Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Pathogens
Pathogens are microorganisms, such as bacteria, viruses, fungi, and parasites, that can cause disease in horses. These microorganisms interact with the equine immune system, often leading to a range of health issues that can affect individual horses or entire populations. Pathogens can be transmitted through various routes, including direct contact, vectors, or environmental exposure. Common equine pathogens include Streptococcus equi, Equine Herpesvirus, and Strongylus vulgaris. Understanding the interactions between equine hosts and pathogens is essential for disease prevention, management, and treatment. This page compiles peer-reviewed research studies and scholarly articles that explore the identification, transmission, and impact of pathogens on equine health.
Observations on the epidemiology of equine hydatidosis in Britain. Of 1388 horses and ponies examined at two abattoirs in the north of England from November 1979 to September 1981, 123 (8.7 per cent) showed evidence of hydatid infection. Prevalence of infection was closely related to age, rising from nil in animals up to two years old to over 20 per cent of those over eight years. Full-mouthed horses and ponies had similar prevalence rates (14.9 and 14.5 per cent, respectively), but horses had nearly twice as many viable infections as ponies. The prevalence of infection varied with the region of origin of full-mouthed horses and ponies, with 18 per cent of th...
Energy metabolism of the contagious equine metritis bacterium. The energy metabolism of the English E-CMO strain of contagious equine metritis bacterium was studied in whole cells and cell extracts. This bacterium appears to have an active Krebs cycle and probably obtains energy by oxidative phosphorylation since glycolysis and the hexose monophosphate pathways appear to be absent. These conclusions are based on the findings that [U-14C]glucose incorporation by this bacterium is below the level of detection, and that respiration is stimulated by Krebs cycle intermediates (i.e., malate, citrate, and succinate), but not by glucose, fructose, maltose, or suc...
Capsular serotypes of Rhodococcus equi. One hundred strains of Rhodococcus equi from various animal species and sources in Australia were examined for capsular serotype. Eighty-four of the strains fell into the existing 7 serotypes, and just under half of the strains belonged to serotype 1. Isolates from the intestines and faeces of horses, cattle, pigs and other species, and from soil, were found to belong to the same serotypes as those recovered from the lungs of foals with R. equi pneumonia. There was no clear relationships between capsular serotype and source of origin of the isolates.
Factors affecting phagocytosis of bacteria by neutrophils in the mare’s uterus. Ten mares, 5 resistant and 5 susceptible to bacterial endometritis, were examined for differences pertaining to the efficiency of phagocytosis of bacteria by neutrophils in the uterus. An assay for chemiluminescence was used to evaluate various schemes of opsonization and relate them to phagocytic rate. 123I-labelled albumin was used to measure protein migration to the inoculated uterus. Neutrophil numbers moving to the uterine lumen were determined. Before inoculation resistant mares were found to have substances in their uterine secretions that opsonized bacteria, resulting in effective phag...
Effects of washing on the bacterial flora of the stallion’s penis. Six stallions were subjected to extensive cleansing of the penis and prepuce with water, Ivory Soap and water, or Betadine surgical scrub and water. The stallions were all washed for 14 days, and then allowed 14 days respite. This pattern of washing and resting was repeated consecutively. Swabs were taken from all 7 stallions twice weekly and semen was collected once a week for bacteriological examination. All forms of cleansing altered the bacterial flora of the stallion's penis; the Ivory Soap tended to encourage the replacement of the normal flora with coliform organisms, while Betadine fav...
Effect of ovarian hormones on the phagocytic response of ovariectomized mares. 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...
Bacteriologic examination of equine fecal flora as a diagnostic tool for equine intestinal clostridiosis. The fecal flora of 56 clinically healthy and 23 sick horses were examined bacteriologically for counts of Clostridium perfringens, molds, coliforms, alpha- and beta-hemolytic streptococci, and microbes belonging to genus Bacillus, as well as for the presence of Salmonella spp. Of the healthy horses, 85.7% had a C perfringens count less than 10(1) colony-forming units/g of feces. Of the healthy horses, lowest counts were found in race-horses. Of the sick horses, equine intestinal clostridiosis was diagnosed in 2 horses with large C perfringens counts (10(4) to 10(7) colony-forming units/g) and ...
Mechanisms of infection in the respiratory tract. Related to its potential vulnerability the respiratory tract has a very complex and effective defence apparatus. The interaction between these defence mechanisms and certain characteristics of aetiological agents results in a pattern in which initial infections by these agents tend to occur at specific sites in the tract. Infections in which the primary portal of entry is in the upper respiratory tract include Bordetella bronchiseptica and Haemophilus spp in pigs; Pasteurella spp in cattle, sheep, pigs; Mycoplasma spp in cattle, sheep, pigs and poultry; equine herpesvirus 1 in horses; infectio...
Babesia equi (Laveran 1901) 1. Development in horses and in lymphocyte culture. The vertebrate development of Babesia equi from infected Hyalomma marginatum in Morocco was investigated in vitro and in vivo. It was demonstrated that the sporozoites of B. equi initiate a phase of exo-erythrocytic schizogony in lymphocytes both in vitro and in vivo. On the other hand, sporozoites did not invade erythrocytes in vitro. The complete vertebrate life cycle of B. equi was simulated in vitro, from the invasion of lymphocytes by sporozoites, to the development of macro- and microschizonts, the invasion of erythrocytes by merozoites, and the subsequent intra-erythrocytic schizogony. ...
