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.
Castagnetti C, Veronesi MC.In the foal, the most common neonatal diseases are responsible for an high non-survival rate. Since intensive care for neonatal foals is usually very expensive an early prognosis for survival at admission or during hospitalization is recommended, as well as a prognosis for future athletic potential. Therefore, prognostic factors for prematurity, septicaemia, other infectious diseases and hospitalized foals are revised and discussed on the base of literature and authors experiences. The advantages and limitations of retrospective and perspective prognostic factors is also presented, and the pos...
Kruger K, Saulez MN, Neser JA, Solberg K.Lead (Pb) intoxication in horses is usually a chronic phenomenon with clinical signs associated with central nervous dysfunction. This report gives details of a case of acute Pb intoxication in a 9-year-old American Saddlebred mare with severe, progressive and ultimately fatal neurological deterioration. During the 4 days of hospitalisation, clinical signs progressed from intermittent headshaking and depression to severe, continuous, uncontrollable manic behaviour. At autopsy, three grey-coloured, hard metal particles were present in the gastrointestinal tract and subsequently found to contain...
Hyera JM, Baipoledi EK.A retrospective serological survey of African horse sickness (AHS) in Botswana covering a 10-year period (1995-2004) is reported. The survey involved horses showing clinical symptoms of the disease; the horses had not been vaccinated against AHS. Over the period surveyed, serological evidence suggestive of infection with AHS virus (AHSV) was found in 99 clinical cases out of which 41.4% (41/99) cases were found during the 1st half (1995-1999) and 58.6 % (58/99) cases were found in the 2nd half of the survey period (2000-2004). These serological findings are discussed in relation to AHSV seroty...
Perkins GA, Goodman LB, Dubovi EJ, Kim SG, Osterrieder N.Early identification of inhalation-transmitted equine herpesvirus type 1 (EHV-1) infections has been facilitated by the availability of a number of real-time quantitative PCR (qPCR) tests. A direct comparison between nasal swab qPCR and traditional virus isolation (VI) requires a method for normalizing the qPCR samples and controlling for PCR inhibitors present in some clinical samples. Objective: To quantify EHV-1 shedding in viral swabs using an internal control and to compare fast qPCR to VI for the detection of EHV-1 in nasal swabs from horses. Methods: Fifteen horses experimentally infect...
Hollis AR, Furr MO, Magdesian KG, Axon JE, Ludlow V, Boston RC, Corley KT.Critical illness is associated with hyperglycemia in humans, and a greater degree and duration of hyperglycemia is associated with nonsurvival. Hypoglycemia is also seen in critically ill humans, and is associated with nonsurvival. This might also be true in the critically ill foal. Objective: To investigate the association of blood glucose concentrations with survival, sepsis, and the systemic inflammatory response syndrome (SIRS). Methods: Blood glucose concentrations at admission (515 foals) and 24 hours (159 foals), 36 hours (95), 48 hours (82), and 60 hours (45) after admission were analy...
Horohov DW, Breathnach CC, Sturgill TL, Rashid C, Stiltner JL, Strong D, Nieman N, Holland RE.While immune modulators are used routinely in equine medicine, their mechanism of action is not always known. Objective: To determine the effect of a commercial preparation of inactivated parapoxvirus ovis (Orf virus; PPVO) on cytokine gene expression by equine peripheral blood mononuclear cells (PBMC) both in vitro and in vivo. Methods: PBMC were prepared from 6 mixed-breed yearlings and cultured in vitro with PPVO with or without Concanavalin A (Con A) for 24 h. Effects on the expression of IFNalpha, IFNbeta IFNgamma, TNFalpha and IL-18 were analysed by real time quantitative PCR (RT-PCR). I...
White SD, Ghoddusi M, Grooters AM, Jones K.An 18-year-old Arabian mare was examined with a large mass on the left hind pastern and fetlock. The mare was located in the Central Valley of northern California, and had never been out of the state. Routine histopathological processing and examination of biopsy samples from the mass showed several hyphal organisms that were delineated with a silver stain. Using immunohistochemistry the organism was diagnosed as Pythium insidiosum. The owner declined debulking surgery, and despite treatment with an immunotherapeutic vaccine, the horse's condition deteriorated leading to euthanasia.
