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.
Nyberg KA, Vinnerås B, Lewerin SS, Kjellberg E, Albihn A.To investigate the inactivation of Salmonella enterica serovar Typhimurium and the faecal indicator Enterococcus faecalis in horse manure:soil mixtures by application of hydrated lime (Ca(OH)(2)). Results: In laboratory incubations, the inhibitory effect of different concentrations of Ca(OH)(2), as well as different application techniques, was tested. Other variables were horse manure:soil ratio, incubation temperature (6 and 14°C) and soil type (sand/clay). Bacterial enumeration by the plate count method in samples taken at increasing intervals revealed that Ca(OH)(2) effectively reduced Sal...
Wada S, Ode H, Hobo S, Niwa H, Katayama Y, Takatori K.To describe a case of superficial keratomycosis caused by Mortierella wolfii (M. wolfii) in a horse. Methods: A thoroughbred filly was presented with painful right eye of 2 days' duration. A superficial corneal ulcer was observed ventrally together with multifocal punctuate opacities axially. Samples were collected by swabbing and scraping the ulcerated lesion and submitted for microbiologic and cytologic examination. Results: Microscopic evaluation of debrided corneal tissue revealed the presence of nonseptate fungal hyphae, and culture of a corneal swab yielded fungal growth. Medical treat...
Gramiccia M.The leishmanioses are diseases caused by protozoa of the genus Leishmania, parasites infecting numerous mammal species, including humans, and transmitted by the bite of phlebotomine sand flies. They are a large group of diseases ranging over inter-tropical zones of America and Africa, and extend into temperate regions of Latin America, Europe and Asia. Pet animals are found infected with different Leishmania species but Leishmania infantum is the most widespread being dogs the main reservoir of zoonotic visceral leishmaniosis (ZVL). Dogs are very susceptible to this parasite and may suffer fro...
Allison K, Taylor NM, Wilsmore AJ, Garforth C.An online survey was conducted to establish horse owners' beliefs, attitudes and practices relating to the use of anthelmintic drugs. Out of a total of 574 respondents, 89 per cent described themselves as 'leisure riders', most of whom took part in a variety of activities including eventing, show jumping, dressage, hunter trials, hunting, driving, endurance and showing. Overall, respondents were generally aware and concerned about the issue of anthelmintic resistance. Less than 60 per cent of all respondents were comfortable with their existing anthelmintic programme, and 25 per cent would lik...
Diab SS, Kinde H, Moore J, Shahriar MF, Odani J, Anthenill L, Songer G, Uzal FA.Clostridium perfringens type C is an important cause of enteritis and enterocolitis in foals and occasionally in adult horses. The disease is a classic enterotoxemia, and the enteric lesions and systemic effects are caused primarily by beta toxin, 1 of 2 major toxins produced by C. perfringens type C. Until now, only sporadic cases of C. perfringens type C equine enterotoxemia have been reported. We present a comprehensive description of the lesions in 8 confirmed cases of type C enterotoxemia in foals and adult horses. Grossly, multifocal to segmental hemorrhage and thickening of the intestin...
Elton D, Bryant N.Despite the availability of vaccines, equine influenza virus (EIV) continues to pose a threat to the racing industry. The virus spreads rapidly in unprotected populations and large scale outbreaks, such as those in South Africa in 2003 and Australia in 2007, can cost billions of pounds. Like other influenza viruses, EIV undergoes antigenic variation, enabling it to evade antibodies generated against previous infection or vaccination. The UK has an active surveillance programme to monitor antigenic drift and participates in an international collaboration with other countries in Europe, Japan an...
Casagrande Proietti P, Bietta A, Coppola G, Felicetti M, Cook RF, Coletti M, Marenzoni ML, Passamonti F.The objective of this manuscript was to validate published PCR-based methods for detection of β-haemolytic Streptococci by comparison with established bacteriological techniques using 85 clinical isolates recovered from uterine swabs of mares with clinical signs of endometritis and to determine the distribution of SeeL/SeeM and SzeL/SzeM superantigens in isolates of Streptococcus equi subsp. equi (S. equi) and S. equi subsp. zooepidemicus (S. zooepidemicus). The conventional bacteriological techniques showed the vast majority of these isolates (78) were S. zooepidemicus with just 5 Streptococ...
