Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Infection
Infections in horses encompass a range of diseases caused by various pathogens, including bacteria, viruses, fungi, and parasites. These infections can affect different systems within the horse, such as the respiratory, gastrointestinal, and integumentary systems, leading to a variety of clinical signs depending on the pathogen and the severity of the infection. Common infectious diseases in horses include equine influenza, strangles, and equine herpesvirus. Diagnosis often involves clinical examination, laboratory testing, and sometimes imaging, to identify the causative agent and assess the extent of the disease. Treatment strategies may include antimicrobial therapy, supportive care, and preventive measures such as vaccination and biosecurity practices. This page aggregates peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, treatment, and prevention of infectious diseases in equine populations.
Mitogen stimulation favours replication of equine herpesvirus-1 in equine blood mononuclear cells by inducing cell proliferation and formation of close intercellular contacts. In the present study, equine herpesvirus-1 (EHV-1)-infected cells were identified in ionomycin/phorbol dibutyrate (IONO/PDB)-stimulated peripheral blood mononuclear cells (PBMC) and the mechanism by which stimulation increases the percentage of infected cells was examined. In the population of viral antigen-positive PBMC, 38.4+/-4.5% were CD5(+) T-lymphocytes (18.1+/-3.2% CD4(+) 13.6+/-1.8% CD8(+)), 18.1+/-5.4% were B-lymphocytes, 8.5+/-3.9% were monocytes and 35% remained unidentified. The role of the cell cycle in the increased susceptibility to EHV-1 upon stimulation was examined by stimula...
[Prevalence of the Salmonella plasmid virulence gene “spvD” in Salmonella strains from animals]. Strains of Salmonella isolated from animals in Germany (n = 878) were analysed for the presence of the spvD gene ("Salmonella plasmid virulence gene D") by DNA-DNA hybridization. The spvD gene was only detected in strains of serovars Typhimurium (93.3%), Enteritidis (97.1%), and Dublin (100%) as well as in two rough strains of Salmonella enterica. Salmonella isolates from mammals carried the gene more frequently (cattle 94.0%, horses 92.6%, pigs 73.7%) than those from birds (33.3%) or reptiles (4.5%). Due to its high prevalence in epidemiologically relevant salmonellae, the virulence factor sp...
Comparative efficacy, persistent effect, and treatment intervals of anthelmintic pastes in naturally infected horses. Eighty horses were involved in a comparative, controlled, and randomised field study conducted in Australia and Brazil. This study was undertaken to address the duration of efficacy (by faecal egg count reduction) of four anthelmintic pastes and to measure the time required between treatments on horses naturally infected by gastrointestinal nematodes. The treatment interval was based on the egg reappearance period (ERP), defined as "the period after treatment when horses have reached a positive egg count equal or superior to 200 eggs per gram (epg) of faeces". Horses were ranked according to p...
Comparison of two methods for presurgical disinfection of the equine hoof. To determine for equine hooves the normal resident aerobic bacterial population and the efficacy of 2 methods of disinfection. Study Design-Measurement of total bacterial, gram-positive bacterial, and gram-negative bacterial surface populations from the frog, sole, and hoof wall after each step of 2 different preoperative surgical disinfection techniques. Methods: Six adult horses. Methods: Hoof wall, sole, and frog samples were collected for quantitative bacteriology before, during, and after 2 multistep antiseptic preparation techniques: Method A-6-minute scrub with povidone-iodine soap, fol...
Inflammatory mediators induce endothelium-dependent adherence of equine eosinophils to cultured endothelial cells. Accumulation of equine eosinophils at sites of parasite infestation or allergic inflammation depends upon their adherence to vascular endothelial cells and subsequent migration through the endothelium and extracellular matrix. This study has examined whether cytokines, which cause endothelial cell-dependent eosinophil adherence in other species, and histamine and substance P, which increase adherence of equine eosinophils to protein coated plastic, induce equine eosinophil adherence to cultured equine digital vein endothelial cell (EDVEC) monolayers. The EDVEC monolayers were stimulated with r...
Borna disease virus-specific circulating immune complexes, antigenemia, and free antibodies–the key marker triplet determining infection and prevailing in severe mood disorders. Borna disease virus (BDV), a unique genetically highly conserved RNA virus (Bornaviridae; Mononegavirales), preferentially targets neurons of limbic structures causing behavioral abnormalities in animals. Markers and virus in patients with affective disorders and schizophrenia have raised worldwide interest. A persistent infection was suggestive from follow-up studies, but inconstant detectability weakened a possible linkage.This study for the first time discloses that detection gaps are caused by BDV-specific circulating immune complexes (CIC), and their interplay with free antibodies and pla...
