Infectious diseases in horses encompass a range of illnesses caused by bacteria, viruses, fungi, or parasites. These diseases can affect various systems within the equine body, leading to symptoms that range from mild discomfort to severe systemic illness. Common infectious diseases in horses include equine influenza, strangles, equine herpesvirus, and West Nile virus. These diseases can be transmitted through direct contact with infected animals, contaminated surfaces, or vectors such as insects. Understanding the mechanisms of transmission, pathogenesis, and immune response is essential for effective prevention and control. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, diagnosis, treatment, and management of infectious diseases in horses.
Weiss M, Horzinek MC.In equine dermis cells infected with Berne virus particles were first detected 10 h after infection. Virions were encountered in all parts of the Golgi system and, infrequently, in the rough endoplasmic reticulum. A unique form of budding of preassembled rigid tubular nucleocapsids was demonstrated. Masses of tubular nucleocapsids of a lesser diameter and electron density were prominent in the cytoplasm and the nucleus of infected cells. Within the Golgi system and cytoplasmic cisternae virions appeared as straight or slightly curved rods. Extremely long, aberrant virions (250 nm) were occasio...
Dieleman EF.This review describes research conducted from 1900-1983 on trypanosomiasis due to Trypanosoma evansi in Indonesia. Clinical signs and post-mortem findings in horses, cattle, buffaloes, pigs and dogs, experimental transmission tests to establish possible surra vectors in Indonesia, and research on chemotherapy and chemoprophylaxis are discussed.
Cordes DO, Perry BD, Rikihisa Y, Chickering WR.Potomac horse fever was reproduced in 15 ponies by transfusion of whole blood originally from two natural cases and subsequently from ponies infected by the transfusions. Incubation periods varied from 9 to 15 days. Affected ponies developed varying degrees of fever, diarrhea, anorexia, depression, and leukopenia. Eleven affected ponies were killed, three died in the acute phase of the disease, and one did not show clinical signs. The most consistent post-mortem findings were fluid contents in the cecum and large colon, and areas of hyperemia (of inconstant degree and distribution) in mucosae ...
Wagstaff KH, Dickson SL, Bailey A.The history of WEE surveillance in Utah is reviewed, beginning with the 1933 outbreak involving 3,958 horses. The step by step formation of the Utah Mosquito Abatement Associations surveillance program from 1957 to the present is discussed. Results of an enlarged sentinel chicken flock surveillance program in Utah during 1983 (3 sero-conversions in September), 1984 and 1985 (no sero-conversion) show the lack of WEE activity in the surveillance area.
Pearson EG, Hedstrom OR, Sonn R, Wedam J.A 4-day-old foal died with bloody diarrhea. Using a mouse neutralization test, Clostridium perfringens type C was isolated from intestinal contents, and alpha and beta toxins were identified. About 4 m of the jejunum had severe necrohemorrhagic enteritis. Microscopically, large, rod-shaped, gram-positive bacteria were seen on necrotic intestinal villi by use of Brown and Hopp's stains.
Dubey JP, Porterfield ML.Multifocal areas of necrosis and infiltrations of mononuclear cells were seen in lung specimens of an equine fetus aborted 2 months before term. Extracellular and intracellular protozoa were seen in the alveolar tissue. Individual organisms were 4 microns by 2.5 microns, and cyst-like structures were 25 microns by 18 microns. Organisms did not stain with periodic acid-Schiff or by use of the immunoperoxidase and peroxidase-antiperoxidase method for Toxoplasma gondii. Twelve days after abortion, the mare had serum antibody titer of less than 1:10 against T gondii.
Calisher CH, Mahmud MI, el-Kafrawi AO, Emerson JK, Muth DJ.Paired sera from 28 nonvaccinated horses with serologically confirmed western equine encephalitis (WEE) virus infections were evaluated for immunoglobulin (Ig)M and IgG directed against WEE virus, by use of enzyme immunoassay. Twenty-one of the horses developed greater than or equal to 4-fold increases or decreases in serum IgM titers in paired serum samples, confirming the diagnosis of WEE in these horses. Of the remaining 7 horses, 1 had stable IgM titers, 1 had a 2-fold increase in IgM titer between paired sera, 2 had 2-fold decreases in IgM titer, and for 3 horses adequate volumes were not...