Dede S, Değer Y, Değer S, Tanritanir P.We have determined the plasma concentrations of copper, zinc, copper/zinc ratio, and carbonic anhydrase activity in horses infected with Babesia equi. The study was conducted in 14 horses with the disease and 10 healthy animals that served as controls. The infection was confirmed by the clinical manifestations of the disease and by Giemsa staining of thin blood smears showing the parasites inside red blood cells. The horses with piroplasmosis had lower plasma levels of zinc, elevated copper, and increased activity of carbonic anhydrase. Consequently, the copper/zinc ratio was also higher than ...
Diallo IS, Hewitson GR, de Jong A, Kelly MA, Wright DJ, Corney BG, Rodwell BJ.Twelve nasal swabs were collected from yearling horses with respiratory distress and tested for equid herpesvirus 1 (EHV-1) and equid herpesvirus 4 (EHV-4) by real-time PCR targeting the glycoprotein B gene. All samples were negative for EHV-1; however, 3 were positive for EHV-4. When these samples were tested for EHV-2 and EHV-5 by PCR, all samples were negative for EHV-2 and 11 were positive for EHV-5. All three samples that were positive for EHV-4 were also positive for EHV-5. These three samples gave a limited CPE in ED cells reminiscent of EHV-4 CPE. EHV-4 CPE was obvious after 3 days and...
Kriegshäuser G, Cullinane A, Kuechler E, Skern T.Equine rhinitis B virus 1 (ERBV1), genus Erbovirus, family Picornaviridae, is a pathogen of horses which causes clinical and subclinical infection of the upper respiratory tract in horses. The virus is widespread in European horse populations and the current standard method for the detection of antibody against ERBV1 is by virus neutralisation (VN). VN tests, however, are labour-intensive and time-consuming, require tissue culture facilities, and generally do not provide same-day results. In this study, a protocol for the high-level expression and purification of recombinant virion protein 1 (...
Underwood C, Southwood LL, McKeown LP, Knight D.Based on clinical observation, it is hypothesised that horses with duodenitis-proximal jejunitis (DPJ) that are treated surgically have a shorter duration, smaller volume, and slower rate of nasogastric reflux (NGR) compared to horses treated medically, are more likely to develop diarrhoea than medically managed cases, and have a higher incisional infection rate than a sample population of horses undergoing abdominal exploration for gastrointestinal disease other than DPJ. Objective: To compare: 1) duration, volume and rate of NGR and the percentage of horses with diarrhoea between medically a...
Szeredi L, Jánosi S, Tenk M.Klebsiella (K.) oxytoca infection induced the abortion of a female equine fetus in the 10th month of pregnancy. Bacteria were cultured from the liver, lung and stomach content. They were labelled with an anti-Mycobacterium bovis antibody in the thymus, liver and lungs and were stained with Giemsa and Brown-Brenn staining in the thymus and lung. The diffusely consolidated lungs contained numerous grey-whitish foci 2-4 mm in diameter, which corresponded to severe pyogranulomatous pneumonia characterised by numerous intraalveolar neutrophils and macrophages and multinucleated Langhans' giant cell...
Brindley MA, Zhang B, Montelaro RC, Maury W.Wild-type strains of equine infectious anemia virus (EIAV) prevent superinfection of previously infected cells. A variant strain of virus that spontaneously arose during passage, EIAV(vMA-1c), can circumvent this mechanism in some cells, such as equine dermis (ED) cells, but not in others, such as equine endothelial cells. EIAV(vMA-1c) superinfection of ED cells results in a buildup of unintegrated viral DNA and rapid killing of the cell monolayer. Here, we examined the mechanism of resistance that is used by EIAV to prevent superinfection and explored the means by which EIAV(vMA-1c) overcomes...
Davis LE, Beckham JD, Tyler KL.Arboviruses continue to be a major cause of encephalitis in North America, and West Nile virus neuroinvasive disease is now the dominant cause of encephalitis. Transmission to humans of North American arboviruses occurs by infected mosquitoes or ticks. Most infections are asymptomatic or produce a flulike illness. Rapid serum or cerebrospinal fluid IgM antibody capture ELISA assays are available to diagnosis the acute infection for all North American arboviruses. Unfortunately, no antiviral drugs are approved for the treatment of arbovirus infection and current therapy is supportive.