Estimate of the national incidence of and operation-level risk factors for colic among horses in the United States, spring 1998 to spring 1999. To estimate the national incidence of, operation-level risk factors for, and annual economic impact of colic among horses in the United States during 1998 and 1999. Methods: Epidemiologic survey. Methods: 21,820 horses on 1,026 horse operations in 28 states. Methods: Horses were monitored for colic for 1 year, and results were recorded in a log that was collected quarterly. Operation-level data were collected via 4 on-site personal interviews. Associations between colic and independent variables adjusted for size of operation were determined. Results: Annual national incidence of colic in the ...
Age distributions of horses with strangulation of the small intestine by a lipoma or in the epiploic foramen: 46 cases (1994-2000). To test the hypothesis that strangulation of the small intestine by a lipoma or in the epiploic foramen is more common in older horses. Methods: Retrospective study. Methods: 46 horses. Methods: Ages of horses with strangulation of the small intestine by a lipoma (n = 29) or in the epiploic foramen (17) were compared with ages of 79 horses with miscellaneous small intestinal lesions. Effects of increasing age on risk of the diseases of interest were examined by use of logistic regression and a 1-sided trend test for binomial proportions. Results: Mean age of the horses with strangulation in th...
Neonatal isoerythrolysis involving the Qc and Db antigens in a foal. In 1992, a multiparous 13-year-old Thoroughbred mare and her 48-hour-old colt were examined because of possible neonatal isoerythrolysis (NI). Supportive treatment was administered, and the foal recovered without requiring a transfusion. According to the owners, the mare had delivered foals without incident during 1987 and 1991. The mare was barren during 1993, but in 1994, delivered a filly that developed severe NI. The foal was given 3 transfusions and eventually recovered without complications. Blood typing analysis of the mare and its foals indicated that all 4 foals were positive for the ...
Comparison of the value of pulsed-field gel electrophoresis, random amplified polymorphic DNA and amplified rDNA restriction analysis for subtyping Taylorella equigenitalis. Eight strains of Taylorella equigenitalis were identified by a polymerase chain reaction using a primer pair specific to the 16S rDNA of T equigenitalis. These eight strains were chosen because they had previously been shown to represent eight distinct genotypes by pulsed-field gel electrophoresis analysis after separate digestion of the genomic DNA with ApaI or NotI. The eight strains could be classified into six or seven types by random amplified polymorphic DNA analysis using different kinds of primers. Amplified rDNA restriction analysis after separate digestion with five restriction enzym...
Lack of antibodies to porcine circovirus type 2 virus in beef and dairy cattle and horses in western Canada. Porcine circovirus type 2 (PCV2) is a recently recognized agent that is consistently associated with postweaning multisystemic wasting disease in swine. There are conflicting data concerning the ability of this virus to infect and cause disease in other species. To determine if normal cattle, cattle affected with various illnesses, and normal horses in endemic areas of PCV2 infection in swine have had PCV2 infections, 100 randomly selected bovine sera, 100 equine sera, and 100 colostrum samples from clinically normal dairy cattle were examined for the presence of antibodies to porcine circovir...
Detection of antibodies to the nonstructural protein (NS1) of influenza A virus allows distinction between vaccinated and infected horses. Antibodies to the nonstructural protein (NS1) of A/equine/Miami/1/63 (H3N8) influenza virus were detected exclusively in the sera of mice experimentally infected with A/Aichi/2/68 (H3N2) and horses infected with A/equine/Kentucky/1/81 (H3N8) or A/equine/La Plata/1/93 (H3N8), but not in those of the animals immunized with the inactivated viruses, by enzyme-linked immunosorbent assay (ELISA) using a recombinant NS1 as antigen. The results indicate that the present method is useful for serological diagnosis to distinguish horses infected with equine H3 influenza viruses from those immunized with ...
Polymorphism identification within 50 equine gene-specific sequence tagged sites. The continued discovery of polymorphisms in the equine genome will be important for future studies using genomic screens and fine mapping for the identification of disease genes. Segments of 50 equine genes were examined for variability in 10 different horse breeds using a pool-and-sequence method. We identified 11 single nucleotide polymorphisms (SNPs) in 9380 bp of sequenced exon, and 25 SNPs, six microsatellites, and one insertion/deletion in 16961 bp of sequenced intron. Of all genes studied 52% contained at least one polymorphism, and polymorphisms were found at an overall rate of 1/613 b...