Lyons ET, Tolliver SC, Kuzmina TA, Collins SS.The activity of three anthelmintics (fenbendazole-FBZ; oxibendazole-OBZ; and pyrantel pamoate-PRT) was ascertained against the ascarid Parascaris equorum in horse foals on eight farms in Central Kentucky (2009-2010) in field tests. A total of 316 foals were treated, and 168 (53.2%) were passing ascarid eggs on the day of treatment. Evaluation of drug efficacy was determined qualitatively by comparing the number of foals passing ascarid eggs in their feces before and after treatment. The main purpose was to obtain data on current activity of these compounds against ascarids. Additionally, the o...
Kyvsgaard NC, Lindbom J, Andreasen LL, Luna-Olivares LA, Nielsen MK, Monrad J.Horses, mules and donkeys are indispensable farming and working animals in many developing countries, and their health status is important to the farmers. Strongyle parasites are ubiquitous in grazing horses world-wide and are known to constitute a threat to equine health. This study determined the prevalence of strongyle infection, the efficacy of ivermectin and fenbendazole treatment, and strongyle re-infection rates of working horses during the dry months in Nicaragua. One hundred and five horses used by farmers for transport of people and goods were randomly allocated into three treatment ...
Vandekerckhove AP, Glorieux S, Gryspeerdt AC, Steukers L, Van Doorsselaere J, Osterrieder N, Van de Walle GR, Nauwynck HJ.Equine herpesvirus type 1 (EHV-1) replicates extensively in the epithelium of the upper respiratory tract, after which it can spread throughout the body via a cell-associated viremia in mononuclear leukocytes reaching the pregnant uterus and central nervous system. In a previous study, we were able to mimic the in vivo situation in an in vitro respiratory mucosal explant system. A plaquewise spread of EHV-1 was observed in the epithelial cells, whereas in the connective tissue below the basement membrane (BM), EHV-1-infected mononuclear leukocytes were noticed. Equine herpesvirus type 4 (EHV-4...
Ribeiro MF, da Silveira JA, Bastos CV.Tick-borne diseases in horses are caused by the intraerythrocytic protozoan parasites Theileria equi and Babesia caballi. Although T. equi is highly endemic in Latin America, the New World vector of this important parasite is controversial. The aim of this study was to test the ability of nymph Amblyomma cajennense ticks acquire infection by T. equi following feeding on infected horses. Three experiments were performed: tick acquisition of T. equi from an experimentally infected horse, tick acquisition of T. equi from naturally infected foals and tick acquisition of T. equi from a chronically ...
Hinney B, Wirtherle NC, Kyule M, Miethe N, Zessin KH, Clausen PH.The objective of the study was to estimate the prevalence of helminths in the horse population of the state of Brandenburg, Germany. One hundred and twenty-six horse farms in the state were selected by randomised stratified sampling. In total, 1,407 horses across all farms were examined coproscopically. The experimental unit was the horse farm: a farm was considered infected when at least one horse on the farm investigated was positive for helminth eggs. Animal details such as age, breed and sex were collected for all study horses and analysed for risk of infection. Risk was defined as horses ...
Yuan Z, Gault EA, Campo MS, Nasir L.Equine sarcoids represent the most common skin tumours in equids worldwide, characterized by extensive invasion and infiltration of lymphatics, rare regression and high recurrence after surgical intervention. Bovine papillomavirus type-1 (BPV-1) and less commonly BPV-2 are the causative agents of the diseases. It has been demonstrated that BPV-1 viral gene expression is necessary for maintaining the transformation phenotype. However, the underlying mechanism for BPV-1 transformation remains largely unknown, and the cellular factors involved in transformation are not fully understood. Previousl...
Franson JC, Hofmeister EK, Collins GH, Dusek RJ.We screened 1,397 feral horses (Equus caballus) on Sheldon National Wildlife Refuge, Nevada, United States, for IgM and IgG against flavivirus during 2004-2006, 2008, and 2009. Positive serum samples were tested for neutralizing antibodies to West Nile virus (WNV) and St. Louis encephalitis virus (SLEV). One animal was positive for antibody against WNV in 2004, but all others tested in 2004-2006 were negative. In 2008 and 2009, we found evidence of increasing seropositive horses with age, whereas seroprevalence of WNV decreased from 19% in 2008 to 7.2% in 2009. No horses were positive for anti...