Zimmerman KL, Crisman MV.This article is presented with two main goals: (1) to provide equine clinicians with a resource for identifying types of serum tests available and (2) to outline briefly the necessary sample type, assay principle, and relative strengths and weakness of the various methods. Specific etiologies are presented and grouped by clinical diagnosis categories, along with brief comments concerning each disorder and its relevant diagnostic assays. This organization provides an abstracted list of infectious disorders commonly considered for the various clinical presentations and a summary of available ser...
Brooks MB.The most common cause of hemorrhage is vascular injury; however, the possibility of hemostatic failure should be considered in the initial differential diagnosis. This article provides an overview of preliminary screening and definitive tests to identify hemostatic defects in horses.
Steel CM.The most important application for synovial fluid (SF) analysis in the horse is in the diagnosis of synovial sepsis. Misdiagnosis of synovial sepsis is costly, and SF analysis makes correct diagnosis more likely, although far from certain. The precision of diagnosis may be increased with polymerase chain reaction analysis for detection of bacterial DNA in SF and with assays for various enzymes and cytokines. These tests are currently not widely available, however, and routine SF analysis remains of prime importance in diagnosis.
Crisman MV, Scarratt WK.Immunodeficiencies are characterized as primary (genetic) or secondary (acquired). Primary immunodeficiencies are relatively uncommon; however, clinically, they present a significant challenge to the practitioner, especially if the underlying disorder goes unrecognized. Secondary immunodeficiencies may present at any age, but failure of passive transfer in neonatal foals is most commonly encountered. This article provides a general overview of clinical signs and diagnosis of primary and secondary immunodeficiencies currently recognized in horses.
Crisman MV, Scarratt WK, Zimmerman KL.Activation of the host response to infection, the "acute-phase response," is a highly organized physiologic reaction that includes changes in concentrations of plasma acute-phase proteins (APPs). The APPs are increasingly being used as markers for prognosis and monitoring response to therapy along with general determinants of equine health. Use of APPs in veterinary medicine is becoming more widespread as more commercial diagnostic kits are being validated. This article reviews the salient features of APPs and examines their current application and potential utility in equine inflammatory diso...
Zoonoses and public healthJuly 22, 2008
Volume 55, Issue 6 291-298 doi: 10.1111/j.1863-2378.2008.01136.x
Zhang W, Shen Q, Mou J, Gong G, Yang Z, Cui L, Zhu J, Ju G, Hua X.Hepatitis E virus (HEV) is a zoonotic pathogen of which several species of animal were reported as reservoirs. Antibodies to HEV and HEV RNA have been detected in some Chinese population and swine groups but few other domestic animals. In this study, to investigate the HEV prevalence, we tested sera from 788 pigs, 100 cows, 50 goats, 49 horses, 101 pet dogs, 105 chickens, 47 duck and 45 pigeons in eastern China for anti-HEV immunoglobulin G (IgG). We also tested 50% of the swine sera, all of sera from the other domestic animals and 13 Shanghai human sera which were positive for anti-HEV immuno...
Ataseven VS, Dağalp SB, Güzel M, Başaran Z, Tan MT, Geraghty B.In this report we examined the presence of specific antibodies against equine herpesvirus type 1 (EHV-1), and equine herpesvirus type 4 (EHV-4) in several equidae, including mules, donkeys, horses. The presence of EHV-1 and EHV-4 in respiratory diseases of equids, and ability of multiplex nested polymerase chain reaction (PCR) screening in simultaneous diagnosis of horses acutely infected by EHV-1 and EHV-4 were also investigated. Sera from 504 horses, mules and donkeys sampled were tested for the presence of EHV-1 and EHV-4 specific antibodies. Blood samples taken from 21 symptomatic horses a...
