Topic:Prophylaxis
Prophylaxis in horses refers to the preventive measures and strategies implemented to protect equine health by reducing the risk of disease occurrence. These measures can include vaccinations, parasite control, nutrition management, and biosecurity practices. Vaccinations help to stimulate the horse's immune system to protect against specific infectious diseases. Parasite control programs aim to minimize the impact of internal and external parasites through strategic deworming and environmental management. Nutrition management ensures that horses receive balanced diets that support their overall health and immune function. Biosecurity practices involve procedures to prevent the introduction and spread of infectious agents within equine populations. This page gathers peer-reviewed research studies and scholarly articles that explore various prophylactic approaches, their implementation, and their effectiveness in maintaining equine health.
Ovine anti-rabies antibody production and evaluation. In view of the disadvantages of human and equine rabies immunoglobulin still there is urgent needs for safe and cost-control anti-rabies immunoglobulins especially for person who have been severely exposed (categories III) to the virus. Our attempt to produce a less immunogenic and cheaper anti-rabies immunoglobulin affordable for those people living in developing countries, has been harnessed the ovine as a bioreactor instead the horse. The animals have been intramuscular immunized, and the plasma processed with 5% caprylic acid to yield IgG with purity of 95%. Moreover, antibody apparently i...
Evaluation of a new premedication protocol for administration of equine rabies immunoglobulin in patients with hypersensitivity. The present study was undertaken to standardize skin testing and to develop a safe and effective premedication protocol for administration of ERIG in those with skin test positivity/hypersensitivity. Methods: A method of grading of skin testing was developed using injection histamine as a positive control. This was evaluated by using it on 517 subjects who had severe (WHO category III) exposure to rabies. A premedication protocol consisting of injections pheniramine, ranitidine, hydrocortisone and adrenaline was evaluated by using it on fifty one subjects who were skin test positive/hypersensi...
Efficacy, duration, and onset of immunogenicity of a West Nile virus vaccine, live Flavivirus chimera, in horses with a clinical disease challenge model. West Nile virus (WNF) is a Flavivirus responsible for a life-threatening neurological disease in man and horses. Development of improved vaccines against Flavivirus infections is therefore important. Objective: To establish that a single immunogenicity dose of live Flavivirus chimera (WN-FV) vaccine protects horses from the disease and it induces a protective immune response, and to determine the duration of the protective immunity. Methods: Clinical signs were compared between vaccinated (VACC) and control (CTRL) horses after an intrathecal WNV challenge given at 10 or 28 days, or 12 months p...
Alternative vaccination against equine botulism (BoNT/C). In Europe the incidence of botulism in horses has increased in the last decade due to the growing popularity of haylage feeding. Recombinant vaccines are safer and less expensive to produce and are generally better tolerated than toxoids. Objective: To investigate whether the recombinant C-terminal half of the heavy chain of the botulinum neurotoxin C (Hc BoNT/C) in combination with an immunstimulatory adjuvant is an appropriate vaccine candidate for horses by testing its efficacy to induce neutralising antibodies and by comparing its immunogenic properties and adverse reactions to a commercia...
Efficacy of azithromycin in preventing pulmonary abscesses in foals. The prophylactic application of azithromycin to prevent pulmonary abscesses in foals was evaluated on a stud with endemic Rhodococcus equi pneumonia. Forty-five foals served as untreated controls in two groups. Twenty-five foals were given azithromycin (10mg/kg) orally once daily for 4 weeks. The foals were examined once a week from birth to the age of 5 months. If clinical signs or leucocytosis were noted and pulmonary sonographic findings (diameter >10 mm) were observed, the diagnosis of abscessing pneumonia was made. The prevalence of pulmonary abscesses was similar in the control groups (3...
Safety and efficacy in geese of a PER.C6-based inactivated West Nile virus vaccine. Studies were performed with an inactivated vaccine against the mosquito-borne flavivirus, West Nile virus (WNV). The mammalian cell line, PER.C6, was selected as the platform for WNV growth since both the neurovirulent strains NY99 and ISR98 that cause epidemics in humans and high mortality in geese, respectively, could be propagated to high titers (10(9) to 10(10)TCID(50)/ml) on these cells. Based on the high DNA homology of the WNV envelope (E) protein and non-structural protein 5 (NS5), and identical neurovirulence in mice and geese, we concluded that NY99 and ISR98 viruses are closely rela...
