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.
Kambayashi Y, Kishi D, Ueno T, Ohta M, Bannai H, Tsujimura K, Kinoshita Y, Nemoto M.Equine coronavirus (ECoV) causes pyrexia, anorexia, lethargy, and sometimes diarrhoea. Infected horses excrete the virus in their faeces, and ECoV is also detected in nasal samples from febrile horses. However, details about ECoV infection sites in the intestinal and respiratory tracts are lacking. To identify the ECoV infection sites in the intestinal and respiratory tracts, we performed an experimental infection study and analysed intestinal and respiratory samples collected from four infected horses at 3, 5, 7, and 14 days post-inoculation (dpi) by real-time reverse transcription polymeras...
Mathewos M, Teshome D, Fesseha H.Parasitic infections can cause a variety of respiratory, intestinal, and other problems in horses, as well as contribute to some performance issues. A cross-sectional study was undertaken in and around Bekoji, South Eastern Ethiopia, from November 2020 to June 2021 to identify species and evaluate the prevalence of gastrointestinal parasites in donkeys and horses, using direct fecal smear, floatation methods, and larval cultures. In this study, the overall prevalence of gastrointestinal nematode parasites was 94.5% (363 out of 384), with donkeys accounting for 95.8% and horses accounting for 9...
Gilbertie JM, Schaer TP, Engiles JB, Seiler GS, Deddens BL, Schubert AG, Jacob ME, Stefanovski D, Ruthel G, Hickok NJ, Stowe DM, Frink A, Schnabel LV.The leading cause of treatment failure in Staphylococcus aureus infections is the development of biofilms. Biofilms are highly tolerant to conventional antibiotics which were developed against planktonic cells. Consequently, there is a lack of antibiofilm agents in the antibiotic development pipeline. To address this problem, we developed a platelet-rich plasma (PRP)-derived biologic, termed BIO-PLY (for the BIOactive fraction of Platelet-rich plasma LYsate) which has potent in vitro bactericidal activity against S. aureus synovial fluid free-floating biofilm aggregates. Additional in vitro st...
Bollig ER, Granick JL, Webb TL, Ward C, Beaudoin AL.Antimicrobials are critical for medicine, but the problem of antimicrobial resistance (AMR) threatens the effectiveness of these valuable drugs. In USA, there are no national- or state-level programs or policies in place to track antibiotic use (AU) in dogs, cats, and horses, despite acknowledgement of this sector's importance to both the AMR problem and its solution. AU measurement is a key part of antibiotic stewardship and AMR prevention. This study aimed to fill existing gaps in the veterinary professions' knowledge of antibiotic prescribing in small animals and horses. To address this aim...
Stemmet GP, Robert MP, Smit Y.Sinusitis is a common occurrence in horses and often develops secondary to dental disease. Extraction of cheek teeth in horses is associated with variable degrees of complications and although postoperative displacement and retention of alveolar plugs has been identified as one such potential complication, few cases of resulting sinusitis have been reported. This manuscript describes a four-year-old Thoroughbred mare that was presented for chronic unilateral left-sided mucopurulent nasal discharge after extraction of the left maxillary second molar tooth two months earlier. Radiographic and co...
El-Hage C, Hartley C, Savage C, Watson J, Gilkerson J, Paillot R.During Australia's first and only outbreak of equine influenza (EI), which was restricted to two northeastern states, horses were strategically vaccinated with a recombinant canarypox-vectored vaccine (rCP-EIV; ProteqFlu™, Merial P/L). The vaccine encoded for haemagglutinin (HA) belonging to two equine influenza viruses (EIVs), including an American and Eurasian lineage subtype that predated the EIV responsible for the outbreak (A/equine/Sydney/07). Racehorses in Victoria (a southern state that remained free of EI) were vaccinated prophylactically. Although the vaccine encoded for (HA) belon...