Sun C, Zhang B, Jin J, Montelaro RC.The identification and characterization of a functional cellular receptor for equine infectious anemia virus (EIAV), designated equine lentivirus receptor-1 (ELR1), a member of the tumour necrosis factor receptor protein family, has been reported previously [Zhang, B. et al. (2005). Proc Natl Acad Sci U S A, 102 , 9918-9923]. The finding of a single receptor for EIAV is distinct from feline, simian and human immunodeficiency viruses, which typically utilize two co-receptors for infection, but is similar to avian and murine oncoviruses, which use single receptors. This study sought to determine...
van Galen G, Delguste C, Sandersen C, Verwilghen D, Grulke S, Amory H.Few studies exist about factors affecting the outcome of horses with tetanus. Methods: 31 equids (30 horses and 1 donkey) with a clinical diagnosis of tetanus admitted to the Equine Clinic of the University of Liege between 1991 and 2006. The cases were divided into two groups according to the outcome (survivors and non-survivors). Methods: The clinical data of survivors and non-survivors were compared using an ANOVA (continuous data) or a Fisher's test (discrete data). Results: The survival rate was 32%. Most animals were 5 years or younger, and none had been appropriately vaccinated. The non...
Russell CM, Axon JE, Blishen A, Begg AP.To assist correct decision-making about antimicrobial treatment of equine neonates with septicaemia. Methods: Retrospective study of microbial blood culture results obtained from foals less than 7 days of age. Methods: Microbial blood culture results from foals less than 7 days of age admitted to an intensive care unit between July 1999 and December 2004 were reviewed. Antimicrobial sensitivity was assessed by the Kirby Bauer disc diffusion method. Antimicrobials were defined as an effective first-line choice antimicrobial if greater than 70% of isolates were susceptible. Multiple drug resista...
Zhang J, Go YY, MacLachlan NJ, Meade BJ, Timoney PJ, Balasuriya UB.Comparative sequence analysis of a series of strains of equine arteritis virus (EAV) of defined virulence for horses, ranging from the horse-adapted virulent Bucyrus (VB) strain to a fully attenuated vaccine strain derived from it, identified 13 amino acid substitutions associated with attenuation. These include 4 substitutions in the replicase proteins and 9 in the structural proteins. Using reverse genetic techniques, these amino acid substitutions were introduced into a virulent infectious cDNA clone pEAVrVBS derived from the VB strain of EAV. Inoculation of horses with the recombinant viru...
Elshafie EI, Sani RA, Hassan L, Sharma R, Bashir A, Abubakar IA.A cross-sectional study was designed to assess the seroprevalence and risk factors associated with Trypanosoma evansi infection among horses, using a total of 527 blood samples obtained from eight states in Peninsular Malaysia. A structured questionnaire was used to collect data on risk factors associated with T. evansi seroprevalence. The overall seroprevalence detected by card agglutination test for T. evansi (CATT/T. evansi) was 13.90% (73/527, CI: 11.2-17.1%). Female and exogenous horses showed a higher risk in association with the disease seroprevalence compared to other groups. The major...
Burns RE, Pesavento PA, McElliott VR, Ortega J, Affolter VK.Three horses presented with variably painful, nonulcerated masses of the head or neck that were diagnosed as glomus tumours. Grossly, they were fleshy, pink to tan masses ranging from 0.4 to 9 cm in diameter, involving either the deep dermis and subcutis or the subcutis and underlying skeletal muscle. Microscopically, neoplastic epithelioid cells were arranged in sheets, cords and packets within lobules. The neoplastic cells frequently abutted and formed nodular bulges into large endothelium-lined vascular spaces, especially around the tumour periphery. Large nerve branches were associated wit...
Schöniger S, Böttcher D, Theuß T, Schoon HA.Endometrial epithelial cells form a luminal barrier and are exposed to pathogens and non-infectious antigens. Toll-like receptors (TLRs) mediate pathogen defenses and tissue homeostasis, but are also involved in the pathogenesis of inflammatory and fibrosing alterations. Endometrial diseases are important causes of subfertility in mares. The pathogenesis of some types of persistent inflammation and periglandular fibrosis (endometrosis) is unknown. The aim of this study was to compare by in situ and in vitro immunohistochemistry the expression of TLRs 2, 4 and 6 in equine endometrial epithelial...