Adeyefa CA.The clinicopathological features and treatment of cases of dermatomycotic infections in horses are reported. Organisms isolated from these cases include Trichophyton mentagrophyte, T. equinum and Micosporum equinum. The Veterinary, medical and economic importance of the disease is discussed.
Lyons ET, Drudge JH, Tolliver SC.The efficacy of 2 injectable formulations of ivermectin, administered intraorally at the dosage of 200 micrograms/kg of body weight, was evaluated against naturally occurring infections by abomasal nematodes in lambs in 2 controlled tests. One test (A) included 17 lambs treated with the equine formulation and 16 nontreated lambs. For the other test (B), 14 lambs were treated with the bovine formulation, and 12 were nontreated. In controlled test A, only mature nematodes were recovered, and removals were 98% to 100% for Haemonchus contortus, Ostertagia circumcincta male, O trifurcata male, Oste...
Burrell MH, Mackintosh ME, Taylor CE.Streptococcus pneumoniae was isolated from nasopharyngeal swabs and tracheal washings taken from Thoroughbred horses in training at three of four separate stables that were sampled during investigations into respiratory disease. The growth of Strep pneumoniae in culture was enhanced by an environment enriched with carbon dioxide. In one stable, five of 15 horses that were sampled repeatedly were found to carry the organism for at least four months. There was an apparent association between lower respiratory tract inflammatory disease and heavy growths (10(6) to 10(8) colony forming units/ml) p...
Mair TS, Taylor FG, Gibbs C, Lucke VM.THE horse appears to possess a strong innate resistance to
tuberculosis because the disease is infrequently recognised even
in countries where the condition is common in other species
(Luke 1958). Reports of the disease are now scarce and earlier
records of infections in horses usually implicated the bovine
strain of Mycobacterium tuberculosis, although avian and
human strains have been isolated. Of 55 equine cases reviewed
by Griffith (1937), 53 were caused by the bovine strain and two
were independently infected with avian and human strains.
Since the implementation of the bovine tu...
Mendoza L, Alfaro AA.Thirty-nine pythiosis equine cases, were studied at the Veterinary Medicine School of the National University of Costa Rica, between 1981 and 1984. Lesions were located in different parts of their anatomy: anterior and posterior extremities, abdomen, thorax, breast and mammary gland, and were characterized by their tumoral appearance with necrotic tissue in which yellow-white coral-like necrotic masses, called kunker or leeches were shown. Splendore-Hoeppli like phenomenon and eosinophilic inflammatory reaction around the hyphae, was microscopically observed. Pythium sp. (Hyphomyces destruens)...
Zink MC, Yager JA, Smart NL.Of 131 cases of Corynebacterium equi infection in horses submitted for necropsy to the Ontario Veterinary College or Veterinary Laboratory Services, OMAF, Guelph, Ontario from 1958 to 1984, 115 were diagnosed as suppurative pneumonia, and of these 55 had associated ulcerative enterocolitis. Only five animals had intestinal involvement without pulmonary lesions. The remaining 11 cases included arthritis/cellulitis, skin abscesses and submandibular lymphadenitis. While the lung, intestine and associated lymph nodes yielded C. equi most frequently, in 21% of cases C. equi was also cultured from p...
Takai S, Kawazu S, Tsubaki S.Humoral immune response to intestinal Rhodococcus (Corynebacterium) equi in horses was studied by enzyme-linked immunosorbent assay. Anti-R. equi immunoglobulin M (IgM), IgG, and IgA antibodies were demonstrated in the healthy horse population. Adult horse levels of anti-R. equi IgM and IgG antibodies were reached by 5 to 9 weeks of age in two healthy newborn foals. R. equi was recovered from the foals in the range of 10(3) to 10(4) per g of intestinal contents. A 1-week-old foal was infected with R. equi by mouth daily for 9 weeks. The foal did not show any clinical signs of illness. Anti-R. ...
