Treatment of a granuloma caused by Halicephalobus gingivalis in a horse. A 12-year-old Arabian gelding with a granuloma caused by the nematode Halicephalobus gingivalis caudal and dorsal to the left orbit was examined. There was no evidence of dissemination of the nematode to the kidneys or the CNS, and the horse was treated with ivermectin (1.2 mg/kg [0.55 mg/lb] of body weight, p.o., every 2 weeks for 3 treatments). The granuloma was surgically debulked 2 days after the first dose of ivermectin. The granuloma resolved with no evidence of nematode infection after 18 months. Halicephalobus gingivalis is a ubiquitous saprophytic nematode that has been reported to in...
Cervical stenotic myelopathy in a horse. A 13-year-old, Thoroughbred gelding presented with a 3-year history of progressive ataxia of all 4 limbs. Physical and neurological examinations indicated a compressive lesion affecting the cervical spinal cord. Radiographs confirmed a lesion, and a myelogram a narrowing of the spinal canal at cervical vertebrae (6-7). Necropsy confirmed cervical stenotic myelopathy.
Effects of oral administration of phenylbutazone to horses on in vitro articular cartilage metabolism. To evaluate the effects of orally administered phenylbutazone on proteoglycan synthesis and chondrocyte inhibition by IL-1beta in articular cartilage explants of horses. Methods: 11 healthy 1- to 2-year-old horses. Methods: Horses were randomly assigned to the control (n = 5) or treated group (4.4 mg of phenylbutazone/kg of body weight, p.o., q 12 h; n = 6). Articular cartilage specimens were collected before treatment was initiated (day 0), after 14 days of treatment, and 2 weeks after cessation of treatment (day 30). Proteoglycan synthesis and stromelysin concentration in cartilage extracts ...
A new modified live equine influenza virus vaccine: phenotypic stability, restricted spread and efficacy against heterologous virus challenge. Flu Avert IN vaccine is a new, live attenuated virus vaccine for equine influenza. We tested this vaccine in vivo to ascertain 1) its safety and stability when subjected to serial horse to horse passage, 2) whether it spread spontaneously from horse to horse and 3) its ability to protect against heterologous equine influenza challenge viruses of epidemiological relevance. For the stability study, the vaccine was administered to 5 ponies. Nasal swabs were collected and pooled fluids administered directly to 4 successive groups of naïve ponies by intranasal inoculation. Viruses isolated from th...
Cultures of equine respiratory epithelial cells and organ explants as tools for the study of equine influenza virus infection. Equine nasal turbinate epithelial cells and tracheal rafts were maintained with sustained viability in culture. Both types of culture supported productive replication of equine influenza virus (equine-2, subtype H3N8) and cell death occurred through apoptosis following viral infection. Thus, primary respiratory epithelial cell and organ cultures of equine origin may be valuable as alternatives to the intact animal for studying the virus-host interaction of equine respiratory viruses including influenza.
In vitro responses of equine colonic arterial and venous rings to adenosine triphosphate. To evaluate the in vitro effects of adenosine tryphosphate (ATP) on vasomotor tone of equine colonic vasculature. Methods: Arteries and veins from the left ventral colon of 14 mixed-breed horses euthanatized for reasons unrelated to cardiovascular or gastrointestinal tract disease. Methods: Endothelium-intact and -denuded arterial and venous rings were precontracted with 10(-7) and 1.8 x 10(-8) M endothelin-1, respectively. In 1 trial, endothelium-intact rings were also incubated with 10(-4) M N omega-nitro-L-arginine methyl ester (L-NAME) to inhibit nitric oxide (NO) production. Adenosine tri...
[Analysis of the genetic structure of the breeding nucleus of the Russian population of purebred Thoroughbred horses at the Extension locus using molecular DNA typing]. Results of the first in Russia survey of the gene pool of the breeding nucleus of the Russian population of thoroughbred horses by means of PCR analysis of the E (Extension) locus MC1R gene mutations are presented. The data on the structure of breeding populations from the leading stud farms Voskhod and Oros with regard to color phenotypes as well as genotype and allele frequencies are presented. The population structure parameters are discussed with respect to possible specific features of microevolution processes.