Löhr CV, Polster U, Kuhnert P, Karger A, Rurangirwa FR, Teifke JP.Actinobacillus suis-like organisms (ASLOs) have been isolated from the genital, respiratory, and digestive tracts of healthy adult horses, horses with respiratory disease, and septic foals. Two foals with congenital hypothyroidism-dysmaturity syndrome from separate farms developed ASLO infection. At necropsy, both had contracted carpal flexor tendons, thyroid hyperplasia, and thrombotic and necrotizing mesenteric lymphangitis and lymphadenitis; one foal also had mandibular prognathism. Numerous ASLOs were isolated from tissues from both foals, including intestine. Biochemical testing and mass ...
Crafford JE, Guthrie AJ, Van Vuuren M, Mertens PP, Burroughs JN, Howell PG, Batten CA, Hamblin C.A polyclonal antibody-based, group-specific, competitive ELISA (C-ELISA) for the detection of antibodies to equine encephalosis virus (EEV) was developed. The assay measures the competition between a specific guinea pig antiserum and a test serum, for a pre-titrated EEV antigen. The C-ELISA detected antibodies to the seven known EEV serotypes. Reference antisera raised against other arboviruses did not cross react with EEV antigen. Negative sera from horses in the United Kingdom were used to establish the baseline for a negative population. Negative and positive populations of South African ho...
Ranjithkumar M, Kamili NM, Saxena A, Dan A, Dey S, Raut SS.Oxidant/antioxidant equilibrium disturbance has already been reported in trypanosome infections by several authors. The present study was aimed to explore the possible oxidant/antioxidant disturbance in surra of naturally infected horses before and after treatment. Fifteen naturally infected horses were chosen to analyse erythrocytic indices, platelet counts, lipid peroxides (LPO), nitric oxide (NO), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) while six healthy animals acted as control. There was a highly significant (P<0.001) reduction in red blood cell (RBC) c...
Berghaus LJ, Giguère S, Sturgill TL, Bade D, Malinski TJ, Huang R.The objectives of this study were to determine the plasma and pulmonary disposition of gamithromycin in foals and to investigate the in vitro activity of the drug against Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) and Rhodococcus equi. A single dose of gamithromycin (6 mg/kg of body weight) was administered intramuscularly. Concentrations of gamithromycin in plasma, pulmonary epithelial lining fluid (PELF), bronchoalveolar lavage (BAL) cells, and blood neutrophils were determined using HPLC with tandem mass spectrometry detection. The minimum inhibitory concentration of gamithr...
Turk R, Habuš J, Flegar-Meštrić Z, Svetina A, Mojčec V, Perkov S, Belić M, Starešina V, Turk N.The aim of the study was to investigate the effect of infection with Leptospira spp. in horses on activities of platelet-activating factor acetylhydrolase (PAF-AH) and paraoxonase-1 (PON1) considering the anti-inflammatory/anti-oxidative properties of both enzymes. A total of 63 sport and leisure horses' sera were chosen among those routinely serologically examined on leptospirosis during the year 2009 in Croatia. Sera were divided into three groups according to the estimated level of antibody titre against Leptospira spp; group 1: sera serologically negative to leptospirosis (antibody titre<5...
Watts AE, Johnson AL, Felippe MJ, Divers TJ.A Thoroughbred gelding in North America was evaluated for Actinobacillus peritonitis on three different occasions over a 4-year period. At each presentation, peritoneal fluid had an elevated nucleated cell count (220,000-550,000 cells/µL) characterised by non-degenerate neutrophils, no visible bacteria, an elevated total protein (4.6-5.5 g/dL) and bacterial culture yielding Actinobacillus spp. Actinobacillus peritonitis appears to be a regional disease occurring in Australia and less commonly in New Zealand and North America. Recurrence, other than incomplete resolution, has not been previous...