Ishiyama T, Shinagawa M, Sato G, Fujinaga K, Padmanabhan R.Equine adenovirus (EAd) DNA prepared from infected bovine kidney (MDBK) cells contained additional sequences of about 100 to 700 bp at the left-hand end of the genome. These aberrant viral genomes were produced even after the first passage of the wild type EAd in MDBK cells and their relative amounts did not change significantly during serial passage. The left terminal fragments of two defective viral DNAs were cloned into the plasmid vector pBR322 and the nucleotide sequences of their terminal regions were analyzed. The data indicate that one viral DNA contained a duplication of the inverted ...
Takai S, Morozumi Y, Higashiyama S, Tsubaki S.Equine neutrophil function was studied in 24 newborn foals, 10 adult horses, and a foal infected with R. equi by the quantitative nitroblue tetrazolium (NBT) reduction test. There was no difference between results in newborn foals and adult horses. A foal naturally infected with R. equi showed normal values of NBT reduction test at birth, and after the initial clinical signs, the spontaneous reduction of NBT by neutrophils was found to be remarkably increased until a week before death
Takai S, Ohkura H, Watanabe Y, Tsubaki S.Quantitative aspects of fecal Rhodococcus (Corynebacterium) equi in newborn foals for 12 weeks after birth were investigated on two horse breeding farms. R. equi was found in the feces of foals during week 1 of life. The greatest numbers of R. equi were present in the feces of foals during the first 8 weeks of their lives, which coincides with the age when foals are most liable to be exposed to R. equi.
Engels M, Nowotny N, Metzler AE, Wyler R, Bürki F.An EHV 1 isolate from the Lippizan Stud at Piber, which caused the abortion and paresis outbreak in 1983, was investigated using 3 known subtype 1 and 2 subtype 2 strains for comparison. Broad-scale restriction enzyme analysis as well as cross-neutralization with hyperimmune sera produced in rabbits were performed, and SDS-PAGE of infected cell proteins was conducted on a limited scale. The Piber isolate was clearly classified as a subtype 1 strain of EHV 1, and showed closest resemblance in its restriction patterns with a British EHV 1 strain, which originated from an outbreak with paretic sy...
Dutta SK, Myrup AC, Thaker SR.Interference between equine herpesvirus types 1 (EHV-1) and 2 (EHV-2) was studied in equine dermis (ED) monolayer cell cultures and equine lymphocyte cultures. Cell cultures were infected with EHV-2, and after a short incubation period, the cultures were superinfected with EHV-1. At various intervals, different measurements of EHV-1 expression in dually infected cultures, compared with those in cultures infected with EHV-1 alone, were studied. In dually infected ED cell cultures, the EHV-1 cytopathic effect, EHV-1 titer, and EHV-1 enzyme-linked immunosorbent assay antigen titer were maximally ...
Markel MD, Madigan JE, Lichtensteiger CA, Large SM, Hornof WJ.Over a 4-year period, vertebral body abscess was diagnosed in 5 young cattle. The laboratory findings in most of these cases did not suggest a diagnosis of vertebral body abscess. The most important basis for diagnosis of this condition was a thorough neurologic examination. In 4 cases, necropsy revealed abscesses in the lungs or thoracic cavity as well, suggesting that a history of pneumonia preceding paresis may favor the diagnosis of vertebral body abscess.
Meyer EE, Morris PG, Elcock LH, Weil J.Rabies was diagnosed in 2 adult Quarter Horses with hindlimb hyperesthesia and progressive weakness. Microscopic examination of the cord and brain of the first horse revealed nonsuppurative meningomyelitis and ganglioneuritis in the cord extending cranially to the 6th cervical segment. Fluorescent antibody test results of both horses were positive for rabies in hindlimb peripheral nerve specimens, but negative in sections of the upper lip. Salivary gland, cerebrum, cerebellum, hippocampus, musculocutaneous nerve, cornea, and optic nerve specimens were tested for rabies by fluorescent antibody ...