Evaluation of the safety, immunogenicity and pharmacokinetics of equine anti-SARS-CoV F(ab’)(2) in macaque. To warrant potential clinical testing, the equine anti-SARS-CoV F(ab')(2) requires evaluation in as many animal models as possible and a safety test in a primate model. In this study, we evaluated the pharmacokinetics, tolerance and immunity of this kind of antibody in macaques and rats. Results showed that the F(ab')(2) fragments had a normal metabolism in injected animals. The general physiological indexes did not differ between animals injected with anti-SARS-CoV F(ab')(2) or saline. However, a mild inflammatory response in local injection site and a moderate immune response against this an...
Pharmacokinetics of acyclovir after intravenous infusion of acyclovir and after oral administration of acyclovir and its prodrug valacyclovir in healthy adult horses. The purpose of this study was twofold. The first aim was to evaluate the oral bioavailability and pharmacokinetics (PKs) of acyclovir in horses after intravenous (i.v.) administration and after oral administration of acyclovir and its prodrug, valacyclovir. Second, we aimed to combine these PK data with pharmacodynamic (PD) information, i.e., 50% effective concentrations (EC(50) values) from in vitro studies, to design an optimal dosage schedule. Three treatments were administered to healthy adult horses: 10 mg of acyclovir/kg of body weight delivered as an i.v. infusion over 1 h, 20 mg of acy...
Low-dose ginseng (Panax quinquefolium) modulates the course and magnitude of the antibody response to vaccination against equid herpesvirus I in horses. The purpose of this study was to determine if ginseng fed at low levels enhances a horse's antibody response to vaccination against Equid herpesvirus 1 (EHV-1). For 28 d, 5 horses received ground, powdered ginseng (35 mg/kg body weight, 1.7 mg/kg total ginsenosides) in molasses as a carrier, and 5 received molasses only. On day 14, each horse was vaccinated against EHV-1. The time course of the antibody response to vaccination was significantly altered in the horses receiving ginseng, a clinically relevant increase in antibody titer being observed by postvaccination day 2 compared with day 6 i...
The different effector function capabilities of the seven equine IgG subclasses have implications for vaccine strategies. Recombinant versions of the seven equine IgG subclasses were expressed in CHO cells. All assembled into intact immunoglobulins stabilised by disulphide bridges, although, reminiscent of human IgG4, a small proportion of equine IgG4 and IgG7 were held together by non-covalent bonds alone. All seven IgGs were N-glycosylated. In addition IgG3 appeared to be O-glycosylated and could bind the lectin jacalin. Staphylococcal protein A displayed weak binding for the equine IgGs in the order: IgG1>IgG3>IgG4>IgG7>IgG2=IgG5>IgG6. Streptococcal protein G bound strongly to IgG1, IgG4 and IgG7, moderately t...
An evidence-based approach to selected joint therapies in horses. There is an enormous volume of published material about most of the agents used to treat or prevent arthritis in horses. Unfortunately, most of the claims made by nearly all purveyors of arthritis medications in such media are largely unsubstantiated. In addition, the quality of the available information is highly inconsistent, making evidence-based recommendations difficult. This article concentrates on injectable polysulfated glycosaminoglycan, injectable hyaluronan, and the common oral "nutraceuticals".
Incisional complications following exploratory celiotomy: does an abdominal bandage reduce the risk? Post operative complications following exploratory laparotomy can be potentially life-threatening, increase post operative morbidity and result in an increase in the length of hospitalisation of the affected individual. No study has evaluated the efficacy of specific strategies to reduce the incidence of post operative incisional complications. Objective: The use of an abdominal bandage following colic surgery through a celiotomy incision would significantly reduce the prevalence of post operative incisional complications. Methods: A controlled, randomised clinical trial to test the hypothesis...
Pilot study investigating the ability of an herbal composite to alleviate clinical signs of respiratory dysfunction in horses with recurrent airway obstruction. Recurrent airway obstruction (RAO), known previously as chronic obstructive pulmonary disease (COPD), is a debilitating respiratory condition that significantly contributes to lost training days and illness in racehorses. Herbs are becoming increasingly popular for the prophylaxis or treatment of the clinical signs of RAO despite a paucity of research on efficacy and safety. We evaluated the ability of an herbal composite containing garlic, white horehound, boneset, aniseed, fennel, licorice, thyme, and hyssop to reduce the clinical signs of RAO, hypothesizing that the product would safely red...
Bovine colostrum as a biologic in clinical medicine: a review. Part I: biotechnological standards, pharmacodynamic and pharmacokinetic characteristics and principles of treatment. Mammals supply their newborn before birth, at birth or shortly after birth with antibodies, immunocytes and humoral constituents. This "borrowed immunity" is a form of passive immunization to protect the newborn against environmental pathogens until it establishes its own pathogen recognition and disposal systems. In cows, goats, horses and some other animal species, most immunoglobulins are obtained from the colostrum, the first milk after birth, via the gut but in humans the majority of immunoglobulins, and those of the IgG-class in particular, are acquired from the mother by placental trans...