Harris SP, Hines MT, Mealey RH, Alperin DC, Hines SA.Rhodococcus equi is an important respiratory pathogen of young foals for which a vaccine has long been sought. Two major impediments to effective vaccination are the functionally immature type I immune responses of neonatal foals and early exposure to the bacterium via the environment. Despite these obstacles, it appears that under specific circumstances foals can develop a protective immune response. In this study we investigated the protective mechanisms behind oral inoculation of foals with virulent R. equi bacteria. Two foals receiving an oral inoculum demonstrated accelerated development ...
Hoet AE, Johnson A, Nava-Hoet RC, Bateman S, Hillier A, Dyce J, Gebreyes WA, Wittum TE.Concurrent to reports of zoonotic and nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) in veterinary settings, recent evidence indicates that the environment in veterinary hospitals may be a potential source of MRSA. The present report is a cross-sectional study to determine the prevalence of MRSA on specific human and animal contact surfaces at a large veterinary hospital during a nonoutbreak period. A total of 156 samples were collected using Swiffers(®) or premoistened swabs from the small animal, equine, and food animal sections. MRSA was isolated and identifi...
Gildea S, Arkins S, Walsh C, Cullinane A.Protection against equine influenza virus (EIV) relies largely on the production of circulating antibodies specific for the haemagglutinin (HA) glycoprotein. The objective of this study was to determine the antibody response of National Hunt horses in training to booster vaccination. The antibody response to the six equine influenza vaccines available in Ireland (three whole inactivated vaccines, two subunit vaccines and a canary pox recombinant vaccine), was monitored by single radial haemolysis (SRH) for six months post vaccination. There was no significant difference between antibody respon...
Hazlett MJ, Kircanski J, Slavic D, Prescott JF.Beta 2 (β2)-toxigenic Clostridium perfringens type A was recovered in large numbers from the intestine of a neonatal foal with colitis. The foal had been treated with gentamicin. Necropsy revealed marked distension of cecum and colon with watery, rust-colored homogeneous fluid and gastric infarction. Microscopic colonic lesions were superficial necrosis of 50% of the colonic mucosal surface and scattered 1-3-mm ulcers with subjacent neutrophilic infiltration and large Gram-positive bacilli in the necrotic mucosa. Beta-2 toxin was demonstrated in the lesions by immunohistochemical staining.
Toribio RE.Critical illness challenges many endocrine homeostatic systems to overcome diseases, stress, and hostile conditions that threaten survival. Coordinated and consecutive responses by the autonomic nervous system, endocrine metabolic adaptations to mobilize and conserve energy and electrolytes, cardiovascular adjustments to maintain organ perfusion, and immunomodulation to overcome infections and inflammation are required. Because most admissions to equine intensive care units are related to horses with gastrointestinal disease and septic foals, most endocrine information during critical disease ...
Elshafie EI, Sani RA, Hassan L, Sharma R, Bashir A, Abubakar IA.Apart from occasional reports of clinical disease affecting horses, there is no information about Trypanosoma evansi in horses in Peninsula Malaysia. Thus, a cross-sectional study was conducted in eight states in Peninsula Malaysia to determine the active presence of T. evansi in horses. A total of 527 blood samples were obtained and examined by haematocrit centrifugation technique (HCT), Giemsa-stained thin blood smear (GSS), morphometric measurements, polymerase chain reaction (PCR) and cloning of PCR products. The results showed an overall parasitological prevalence of 0.57% (3/527, CI: 1.6...
Curik I, Fraser D, Eder C, Achmann R, Swinburne J, Crameri R, Brem G, Sölkner J, Marti E.To investigate whether the equine major histocompatibility complex (MHC) gene region influences the production of mould-specific immunoglobulin E antibodies (IgE), alleles of the equine leukocyte antigen (ELA-A) locus and three microsatellite markers (UM-011, HTG-05 and HMS-42) located on the same chromosome as the equine MHC were determined in 448 Lipizzan horses. Statistical analyses based on composite models, showed significant associations of the ELA-A and UM-011 loci with IgE titres against the recombinant Aspergillus fumigatus 7 antigen (rAsp f 7). UM-011 was also significantly associate...