Donahue JM.Eighty-seven of 283 isolates of salmonellae recovered from horses in Kentucky by the Livestock Disease Diagnostic Center from July 1, 1980 through June 30, 1984 were Salmonella agona. No isolations of S agona were made from Jan 1, 1972 through June 30, 1980. Salmonella agona was isolated from horses on 56 farms and most of the isolations were made in the spring. All age classes of horses were involved. Clinical forms of salmonellosis observed were diarrhea, septicemia, infertility, and abortion. Antibiotic susceptibilities were determined for 83 of the 87 isolates, and 79 were resistant to mul...
Tenter AM, Friedhoff KT.The sensitivity and specificity of the complement fixation (CF) test for the diagnosis of Babesia infections in equines was assessed, using the indirect fluorescent antibody (IFA) test as a reference. Antibodies were first detected between 11 and 20 days post infection (dpi) in the CF test and between 7 and 14 dpi in the IFA test in ponies infected experimentally with B. equi (USDA strain). The CF test became negative in four of five ponies 63-174 dpi although B. equi was demonstrated microscopically in two of these four ponies up to 364 and 455 dpi. The IFA test remained positive up to 476 dp...
Bannai H, Kambayashi Y, Tsujimura K, Nagashima T, Takebe N, Tominari M, Nemoto M, Ohta M.The antibody response in horses inoculated with 2 doses of a live equine herpesvirus type 1 vaccine with different vaccination intervals (1 to 3 months) was evaluated with regard to the persistence of virus-neutralizing (VN) antibodies. The durations for which the geometric mean VN titers were maintained significantly higher than those before the first vaccination (P<0.05) were up to 5 months in horses that received the vaccination with a 1-month interval (n=17) and 7 months for those that received it with a 2-month (n=17) or 3-month interval (n=14 or 17). The vaccination program with the 2...
van de Moer A, Rice M, Wilks CR.A type-specific monoclonal antibody was produced by immunizing mice with purified equid herpesvirus-1 (EHV-1). The EHV-1 specific mAb reacted with all the EHV-1 strains tested so far by indirect ELISA, immunofluorescence, and immunoperoxidase tests. No reactions were detected with the EHV-4, EHV-2, or EHV-3 strains tested. The indirect immunofluorescence and immunoperoxidase tests showed that the nuclei of infected cells were predominantly stained by this mAb. Triton treatment of the virus and immunogold labeling experiments indicated that the nucleocapsid of EHV-1 was the target antigen of th...
Buzzell GR, Tariq S, Traversa D, Schuster R.The infective larva of the spirurid nematode Habronema muscae, a parasite of houseflies, was measured and specimens fixed in Karnovsky's fluid were examined by scanning electron microscopy. The oral opening contains six teeth and is surrounded by large bilobed dorsal and ventral lips and smaller lateral lips. A pair of amphids lie behind the lateral lips. There are two rows of four cephalic papillae. The body is deeply ridged, both transversely and longitudinally. The caudal end of the worm is studded by small papillae. The position of the anal opening is somewhat ambiguous. These larval morph...
Minervino AHH, Andersson E, Norlander E, Moreira TR, Gennari SM, Mercado Caruso N, Moraes Filho J, Marcili A, Martins TF, Labruna MB.From a previous large epidemiological survey, we randomly selected 474 serum samples (463 horses and 11 mules) distributed among four municipalities of Pará state, Amazon region, Brazil, and from three types: farm animal, urban carthorse, and sport horse. Samples were tested by indirect fluorescence antibody test (IFAT ≥ 64) for antibodies reactive to spotted fever group (SFG) rickettsiae using Rickettsia rickettsii as crude antigens. From the 474 equids tested, 149 (31.4%) had ticks attached during sampling, belonging mostly to the species Dermacentor nitens. The overall seroprevalence...
Ahearne MM, Pentzke-Lemus LL, Romano AM, Larsen ED, Watson AM, O'Fallon EA, Landolt GA.Equine influenza virus is a common cause of respiratory disease in equids. Few reports describe clinical presentation and disease progression in donkeys. Objective: Describe the clinical and diagnostic findings, outcome, and pathologic lesions associated with influenza pneumonia in donkeys. Methods: Thirteen unvaccinated donkeys ranging from 1 week to 12 years of age and sharing clinical signs and exposure history. Methods: Retrospective case series. Medical records from June to July 2020 at the Colorado State Veterinary Teaching Hospital and collaborating referring veterinary practices wer...
