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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.
Tissue and cell tropism of African horse sickness virus demonstrated by immunoperoxidase labeling in natural and experimental infection in horses in South Africa. Tissues from 196 experimental and confirmed natural cases of African horse sickness (all 9 serotypes) were examined with a standardized and validated immunohistochemical assay for detection of the causative virus. The study confirmed that heart and lung are the main target tissues for African horse sickness virus (across all serotypes), followed closely by spleen. It also indicated that microvascular endothelial cells and monocyte-macrophages are the main target cells for virus replication. The importance of monocytes as target cells was emphasized, with relatively few tissue macrophages conta...
Animal and human rabies in Mongolia. The prevalence of animal rabies differs in each area of Mongolia. Wolves (Canis lupus Linnaeus, 1758), foxes ( Vulpes vulpes Linnaeus, 1758), corsac foxes (Vulpes corsac Linnaeus, 1768) and manuls (Felis manul Pallas, 1778) are considered to be the infective wild animals in natural foci. Amongst livestock, cattle have had the most rabies cases, followed by camels, sheep, goats and horses. The peak prevalence of animal rabies occurred in the 1970s. Dundgovi Province had the highest incidence during that period. The number of rabies cases in animals decreased during the 1980s. This may have been...
Use of Ir192 interstitial brachytherapy for an equine malignant dermal schwannoma. A 10-year-old Hanoverian mare was evaluated for a right buccal swelling that recurred 3 months following surgical resection. Ultrasonographic examination showed a broadly pedunculated subcutaneous mass at the level of 106-109 and 406-409 cheek teeth associated with an erosive mucosal lesion on the inside of the cheek. Histological examination of a biopsy specimen revealed a well-demarcated, malignant, dermal schwannoma. Following subcutaneous placement of platinum coated Ir192 wires under general anaesthesia, low-dose radiation of 5 gray per day was delivered for 14 days. Short-term complicati...
Lawsonia intracellularis and virulent Rhodococcus equi infection in a thoroughbred colt. A 26-month-old thoroughbred colt with a 4-month history of continuous diarrhoea and weight loss was subject to necropsy examination. The small intestinal mucosa was thickened and this change particularly affected the terminal ileum. Microscopical examination revealed multifocal epithelial hyperplasia, with multifocal granulomas and marked lymphocytic infiltration of the lamina propria. Numerous gram-negative argyrophilic curved bacilli were observed within the cytoplasm of affected enterocytes. Macrophages and epithelioid cells forming the granulomas had abundant, lightly eosinophilic, foamy c...
Enteric dysganglionosis resembling intestinal neuronal dysplasia in a foal with bacterial colitis. A 5-day-old quarter horse colt with a history of hypothermia, agonal breathing, and diarrhea was euthanized. At necropsy, numerous slightly raised, discrete, closely approximated submucosal nodules were observed in the colon and small intestine. Histologically, these nodules were composed of expanded submucosal mesenchyme that contained numerous neurons either individually or in ganglia. Thirty-two percent of these ganglia included 8 or more neurons, in contrast to 6% in an age-matched foal. Some nodules had necrosuppurative inflammation with vasculitis, thrombosis, and bacterial colonization....
Pathological changes caused by Anoplocephala perfoliata in the equine ileocecal junction. Gastrointestinal motility disorders represent a significant cause of morbidity and mortality in horses. Previously regarded as a non-pathogenic tapeworm, Anoplocephala perfoliata has been recently associated with equine colic. In this study, pathological changes related to A. perfoliata at the ileocecal junction were investigated in 31 slaughtered horses. Our results showed a significant relationship between parasitic burden and grading of histopathological lesions in both the mucosa and submucosa. Moreover, in infested horses, hypertrophy of the circular muscle layer was determined. Finally, ...
Evaluation of diagnostic techniques for Anoplocephala perfoliata in horses from Alberta, Canada. Accurate diagnosis of parasites within individual hosts remains a difficult task. Incorrect and/or inaccurate diagnosis restricts the potential for targeted treatment of individuals and limits our understanding of key epidemiological characteristics of potential pathogens of domestic stock. In this study, we compared the specificity and sensitivity of four diagnostic methods for determination of the presence and intensity of the cestode Anoplocephala perfoliata in horses. Over 400 horses from an abattoir in south-central Alberta were evaluated for the presence and number of cestodes. Thirty on...
