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.
Black WD, Hartley CA, Ficorilli NP, Studdert MJ.Equine rhinitis B virus (ERBV), genus Erbovirus, is most closely related to the Cardiovirus genus in the family Picornaviridae. The structural proteins (VP1-4) of erboviruses are not well described, but are predicted by sequence to be 35, 29, 26 and 7 kDa. Methods for the purification of cardioviruses (polyethylene glycol, trypsin treatment) were used to characterise the structural proteins of ERBV1. Only one of the virus proteins detected was an expected molecular mass, and this 26 kDa protein was identified as VP3 by N-terminal amino acid sequencing. N-terminal sequencing of the 56 and a 29 ...
Morita H, Shiratori C, Murakami M, Takami H, Toh H, Kato Y, Nakajima F, Takagi M, Akita H, Masaoka T, Hattori M.Four bacterial strains, designated ST18(T), HM244, HM250 and DI49, were isolated from the fresh faeces of four thoroughbred horses in Japan. Cells were Gram-positive, strictly anaerobic, catalase-negative, non-spore-forming, non-motile rods that occurred in chains. They were placed in the same subcluster based on 16S rRNA gene sequence analysis, phenotypic characteristics and levels of DNA-DNA relatedness. Their DNA G+C content ranged from 36 to 38 mol%. Lactobacillus catenaformis, Lactobacillus vitulinus and Catenibacterium mitsuokai belong to cluster XVII of the Clostridium subphylum. Strain...
Kelmer G, Schumacher J.Abdominal incisional hernias in over 40 horses were repaired by exposing the hernial sac and ring and closing the ring with absorbable, interrupted, inverted, cruciate sutures after inverting the hernial sac into the peritoneal cavity. A mesh was sutured, under tension, over the closed ring. Placing the mesh subcutaneously, rather than in the retroperitoneal space, simplified the dissection and minimised the likelihood of penetrating the peritoneal cavity, a problem common to techniques of hernia repair in which the mesh is implanted into the retroperitoneal space. Implanting the mesh subcutan...
Journal of medical entomologyDecember 9, 2008
Volume 45, Issue 6 1152-1155 doi: 10.1603/0022-2585(2008)45[1152:tobcbd]2.0.co;2
Schwint ON, Knowles DP, Ueti MW, Kappmeyer LS, Scoles GA.The tropical horse tick, Dermacentor nitens, is a natural vector of Babesia caballi in the Americas. B. caballi, one of the etiologic agents of equine piroplasmosis, occurs widely throughout the world, but the United States and a few other countries are considered to be free of infection. B. caballi is transovarially transmitted by the one-host tick D. nitens; we tested the hypothesis that B. caballi can persist in multiple generations of D. nitens in the absence of opportunity to reacquire infection from a susceptible equine host. Partially engorged female D. nitens were collected from a B. c...
Liu T, Nerren J, Liu M, Martens R, Cohen N.Neonates are thought to be generally deficient in production of Th-1-associated cytokines at birth, and thereby more susceptible to bacterial infections. Using neonatal foals as a model, this study examined the age-dependent maturation of both basal and stimulus-induced immune responses, as reflected by the expression of a panel of Th-1-associated and pro-inflammatory cytokines. Results showed that although the basal production of IFN-gamma and IL-6 was impaired (P<0.05) in PBMCs of neonatal foals at birth, the basal production of IL-8, IL-12(p35/p40) and IL-23(p19/p40) were either in exces...
Allen GP.To identify risk factors associated with development of clinical neurologic signs in horses exposed to equine herpesvirus-1 (EHV-1). Methods: 36 adult horses. Methods: Blood samples collected before and after challenge inoculation with nonneuropathogenic or neuropathogenic EHV-1 were analyzed for leukocyte-associated viremia, serum neutralizing antibody, and EHV-1-specific cytotoxic T-lymphocyte precursors (CTLPs). Associations between variables and neurologic disease and correlations between age category or breed and development of neurologic disease were examined. Results: 9 horses developed...
Mori A, De Benedictis P, Marciano S, Zecchin B, Zuin A, Zecchin B, Capua I, Cattoli G.Equine rhinitis A and B viruses (ERAV and ERBV) are respiratory viruses of horses belonging to the family Picornaviridae. Although these viruses are considered to cause respiratory disease in horses and are potentially infectious for humans, little is known about their prevalence and pathogenesis. Virus isolation is often unsuccessful due to their inefficient growth and lack of cytopathic effect in cell cultures. Therefore, molecular assays should be considered as the method of choice to detect infection in symptomatic or apparently healthy horses. In the present study, a novel real-time duple...