Brewer K, Shults TF, Machin J, Kudrimoti S, Eisenberg RL, Hartman P, Wang C, Fenger C, Beaumier P, Tobin T.Three low concentration methamphetamine "positive" tests were linked to use of a methamphetamine-contaminated trailer to transport the affected horses. This incident establishes methamphetamine as a human-use substance that can inadvertently enter the environment of racing horses, resulting in urinary methamphetamine "positives;" an interim regulatory cut-off of 15 ng/mL for methamphetamine in post-race urine is proposed. Trois tests «positifs» de faibles concentrations de méthamphétamine ont été associés à l’utilisation d’une remorque contaminée par les méthamphétamines qui é...
Pitzer JB, Kaufman PE, Hogsette JA, Geden CJ, Tenbroeck SH.Beginning in November 2007 and continuing until December 2009, weekly stable fly, Stomoxys calcitrans (L.), surveillance was conducted at four equine facilities near Ocala, FL, by using alsynite sticky traps for adults and by searching immature developmental sites for pupae. Adult stable fly trap captures were highly variable throughout the year, ranging from 0 to 1,400 flies per trap per farm. The greatest adult stable fly activity was observed during the spring months of March and April, with weekly three-trap means of 121 and 136 flies per farm, respectively. The importance of cultural cont...
Sampieri F, Allen AL, Pusterla N, Vannucci FA, Antonopoulos AJ, Ball KR, Thompson J, Dowling PM, Hamilton DL, Gebhart CJ.The objective of this study was to demonstrate the susceptibility of rabbits to Lawsonia intracellularis obtained from a case of clinical equine proliferative enteropathy (EPE). This is a preliminary step toward developing a rabbit infection model for studying pathogenesis and therapy of EPE in horses. Nine does were equally assigned to 3 groups. Animals in 2 groups (Group 1 and Group 2) were orally inoculated with different doses of cell-cultured L. intracellularis. Controls (Group 3) were sham-inoculated. Feces and blood were collected before the rabbits were infected and at 7, 14, and 21 da...
Caron JP, Fretz PB, Bailey JV, Barber SM.Arthrodesis of the proximal interphalangeal joint was used to treat lameness resulting from osteoarthrosis and for closed subluxation in 35 horses. Six horses had bilateral arthrodeses. Several conventional internal fixation techniques and a three converging screw method were used. Criteria for success included the horse performing its previous or intended athletic activity and the owner being satisfied with the outcome. Using these criteria, a successful outcome was obtained in 65% of the 26 animals in which adequate follow-up was available. A successful outcome was observed in four of six ho...
Schein FB, Maia MO, Witter R, Marcili A, Camargo LM, Dutra V, Nakazato L, Candido SL, Almeida EM, Oliveira ACS, Pacheco RC.We evaluated the distribution of piroplasmids in equids from the Mato Grosso state in Midwestern Brazil using molecular methods and the interspecific genetic diversity. For this, 1,624 blood samples of equids from 973 farms were examined by PCR, using primer pairs that amplify a fragment of the genes rap-1 and ema-1 of Babesia caballi and Theileria equi, respectively. For molecular characterization and phylogenetic studies, 13 and 60 sequences of the rap-1 and ema-1 genes, respectively, were used to build a dendogram using maximum parsimony. B. caballi and T. equi were detected in 4.11% and 28...
Yang J, Ellison S, Gogal R, Norton H, Lindsay DS, Andrews F, Ward D, Witonsky S.Equine protozoal myeloencephalitis (EPM) is one of the most common neurologic diseases of horses in the United States. The primary etiologic agent is Sarcocystis neurona. Currently, there is limited knowledge regarding the protective or pathophysiologic immune response to S. neurona infection or the subsequent development of EPM. The objectives of this study were to determine whether S. neurona infected horses with clinical signs of EPM had altered or suppressed immune responses compared to neurologically normal horses and if blood sample storage would influence these findings. Twenty clinical...