Balkema-Buschmann A, Fischer K, McNabb L, Diederich S, Singanallur NB, Ziegler U, Keil GM, Kirkland PD, Penning M, Sadeghi B, Marsh G, Barr J....Since the identification of Hendra virus (HeV) infections in horses in Australia in 1994, more than 80 outbreaks in horses have been reported, and four out of seven spillover infections in humans had a fatal outcome. With the availability of a subunit vaccine based on the HeV-Glycoprotein (HeV-G), there is a need to serologically ifferentiate the nfected from the accinated nimals (DIVA). We developed an indirect ELISA using HeV-G expressed in and HeV-Nucleoprotein (HeV-N) expressed in recombinant baculovirus-infected insect cells as antigens. During evaluation, we tested panels of sera from n...
Yamazaki A, Suganuma K, Kayano M, Acosta TJ, Saitoh T, Valinotti MFR, Sanchez AR, Inoue N.Animal trypanosomosis, caused by Trypanozoon trypanosomes (Trypanosoma evansi and T. equiperdum), and Trypanosoma vivax, is endemic to South American countries and has a negative impact on the livestock industry. However, the risk factors for trypanosomosis in Paraguay remain unknown. This study aimed to determine the risk factors for equine trypanosomosis in Paraguay based on a PCR-based molecular survey and individual horse sampling data. In this study, 739 blood samples were collected from horses in 16 departments of Paraguay between August 2019 and November 2020. To elucidate the risk fact...
Coultous RM, Sutton DGM, Boden LA.Equine piroplasmosis (EP) is currently not endemic in the UK, despite a lack of formal surveillance and the presence of carrier horses in the equine population. Pathogen establishment would have significant welfare and economic impacts on the national equine industry, but the disease is often overlooked by UK practitioners. Objective: To assess the risk of disease entry, exposure and consequences to the UK equine population. Methods: Qualitative risk assessment. Methods: A qualitative risk assessment was constructed utilising the current World Organisation for Animal Health (OIE) published fra...
Daniels A, Pezzanite LM, Griffenhagen GM, Hendrickson DA.The frequency of surgical site infection (SSI) following orthopaedic implant placement in horses has been reported but not compared with respect to specific antibiotic protocols administered. To determine factors associated with SSI in horses undergoing proximal interphalangeal joint (PIPJ) arthrodesis including perioperative antibiotic protocols. Records were evaluated (2010-2019), and horses undergoing PIPJ arthrodesis were identified. Patient signalment, supervising surgeon, reason for surgery, limb, implants placed, anaesthetic time, duration casting/coaptation postoperatively, antibiotic ...
Lv K, Zhang Y, Yang Y, Liu Z, Deng L.Equine piroplasmosis (EP) is a type of blood protozoan disease caused by tick-borne parasites, (), () and . While many studies have been conducted on EP diagnosis, diagnostic methods exhibiting high sensitivity and specificity remain lacking. Therefore, nested PCR (nPCR) and duplex real-time fluorescence quantitative PCR (qPCR) that can simultaneously detect both and causing agents were established and compared. The two techniques were used to analyze 36 horse blood samples for EP. This set of samples was also detected by a multinested PCR (mnPCR) targeting the gene of and the gene of ....
Venturini C, Bowring B, Partridge SR, Ben Zakour NL, Fajardo-Lubian A, Lopez Ayala A, Qin J, Totsika M, van Galen G, Norris J, Iredell J.The global epidemiology of multidrug resistant Klebsiella pneumoniae, a serious threat to both animal and human health, is dominated by the spread of pathogenic clones, each separately evolving via acquisition of transferable antibiotic resistance or niche-specific virulence determinants. In horses, K. pneumoniae infection can lead to severe respiratory illness. Here, we characterized multiple isolates recovered from bronchial aspirates of a mare with pneumonia refractory to antibiotics. First, we used a combination of standard microbiology, bacteriophage cross-susceptibility and antibiotic re...
da Silva TRO, Gonçalves PNC, Marcus VB, Mucellini CI, Dos Santos IR, Kommers G, Driemeier D, Flores EF, Cargnelutti JF, Flores MM.For approximately one decade, a novel papillomavirus termed Equus caballus papillomavirus-2 (EcPV-2) has been associated with equine penile/preputial papillomas and squamous cell carcinomas (SCCs). It is currently believed that the virus has a carcinogenic activity, being able to induce such neoplastic lesions. After being first described, EcPV-2 has been detected in many countries from North America, Europe, and Asia; however, to date, it has not been reported in Brazil. The aim of this research was to investigate the presence of EcPV-2 in penile/preputial papillomas and SCCs of Brazilian hor...