Corona A, Cherchi R.Bacteriological surveillance is little applied in management of equine frozen semen but it is quite important to verify the microbial contamination in order to find out the chance of transmission of pathology to the mare in AI. Authors describe a qualitative and quantitative analysis for bacterial contamination on long time (3-17 years) equine frozen semen stored in liquid nitrogen. The semen checked, produced in Italy and in another Europe country, was cryopreserved in liquid nitrogen inside sealed plastic straws. One hundred and ten straws were checked out for pathogenic and no pathogenic ba...
Cuny C, Strommenger B, Witte W, Stanek C.During 2006 and 2007 small clusters of methicillin-resistant Staphylococcus aureus (MRSA) infections in horses were recorded in different clinical departments of a veterinary university. The infections were caused by different MRSA clones (ST1, ST254, and ST398). In the same time, nasal colonization of veterinarians, veterinary personnel, and students was observed indicating transmission to humans.
Dacre I, Kempson S, Dixon PM.Examination of 57 apically infected maxillary cheek teeth (CT) showed one or more viable pulps and minimal apical calcified tissue changes present in recently infected CT. With chronic infections, pulps were necrotic or absent, pulp horns were filled with food if occlusal pulpar exposure was present, and gross caries of dentine was occasionally present. With chronic infections, the apical changes varied from gross destructive changes in some teeth, to extensive proliferative calcified apical changes in others. Infundibular caries was believed to cause apical infection in just 16% of infected (...
Hassan AA, Ulbegi-Mohyla H, Kanbar T, Alber J, Lämmler C, Abdulmawjood A, Zschöck M, Weiss R.The present study was designed to characterize phenotypically and genotypically seven Arcanobacterium haemolyticum strains obtained from infections of six horses. All seven strains showed the cultural and biochemical properties typical of A. haemolyticum and were susceptible to most of the antibiotics tested. The species identification could be confirmed by amplification and sequencing of the 16S rRNA gene and the 16S-23S rRNA intergenic spacer region and by PCR amplification of species-specific parts of the gene encoding phospholipase D in A. haemolyticum. Use of the latter could possibly imp...
Dacre IT, Kempson S, Dixon PM.Examination of 41 extracted, apically infected mandibular cheek teeth (CT) without obvious causes of infection included radiography, computerised axial tomography and decalcified and undecalcified histology. In CT with recent infections, some pulps remained viable, with proliferative soft and calcified tissue changes confined to the apex. With more advanced CT infections, occlusal pulpar exposure was sometimes present (in 34% of the 41 CT), some infected pulp chambers were filled with necrotic pulp or food, and extensive destructive or proliferative changes were present in the calcified apical...
De Souza PN, Bomfim TC, Huber F, Abboud LC, Gomes RS.To detect Cryptosporidium sp., Giardia sp. and Eimeria leuckarti in horses, fecal samples were collected from three different handling horse groups from the state of Rio de Janeiro, Brazil. Group A was composed of "Mangalarga Marchador" pure breed horses, Group B was formed by horses of a Military Corporation and Group C by stray horses captured by the Center of Zoonosis Control Paulo Dacorso Filho. A total of 396 fecal samples were collected, 212 samples from Group A, 154 samples from Group B and 30 from Group C. The material was submitted to the centrifugation - flotation technique and stain...
van den Enden MS, Dixon PM.Examination of 110 cheek teeth (CT) that were clinically extracted (between 2004 and 2008) because of apical infection (n=79; mean dental age 3.5 years) or idiopathic CT fractures (n=31; median dental age 8.5 years), including examinations of transverse and longitudinal sections, showed the apical infections to be mainly (68%) due to anachoresis, with the residual cases caused by periodontal spread, infundibular caries spread, fissure fractures and dysplasia. The idiopathic fracture patterns were similar to previously described patterns. Occlusal pulpar exposure was found in 32% of apically in...
Hobson-Peters J, Toye P, Sánchez MD, Bossart KN, Wang LF, Clark DC, Cheah WY, Hall RA.Using a monoclonal antibody directed to domain I of the West Nile virus (WNV) envelope (E) protein, we identified a continuous (linear) epitope that was immunogenic during WNV infection of horses. Using synthetic peptides, this epitope was mapped to a 19 aa sequence (WN19: E147-165) encompassing the WNV NY99 E protein glycosylation site at position 154. The inability of WNV-positive horse and mouse sera to bind the synthetic peptides indicated that glycosylation was required for recognition of peptide WN19 by WNV-specific antibodies in sera. N-linked glycosylation of WN19 was achieved through ...