Efficacy of a cold-adapted, intranasal, equine influenza vaccine: challenge trials. A randomised, controlled, double-blind, influenza virus, aerosol challenge of horses was undertaken to determine the efficacy of a cold-adapted, temperature sensitive, modified-live virus, intranasal, equine influenza vaccine. Ninety 11-month-old influenza-naïve foals were assigned randomly to 3 groups (20 vaccinates and 10 controls per group) and challenged 5 weeks, 6 and 12 months after a single vaccination. Challenges were performed on Day 0 in a plastic-lined chamber. Between Days 1 and 10, animals were examined daily for evidence of clinical signs of influenza. Nasal swabs for virus isol...
The mucosal humoral immune response of the horse to infective challenge and vaccination with equine herpesvirus-1 antigens. Equine herpesvirus-1 (EHV-1) remains a frequent cause of upper respiratory tract infection and abortion in horses worldwide. However, little is known about the local antibody response elicited in the upper airways of horses following exposure to EHV-1. This study analysed the mucosal humoral immune response of weanling foals following experimental infection with virulent EHV-1, or vaccination with either of 2 commercial vaccines. Twenty weanlings were assigned to 5 groups and were inoculated with, or vaccinated against, EHV-1 following different regimens. Finally, all weanlings were simultaneo...
Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of two 7-hole 3.5-mm broad and two 5-hole 4.5-mm narrow dynamic compression plates. To compare the biomechanical characteristics and mode of failure of two different dynamic compression plate (DCP) techniques for proximal interphalangeal joint (PIPJ) arthrodesis in horses. Methods: Randomized block-design blocking on horse (1-5), method of fixation (two 7-hole, 3.5-mm broad DCP vs two 5-hole, 4.5-mm narrow DCP), side (left, right), and end (front, hind). Constructs were loaded to failure in 3-point bending in a dorsal-to-palmar (plantar) direction. Methods: Ten paired limbs from 5 equine cadavers. Methods: Two 7-hole, 3.5-mm broad dynamic compression plates (bDCP) were used i...
Detection of IgG and IgE serum antibodies to Culicoides salivary gland antigens in horses with insect dermal hypersensitivity (sweet itch). We postulated that all horses exposed to the bites of Culcoides (midges) would have an antibody response to the antigen secreted in Culcoides saliva, but that IgE antibody would be restricted to allergic individuals. Using immunohistology on sections of fixed Culicoides, we have demonstrated the presence of antibodies in horse serum which recognise Culicoides salivary glands. Antibodies were detected in the serum of horses with insect dermal hypersensitivity and in the serum of normal horses exposed to Culicoides bites. In contrast, no antibodies were detected in serum from native Icelandic po...
Effects of exercise on biomechanical properties of the superficial digital flexor tendon in foals. To determine the effects of exercise on biomechanical properties of the superficial digital flexor tendon (SDFT) in foals. Methods: 43 Dutch Warmblood foals. Methods: From 1 week until 5 months of age, 14 foals were housed in stalls and not exercised, 14 foals were housed in stalls and exercised daily, and 15 foals were maintained at pasture. Eight foals in each group were euthanatized at 5 months, and remaining foals were housed together in a stall and paddock until euthanatized at 11 months. After euthanasia, SDFT were isolated and fit in a material testing system. Mean cross-sectional area ...
Evaluation of IgG concentration and IgG subisotypes in foals with complete or partial failure of passive transfer after administration of intravenous serum or plasma. The purpose of this study was to evaluate the ability of an equine plasma product i.v. and a concentrated serum product i.v. to deliver antibodies to 46 foals with failure of passive transfer (FPT). Treatment of FPT was as per manufacturers recommendations, using plasma (950 ml/unit) or a concentrated serum product (250 ml/unit). Significant variables affecting the 3 day post-transfusion serum immunoglobulin G (IgG) concentration of foals included body weight, pretransfusion IgG concentration, number of product units transfused, foaling season and product administered. Plasma treatment had a g...