Wilson J, De Donato M, Appelbaum B, Garcia CT, Peters S.Overtraining syndrome (OTS) is the reduction in performance due to excess training and lack of proper recovery, which can lead to a chronic deprivation of energy and reduction in the repair of damage that can accumulate over time. Here, the effect of acute, intense physical exercise on the expression of innate and adaptive immune genes in 12 racing-bred American Quarter Horses, after resting for 3 days and immediately after intense exercise for 1.8 miles were compared. The expression of 84 genes related to innate and adaptive immune responses was analyzed. Significant variation among individua...
Juffo GD, Bassuino DM, Gomes DC, Wurster F, Pissetti C, Pavarini SP, Driemeier D.The Salmonella sp. genus is identified in several species, and the zoonosis it causes is one of the most important types worldwide. The specifics of salmonellosis vary according to the function of the serovar involved, the species affected, age and predisposing factors. However, few cases of equine salmonellosis have been reported. This study presents ten confirmed salmonellosis cases in equines in southern Brazil. Six were adult animals with stress factors preceding the disease, while four were foals, three of which presented with hyperacute manifestations. The main clinical signs were diarrh...
Kuzmina TA.Analysis of the influence of horse-keeping conditions by contamination of the environment (pastures, paddocks, and stalls) by the strongylid infective larvae (L(3)) was carried out at various types of horse farms, hippodromes, and riding clubs in Ukraine. A total of 1,237 horses from three types of horse-keeping conditions were examined. Epidemiological studies of stall and grazing area (pasture and paddocks) contamination by L(3) were performed at hippodrome (stalled horse-keeping) and horse farms with stall/paddock-keeping and stall/pasture-keeping conditions. Grass and stall litter samples ...
Cruz F, Fores P, Mughini-Gras L, Ireland J, Moreno MA, Newton JR.Equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4) have a worldwide distribution and cause respiratory disease, abortion, neonatal death and myeloencephalopathy in susceptible horses. Given the scarcity of serological EHV-1/EHV-4 data in Spain, the objective of this cross-sectional study was to estimate the seroprevalence of EHV-1/EHV-4 and to identify potential horse-level and stud farm-level factors associated with EHV-1/EHV-4 in the breeding Spanish Purebred (SP) horse population in central Spain. Serum samples from 334 SP unvaccinated horses, collected between September 2011 and November...
Underwood C, van Eps AW, Ross MW, Laverman P, van Bloois L, Storm G, Schaer TP.Liposomes are phospholipid nanoparticles that extravasate at sites of increased vascular permeability. They have potential in equine medicine for targeted drug delivery and diagnostic imaging of infectious, inflammatory and neoplastic lesions. Objective: This study evaluates the safety and biodistribution of i.v. polyethyleneglycol(PEG) liposomes in normal horses. Methods: PEG-liposomes were prepared by the film hydration method and labelled using (99m) Tc-hexamethyl-propylene-amine-oxime. A single dose of 0.24 µmol/kg bwt (99m) Tc-PEG-liposomes and 2.4 µmol/kg bwt unlabelled PEG-liposomes...
Spencer JA, Ellison SE, Guarino AJ, Blagburn BL.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome seen in horses from the Americas and is mainly caused by Sarcocystis neurona. Cell-mediated immune responses to mitogens have been shown to be reduced in horses with EPM, although it is not known whether the parasite causes this immunosuppression or if the immunosuppression is required for disease manifestation. Recently, a 29-kDa surface antigen from S. neurona merozoites was identified as being highly immunodominant on Western blot. This antigen has been sequenced and cloned, and the expressed protein has been named SnSAG1. Is...
Cappelli K, Cook RF, Stefanetti V, Passamonti F, Autorino GL, Scicluna MT, Coletti M, Verini Supplizi A, Capomaccio S.Equine infectious anaemia virus (EIAV) is a lentivirus with an almost worldwide distribution that causes persistent infections in equids. Technical limitations have restricted genetic analysis of EIAV field isolates predominantly to gag sequences resulting in very little published information concerning the extent of inter-strain variation in pol, env and the three ancillary open reading frames (ORFs). Here, we describe the use of long-range PCR in conjunction with next-generation sequencing (NGS) for rapid molecular characterization of all viral ORFs and known transcription factor binding mot...