Sievert M, Schuler G, Büttner K, Wehrend A.The timely diagnosis of abnormalities in the passive transfer of colostral immunoglobulins is important for the health and development of newborn foals. This study investigated three different methods for measuring immunoglobulin G concentration in neonatal foals. Comparison of a commercial SNAP assay, total protein concentration determination, and total globulin calculation by subtracting the albumin fraction from total protein as an indirect parameter was performed on a quantitative ELISA, which served as a reference method. The study included 119 samples from 148 foals between the age of 1 ...
Hu Y, Jia Q, Liu J, Sun W, Bao Z, Che C, Wu G, Fan B, Jarhen , Ran D.Equid alphaherpesvirus 1 (EHV-1) is prevalent in China, and causes notable economic damage to the equine industry. However, there is no information regarding the molecular characteristics and pathogenicity of the Chinese strains. Therefore, an EHV-1 strain, named YM2019, was isolated from the lung tissue of an aborted horse fetus in Xinjiang, China, and its genome and pathogenicity were analyzed. The full genome of the isolate was 150,267 base pairs in length, with 56.7% G + C content. Genetic and phylogenetic analysis showed that strain YM2019 (GenBank: MT063054) belonged to the ORF30 N75...
Price D, Barnum S, Mize J, Pusterla N.The purpose of this study was to explore sampling options for a reliable and logistically more feasible protocol during a large EHV-1 outbreak. Seventeen horses with clinical infection as well as nineteen healthy herdmates, all part of an EHM outbreak, were enrolled in the study. Each horse was sampled two-four times at intervals of 2-6 days during the outbreak. All samples were collected using 6'' rayon-tipped swabs. Nasal secretions were used as the diagnostic sample of choice. Additional samples, including swabs from the muzzle/nares, swabs from the front limbs, rectal swabs, swabs of the f...
Boelow H, Krücken J, Thomas E, Mirams G, von Samson-Himmelstjerna G.Due to high prevalence of anthelmintic resistance in equine helminths, selective treatment is increasingly promoted and in some countries a positive infection diagnosis is mandatory before treatment. Selective treatment is typically recommended when the number of worm eggs per gram faeces (epg) exceeds a particular threshold. In the present study we compared the semi-quantitative sedimentation/flotation method with the quantitative methods Mini-FLOTAC and FECPAK in terms of precision, sensitivity, inter-rater reliability and correlation of worm egg counts to improve the choice of optimal diagn...
Nielsen SS, Bicout DJ, Calistri P, Canali E, Drewe JA, Garin-Bastuji B, Gonzales Rojas JL, Gortázar C, Herskin M, Michel V, Miranda Chueca MÁ.... () was identified among the most relevant antimicrobial-resistant (AMR) bacteria in the EU for cattle and horses in previous scientific opinions. Thus, it has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as in Article 9, and Article 8 for listing animal species related to the bacterium. The assessment has been performed following a methodology previously published. The outcome...
One health outlookMay 9, 2022
Volume 4, Issue 1 9 doi: 10.1186/s42522-022-00065-y
Gömer A, Puff C, Reinecke B, Bracht S, Conze M, Baumgärtner W, Steinmann J, Feige K, Cavalleri JMV, Steinmann E, Todt D.The Equine Hepacivirus (EqHV) is an equine-specific and liver-tropic virus belonging to the diverse genus of Hepaciviruses. It was recently found in a large donkey (Equus asinus) cohort with a similar seroprevalence (30%), but lower rate of RNA-positive animals (0.3%) compared to horses. These rare infection events indicate either a lack of adaptation to the new host or a predominantly acute course of infection. Methods: In order to analyze the susceptibility and the course of EqHV infection in donkeys, we inoculated two adult female donkeys and one control horse intravenously with purified Eq...