Diagnostic methods in infectious respiratory disease. For laboratory diagnosis of respiratory disease it is of overwhelming importance that the specimens taken are adequate, taken from the correct site and at the correct time. The lower regions of the respiratory tract are particularly difficult to sample but are more likely to yield the causative agent of a pneumonia. Infections involving the upper respiratory tract are much easier to sample and appropriate aspiration apparatus can be used. Consideration must be given to the timing of sample collection in relation to the life cycle of the causative micro-organism. Sampling of several animals is ...
Nasal aspergillosis in three horses. Three horses were referred for investigation of a unilateral foul smelling scanty nasal discharge, complicated in one case by intermittent epistaxis. Thick purulent material or a mycotic plaque was identified by an endoscopic examination of the middle meatus but in two horses this had to be repeated under general anaesthesia before the abnormalities were detected. Aspergillus fumigatus was cultured from all three cases and septate hyphae were identified on smears from lesions. Histological examination of the lesion in one case revealed a fungal mycelium. Topical treatment with natamycin soluti...
Serum concentrations of trimethoprim and sulfadiazine following oral paste administration to the horse. Two fasted and 2 fed horses were dosed orally with a combined trimethoprim and sulfadiazine paste formulation at a dose of 35 mg (1:5 combined active ingredients)/kg. Serum concentrations of each drug were determined periodically for 3 consecutive days for the 4 horses. The extent and rate of absorption for trimethoprim were variable, but peak serum concentrations occurred generally within 3 hours; sulfadiazine absorption was slower, reaching peak concentrations by 6 hours. Fasting did not have a consistent effect on the serum concentration profiles for either drug. Both drugs achieved serum c...
Bacteriological and serological studies of haemophilus equigenitalis, agent of contagious equine metritis. Seventeen strains of haemophilus equigenitalis isolated from the cervix, clitoris, and urethra of mares were biochemically characterized with the API 10E and APIZYM test kit systems, conventional biochemical tests, and the porphyrin test. Antisera were prepared in rabbits. All of the strains were positive to the porphyrin test, and the requirement for factor X (hemin) or V (nicotinamide adenine dinucleotide) was not shown. Catalase, oxidase, phosphatase, and phosphoamidase tests were positive with all of the strains. Aminopeptidase (arylamidase) activity has been detected on beta-naphthylamide...
The relationship of two equine mycoplasmas to Mycoplasma mycoides. Two unidentified mycoplasmas, N3 and N11, isolated from the respiratory tract of horses, were found to cross-react with strains of M. mycoides subsp. mycoides in indirect immunofluorescence tests, growth-inhibition tests carried out by the running drop/agar-well method, and in complement-fixation and double immunodiffusion tests. Serologically, the equine mycoplasmas were not completely identical with any of the reference strains of M. mycoides with which they were compared. Their cultural characteristics, ability to digest coagulated serum and casein, and survival at 45 degrees C, however, su...
Intestinal threshold of an enzootic strain of Venezuelan encephalitis virus in Culex (Melanoconion) taeniopus mosquitoes and its implications to vector competency and vertebrate amplifying hosts. The minimal intestinal dose of an enzootic strain of Venezuelan encephalitis (VE) virus for Culex (Melanoconion) taeniopus mosquitoes caught at a marsh habitat of VE virus in Guatemala was less than five plaque forming units (pfu) of virus. Ingestion of this dose of virus in blood of viremic hamsters resulted in transmission of virus to other hamsters. This low intestinal threshold of an enzootic strain of VE virus indicates that the natural Guatemalan population of Cu. (Mel.) taeniopus can acquire VE virus from vertebrates that have viremia levels as low as 1,000-5,000 pfu/ml of blood, provid...
Coprophilous fungi of the horse. A total of 1267 microfungi, including 35 Myxomycetes, were recorded from the fecal samples of the 60 horses; of these 395 were found on 20 saddle-horse feces, 363 on 20 race-horses and 509 on 20 working horses. Eighty two species representing 53 genera were recorded; of these 7 were Zygomycetes, 18 Ascomycetes, 1 Basidiomycetes and 25 Fungi Imperfecti: 2 Myxomycetes. Common coprophilous fungi are in decreasing order Pilobolus kleinii, Saccobolus depauperatus, Mucor hiemalis, Lasiobolus ciliatus, Podospora curvula, Petriella guttulata, M. circinelloides, Coprinus radiatus, Dictyostelium mucoroi...
Epidemiology of Strongylus vulgaris infection of the horse in Morocco. Between August 1978 and July 1979 the anterior mesenteric artery and its branches were collected regularly from adult horses and examined for Strongylus vulgaris larvae. The incidence of infection varied from 55 to 100% (annual mean 80%). The mean monthly number of larvae ranged form 3 to 22 with an annual overall mean of 13. The arterial infection was at its minimum in December to January, rose gradually to attain the peak in June and declined thereafter. These observations indicated that S. vulgaris is an annual species in Morocco, infection occurring during the rainy season (November-April)...
The susceptibility of isolates of Corynebacterium equi to antimicrobial drugs. Fifty-one isolates of Corynebacterium equi recovered from pigs and horses belonging to two capsular serotypes were tested for susceptibility to antimicrobial agents. No clear differences were detected in sensitivity between isolates of different sources or serotypes. All isolates were sensitive to less than 0.25 micrograms/ml of erythromycin and gentamicin. The following minimum inhibitory concentrations (MICs) of antimicrobial agents were determined for greater than or equal to 90% of isolates: methicillin greater than 16 micrograms/ml, clindamycin 1-2 micrograms/ml, tobramycin less than or e...
Isolation of antibiotic-resistant Salmonella krefeld from clinical veterinary materials. Six isolations of Salmonella krefeld were made from clinical veterinary specimens. These isolates were multiply resistant to several antimicrobial agents commonly used to treat salmonellosis.