Graves KT, Henney PJ, Ennis RB.Laminin 5 is a heterotrimeric basement membrane protein integral to the structure and function of the dermal-epidermal junction. It consists of three glycoprotein subunits: the alpha3, beta3 and gamma2 chains, which are encoded by the LAMA3, LAMB3 and LAMC2 genes respectively. A mutation in any of these genes results in the condition known as hereditary junctional epidermolysis bullosa (JEB). A 6589-bp deletion spanning exons 24-27 was found in the LAMA3 gene in American Saddlebred foals born with the skin-blistering condition epitheliogenesis imperfecta. The deletion confirms that this autoso...
Belknap JK, Moore JN, Crouser EC.The horse with gram negative sepsis is known to be at particular risk of succumbing to laminitis. This review summarizes recent evidence indicating that similar pathologic events relating to inflammatory injury occur in laminar failure in laminitis as occur in organ injury/failure in human sepsis. The discussion also points out some important differences between the laminae and target organs in human sepsis that impact the clinical nature of the disease.
Heinrich A, Riethmüller D, Gloger M, Schusser GF, Giese M, Ulbert S.Equine Arteritis Virus (EAV) belongs to the Arteriviridae and causes viral arteritis in horses. In an attempt to develop novel and save therapies against the infection it was tested whether EAV is susceptible to RNA interference (RNAi) in an equine in vitro system. Horse cells were transfected with chemically synthesized small interfering RNA oligonucleotides (siRNAs) and challenged with EAV. Application of these siRNAs led to a significant protection of the cells, and virus titers decreased drastically. siRNAs derived from DNA plasmids expressing small hairpin RNAs (shRNAs) were also effectiv...
Gardiner DW, Teifke JP, Podell BK, Kamstock DA.An 18-year-old Arabian stallion was presented for recent onset of stranguria. Physical examination of the distal portion of the glans penis revealed multiple, smooth, glistening, grayish-pink, variably sized, exophytic, nodular masses circumferentially surrounding the external urethral orifice. Partial penile amputation was performed, and the entire specimen was submitted for histological evaluation. Microscopically, the masses consisted of abundant amounts of loosely arranged fibrovascular stroma with low numbers of spindloid to stellate fibrocytes. The overlying epithelium was mildly to mode...
Vengust M, Wen X, Bienzle D.A 4-year-old donkey was evaluated for progressive neurological abnormalities consisting of depression, stupor, weakness, and recumbency. Diagnostic evaluation for viral involvement identified an asinine herpesvirus in DNA extracted from deep pharyngeal swabs. Specific primers were designed based on comparison with equine herpesviral DNA polymerase sequences and yielded an 875-base pair product from the donkey. This sequence had complete identity with short sequences of asinine herpesvirus previously identified in donkeys with interstitial pneumonia. Amino acid analysis of the entire sequence i...
Coffman EA, Abd-Eldaim M, Craig LE.A pregnant 18-year-old Quarterhorse mare presented with fever, anorexia, tachycardia, tachypnea, and gastrointestinal hypermotility at day 68 of gestation. Potomac horse fever was diagnosed based on polymerase chain reaction (PCR) analysis of whole blood and a high antibody titer to Neorickettsia risticii. The mare made a rapid clinical recovery following antibiotic therapy, but aborted 98 days later. Necropsy on the aborted fetus revealed lymphohistiocytic colitis, lymphadenitis, myocarditis, and hepatitis. The placenta was grossly and histologically normal. Formalin-fixed lymph node, thymus,...
Vengust M, Baird JD, van Dreumel T, Ackerley C, Bienzle D.A case of a 1-month-old Thoroughbred foal with dysphagia, salivation, pyrexia, oral mucosal pustules, and esophageal ulceration is reported. Swabs from the ulcerated lesions yielded Equid herpesvirus 2 (EHV-2) in virus isolation assays, and histopathology of a biopsy from the esophageal lesion identified nuclear inclusions suggestive of herpesviruses. Immunohistochemical staining with antibodies specific for EHV-2 was positive for epithelial cells in the vicinity of the ulcer but not in more distant mucosa. Electron microscopic evaluation of the biopsy showed herpesviral particles in epithelia...