Doerffel A, Reinert A, Böttcher D, Winter K, Brehm W, Gittel C.Complications associated with indwelling intravenous catheters vary from minor to severe. Changes in tissue architecture and vein structure may be detectable prior to clinical alterations. The aim of the study was to characterize and compare changes in a catheterized vein and surrounding tissue by clinical and ultrasonographic examination. Microbiological infestation of catheter specimens was assessed. Methods: In this prospective, observational, clinical study 55 horses with an indwelling intravenous catheter have been included. Subsequent to catheter placement, vein and surrounding tissue we...
Gehlen H, Rutenberg D, Simon C, Reinhold-Fritzen B, Drozdzewska K.The aim of this review is to describe general guidelines of hygiene measures in the horse stable as well as to provide current recommendations for an outbreak of a common infectious disease. General cleanliness, hand hygiene, avoidance of stress, regular deworming, and vaccinations belong to the basic hygiene measures in a horse herd. All new or returning equids should be submitted to a quarantine period as an important prevention measure. Repeated washing and disinfection of hands may prevent spreading of infectious agents to people and horses.The conception of a hygiene plan, including gener...
Koch DW, Ericksen KA, Easley JT, Hackett ES.To report the clinical outcomes of horses with chronic guttural pouch infection characterized by accumulation of mucopurulent material following transpharyngeal diode laser fenestration. 13 client-owned horses. Horses undergoing diode laser fenestration for chronic guttural pouch infection were identified by medical record search. Signalment, disease history, presence of mucopurulent empyema or chondroids, and pre- and postoperative therapy were recorded. Owners were contacted for follow-up information at a minimum of 6 months following surgery. 13 horses underwent laser fenestration for chron...
Soza-Ossandón P, Rivera D, Allel K, González-Rocha G, Quezada-Aguiluz M, San Martin I, García P, Moreno-Switt AI.Healthcare-associated infections caused by Staphylococcus, particularly Staphylococcus aureus, represent a high risk for human and animal health. Staphylococcus can be easily transmitted through direct contact with individual carriers or fomites, such as medical and non-medical equipment. The risk increases if S. aureus strains carry antibiotic resistance genes and show a phenotypic multidrug resistance behavior. The aim of the study was to identify and characterize methicillin resistant coagulase-positive staphylococci (MRSA) and coagulase-negative staphylococci (MRCoNS) in equine patients an...
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 ...
Da Silva-Álvarez E, Gómez-Arrones V, Martín-Cano FE, Gaitskell-Phillips G, Ortiz-Rodríguez JM, Carrasco JJ, Gil MC, Peña Vega FJ....In this study, uterine blood flow area (BFA) has been evaluated for the first time using power Doppler ultrasound (PD) as a marker of endometritis in mares and jennies. The uterine BFA in healthy mares was greater in oestrus than in diestrus (p < .001). However, differences in endometrial blood flow between oestrus and diestrus were not observed in mares with endometritis. The uterine blood flow in healthy jennies is not affected by the oestrus cycle. Both species showed an increase in endometrial BFA in pathological uterine conditions compared to controls. BFA was a good marker of endome...
Narváez SÁ, Fernández I, Patel NV, Sánchez S. is an important veterinary pathogen that takes the lives of many foals every year. With the emergence and spread of MDR to current antimicrobial treatment, new tools that can provide a fast and accurate diagnosis of the disease and antimicrobial resistance profile are needed. Here, we have developed and analytically validated a multiplex qPCR for the simultaneous detection of and related macrolide resistance genes in equine respiratory samples. The three sets of oligos designed in this study to identify housekeeping gene and macrolide resistance genes (46) and (51) showed high analytic se...
Li Y, Lan Y, Zhang S, Wang X.Increasing evidence reveals the importance of gut microbiota in animals for regulating intestinal homeostasis, metabolism, and host health. The gut microbial community has been reported to be closely related to many diseases, but information regarding diarrheic influence on gut microbiota in horses remains scarce. This study investigated and compared gut microbial changes in horses during diarrhea. The results showed that the alpha diversity of gut microbiota in diarrheic horses decreased observably, accompanied by obvious shifts in taxonomic compositions. The dominant bacterial phyla (, and )...