Isolation and partial sequencing of Equid herpesvirus 5 from a horse in Iceland. Horses are hosts to 2 types of gammaherpesviruses, Equid herpesvirus 2 and 5 (EHV-2 and EHV-5, respectively). Both EHV-2 and EHV-5 are common in horses in Iceland. An Icelandic EHV-5 isolate was recovered by sequential culture in primary fetal horse kidney and rabbit kidney cells. Glycoprotein B, glycoprotein H, and DNA terminase genes of the isolate were fully sequenced, and the DNA polymerase gene was partly sequenced. To date, the glycoprotein B gene of EHV-5 was the only gene that has been reported to be completely sequenced in addition to small parts of the glycoprotein H, DNA polymerase,...
Cystic echinococcosis due to Echinococcus equinus in a horse from southern Germany. In Europe, cystic echinococcosis is rare in horses and is mostly diagnosed at slaughter or postmortem examination. Equine cystic echinococcosis can be caused by various Echinococcus taxa, but only Echinococcus equinus (the "horse strain") is known to produce fertile cysts. In Europe, E. equinus appears to be endemic in Great Britain, Ireland, Spain, and Italy and has sporadically been reported in Belgium and Switzerland. The present report describes the first case of a molecularly confirmed E. equinus infection in a horse foaled and raised in Germany. The 19-year-old mare was presented for exa...
Immunohistochemical study of matrix metalloproteinases-2 and -9, macrophage inflammatory protein-2 and tissue inhibitors of matrix metalloproteinases-1 and -2 in normal, purulonecrotic and fungal infected equine corneas. Determine the effects of matrix metalloproteinases (MMPs)-2, -9, macrophage inflammatory protein-2 (MIP-2), tissue inhibitors of matrix metalloproteinase (TIMP)-1 and -2 by immunohistochemical expression in fungal affected and purulonecrotic corneas. Methods: Paraffin-embedded equine corneal samples; normal (n = 9), fungal affected (FA; n = 26), and purulonecrotic without fungi (PN; n = 41) were evaluated immunohistochemically for MMP-2, -9, MIP-2, TIMP-1 and -2. The number of immunoreactive inflammatory cells was counted and statistics analyzed. Western blot was performed to detect MMP-2, MMP...
OAS1 polymorphisms are associated with susceptibility to West Nile encephalitis in horses. West Nile virus, first identified within the United States in 1999, has since spread across the continental states and infected birds, humans and domestic animals, resulting in numerous deaths. Previous studies in mice identified the Oas1b gene, a member of the OAS/RNASEL innate immune system, as a determining factor for resistance to West Nile virus (WNV) infection. A recent case-control association study described mutations of human OAS1 associated with clinical susceptibility to WNV infection. Similar studies in horses, a particularly susceptible species, have been lacking, in part, because...
Intra- and interhost evolutionary dynamics of equine influenza virus. Determining the evolutionary basis of cross-species transmission and immune evasion is key to understanding the mechanisms that control the emergence of either new viruses or novel antigenic variants with pandemic potential. The hemagglutinin glycoprotein of influenza A viruses is a critical host range determinant and a major target of neutralizing antibodies. Equine influenza virus (EIV) is a significant pathogen of the horse that causes periodical outbreaks of disease even in populations with high vaccination coverage. EIV has also jumped the species barrier and emerged as a novel respirator...
Surgical treatment of septic jugular thrombophlebitis in nine horses. To report a technique for surgical treatment of septic jugular thrombophlebitis unresponsive to medical treatment. Methods: Case series. Methods: Horses (n=9) with septic jugular thrombophlebitis unresponsive to medical treatment. Methods: Jugular vein thrombectomy was performed under standing sedation and local anesthesia. The contents of the affected portion of vein were removed by multiple incisions in the vein, with the incisions left open to drain and heal by second intention. Results: The technique was curative in all instances, although 2 horses required a 2nd procedure. One horse requi...
Orthopedic infections in equine long bone fractures and arthrodeses treated by internal fixation: 192 cases (1990-2006). To determine the rate of postoperative infection (POI) for internal fixation repaired equine long bone fractures and arthrodeses and identify associated risk factors. Methods: Case series. Methods: Horses (n=192) with fracture repair of the third metacarpal and metatarsal bones, radius, ulna, humerus, tibia, and femur, or arthrodesis with internal fixation. Methods: Medical records (1990-2006) were reviewed for signalment, anatomic location, fracture classification and method of repair, technique and surgical duration, bacterial species isolated, postoperative care, onset of POI, and outcome. ...