Loftus JP, Johnson PJ, Belknap JK, Pettigrew A, Black SJ.Inflammation and dysregulation of endogenous matrix metalloproteinase (MMP) production are implicated in the development of equine laminitis. In this study, we examine quantitative relationships among levels of leukocyte-derived proMMP-9 and MMP-9, lamellar proMMP-2 and MMP-2, and expression of proMMP-2 processing enzymes, MT1-MMP/PACE4, as steps towards determining whether inflammation and dysregulation of endogenous MMP production are independent or co-dependent processes. Methods: Archived samples of lamellae from horses with naturally acquired laminitis (n = 12), and from horses administer...
Simhofer H, Stoian C, Zetner K.The aim of this study was to evaluate the long-term results of apicoectomy and retrograde endodontic treatment in 12 horses with apical cheek teeth infections. The affected apices were removed using a diamond bur mounted on a dental drill, and after pulp removal the root canals were filed with Hedstrøm files and then alternately flushed with sodium hypochlorite, hydrogen peroxide and alcohol. The pulp canals were dried and filled with endodontic cement and gutta-percha points. An undercut was made in the apical aspect of the root canals that were then sealed with self-curing glass ionomer cem...
Sanchez LC, Giguère S, Lester GD.To identify factors associated with short-term survival in bacteremic neonatal foals, evaluate the racing performance of Thoroughbred survivors, and evaluate changes in causative organisms and their antimicrobial susceptibility. Methods: Retrospective case series. Methods: 423 bacteremic foals. Methods: Medical records of foals that were hospitalized in 1982 through 2007 were reviewed, and those with bacteremia were included in the study. Data retrieved included signalment, physical examination and clinicopathologic findings at admission, localized infections, concurrent illnesses, duration of...
Scott Weese J.Antimicrobial resistance (AMR) is an emerging problem in companion animals, because of difficult-to-treat infections, possible pressure to use antimicrobials that are important in human medicine, and potential zoonotic transmission. The extent and importance of AMR in companion animals are poorly understood, in part because of limited surveillance; however, it is clear that resistance is problematic in many pathogens and commensals, including staphylococci, enterococci, Escherichia coli and Salmonella.
de Raat IJ, van den Boom R, van Poppel M, van Oldruitenborgh-Oosterbaan MM.Insect bite hypersensitivity (IBH) in horses is most likely caused by Culicoides species, although other insects may also play a role. Until now no effective cure has been found for this condition, although numerous therapeutic and preventive measures have been used to control insect hypersensitivity. One such method is to apply a topical insecticide to horses. In this study, the effect of a topical insecticide containing permethrin (3.6%) was examined in seven pairs of horses. The horses were placed inside a tent trap to collect Culicoides spp. and other insects attracted to the horses on two...
Burton S, Reid-Smith R, McClure JT, Weese JS.Methicillin-resistant Staphylococcus aureus (MRSA) colonization was not identified in any of 497 horses from Atlantic Canada. Methicillin-susceptible S. aureus (MSSA) was isolated from a subsample of 19/242 (7.9%) horses. Colonization with MSSA is relatively common in healthy horses in Atlantic Canada, but MRSA is currently rare or absent. Colonisation par Staphylococus aureus de chevaux en santé sur la côte atlantique du Canada. La colonisation par Staphylococus aureus résistant à la méthicilline (SARM) n’a été identifiée sur aucun des 497 chevaux testés provenant de la côte atlan...
Olafsdóttir G, Svansson V, Ingvarsson S, Marti E, Torsteinsdóttir S.One of the prerequisite for developing DNA vaccines for horses are vectors that are efficiently expressed in horse cells. We have analysed the ectopic expression of the human serum albumin gene in primary horse cells from different tissues. The vectors used are of pcDNA and pUC origin and include the cytomegalovirus (CMV) promoter. The pUC vectors contain CMV intron A whereas the pcDNA vectors do not. Insertion of intron A diminished the expression from the pcDNA vectors whereas insertion of a Kozak sequence upstream of the gene in two types of pUC vectors increased significantly the in vitro ...
Dacre IT, Shaw DJ, Dixon PM.Histological measurements of dimensions of primary, regular secondary and irregular secondary dentine, pulp diameter and assessment of the levels of predentine, resting lines and enlarged areas of intertubular dentine were performed in apically infected mandibular and maxillary cheek teeth (CT). These examinations showed significantly reduced regular and irregular secondary dentine thickness in diseased as compared to control CT, with 21/26 infected maxillary CT and 15/18 infected mandibular CT having reduced regular secondary dentine (varying between 27.4% and 89.1% reduced secondary dentine ...