Peckle M, Santos H, Pires M, Silva C, Costa R, Vitari G, Camilo T, Meireles N, Paulino P, Massard C.Experimental studies have demonstrated that () transmits to horses. However, the degree and dynamics of this protozoan infection in the vector's organism have not been fully elucidated. Therefore, this study aimed to evaluate the infection rate and parasitic load of in , the infection dynamics in this arthropod during experimental infestation in a horse chronically infected with , and to evaluate the trans-stadial and intrastadial transmission competence of by . The experimental infestation period of on the horse was 33 days, but males were found on the animal up to 60 days post-infestat...
Burns SJ, Westerman AG, Harrison LR.Mare Reproductive Loss Syndrome (MRLS) is the term given to abortions in mares associated with Eastern Tent caterpillars (ETC; Malacosoma americanum). This paper aims to examine if the hypothesis for a toxin as the cause of MRLS holds up to testing using Westerman's Correlates of Causal Strength of Evidence (WCCSE) and fits with known environmental factors that influence the occurrence of MRLS. Using WCCSE all correlates fit with a toxin as a potential causative agent. Environmental factors also fitted with this hypothesis. MRLS events were associated with higher than normal ambient temperatur...
Carvalho GM, Ramos CP, Lobato FCF, Guedes RMC, Giaretta PR, Silva ROS.Despite the known importance of Clostridioides (Clostridium) difficile infection (CDI) in animals, there are no published guidelines for the diagnosis of CDI. The performance of the available commercial methods, all standardized for human stool samples, can vary according to the animal species. Thus, the aim of the present study was to review the literature on the detection of C. difficile in pigs, horses, and dogs. The detection of toxins A and B using enzyme immunoassays seems to have low performance in piglet and dog samples, while it shows high sensitivity for the diagnosis of CDI in foal...
Tapia D, Sanchez-Villamil JI, Torres AG.Burkholderia mallei (Bm) is a facultative intracellular pathogen and the etiological agent of glanders, a highly infectious zoonotic disease occurring in equines and humans. The intrinsic resistance to antibiotics, lack of specific therapy, high mortality, and history as a biothreat agent, prompt the need of a safe and effective vaccine. However, the limited knowledge of protective Bm-specific antigens has hampered the development of a vaccine. Further, the use of antigen-delivery systems that enhance antigen immunogenicity and elicit robust antigen-specific immune responses has been limited a...
O'Neill T, Kydd JH, Allen GP, Wattrang E, Mumford JA, Hannant D.The frequency of antigen-specific, genetically restricted cytotoxic T lymphocyte precursors (CTLp) was measured in peripheral blood mononuclear cells (PBMC) of ponies before and after infection with equid herpesvirus 1 (EHV1). Split-well limiting dilution analysis (LDA) was developed to measure CTLp frequency using EHV1-infected 51Cr-labelled lymphoblasts as targets. Extensive characterisation showed that recombinant human interleukin-2, autologous antigen presenting cells and equine serum containing virus neutralising antibody were necessary for maturation of CTLp into effector CTL in vitro. ...
Madewell BR, Tang YJ, Jang S, Madigan JE, Hirsh DC, Gumerlock PH, Silva J.Intestinal colonization with toxigenic strains of Clostridium difficile was documented in 9 of 10 horses with acute onset diarrhea in a veterinary medical teaching hospital, whereas a similar isolate was detected in only 1 of 23 other horses without diarrhea in the hospital. One horse with diarrhea was infected simultaneously with both C. difficile and Salmonella krefeld. Clostridium difficile was detected by fecal culture on selective medium, confirmed with a latex particle agglutination test, and identified as toxigenic by polymerase chain reaction amplification of toxin A and toxin B gene s...