Glycaemic and insulinaemic response of quarter horses to concentrates high in fat and low in soluble carbohydrates. Quarter Horses are particularly susceptible to polysaccharide storage myopathy (PSSM). Nutritional therapy and possibly prophylaxis includes fat-supplemented diets whilst starch supply should be kept to a minimum. Objective: To investigate the glycaemic and insulinaemic response of clinically normal Quarter Horses to concentrates high in fat and low in starch. Methods: Twelve Quarter Horses were studied. The precondition for inclusion in the study population was that the horses had not shown clinical signs of myopathy. The Quarter Horses were fed according to a 4 x 4 Latin square design haylag...
Thoracic trauma in horses. Thoracic trauma represents an important cause of morbidity in mortality after injury in human beings and animals. After any form of suspected chest wall trauma, initial emergency management should include assurance of a patent airway and adequate ventilation, along with treatment for shock if present. As with any open wound, tetanus prophylaxis should be instituted. Types of trauma to the thoracic region of the horse include pectoral and axillary lacerations, penetrating chest wounds, flail chest, fractures of the ribs, blunt thoracic trauma, and several potential sequelae that include pneumot...
Avian titer development against West nile virus after extralabel use of an equine vaccine. West Nile virus affects many animals, but the highest prevalence of morbidity and mortality is observed in birds, horses, and humans. The purpose of this study was to determine a protocol in birds of prey and corvids, using a vaccine developed for horses. The birds were assigned to five groups. Groups 1-4 received 0.25 ml, 0.5 ml, 0.75 ml, and 1.0 ml, respectively, and group 5 served as a control group. The greatest percentage of seroconversion (58.3%) was observed in the vaccine group that received a dose of 1.0 ml administered thrice, 3 wk apart. This report demonstrates that a vaccine devel...
Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California. A prospective cohort study was used to estimate the incidence of West Nile virus (WNV) infection in a group of unvaccinated horses (n = 37) in California and compare the effects of natural WNV infection in these unvaccinated horses to a group of co-mingled vaccinated horses (n = 155). Horses initially were vaccinated with either inactivated whole virus (n = 87) or canarypox recombinant (n = 68) WNV vaccines during 2003 or 2004, prior to emergence of WNV in the region. Unvaccinated horses were serologically tested for antibodies to WNV by microsphere immunoassay incorporating recombinant WNV E ...
Efficacy of a canarypox-vectored recombinant vaccine expressing the hemagglutinin gene of equine influenza H3N8 virus in the protection of ponies from viral challenge. To determine onset and duration of immunity provided by a 2- or 3-dose series of a new canarypox-vectored recombinant vaccine for equine influenza virus (rCP-EIV vaccine) expressing the hemagglutinin genes of influenza H3N8 virus strains A/eq/Kentucky/94 and A/eq/Newmarket/2/93 in ponies. Methods: Forty-nine 1- to 3-year-old male Welsh Mountain Ponies that were seronegative for equine influenza virus. Methods: Vaccinated and control ponies were challenged with aerosolized influenza virus A/eq/Sussex/89 (H3N8), representative of the Eurasian lineage of circulating influenza viruses. In trial 1,...
Experiences with new generation vaccines against equine viral arteritis, West Nile disease and African horse sickness. Viral diseases constitute an ever growing threat to the horse industry worldwide because of the rapid movement of large numbers of horses for competition and breeding. A number of different types of vaccines are available for protective immunization of horses against viral diseases. Traditional inactivated and live-attenuated (modified live virus, MLV) virus vaccines remain popular and efficacious but recombinant vaccines are increasingly being developed and used, in part because of the perceived deficiencies of some existing products. New generation vaccines include MLVs with deletions and/or...
Effect of hyperimmune plasma on the severity of pneumonia caused by Rhodococcus equi in experimentally infected foals. This study evaluated the prophylactic effectiveness of hyperimmune plasma (HIP) as an aid in the prevention of pneumonia caused by experimental infection with Rhodococcus equi. Thirty neonatal foals were administered R. equi HIP or saline at 2 days of age and were infected with virulent R. equi at 7 days. All foals developed signs or symptoms of respiratory disease. Radiographic scores on day 28 and neutrophil concentrations on day 49 were significantly greater in control foals, and time to respiratory effort score of 2 or higher was significantly shorter for control foals. Three foals, all in...