Wescott RB.Equine anthelmintics and the resistance of nematode parasites to anthelmintics are reviewed. Recommendations are made for effective treatment of these parasites and for procedures that can be performed to minimize the problem in the future.
Dart AJ, Hutchins DR, Begg AP.A 12-year-old Thoroughbred mare, with a history of anorexia, dramatic weight loss, fluctuating pyrexia and intermittent diarrhoea after an episode of colic, was presented for examination with depression, emaciation and ataxia. Thoracic and abdominal paracenteses yielded copious quantities of inflammatory exudate. Palpation per rectum revealed an enlarged spleen. The primary alterations in haematology included a severe leucocytosis with a left shift, and a hyperproteinaemia characterised by hypoalbuminaemia and hypergammaglobulinaemia. Post-mortem examination revealed a low grade pleurisy and p...
Harvey SP, Minter JM.In this study, the subspecies differentiation of 25 isolates of Burkholderia mallei was attempted based on their ribotype polymorphisms. The isolates were from human and equine infections that occurred at various times around the world. DNA samples from each isolate were digested separately with PstI and EcoRI enzymes and probed with an Escherichia coli-derived 18-mer rDNA sequence to identify diagnostic fragments. Seventeen distinct ribotypes were identified from the combined data obtained with the two restriction enzymes. The results demonstrate the general utility of ribotyping for the subs...
Cox KS, Nelson BB, Wittenburg L, Gold JR.Regional limb perfusion (RLP) is an effective treatment option for injuries and infections of the distal limb in horses. Using ceftiofur sodium in RLP has been studied due to its superior spectrum of Gram-positive organisms compared to aminoglycosides, but it is not known if this antimicrobial drug adequately penetrates subcutaneous tissue and bone. Objective: To determine the concentration of ceftiofur in plasma, subcutaneous tissue and bone in horses after RLP. Methods: Experimental prospective study. Methods: Six healthy horses were used in this study. Under standing sedation, an Esmarch to...
Scare JA, Steuer AE, Shaffer CL, Slusarewicz P, Mousley A, Nielsen MK.In vitro maintenance of helminth parasites enables a variety of molecular, pharmaceutical and immunological analyses. Currently, the nutritional and environmental in vitro requirements of the equine ascarid parasite, Parascaris spp., have not been determined. Additionally, an objective method for assessing viability of Parascaris spp. intestinal stages does not exist. The purpose of this study was to ascertain the in vitro requirements of intestinal stages of Parascaris spp., and to develop a viability assessment method. A total of 1045 worms were maintained in a total of 212 cultures. Worms o...
Valk N, Doherty TJ, Blackford JT, Abraha TW, Frazier DL.The effect of cisapride pretreatment on gastric emptying in horses was determined by measuring serum concentrations of acetaminophen, a drug known to be readily absorbed in the small intestine but not in the stomach. The time to reach maximum serum acetaminophen concentrations (Tmax), the maximum serum concentrations (Cmax) and the area under the serum acetaminophen concentration vs. time curves (AUC) were compared among treatment groups. In the first part of the study, the effect of orally administered cisapride (0.1, 0.2 and 0.4 mg/kg bwt) on gastric emptying was examined in 6 normal fasted ...
Laviada MD, Arias M, Sánchez-Vizcaíno JM.The structural and non-structural proteins induced by African horsesickness virus serotype 4 (AHSV-4) in infected Vero cells were analysed by SDS-PAGE. Twenty-two virus-induced polypeptides were detected in infected cells by comparison with the polypeptides of mock-infected cells, of which four major (VP2, VP3, VP5 and VP7) and three minor (VP1, VP4 and VP6) structural proteins and four non-structural proteins (P58, P48, P21 and P20) were shown to be virus-coded, as deduced from electrophoretic and antigenic studies of purified virions and infected cells. The proteins that elicit the major ant...
Maxwell LK.Since vaccination may not prevent disease, antiherpetic drugs have been investigated for the therapy of several equine herpesviruses. Drug efficacy has been assessed in horses with disease, but most evidence is in vitro, in other species, or empirical. Oral valacyclovir is most often administered in the therapy of equine herpesvirus type-1 (EHV-1) to protect adult horses from equine herpesvirus myeloencephalopathy, while oral acyclovir is frequently administered for EHV-5 infection in the therapy of equine multinodular pulmonary fibrosis. Other antiherpetic drugs are promising but require furt...