Crabb BS, Nagesha HS, Studdert MJ.Equine herpesvirus 4 (EHV4) glycoproteins of M(r) 63K and 250K were identified in the supernatant of infected cell cultures. The 63K glycoprotein was type-specific; that is, it reacted with monospecific sera from horses that had been immunized or infected with EHV4, but not with monospecific sera from horses immunized or infected with EHV1, a closely related alphaherpesvirus. It was postulated that the secreted protein may be the homologue of similarly secreted glycoproteins of herpes simplex virus 2 glycoprotein G (HSV2 gG) and pseudorabies virus (PRV) gX, which is the homologue of HSV2 gG. T...
Bergström K, Aspan A, Landén A, Johnston C, Grönlund-Andersson U.Methicillin-resistant Staphylococcus aureus (MRSA) in animals is a rare finding in Sweden. In horses, MRSA was first detected in a screening survey in 2007. In 2008, six clinical cases occurred in an equine hospital, indicating an outbreak. Methods: All MRSA isolates detected, 11 spa-type t011 and one t064 (n = 12), in infected horses (n = 10) and screening of horses (n = 2) in Sweden from December 2007 to March 2010 were retrospectively analysed with pulsed-field gel electrophoresis (PFGE) using Cfr9I and ApaI restriction enzymes, to study relationship between the isolates. Medical records of...
Wagner B, Perkins G, Babasyan S, Freer H, Keggan A, Goodman LB, Glaser A, Torsteinsdóttir S, Svansson V, Björnsdóttir S.Neonatal foals respond poorly to conventional vaccines. These vaccines typically target T-helper (Th) cell dependent B-cell activation. However, Th2-cell immunity is impaired in foals during the first three months of life. In contrast, neonatal basophils are potent interleukin-4 (IL-4) producers. The purpose of this study was to develop a novel vaccine triggering the natural capacity of neonatal basophils to secrete IL-4 and to evaluate if vaccination resulted in B-cell activation and antibody production against EHV-1 glycoprotein C (gC). Neonatal vaccination was performed by oral biotinylated...
Sponseller BA, Sparks WO, Wannemuehler Y, Li Y, Antons AK, Oaks JL, Carpenter S.The principal neutralizing domain (PND) of equine infectious anemia virus (EIAV) is located in the V3 region of SU. Genetic variation in the PND is considered to play an important role in immune escape and EIAV persistence; however, few studies have characterized genetic variation in SU during the inapparent stage of disease. To better understand the mechanisms of virus persistence, we undertook a longitudinal study of SU variation in a pony experimentally inoculated with the virulent EIAV(Wyo). Viral RNA isolated from the inoculum and from sequential sera samples was amplified by RT-PCR, clon...
Blakeslee JR, Olsen RG, McAllister ES, Fassbender J, Dennis R.Five horses were experimentally exposed to equine herpesvirus 2 strain LK. Two young foals developed chronic pharyngitis (98 and 232 days, respectively). Growth characteristics, cytopathic effects (CPE), inclusion body formation, ether sensitivity, and immunofluorescent analysis indicated that the virus recovered from infected animals was a herpesvirus serologically identical with, or at least antigenically related to EHV-2 strain LK. No significant complement-fixing (CF) or virus-neutralizing (VN) antibody responses were observed in adult horses while both foals demonstrated a rise in CF anti...
Burrell MH.A group of racehorses in training was examined on several occasions with a fibreoptic endoscope and monitored for viral infection. Only equine herpes virus-2 (EHV-2) infection was detected. Pharyngeal lymphoid hyperplasia (PLH) was present in all horses and decreased in severity with age. There was no association between PLH severity and antibody titres to EHV-1, or with the isolation of EHV-2. Finishing position in races was not affected by PLH severity. Exercise induced pulmonary haemorrhage (EIPH) was evident on 23 out of 49 (47 per cent) examinations after maximal speed training exercise. ...
Aleman M, Magdesian KG, Peterson TS, Galey FD.A 4-month-old American Paint filly was evaluated because of sudden onset of ataxia that progressed to recumbency. Five additional horses from the same and neighboring premises developed signs of poor performance, generalized weakness, ataxia, and recumbency; 2 of those horses were also evaluated. A new batch of a commercial feed supplement had been introduced to the horses' diet on each farm within the preceding 3 days. Results: Other than recumbency, findings of physical and neurologic examinations of the foal were unremarkable. The other 2 horses had generalized weakness and mild ataxia, and...