Amer MM, Desouky AY, Helmy NM, Abdou AM, Sorour SS.Strongylid and non-strongylid nematodes are one of the most important parasites infecting equines. The traditional method to identify these nematodes is through coproscopy and fecal culture. Because of the scarcity of data published in Egypt discussing the morphometric features of infective 3 larvae of these nematodes, this study aims to provide a morphometric key for L3 of common strongylid and non-strongylid nematodes infecting Egyptian equines. For this reason, we cultured fecal samples containing GINs eggs and 3 larval stages were identified based on their morphology (i.e., shape and numbe...
Nemoto M, Tamura N, Bannai H, Tsujimura K, Kokado H, Ohta M, Yamanaka T.Baloxavir marboxil (BXM), an inhibitor of the cap-dependent endonuclease of the influenza virus polymerase acidic protein (PA), exerts an antiviral effect against influenza A virus. It has been available in Japan since March 2018. This study evaluated the antiviral efficacy of BXM against equine influenza A virus (EIV) by an experimental challenge study using horses. Six horses were experimentally inoculated with EIV, and BXM was administered to the three horses at 2 days post inoculation. Horses treated with BXM showed milder clinical signs than horses without treatment and shed less virus. T...
Mair TS, Lane JG.Case records are reviewed of 51 adult horses in which a diagnosis of pneumonia, pulmonary abscess or pleuritis had been made. Forty-five horses were afflicted with pneumonia and/or pulmonary abscesses; in 11 of these the infection was primary, whereas in 34 it was secondary to another disease process (inhalation of food or saliva, thoracic trauma, generalised infection, airway disease, neoplasia or thromboembolism). Of the 11 horses with primary pulmonary infections, 10 appeared to be associated with a previous episode of stress; this took the form of long distance travel in eight cases. There...
Karasek I, Butler C, Baynes R, Werners A.Ectoparasites infestations are a growing concern to horse owners and equine veterinarians alike. Ectoparasites cause significant health and welfare issues and can potentially can serve as vectors for a variety of pathogens. The prevalence of ectoparasites increases around the world, and especially in horses information on the successful prevention and treatment of ectoparasite infestations in scarce and in many instances anecdotal. This poses a challenge to the equine veterinarian and off-label use of drugs can lead to detrimental effects in horses. In this review we describe the current avail...
Causey RC, Artiushin SC, Crowley IF, Weber JA, Homola AD, Kelley A, Stephenson LA, Opitz HM, Guilmain S, Timoney JF.Attenuated Salmonella enterica serovar Typhimurium MGN707, expressing the SzP protective protein of the MB9 serovar of Streptococcus equi subspecies zooepidemicus (SzP-MB9) was tested for its safety and efficacy as a nebulised intranasal vaccine against streptococcal uterine infections in mares. In a preliminary study, vaccinated mares (n=5) displayed serum, nasal and uterine responses (P<0.05) to S. Typhimurium lipopolysaccharide (St-LPS). Subsequently, vaccinated mares (expressor group, n=7), but not mares vaccinated with the vector only (control group, n=7), displayed significant increas...
Morris DD, Moore JN, Crowe N, Moldawer LL.A study was conducted to determine whether serum interleukin-6 (IL-6) activity increased in horses during experimentally induced endotoxemia and whether serum IL-6 activity correlated to changes in clinical or laboratory data. Six clinically normal horses were given endotoxin IV (30 ng/kg of body weight) in 0.9% NaCl solution over 1 hour. Five of these and 1 additional horse served as controls and were given only 0.9% NaCl solution. Venous blood, for determination of serum IL-6 activity and WBC count, was collected before and at various times through 8 hours after the start of endotoxin or NaC...
Fernie DS, Batty I, Walker PD, Platt H, Mackintosh ME, Simpson DJ.The vaccination of four ponies on two occasions with a formolised culture of Haemophilus equigenitalis produced a high circulating antibody titre to the organism in each pony. Three out of four vaccinated and all of three unvaccinated ponies developed typical symptoms of contagious equine metritis (CEM) when subsequently challenged with a vaginal exudate containing H equigenitalis. Similarly, three ponies which had previously been infected with H equigenitalis and which had recovered spontaneously also developed contagious equine metritis when rechallenged with the organism. The clinical and b...