Salmon SA, Walker RD, Carleton CL, Robinson BE.A gram-variable pleomorphic bacillus was isolated from the reproductive tracts of 4 mares during routine prebreeding soundness examinations. Using a commercial bacterial identification system, these organisms were identified as Streptococcus acidominimus. However, colonial and Gram-staining characteristics did not support this identification. Subsequent testing indicated the organism was similar to Gardnerella vaginalis. Additional growth and biochemical analysis performed in our laboratory and at the Michigan Department of Public Health and by the Center for Disease Control, Atlanta, Georgia,...
Daels PF, Starr M, Kindahl H, Fredriksson G, Hughes JP, Stabenfeldt GH.The infusion of Salmonella typhimurium endotoxin into pregnant mares resulted in a biphasic release pattern of PGF-2 alpha as determined by 15-keto-13,14-dihydro-PGF-2 alpha concentrations. The initial phase of 1 h duration was followed by accentuated release by 2 h after infusion; concentrations reached basal levels by 6 h. In 7 mares at 23, 26, 29, 33, 36, 53 and 55 days of gestation, fetal death occurred between 36 and 120 h after infusion; 12 mares at 46, 51, 56, 59, 65, 71, 73, 85, 103, 138, 283 and 318 days of gestation did not abort after endotoxin infusion. Luteal activity was compromi...
Ortega-García MV, Salguero FJ, García N, Domínguez M, Moreno I, Berrocal A.Cutaneous forms of leishmaniosis due to Leishmania braziliensis have been reported in horses in the New World. Domestic animals play a role in the transmission of the disease. In Costa Rica, human cases of L. braziliensis, L. panamensis and L. infantum have been reported. The present report describes five cases of equine cutaneous leishmaniosis in Costa Rica. The aetiological diagnosis was based on the presence of the parasite within the lesions. Skin biopsies were used to perform histopathological analyses of the lesions. Immunohistochemistry was used to detect the presence of the Leishmania ...
Equine sarcoids develop upon bovine papillomavirus type 1 or 2 (BPV1, BPV2) infection in conjunction with trauma and represent the most common tumour disease in horses and other equids, including donkeys. In face of a sarcoid outbreak involving 12 of 111 donkeys and mules at the 'Rifugio degli Asinelli', a subsidiary charity organization of The Donkey Sanctuary, non-invasively collected sample material including crusts, dandruff, swabs and hair roots was collected from sarcoid-affected and 26 healthy donkeys, as well as dandruff from a grooming kit and tabanids caught from or in the vicinity o...
Hepworth-Warren KL, Nelson N, Dembek KA, Young KAS.Thoracic ultrasonography (TUS) is widely used in equine practice but comparison to radiography is limited in horses. Unassigned: To validate a novel, objective scoring system for TUS in adult horses and to compare ultrasonographic and radiographic findings. Unassigned: 13 healthy horses and 9 with confirmed bacterial pneumonia. Unassigned: Prospective study in which TUS and radiography were performed on healthy horses and those with bacterial pneumonia confirmed by clinical signs and results of transtracheal wash analysis. Ultrasonography was scored utilizing a novel scoring system evaluating ...
Saadi, A, Tavassoli, M, Dalir-Naghadeh, B, Samiei A.Dictyocaulus arnfieldi is a lungworm commonly found in equids; however, relatively little is known about it. The aim of the present study was to establish the prevalence of equine lungworms in naturally-infected working and sporting horses, donkeys and mules in rural areas of Urmia, northwest Iran. The fecal samples were collected from 299 working horses, 57 sporting horses, 66 donkeys and 37 mules during the period March 2014 to June 2016. The collected fecal samples were processed within 48 hours following rectal sampling. The larval count/g (LPG) of feces was determined using the Baermann t...
Miranda-CasoLuengo AA, Miranda-CasoLuengo R, Lieggi NT, Luo H, Simpson JC, Meijer WG.Rhodococcus equi is a facultative intracellular pathogen of macrophages and the causative agent of foal pneumonia. R. equi virulence is usually assessed by analyzing intracellular growth in macrophages by enumeration of bacteria following cell lysis, which is time consuming and does not allow for a high throughput analysis. This paper describes the use of an impedance based real-time method to characterize proliferation of R. equi in macrophages, using virulent and attenuated strains lacking the vapA gene or virulence plasmid. Image analysis suggested that the time-dependent cell response prof...