Palomero AM, Hernández JA, Cazapal-Monteiro CF, Balán FA, Silva MI, Paz-Silva A, Sánchez-Andrade R, Vázquez MSA.The integrated control of strongyles was assayed for a period of three years in wild equids (zebras, European donkeys, and African wild asses) captive in a zoo and infected by strongyles. During three years control of parasites consisted of deworming with ivermectin + praziquantel; equids also received every two days commercial nutritional pellets containing a blend of 10 - 10 spores of the fungi + per kg meal. Coprological analyses were done monthly to establish the counts of eggs of strongyles per gram of feces (EPG). The reductions in the fecal egg counts (FECR) and in the positive horses...
Takai S, Kawazu S, Tsubaki S.Humoral immune response to intestinal Rhodococcus (Corynebacterium) equi in horses was studied by enzyme-linked immunosorbent assay. Anti-R. equi immunoglobulin M (IgM), IgG, and IgA antibodies were demonstrated in the healthy horse population. Adult horse levels of anti-R. equi IgM and IgG antibodies were reached by 5 to 9 weeks of age in two healthy newborn foals. R. equi was recovered from the foals in the range of 10(3) to 10(4) per g of intestinal contents. A 1-week-old foal was infected with R. equi by mouth daily for 9 weeks. The foal did not show any clinical signs of illness. Anti-R. ...
Mohamed FH, Abu Samra MT, Ibrahim KE, Idris SO.Cutaneous habronemiasis in 15 horses and 5 donkeys is described. The lesions were distributed in many parts of the body involving the medial canthus, shoulder and pectoral regions, knee and fetlock joints, abdominal wall and prepuce. Some animals had more than one lesion. The lesions were ulcerative and filled with soft light red granulation tissue. When curretted, the deeper layers revealed a dense fibrous tissue with calcified foci. Close examination of the lesions showed that the superficial layer of this dense fibrous tissue contained small caseated and necrotic foci. The same features pre...
Ramos CP, Lopes EO, Oliveira Júnior CA, Diniz AN, Lobato FCF, Silva ROS.Considering the lack of studies evaluating the performance of commercially available methods for diagnosis of Clostridioides (Clostridium) difficile infection (CDI) in animals, the present study aimed to assess an immunochromatographic test for detection of glutamate dehydrogenase (GDH) and A/B toxins of C. difficile, also evaluated by an ELISA kit, in foals and neonatal piglets. Intestinal contents of 47 piglets and feces of 35 foals were tested to GDH antigen and A/B toxins in a lateral flow method (Ecodiagnostica, Brazil). Also, these samples were submitted to A/B toxin detection by an ELIS...
Werners AH.Endotoxins, constituents of the cell wall of gram-positive and gram-negative bacteria, regularly result in severe illness and death in horses. In endotoxaemia, these constituents are present in the systemic circulation; in septicaemia, whole microbes invade normally sterile parts of the body. Interaction of these endotoxins with pathogen recognition receptors leads to an inflammatory response that cannot always be sufficiently contained and hence needs direct treatment. Over the last decennia, our understanding of the pathophysiology of endotoxaemia and septicaemia has significantly increased....
Köhne M, Tönissen A, Unruh C, Pruß D, Sieme H.Pyometra is an uncommon condition in mares associated with various symptoms. Here, we report a case of a 13-year-old Icelandic barren maiden mare with recurrent vaginal discharge. Ultrasonographically, the mare displayed intrauterine spherical masses of inhomogenous texture, which were identified as purulent concrements in hysteroscopy. The purulent concrements were successfully removed via uterine lavage after endoscope-assisted comminution. Microbiologic examination of the concrements revealed growth of Streptococcus equi subspecies zooepidemicus, Actinobacillus species, Pseudomonas aerugino...
Wollanke B, Gerhards H, Brem S, Kopp H, Meyer P.Between February 1993 and July 1997, 150 horses suffering from recurrent uveitis were subjected to parsplana vitrectomy. In these horses, antibody titers to Leptospira serovars were determined in serum samples and in samples from diluted vitreous collected during vitrectomy. Although the vitreous samples were diluted with 250 ml of balanced salt solution, in 86 of the 150 vitreous samples (= 57%) the antibody titers were higher than in the serum samples. Additionally, serum samples from 77 horses suffering from ERU, but which were not subjected to vitrectomy, and serum samples from 97 horses w...