Perez-Ecija A, Mendoza FJ, Estepa JC, Bautista MJ, Pérez J.A 2-month-old foal with septic shock and severe respiratory distress was referred to the Veterinary Teaching Hospital. Due to poor prognosis, the foal was euthanized. Histopathology showed lesions suggestive of Rhodococcus equi infection associated with a diffuse interstitial infiltrate of foamy macrophages and syncytial cells presenting large acidophilic intranuclear inclusion bodies, fibrin exudates and hyaline membranes. Bacteriological examination from lung and respiratory exudates confirmed R. equi infection, whilst immunohistochemistry and PCR yielded a positive result for Equid herpesvi...
Wahl K, Adams SB, Moore GE.To assess fetlock joint contamination with tissue debris and hair after arthrocentesis. Methods: Experimental. Methods: Fetlock joint tissues (n = 10 horses). Methods: Soft tissue flaps including the joint capsule were dissected from the dorsal fetlock joints of 7 anesthetized horses leaving an intact proximal base. Needles inserted through the tissue flaps were flushed into tissue cell culture plates and examined for debris. Studies were repeated on excised fetlock tissue preparations after being stored for 5 days. Variables included gauge and type of needle, insertion of spinal needles with ...
Koroleva E, Steffen HC, Bosch C, Flemming L, Botha A.Increasing cases of equine infertility and early embryonic loss in the Western Cape, South Africa, were documented in recent years. These appeared to be associated with Corynebacterium uterequi isolated from the uteri of infected mares. The purpose of this study was, therefore, to investigate the physiology and potential pathogenicity of this bacterium. Histopathological analyses were conducted on five mares suffering from reproductive complications, and from which Corynebacterium strains were detected on culture of uterine swabs. The histopathology revealed that the mares suffered from variou...
Zak A, Siwinska N, Slowikowska M, Borowicz H, Ploneczka-Janeczko K, Chorbinski P, Niedzwiedz A.Commensal bacterial and fungal flora of the conjunctival sac has been described in horses and other animals. The identification of commensal flora of the conjunctival sac may aid in the diagnosis of ocular inflammatory diseases, such as conjunctivitis or more severe ulcerative keratitis, common in horses. Moreover, damage of ocular protective barriers may lead to an opportunistic infection. The study was carried out in Silesian horses kept at a single breeding center in South-western Poland, in order to limit any breed-dependant and climate-dependant variables affecting the results. Following ...
Bucki EP, Giguère S, Macpherson M, Davis R.The objectives of this study were to investigate the pharmacokinetics of once-daily amikacin in healthy neonates, to determine amikacin concentrations in hospitalized foals, and to determine the minimum inhibitory concentrations (MICs) of amikacin against gram-negative isolates from blood cultures in septic foals. Median half-life, clearance, and volume of distribution of amikacin in healthy 2- to 3-day-old foals after administration of an intravenous bolus of amikacin (25 mg/kg) were 5.07 hours (4.86-5.45 hours), 1.82 mL/min/kg (1.35-1.97 mL/min/kg), and 0.785 L/kg (0.638-0.862 L/kg), respect...
Traub-Dargatz JL, Weese JS, Rousseau JD, Dunowska M, Morley PS, Dargatz DA.Reduction factors (RFs) for bacterial counts on examiners' hands were compared when performing a standardized equine physical examination, followed by the use of one of 3 hand-hygiene protocols (washing with soap, ethanol gel application, and chlorohexidine-ethanol application). The mean RFs were 1.29 log10 and 1.44 log10 at 2 study sites for the alcohol-gel (62% ethyl alcohol active ingredient) protocols and 1.47 log10 and 1.94 log10 at 2 study sites for the chlorhexidine-alcohol (61% ethyl alcohol plus 1% chlorhexidine active ingredients) protocols, respectively. The RFs were significantly d...
Ruggles AJ, Beech J, Gillette DM, Midla LT, Reef VB, Freeman DE.A 13-year-old Quarter Horse gelding was referred for evaluation of a draining tract and fracture of the right hemimandible of 4 weeks' duration. Two days prior to admission, the horse had developed pigmenturia. Radiography of the mandible revealed a fracture of the vertical ramus of the right hemimandible, loss of the right lower second premolar, and osteomyelitis involving an extensive portion of the hemimandible. Ultrasonography of the left kidney revealed loss of normal renal architecture. Histologic examination of tissue obtained from the right hemimandible revealed granulomatous osteomyel...