Stokes A, Corteyn AH, Murray PK.A group of three horses was experimentally infected with equine herpesvirus type 1 (EHV-1) and showed clinical signs characterised by a biphasic febrile response, leucopenia and cell associated viraemia accompanied by virus shedding from the nasopharynx. A second exposure to the virus 18 days later resulted in the isolation of virus from the nasopharynx of one horse. This and a further group of three EHV-1 seropositive horses were subsequently infected with equine herpesvirus type 4 (EHV-4) 147 days after the initial EHV-1 infection and virus was shed from the nasopharynx in the absence of cli...
Smith KM, Barber SM.A two year old Thoroughbred gelding, presented with guttural pouch hemorrhage, had the internal and external carotid arteries ligated. Guttural pouch mycosis was detected on endoscopic examination. After one month of topical antifungal therapy, the horse was returned and euthanized because of recurrent epistaxis. A bacterial infection of the guttural pouch with associated ulceration and hemorrhage from the maxillary artery was found at necropsy.A two year old grade gelding had ulceration and hemorrhage from the external carotid artery. Utilizing balloon-tipped catheters and arterial ligation, ...
Wilson AD.Horses are affected by a wide variety of arthropod ectoparasites, ranging from lice which spend their entire life on the host, through ticks which feed over a period of days, to numerous biting insects that only transiently visit the host to feed. The presence of ectoparasites elicits a number of host responses including innate inflammatory responses, adaptive immune reactions and altered behaviour; all of which can reduce the severity of the parasite burden. All of these different responses are linked through immune mechanisms mediated by mast cells and IgE antibodies which have an important ...
Inácio SV, de Brito RL, Zucatto AS, Coelho WM, de Aquino MC, Aguirre Ade A, Perri SH, Meireles MV, Bresciani KD.The present study aimed to analyze the occurrence of infection by Cryptosporidium spp. in mares and their respective foals. This study was carried out in 11 farms located in the municipalities of Araçatuba, Birigui, Guararapes and Santo Antônio do Aracangua, in the northwest region of the State of Sao Paulo, from November 2010 to March 2011. A total of 98 mares and 98 foals of several breeds were analyzed; among foals, 59 were males and 39 females, aged from three to 330 days. Feces were collected directly from the rectal ampulla, purified and processed according to modified Kinyoun stain. O...
Gustafson SB, McIlwraith CW, Jones RL.Four groups of 8 horses each had 1 midcarpal joint injected with 33 colony-forming units (CFU) of viable Staphylococcus aureus plus: 1 ml of saline solution (group 1, control), 250 mg of polysulfated glycosaminoglycan (PSGAG, group 2), 100 mg of methylprednisolone acetate (group 3), or 20 mg of sodium hyaulronate (group 4). Horses were euthanatized, and samples were obtained on the basis of clinical signs of septic arthritis that were nonresponsive to phenylbutazone administration. One group-1 horse, all 8 group-2 horses, 3 group-3 horses, and 4 group-4 horses were culture-positive for S aureu...
Kalinowski M, Grądzki Z, Jarosz Ł, Kato K, Hieda Y, Kakuda T, Takai S.Rhodococcus equi is an important bacterial pathogen in foals up to 6 months old, widespread in horse farms all over the world. It was found that only virulent R. equi strains expressing 15-17 kDa virulence-associated protein (VapA) and having large virulence plasmid of 85-90 kb containing vapA gene are pathogenic for horses. To date, 12 plasmid types have been reported in VapA positive strains from horses. There are no data concerning plasmid types of Polish field R. equi strains isolated from horses and horse farm environment. The aim of the study is to determine plasmid profiles of virulent ...
Scofield D, Black J, Wittenburg L, Gustafson D, Ferris R, Hatzel J, Traub-Dargatz J, McCue P.Systemic administration of ceftiofur crystalline free acid (CCFA) may be a potential treatment for infectious endometritis caused by Streptococcus equi ssp. zooepidemicus (S. zooepidemicus) and other susceptible bacterial organisms in the mare. Objective: To determine if i.m. administration of CCFA at the label dose will exceed the minimum inhibitory concentration (MIC) of S. zooepidemicus in the endometrium following single administration and multiple administration protocols. Methods: Experimental pharmacokinetic study. Methods: Three mares (Group 1) were administered a single i.m. dos...
Singh G, Singh NK, Singh H, Rath SS.A total of 311 equine faecal samples (190 horses and 121 mules) collected from six districts of Central Plain Zone, Punjab were examined using standard coprological methods. The results showed an overall prevalence of 27.33 % for strongyles with rare to mild type of infection as evident from egg per gram of faeces. In particular, amongst the examined samples, 17.90 % of horses and 42.14 % of mules were infected and the difference was statistically significant (P < 0.01). Identification of the faecal culture harvested larval stages, showed 56 % and 46 % of horses and mules, respectively, ...