Prevalence and clinical implications of anthelmintic resistance in cyathostomes of horses. To determine the prevalence and clinical implications of anthelmintic resistance in cyathostomes of horses. Methods: Prospective study. Methods: 80 horses on 10 farms in a 5-county region of northeast Georgia. Methods: On each farm, horses were stratified in descending order according to pretreatment fecal egg count (FEC), blocked into groups of 4, and then randomly assigned to 1 of 4 treatment groups: no treatment (controls), and treatment with pyrantel pamoate, fenbendazole, or ivermectin. Fecal samples were collected 24 hours prior to treatment and 2, 4, and 6 weeks after treatment for dete...
Characterisation of Rhodococcus equi strains isolated from foals and from immunocompromised human patients. The cultural, morphological, biochemical, serological characteristics and antibiotic susceptibility of 25 Rhodococcus equi strains isolated from lungs and lung abscesses of pneumonic foals and 5 R. equi strains isolated from immuno-compromised human patients were examined. All R. equi strains showed common cultural, morphological and biochemical characteristics both with conventional tests and on the basis of their enzyme profile. The R. equi strains examined were resistant to penicillins with the exception of ampicillin, to sulphamethazine and several strains also to sulphamethoxazole-trimeth...
Rose bengal positive epithelial microerosions as a manifestation of equine keratomycosis. Purpose To describe the clinical appearance of corneal epithelial cell microerosions associated with keratomycosis in the horse. METHODS: Retrospective clinical study. RESULTS: Multifocal, punctate, superficial corneal opacities with positive rose bengal retention were noted in six horses with presumed 'viral keratitis'. Faint fluorescein staining was also present in three cases. Equine herpesvirus tissue culture inoculation was negative for a cytopathic effect in three cases. Aspergillus (n = 3), Curvularia (n = 1), and an unidentified fungus (n = 1) were cultured in five horses, and hyphae f...
Posterior lamellar keratoplasty for treatment of deep stromal absesses in nine horses. OBJECTIVE: To describe and evaluate the use of posterior lamellar keratoplasty as a surgical treatment for deep corneal stromal abscesses in horses. Animals studied Nine horses of various breeds and ages that presented with corneal stromal abscesses located in the posterior one-third of the cornea. Procedure Retrospective medical record study. RESULTS: Nine horses had deep corneal stromal abscesses that were treated with posterior lamellar keratoplasty. Median patient age was 3 years. Six patients were females and three were geldings. Medical therapy alone had been attempted prior to surgery i...
Ulcerative keratitis caused by beta-hemolytic Streptococcus equi in 11 horses. Purpose To describe 11 clinical cases of ulcerative keratitis in horses associated with beta-hemolytic Streptococcus equi in Florida, USA. METHODS: Retrospective clinical study (1996-99). RESULTS: Beta-hemolytic Streptococcus equi was cultured from 11 horses with deep ulcers, descemetoceles or iris prolapse (n = 8), a suture abscess found with a penetrating keratoplasty for a stromal abscess (n = 1), and ulceration that developed following keratectomy/irradiation for corneal squamous cell carcinoma (n = 2). Beta-hemolytic Streptococcus equi subspecies zooepidemicus was found in 10 eyes and sub...
[Equine protozoal myeloencephalitis in the Netherlands? An overview]. Equine protozoal myeloencephalitis (EPM) was diagnosed in a Dutch Warmblood gelding a few months after its export to the United States. The horse came back and was treated here. Additionally, an overview of the disease complex 'EPM' is given. Mode of infection, diagnosis of disease and its differential diagnoses, and general therapeutic options are presented. Although EPM due to infection with Sarcocystis neurona in Europe seems restricted to those horses that return or are imported from North America, the possibility of future cases of EPM caused by an infection with Neospora spp. is briefly ...
Bacterial isolates from blood and their susceptibility patterns in critically ill foals: 543 cases (1991-1998). To assess microorganisms isolated from blood specimens obtained from critically ill neonatal foals and to evaluate their antimicrobial susceptibility patterns. Methods: Retrospective study. Methods: 543 neonatal foals. Methods: Medical records of foals that were < 1 month old and were admitted to a referral neonatal intensive care unit were reviewed for results of bacteriologic culture of blood and antimicrobial susceptibility patterns. Results: At least 1 microorganism was isolated from 155 of 543 (28.5%) foals. Escherichia coli was the most commonly isolated bacterium. A single gram-posit...