Vera JHS, Fachiolli DF, Ramires LM, de Lima Saes I, Yamada PH, Gonçalves JA, de Oliveira K, do Amarante AFT, de Soutello RVG.The objectives of the present study were to evaluate the efficacy of three anthelmintic drugs, i.e. fenbendazole, ivermectin and moxidectin; to determine the genera and species of the most abundant strongyles; and to investigate parasite control measures used in herds of horses in the western region of the state of São Paulo, Brazil. This study was onducted between February and December 2013 on 10 farms in this region. Coprological evaluations were conducted for counting the numbers of eggs per gram of feces (EPG) and coprocultures were made in order to identify third-stage larvae (L3) of str...
Morris DD, Moore JN.A study was performed to determine prevalence of tumor necrosis factor (TNF) activity in serum of equine neonates with presumed sepsis and to determine correlation between serum TNF activity and severity and outcome of disease. Twenty foals less than 21 days old were considered suitable for inclusion in this study by satisfying clinical and laboratory criteria suggestive of septicemia. At admission, blood samples were collected from all foals for determination of serum TNF activity, then clinical course and outcome of disease were recorded. Thirty-one clinically normal foals less than 21 days ...
Kidd JA, Barr AR, Tarlton JF.Thirty-nine samples of synovial fluid were collected from the joints of 32 horses with suspected septic arthritis and 39 samples were collected from horses euthanased for non-orthopaedic conditions. The white blood cell counts (WBCC) were determined and the pro and active forms of matrix metalloproteinases (MMPs) 2 and 9 were measured by gelatin zymography and image analysis in each sample. The initial measurements of the ratio of proMMP9:proMMp2 and WBCC were good prognostic indicators of the survival of the horses. There was no significant relationship between the interval between the injury...
Marques SM, Scroferneker ML.The objective of this study was to determine the occurrence of Onchocerca cervicalis in 1200 adult horses from rural areas of Rio Grande do Sul, Brazil. Umbilical skin specimens measuring 2 x 2 cm were minced, suspended in 10 ml of distilled water and incubated at room temperature overnight. The liquid volume was centrifuged and the sediment was screened for microfilariae. The ligamentum nuchae were totally removed, preserved in ice and dissected for the detection of adult forms of Onchocerca cervicalis. Microfilariae of Onchocerca cervicalis were detected in midventral skin biopsy samples in ...
Laegreid WW, Skowronek A, Stone-Marschat M, Burrage T.There are three clinicopathologic syndromes associated with African horsesickness (AHS) virus infection in horses. These different forms of AHS (pulmonary, cardiac, and fever forms) vary in the organs affected, the severity of lesions, time of onset of clinical signs and mortality rates. We have studied the effects of infection with three cell culture passaged variants of AHS virus in naive North American horses. One of these viruses, AHS/4SP, consistently caused the pulmonary form of AHS with rapid onset of severe pulmonary edema and 100% mortality. A second variant, AHS/9PI, resulted in sign...
Davidson AJ, Hodgkinson JE, Proudman CJ, Matthews JB.To investigate cytokine responses in cyathostomin infection, we quantified mucosal interleukin-4 (IL-4), interleukin-10 (IL-10), tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma by reverse transcriptase-competitive polymerase chain reaction. The analysis was performed on large intestinal wall samples obtained from six anatomical sites spanning the caecum and colon of 17 naturally exposed horses. The numbers of developing larvae (DL) and early third stage larvae (EL3) were ascertained using transmural illumination and pepsin digestion techniques, respectively. Levels of each cytoki...
Howe DK, MacKay RJ, Reed SM.Equine protozoal myeloencephalitis (EPM) can be caused by either of 2 related protozoan parasites, Sarcocystis neurona and Neospora hughesi, although S. neurona is the most frequent etiologic pathogen. Horses are commonly infected, but clinical disease occurs infrequently; the factors influencing disease occurrence are not well understood. Risk factors for the development of EPM include the presence of opossums and prior stressful health-related events. Attempts to reproduce EPM experimentally have reliably induced antibody responses in challenged horses but have not consistently produced acut...