Shively MA, Banks KL, Greenlee A, Klevjer-Anderson P.Equine infectious anemia is a chronic disease of horses caused by a nononcogenic retrovirus. Studies were undertaken to determine the types of cells involved in the in vitro lymphoproliferative response to viral antigens and the dynamics of this reaction. It was observed that reactive lymphocytes were present at unpredictable times in the peripheral blood of infected horses. This reaction was shown to be specific for the interaction of equine infectious anemia virus and T lymphocytes. Enriched B-lymphocyte populations did not divide when exposed to equine infectious anemia virus. Macrophages w...
Kristula MA, Smith BI.Contagious Equine Metritis (CEM), a venereal disease of horses caused by the bacterium Taylorella equigenitalis, was first diagnosed in 1977 and subsequently spread to many nations [Proc 24th AM Assoc Equine Pract (1979) 287]. The disease was confirmed in the United States in 1978 [Proc Am Assoc Equine Pract (1983) 295]. Specific regulatory procedures for this disease have been established in the United States and 37 other countries. From 1999 through 2001, four of 120 imported European stallions tested positive for CEM at a quarantine facility in Darlington, MD, USA. Two stallions were identi...
Richards KS, Riley EM, Taylor DH, Morris DL.Protoscoleces of Echinococcus granulosus were subjected to high concentrations of praziquantel (10-1000 micrograms/ml medium or cyst fluid) for a short, 10 min duration in vitro or in situ within cysts. Drug efficacy was then monitored either by in vitro culture in drug-free medium and/or by passage into rodents. The in vitro test of effectiveness suggested that ovine-derived protoscoleces were more sensitive than those of equine origin, and that the in vitro method of treatment was more successful than that performed in situ. However, the subsequent passage of treated protoscoleces, whether i...
Ramsay JD, Evanoff R, Mealey RH, Simpson EL.In racehorses, serum gamma-glutamyltransferase (GGT) activity is positively correlated with cumulative days in training and, when ≥100 IU/L, has been associated with poor performance. The prevalence of increased GGT activity in North American Thoroughbreds and its aetiopathogenesis are unknown. Four emerging viruses, pegivirus E (PgV E; equine pegivirus), hepacivirus A (HcV A; equine hepacivirus), pegivirus D (PgV D; Theiler's disease virus), and equine parvovirus-hepatitis (EqPV-H) have been identified in horses with clinical and subclinical hepatopathy. Available prevalence data indicate ...
Saes IL, Vera JHS, Fachiolli DF, Yamada PH, Dellaqua JVT, Saes RL, Amarante AFT, Soutello RVG.The aim of this study was to determine the time required by different anthelmintic agents to reduce strongyle egg shedding in horses. Fifty horses were divided into five homogenous groups based on faecal egg counts (FECs). Treatment groups received either ivermectin; moxidectin; fenbendazole; piperazine; or no treatment (control group). Faecal examinations were performed 4, 8, 12, 18, 24, 36 and 48h after the anthelmintic treatment. After this period, faecal samples were taken every 24h over the next 12days and finally on alternate days (48-h intervals) for another 14days until the end of the ...
Farkas R, Hall MJ.Veterinarians in Hungary were asked to complete a questionnaire on traumatic myiasis; of the 664 veterinarians contacted, 247 replied (37.2 per cent) and of these 209 (84.6 per cent) reported myiasis to be a problem among the livestock they treated. Infestation levels of > 10 per cent of animals were reported in sheep, cattle and horses. The myiasis season lasted from March to November with most cases reported in July and August. Significantly more respondents reported that fly larvae were present deep in wounds rather than superficially, consistent with infestations due to the obligate parasi...
Foil LD, Klei TR, Miller RI, Church GE, Foil CS, French DD, Smith JN.Seasonal changes in density and spatial distribution of Onchocerca cervicalis microfilariae were studied in ventral-midline skin of 15 infected pony mares in southern Louisiana. Triple running mean analysis of data over a 13-mo period indicated that a distinct pattern exists in total microfilariae population density and in microfilariae occurrence in different levels of the dermis. Microfilariae density reaches peak levels in the spring followed by a 58% decrease in the summer, a 19% increase in the fall, and a decrease to the lowest numbers in the winter. Microfilariae were found in all level...