Venezuelan equine encephalitis virus vaccine candidate (V3526) safety, immunogenicity and efficacy in horses. A new vaccine, V3526, is a live-attenuated virus derived by site-directed mutagenesis from a virulent clone of the Venezuelan equine encephalitis virus (VEEV) IA/B Trinidad donkey (TrD) strain, intended for human use in protection against Venezuelan equine encephalitis (VEE). Two studies were conducted in horses to evaluate the safety, immunogenicity, ability to boost and protective efficacy of V3526 against challenges of TrD and VEEV IE 64A99. Horses were vaccinated subcutaneously (SC) with 10(7), 10(5), 10(3) or 10(2) plaque-forming units (pfu) of V3526. Control horses were sham immunized. I...
Efficacy of oseltamivir phosphate to horses inoculated with equine influenza A virus. We investigated the efficacy of the oral administration of oseltamivir phosphate (OP) in horses experimentally infected with equine influenza A virus (H3N8). Nine horses were divided into three horses each of control, treatment and prophylaxis groups. An administration protocol for the treatment group (2 mg/kg of body weight, twice a day for five days) was started immediately after the onset of pyrexia (above 38.9 degrees C). An administration protocol for the prophylaxis group (2 mg/kg of body weight, once a day for five days) was started on a day before viral inoculation. In the treatment gr...
[The incidence of Dicrocoelium dendriticum in Emmental]. A cross-sectional field study on the prevalence of Dicrocoelium dendriticum was performed in the Emmental. The study included 211 bovines, 170 equines, 20 ovines, 46 caprines and 23 rabbits (from 119 farms). In addition, laboratory routine diagnostic data obtained from 2.840 animals--all originating from the same area of investigation--were assessed in the same way. The infection extent concerning the different animal species were the following: bovines 46%, equines 12%, ovines 30%, caprines 48% and rabbits 9%. Univariate analyses of baseline epidemiological data identified no significant risk...
Immune suppression of challenged vaccinates as a rigorous assessment of sterile protection by lentiviral vaccines. We previously reported that an experimental live-attenuated equine infectious anemia virus (EIAV) vaccine, containing a mutated S2 accessory gene, provided protection from disease and detectable infection after virulent virus (EIAV(PV)) challenge [Li F, Craigo JK, Howe L, Steckbeck JD, Cook S, Issel C, et al. A live-attenuated equine infectious anemia virus proviral vaccine with a modified S2 gene provides protection from detectable infection by intravenous virulent virus challenge of experimentally inoculated horses. J Virol 2003;77(13):7244-53; Craigo JK, Li F, Steckbeck JD, Durkin S, Howe L...
Formulation with CpG ODN enhances antibody responses to an equine influenza virus vaccine. Previous studies have shown that protection against equine influenza virus (EIV) is partially mediated by virus-specific IgGa and IgGb. In this study we tested whether addition of a CpG ODN formulation to a commercial killed virus vaccine would enhance EIV-specific IgGa and IgGb antibody responses, and improve protection against an experimental EIV challenge. Thirty naïve horses were assigned to one of three groups and vaccinated as follows: 10 were given vaccine (Encevac TC4, Intervet Inc.) alone, 10 were given vaccine plus 0.25 mg CpG ODN 2007 formulated with 30% Emulsigen (CpG/Em), and 10 ...
Laboratory diagnosis of equine rabies and its implications for human postexposure prophylaxis. Laboratory diagnosis is essential to confirm suspected cases of equine rabies and to determine the medical care needed for human postexposure antirabies prophylaxis. Equine rabies transmitted by the vampire bat, Desmodus rotundus, has increased gradually in the State of São Paulo. The present study has several objectives, the most important being the evaluation of fluorescent antibody test (FAT) and virus-isolation laboratory tests performed with different equine nervous system tissues (cortical, hippocampus, cerebellar, brainstem and cervical medullar) to determine the tissue for which the t...
Prophylactic administration of ponazuril reduces clinical signs and delays seroconversion in horses challenged with Sarcocystis neurona. The ability of ponazuril to prevent or limit clinical signs of equine protozoal myeloencephalitis (EPM) after infection with Sarcocystis neurona was evaluated. Eighteen horses were assigned to 1 of 3 groups: no treatment, 2.5 mg/kg ponazuril, or 5.0 mg/kg ponazuril. Horses were administered ponazuril, once per day, beginning 7 days before infection (study day 0) and continuing for 28 days postinfection. On day 0, horses were stressed by transport and challenged with 1 million S. neurona sporocysts per horse. Sequential neurologic examinations were performed, and serum and cerebrospinal fluid w...