Chapman GE, Baylis M, Archer D, Daly JM.Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods, including mosquitoes, biting midges (Culicoides), sandflies and ticks. These include the flaviviruses (Japanese encephalitis, West Nile and Murray Valley encephalitis), alphaviruses (eastern, western and Venezuelan encephalitis) and the orbiviruses (African horse sickness and equine encephalosis). This review provides an overview of the challenges faced in the surveillance, prevention and control of the major equine arboviruses, particularly in the context of these viruses emerging in ...
Li J, Li Y, Moumouni PFA, Lee SH, Galon EM, Tumwebaze MA, Yang H, Huercha , Liu M, Guo H, Gao Y, Benedicto B, Zhang W, Fan X, Chahan B, Xuan X.Q fever, spotted fever rickettsioses and equine piroplasmosis, are some of the most serious equine tick-borne diseases caused by Coxiella burnetii, Rickettsia spp., Babesia caballi and/or Theileria equi. This study surveyed and molecularly characterized these pathogens infecting horses in ten ranches from XUAR, China using molecular technology. Among 200 horse blood samples, 163 (81.5%) were infected with at least one of the pathogens. Rickettsia spp. was the most prevalent pathogen (n = 114, 57.0%), followed by C. burnetii (n = 79, 39.5%), T. equi (n = 79, 39.5%) and B. caballi (n = 4...
Theoret C.Horses are predisposed to traumatic wounds that can be labor intensive and expensive to manage. Skin has a considerable potential for efficient and functional repair however, while cutaneous repair is a regenerative process in the fetus, this capability declines in late gestation as inflammation and scarring alter the outcome of healing. The historical gold standard for replacement of lost skin is the autologous skin graft. However, the horse's lack of redundant donor skin limits the practicality of full-thickness grafting to smaller wounds; moreover, graft failure is relatively common in equi...
Jones RL, Adney WS, Shideler RK.Clostridium difficile was isolated from the feces of 27 of 43 diarrheic foals (63%), and cytotoxin was detected in feces from 28 diarrheic foals (65%). The foals had not received any antimicrobial treatment before the onset of diarrhea. C. difficile was not isolated from feces of 18 normal foals without diarrhea and 62 adult horses (P less than 0.005). This finding of C. difficile and its toxins in association with diarrhea in foals adds another possible cause to the list of infectious agents which may cause diarrhea in foals.
Nemoto M, Imagawa H, Tsujimura K, Yamanaka T, Kondo T, Matsumura T.Reverse transcription loop-mediated isothermal amplification (RT-LAMP) was applied to detection of equine rotavirus. Because equine rotavirus of the single P genotype, P[12], is predominant in the equine population worldwide, an RT-LAMP primer set was designed to target the genotype P[12] sequence and thus detect equine rotavirus. The detection limit of the RT-LAMP assay was 10(3) copies of viral RNA, whereas that of semi-nested RT-PCR for genotype P[12] was 10(5) copies. The RT-LAMP assay specifically amplified genotype P[12] but did not amplify the other P genotype strains. The RT-LAMP assay...
Reed SM, Howe DK, Morrow JK, Graves A, Yeargan MR, Johnson AL, MacKay RJ, Furr M, Saville WJ, Williams NM.Recent work demonstrated the value of antigen-specific antibody indices (AI and C-value) to detect intrathecal antibody production against Sarcocystis neurona for antemortem diagnosis of equine protozoal myeloencephalitis (EPM). Objective: The study was conducted to assess whether the antigen-specific antibody indices can be reduced to a simple serum : cerebrospinal fluid (CSF) titer ratio to achieve accurate EPM diagnosis. Methods: Paired serum and CSF samples from 128 horses diagnosed by postmortem examination. The sample set included 44 EPM cases, 35 cervical-vertebral malformation (CVM) ca...