Scedosporium prolificans infection associated with arthritis and osteomyelitis in a horse. Scedosporium prolificans was associated with arthritis and degenerative osteomyelitis in a 6-year-old Thoroughbred racehorse. The horse was suspected to have an inflammatory lesion of the interosseous tendon, but treatment had resulted in only a minimal response. Shortly after diagnostic arthrocentesis of the left metacarpophalangeal joint was performed, the joint became severely swollen, and radiography of the area revealed lysis of the distal end of the third metacarpal bone, the proximal sesamoid bones, and the proximal end of the proximal phalanx. The horse did not respond to treatment and...
Application of Sartwell’s model (lognormal distribution of incubation periods) to age at onset and age at death of foals with Rhodococcus equi pneumonia as evidence of perinatal infection. The distributions of the incubation periods for infectious and neoplastic diseases originating from point-source exposures, and for genetic diseases, follow a lognormal distribution (Sartwell's model). Conversely, incubation periods in propagated outbreaks and diseases with strong environmental components do not follow a lognormal distribution. In this study Sartwell's model was applied to the age at onset and age at death of foals with Rhodococcus equi pneumonia. The age at onset of clinical signs and age at death were compiled for 107 foals that had been diagnosed with R. equi pneumonia at b...
Streptococcal meningitis resulting from contact with an infected horse. We report a case of group C streptococcal meningitis in a woman with a history of close animal contact as well as head trauma as a result of a kick by a horse. Blood and cerebrospinal fluid cultures grew Streptococcus equi subsp. zooepidemicus, as did a throat culture taken from the colt that had kicked her 2 weeks prior to admission.
Transmission of endoparasites in horse foals born on the same pasture on a farm in central Kentucky (1996-1999). Research carried out during the last 4 years (1996-1999) of an 11-year study of the prevalence of internal parasites naturally transmitted to horse foals born on the same pasture on a farm in central Kentucky is presented here. Horses in this herd were not treated with any antiparasitic compound for over 20 years except for a replacement stallion in 1994. A total of 22 species, including 12 species of small strongyles, were recovered in the 4-year period. Transmission patterns of all species (n=35) of endoparasites recovered are compared for the 11-year study. Some of the changes were an incre...
Application of fluorescent in situ hybridization for specific diagnosis of Pneumocystis carinii pneumonia in foals and pigs. Fluorescent in situ hybridization, immunohistochemistry, and Grocott's methenamine-silver nitrate staining were compared as diagnostic methods for Pneumocystis carinii pneumonia in formalin-fixed lung tissue from foals and pigs. An oligonucleotide probe targeting 18S ribosomal RNA of P. carinii was designed for in situ hybridization, and a commercially available monoclonal antibody was used for immunohistochemistry. Samples from six foals and 10 pigs with P. carinii pneumonia, as verified by Grocott's methenamine-silver nitrate staining, were examined concurrently with samples from seven anima...
Immunity to Rhodococcus equi: antigen-specific recall responses in the lungs of adult horses. Rhodococcal pneumonia is an important disease of young horses that is not seen in immunocompetent adults. Since all foals are normally exposed to Rhodococcus equi in their environment, we hypothesized that most develop protective immune responses. Furthermore, these antigen-specific responses were hypothesized to operate throughout adult life to prevent rhodococcal pneumonia. A better understanding of the mechanisms of immune clearance in adult horses would help define the requirements for an effective vaccine in foals. Adult horses were challenged with virulent R. equi by intrabronchial inocu...
PCR detection of bovine papilloma virus DNA in superficial swabs and scrapings from equine sarcoids. The purpose of this study was to examine if bovine papilloma virus (BPV) DNA can be detected in superficial swabs or scrapings from equine sarcoids. Samples were obtained from 92 sarcoids and 20 non-sarcoidal control lesions. The polymerase chain reaction technique was used with a first primer set to check whether DNA extraction was successful, and with a second primer set specific for BPV-DNA. DNA isolation was successful in 88% of the swabs and 93% of the scrapings. All control lesions were negative for BPV-DNA.
A long-term study of 277 cases of equine sinonasal disease. Part 2: treatments and results of treatments. The treatments of 277 horses with equine sinonasal disease (1984-1996), described by Tremaine and Dixon (2001), are reported here. Long-term (median duration 24 months) outcomes of treatment of the more common disorders were good, with 92% of horses with sinonasal mycosis, 84% with primary sinusitis, 82% with sinus cysts, 78% with dental sinusitis and 75% with sinonasal trauma reported to have complete remission of clinical signs. However, only 33% of horses with progressive ethmoidal haematoma (PEH) and 12% with sinonasal neoplasia reported long term remission of clinical signs.