Tencza SB, Islam KR, Kalia V, Nasir MS, Jolley ME, Montelaro RC.The control of equine infectious anemia virus (EIAV) infections of horses has been over the past 20 years based primarily on the identification and elimination of seropositive horses, predominantly by a standardized agar gel immunodiffusion (AGID) assay in centralized reference laboratories. This screening for EIAV-seropositive horses has been to date hindered by the lack of a rapid diagnostic format that can be easily employed in the field. We describe here the development of a rapid solution-phase assay for the presence of serum antibodies to EIAV based on fluorescence polarization (FP) (pat...
Thieulent CJ, Sutton G, Toquet MP, Fremaux S, Hue E, Fortier C, Pléau A, Deslis A, Abrioux S, Guitton E, Pronost S, Paillot R.Equid alphaherpesvirus-1 (EHV-1) is one of the main pathogens in horses, responsible for respiratory diseases, ocular diseases, abortions, neonatal foal death and neurological complications such as equine herpesvirus myeloencephalopathy (EHM). Current vaccines reduce the excretion and dissemination of the virus and, therefore, the extent of an epizooty. While their efficacy against EHV-1-induced abortion in pregnant mares and the decreased occurrence of an abortion storm in the field have been reported, their potential efficacy against the neurological form of disease remains undocumented. No ...
Ossiprandi MC, Buttrini M, Bottarelli E, Zerbini L.Clostridium difficile, associated with a wide spectrum of diseases in humans, as well as in several animal species, is an important cause of colitis in adult horses and foals. The aim of this study was to investigate by toxin gene profile and PCR-ribotyping the molecular characteristics of 14 C. difficile strains isolated from 42 faeces of healthy horses. Both toxin genes, tcdA and tcdB, were present in only 1 isolate (7.1%). Six isolates (42.9%) demonstrated tcdA-/tcdB+ genotype, and seven isolates (50.0%) were tcdA-/tcdB-. All strains were binary toxin genes negative (cdtA-/cdtB-). The PCR-p...
Moura I, Radhouani H, Torres C, Poeta P, Igrejas G.Lusitano horses were investigated in order to detect the presence of vancomycin-resistant enterococci. vanA isolates showed high level vancomycin (Minimum inhibitory concentration; MIC > or = 128 mg/l) and teicoplanin resistance (MIC 64 mg/l), as well as resistance to ciprofloxacin, erythromycin and tetracycline. The tet(L) and erm(B) genes, associated with tetracycline and erythromycin resistance, respectively, were found in all vanA isolates. The intestinal tract of Lusitano horses can be a potential reservoir for vanA-containing enterococci.
Monahan CM, Taylor HW, Chapman MR, Klei TR.Protection from Strongylus vulgaris infection through immunization with radiation-attenuated third-stage larvae (L3) or crude soluble homogenates from larval or adult stages was examined. Yearling ponies raised parasite-free were divided into 3 immunization groups: radiation-attenuated L3; soluble adult somatic extracts; larval somatic extracts with excretory/secretory products (E/S) from in vitro culture; and 1 medium control group. Ponies were immunized twice; attenuated larvae were administered orally and somatic extracts or controls injected intramuscularly with adjuvant. Approximately 6 w...
Lavoie JP, Couture L, Higgins R, Laverty S.Bacterial isolations were reviewed from equine trachea, guttural pouch, uterus, wounds, abscesses, blood, synovial fluid, and abdominal fluid submitted to the Clinical Bacteriology Laboratory of the School of Veterinary Medicine at the University of Montreal for aerobic bacterial culture from 1986 to 1988. Of the 733 samples submitted, 324 (44%) were positive for bacterial growth, and 233 antimicrobial sensitivity tests were performed. Seventy-six percent of all positive samples yielded one bacterial species and two were isolated from 22% of positive samples. Streptococcus zooepidemicus, Esche...
Hendrickson EHS, Lykkjen S, Dolvik NI, Olstad K.Young Standardbred horses frequently develop fragments in joints. Some fragments represent osteochondrosis; others are considered developmental, but it is uncertain whether they result from preceding osteochondrosis. Osteochondrosis occurs as a consequence of failure of the cartilage canal blood supply and ischaemic chondronecrosis. In heritably predisposed foals, failure was associated with incorporation of vessels into bone. However, bacterial vascular failure was also recently documented in foals suffering spontaneous infections, proving that bacteria can cause osteochondral lesions in foal...