Chesters PM, Allsop R, Purewal A, Edington N.Results from Southern hybridization and PCR amplification experiments using a randomly synthesized reverse transcription-PCR product showed that peripheral blood leukocytes from horses showing no clinical signs of disease expressed a putative latency-associated transcript antisense to and overlapping the 3' end of the equid herpesvirus 1 (EHV-1) immediate-early gene (gene 64). A PCR product derived from this transcript has > or =96% identity with the published EHV-1 sequence. In situ hybridization studies of equine bronchial lymph nodes corroborated these findings and are consistent with re...
Boersema JH, Eysker M, Maas J, van der Aar WM.The reappearance of strongyle eggs in faeces after treatment with ivermectin or pyrantel embonate was investigated in 22 foals, 36 yearlings, and 45 adult horses on five Dutch horse farms. The results confirmed earlier studies which showed an egg reappearance period of 9 and 6 weeks after ivermectin and pyrantel treatment, respectively. There were no differences between the egg reappearance periods of foals, yearlings, and adult horses. The mean egg counts of the yearlings were, however, consistently higher than the mean egg counts of the adult horses and foals in both ivermectin- and pyrantel...
Crowhurst FA, Dickinson G, Burrows R.An outbreak of paresis occurred on a small isolated stud farm in July 1980. Of the 42 horses on the stud, infection was confined to a group of nine in-foal mares and their foals and eight other horses which were either housed together at night or grazed adjacent pastures. Eight mares and two geldings developed ataxia or paresis and one mare died. Equid herpesvirus 1 was isolated from 17 animals and serological studies confirmed that 24 of 26 animals sampled had experienced infection.
Gather T, Walter S, Pfaender S, Todt D, Feige K, Steinmann E, Cavalleri JM.The recently discovered nonprimate hepacivirus (NPHV) naturally infects horses and is the closest known homolog of hepatitis C virus to date. Within a follow-up study acute field infections were monitored in four young Thoroughbred horses until the ages of 12-13 months. Serum samples were analyzed for the presence of NPHV RNA and anti-NPHV NS3 antibodies and liver specific parameters were evaluated. The four young horses were not able to clear infection, but remained chronically infected for the entire monitored time period despite the presence of NPHV specific antibodies.
Johnson JA, Prescott JF, Markham RJ.Six foals were inoculated intrabronchially with a suspension of Corynebacterium equi. Six weeks before this challenge, three foals were vaccinated with a C. equi bacterin. Three foals were unvaccinated controls. All foals developed a severe bronchopneumonia in the inoculated lung, indicating that vaccination was not protective. Three foals (two vaccinated, one control) were killed eight to nine days after infection. One control died on day 9 with lesions of disseminated intravascular coagulation. The remaining two foals (one vaccinated, one control) were killed on day 17. C. equi was cultured ...
Vieira RF, Vidotto O, Vieira TS, Guimaraes AM, Santos AP, Nascimento NC, Santos NJ, Martins TF, Labruna MB, Marcondes M, Biondo AW, Messick JB.The aims of this study were to determine the prevalence of hemoplasmas in a rural Brazilian settlement's population of human beings, their dogs and horses, highly exposed to tick bites; to identify the tick species parasitizing dogs and horses, and analyze factors associated with their infection. Blood samples from 132 dogs, 16 horses and 100 humans were screened using a pan-hemoplasma SYBR green real-time PCR assay followed by a species-specific TaqMan real-time PCR. A total of 59/132 (44.7%) dog samples were positive for hemoplasmas (21 Mycoplasma haemocanis alone, 12 ' Candidatus Mycoplasma...
Watson ED.Post-breeding endometritis is a major cause of subfertility in the mare. Endometritis is a normal event in the immediate period after mating, but the presence of ultransonographically visible uterine fluid more than 12 h later is thought to be evidence of uterine pathology. In mares that are free of venerally transmitted endometritis, treatment is aimed at removing the intraluminal fluid. If the endometritis persists past day 5, when the embryo enters the uterine lumen, the cytotoxic environment will not be compatible with pregnancy. Reproductive anatomy, defective myometrial contractility, lo...