Evaluation of rapid antigen detection kits for diagnosis of equine rotavirus infection. We evaluated antigen detection kits for human rotavirus with regard to their usefulness for diagnosing equine rotavirus infection. Limiting dilution analyses showed that of the seven kits investigated the Dipstick `Eiken' Rota (Dipstick) had the highest sensitivity to two serotypes of equine rotavirus. The Dipstick did not cross-react with several equine intestinal pathogens. An investigation using 249 fecal samples indicated that the sensitivity of the Dipstick was 81.9% and 47.3%, and its specificity was 98.2% and 99.0%, and its concordance rate was 92.8% and 68.3%, compared with values obta...
Identification of cellular proteins interacting with equine infectious anemia virus S2 protein. The macrophage-tropic lentivirus, equine infectious anemia virus (EIAV), encodes the small auxiliary protein S2 from a short open reading frame that overlaps the amino terminus of env EIAV S2 is dispensable for virus replication in cultured cells but is required for disease production. S2 is approximately 7 kDa and has no overall amino acid sequence homology to other cellular or viral proteins. Therefore it is likely that S2 plays a role as an adaptor protein. To further investigate S2 function we performed a yeast-2-hybrid screen to identify cellular proteins that interact with EIAV S2. The s...
Are macrocyclic lactones useful drugs for the treatment of Parascaris equorum infections in foals? A study was carried out to assess the field efficacy of moxidectin (MOX) against Parascaris equorum in foals. A total of 70 foals from 2 Italian thoroughbred (Farms 1 and 2) stud farms and one trotter stud farm (Farm 3), aged 3-5 months and with faecal egg counts (FEC) f>or=300 eggs per gram (EPG) were included in the study. On each farm, foals were divided into 2 groups (of 10, 8 and 10 foals, respectively) and treated with either moxidectin (MOX, 400 mcg/kg b.w.) or ivermectin (IVM, 200 mcg/kg b.w.) on day 0 and examined for faecal count reduction (FECR) on day 14. Five, 4 and 5 foals, re...
Haemotrophic Mycoplasma infection in horses. Haemotrophic mycoplasmas (HM) are parasites on the surface of red blood cells and known to infect a wide range of animals. However, there are no previous evidences of HM infections in horses. In this study HM were detected for the first time in the blood of two horses suffering from poor performance, apathy, weight loss, and anaemia. Using a HM specific PCR assay and subsequent sequencing the infective agents isolated from the blood of said horses were confirmed as closely related to the HM species Mycoplasma haemofelis and 'Candidatus Mycoplasma haemobos'.
Treatment efficacy of trimethoprim sulfamethoxazole, pentoxifylline and altrenogest in experimentally induced equine placentitis. The objective was to determine if long-term treatment with trimethoprim sulfamethoxazole (antimicrobial), pentoxifylline (anti-inflammatory/anti-cytokine) and altrenogest (synthetic progestin), would improve pregnancy outcome in mares with experimentally induced placentitis. Seventeen normal, pregnant pony mares were enrolled in the study at 280-295 d of pregnancy. Placentitis was induced in all mares by intra-cervical inoculation of Streptococcus equi subsp. zooepidemicus (10(7) CFU). Five mares served as infected, untreated control animals (Group UNTREAT). Twelve mares (Group TREAT) were inf...
Mycobacterium ulcerans infections in two horses in south-eastern Australia. Two horses were diagnosed as having Mycobacterium ulcerans infections. The first was a 21-year-old Quarterhorse-cross mare living in Mallacoota (a coastal town near the border of New South Wales and Victoria, Australia) that presented with lichenification, hair-loss and oedema on a fetlock, which subsequently ulcerated, as well as a non-healing ulcer on the wither. The second horse was a 32 year-old Standardbred gelding from Nicholson, near Bairnsdale, Victoria, that had an ulcerated lesion on its caudal thigh. Histologically, there were characteristic changes seen with M. ulcerans infections ...