Zarski LM, Vaala WE, Barnett DC, Bain FT, Soboll Hussey G.Equine herpesvirus 1 (EHV-1) ubiquitously infects horses worldwide and causes respiratory disease, abortion, and equine herpesvirus myeloencephalopathy. Protection against EHV-1 disease is elusive due to establishment of latency and immune-modulatory features of the virus. These include the modulation of interferons, cytokines, chemokines, antigen presentation, and cellular immunity. Because the modulation of immunity likely occurs at the site of first infection-the respiratory epithelium, we hypothesized that the mucosal influenza vaccine Flu Avert I.N. (Flu Avert), which is known to stimulat...
Morton AC, Baseggio N, Peters MA, Browning GF.Pulsed field gel electrophoresis of restriction endonuclease digested genomic DNA from a collection of clinical isolates of Rhodococcus equi was used to compare strain diversity on different Thoroughbred horse farms over time. Restricted diversity was found among the isolates tested, as the same strains were detected on multiple farms and in multiple years. Marked variation occurred in strain prevalence with some strains being represented by single isolates, and the most prevalent by 26 isolates. There were dominant strains on some farms and the prevalence of some strains differed between farm...
McCollum WH.Twenty horses that were seronegative for equine arteritis virus antibodies were inoculated IM with live equine arteritis virus vaccine. The inoculation did not cause clinical signs of disease. A mild, transient febrile reaction developed in 6 horses, 3 of which were in poor condition before inoculation. Six horses, 2 of which were in poor condition before inoculation, experienced mild lymphopenia. Necropsy revealed mild lesions in the lymph nodes of 6 horses (3 of which were in poor condition before inoculation). Maximum concentrations of virus were detected in the lymph nodes and were consist...
Searcy GP, Orr JP.A nine year old quarter horse exhibited progressive weight loss and inappetance over a 47 day period. There was clinical evidence of pleuritis and pneumonia substantiated by leukocytosis and elevated protein in pleural fluid. Over the entire period the horse was neutropenic and had circulating abnormal immature granulocytes and low numbers of blast cells. Anemia and thrombocytopenia progressively worsened. Bone marrow examination revealed very few mature granulocytes but large numbers of immature cells of the granulocytic series and marked megaloblastic transformation of erythroid cells. These...
The genus includes species with a wide geographical spread that cause pathology in humans and animals. In this context, an epidemiological study of infection was carried out in the northeastern part of Romania to investigate for the first time the prevalence of this infection in pigs, horses, wild boars and bears, the geographical distribution of species and the natural reservoir of infection. Between 2010 and 2015, a total of 166,270 animals were examined by the method of artificial digestion, in order to calculate the annual and general prevalence of infection, according to the host and...
Dembek KA, Hurcombe SD, Stewart AJ, Barr BS, MacGillivray KC, Kinee M, Elam J, Toribio RE.Critically ill foals often present to veterinary hospitals with impaired organ perfusion which can be demonstrated by increased blood L-lactate concentrations. As a compensatory mechanism to low blood pressure and electrolyte abnormalities, aldosterone and arginine vasopressin (AVP) are released to restore organ perfusion and function. Several studies have investigated the ability of blood L-lactate concentrations to predict severity of disease and outcome in critically ill human patients, adult horses and foals. However, information on the aldosterone and AVP response to hypoperfusion and its...
Asbury AC, Hansen PJ.Fourteen mares, 7 susceptible and 7 resistant to bacterial endometritis, were used to provide circulating and uterine-derived neutrophils. Uterine neutrophils were recruited by inoculating cell-free filtrates of Streptococcus zooepidemicus, or control vehicle. Mares were assigned to schedules for collection of neutrophils at oestrus or dioestrus. Phagocytic activity of circulating and uterine cells was evaluated by an assay for chemiluminescence after addition of opsonized streptococci. Chemiluminescence generated by circulating neutrophils was greater (P less than 0.05) for susceptible mares ...