Rib osteomyelitis in three foals. Three foals aged between 21 and 44 days were presented for evaluation of pyrexia and lameness. Each had subcutaneous abscessation associated with osteomyelitis of a rib at the costochondral junction and pathological fracture of the affected rib; one foal had more than one rib affected. Other localised sites of infection included other sites of osteomyelitis, omphalophlebitis, uveitis, enterocolitis, and calcaneal bursitis. The subcutaneous abscessation and rib osteomyelitis was treated surgically in two foals. Salmonella typhimurium was isolated from the subcutaneous abscess in one foal and fr...
Antimicrobial delivery by intrasynovial catheterisation with systemic administration for equine synovial trauma and sepsis. To present the technique for intra-articular catheter placement and report the clinical outcomes of 38 cases of equine synovial trauma and/or infection treated with broad-spectrum antimicrobials administered via an intrasynovial catheter (ISC). Methods: Retrospective study. Methods: Medical records of 38 horses treated for synovial trauma and sepsis with frequent antimicrobial administration through an ISC from 1995 to 2008 were reviewed. Follow-up information was obtained via clinical re-evaluation or telephone contact with the owners. Results: The majority of horses (84%) received amikacin a...
Histopathological characteristics of an ossifying fibroma formed in the maxilla of a racehorse. A 1-year-old male thoroughbred racehorse experienced swelling of the left upper lip. The swelling was attributable to enlargement around the incisive bone of the interdental space posterior to the third incisor in the left maxilla. Even after two operations to reduce the bulk of the mass, it continued to increase in size. Dyspnea caused by stenosis of the nasal cavity forced us to perform euthanasia, and a pathological examination was conducted. Macroscopic examination of a section of the mass revealed the formation of multiple areas of solid fibrous tissue, and trabeculae within the incisive ...
Myofibroblastic fibrosarcoma with multifocal osseous metaplasia at the site of equine influenza vaccination. We describe a fibrosarcoma in a 12-year-old Quarterhorse x Arabian gelding as a sequela to equine influenza vaccination. Shortly after the second vaccination, swelling at the site was noticed by the owner and it continued to increase in size over the following 6 months. Biopsy of the mass indicated a fibrosarcoma had developed at the vaccination site. It was approximately 20 cm in diameter and elevated well above the level of the skin. There was no clinical evidence of metastases to the lungs or local lymph nodes. Surgical resection of the mass was performed and the wound healed by first and s...
Severe anthrax outbreaks in Italy in 2004: considerations on factors involved in the spread of infection. Anthrax is a disease of humans and animals caused by the encapsulated, spore-forming Bacillus anthracis. In Italy, anthrax is normally a sporadic disease. During the summer 2004, anthrax broke out in the Basilicata, in southern Italy, a region with a low prevalence of anthrax in which vaccination had been suspended since 1998. The disease involved several animals in few weeks and in a large area. Over 41 days, 81 cattle died, as well as 15 sheep, 9 goats, 11 horses and 8 deer. The Multiple-locus Variable-Number Tandem Repeats Analysis (MLVA) showed that all the 53 isolates belonged to the Clus...
Selection of a rare neutralization-resistant variant following passive transfer of convalescent immune plasma in equine infectious anemia virus-challenged SCID horses. Vaccines preventing HIV-1 infection will likely elicit antibodies that neutralize diverse strains. However, the capacity for lentiviruses to escape broadly neutralizing antibodies (NAbs) is not completely understood, nor is it known whether NAbs alone can control heterologous infection. Here, we determined that convalescent immune plasma from a horse persistently infected with equine infectious anemia virus (EIAV) neutralized homologous virus and several envelope variants containing heterologous principal neutralizing domains (PND). Plasma was infused into young horses (foals) affected with se...
Epiphyseal cartilage canal blood supply to the metatarsophalangeal joint of foals. It is presently unknown whether cartilage ischaemia plays any part in the pathogenesis of osteochondral fragmentation within the equine metatarsophalangeal joint, as no detailed studies on microcirculation in the area have been reported. Objective: To describe the developmental pattern of the blood supply to the epiphyseal growth cartilage in the metatarsophalangeal joint of foals. Methods: Eight Standardbred foals were sacrificed between birth and age 7 weeks to undergo a barium perfusion procedure to demonstrate vessels within growth cartilage canals of one hindlimb. The metatarso-phalangeal...