Vignjević G, Vrućina I, Sestak I, Turić N, Bogojević MS, Merdić E.The West Nile Virus (WNV) is a zoonotic arbovirus that has recently been causing outbreaks in many countries in southern and Central Europe. In 2012, for the first time, it caused an outbreak in eastern Croatia with total of 7 human clinical cases. With an aim of assisting public health personnel in order to improve survey protocols and vector control, the high risk areas of the WNV transmission were estimated and mapped. The study area included cities of Osijek and Slavonski Brod and 8 municipalities in Vukovarsko-Srijemska County. Risk estimation was based on seroprevalence of WNV infections...
Epstein K, Cohen N, Boothe D, Nieuwoudt C, Chandler J.In many cases of equine infectious disease, long-term administration of antimicrobial drugs is required. Oral agents are preferred because of the relative ease of administration compared with other routes. Enrofloxacin has been shown to be effective against a variety of equine pathogens, but oral administration of this drug has proved difficult in horses. An oral gel formulation made from the injectable cattle product produces blood levels sufficient to resolve infections caused by a variety of common equine pathogens.
Diesing L, Steuber S, Ahmed JS.Using luminol-dependent chemiluminescence (LCL), the specificity of antibodies to variable antigen type (VAT)-populations of Trypanosoma evansi was studied in four infected ponies. Trypanosomes of each wave of parasitemia were isolated and multiplied in irradiated mice. Their opsonization by serum collected during the infection was investigated with LCL and results for isolated VAT-populations are shown in the paper. Antibodies specific to each VAT-population were first found three days after the maximum of a parasitemic wave. There was no cross reactivity between different VAT-populations. LC...
Klug E, Sieme H, Peters E.Equine artificial insemination (AI) meanwhile has been widely established in the warm blood horse industry. Because of its importance consistent hygienic aspects and their significance for the use of stallions as semen donors in AI-programs are presented and clarified. Incidence as well as importance of equine venereal infectious diseases are considered. Data of physiological bacterial genital flora and treatment principles of therapeutic control of venereal infectious bacterial agents as well as a model of control of Equine Viral Arteritis are given. A prophylactic hygiene program for donor s...
Chaiyabutr N, Wattanaphansak S, Tantilerdcharoen R, Akesowan S, Ouisuwan S, Naraporn D.African horse sickness (AHS) is a non-contagious, high mortality, and insect-borne disease caused by a double-stranded RNA virus from the genus Orbivirus. The study aimed to develop inactivated vaccines serotype 1 inactivated AHS vaccine (IAV) and to compare the effect of IAV on antibody responses in young naïve horses and adult horses pre-immunized with live-attenuated AHS virus (AHSV) serotypes 1, 3, and 4 live-attenuated vaccine (LAV). Unassigned: A total of 27 horses were vaccinated in two trials. Twelve AHS naïve young horses and 15 adult horses were divided into three groups of 4 and 5...
Cazeau G, Leblond A, Sala C, Froustey M, Beck C, Lecollinet S, Tapprest J.Few studies about the use of quantitative equine mortality data for monitoring purposes are available. Our study evaluated the utility of monitoring emerging equine diseases using mortality data collected by rendering plants. We used approaches involving modelling of historical mortality fluctuations and detection algorithm methods to analyse changes in equine mortality in connection with the West Nile Virus (WNV) outbreak that occurred between July and September 2015 along the Mediterranean coast of France. Two weeks after the first equine WNV case was detected by clinical surveillance, detec...
De Clercq D, van Loon G, Nollet H, Delesalle C, Lefère L, Deprez P.Between 1999 and 2001, seven horses with fever, dysphagia and a history of chronic upper respiratory tract infection lasting between three weeks and three months were examined. They had been treated unsuccessfully with a variety of antibiotics for three to four weeks. A deep abscess in a retropharyngeal lymph node was diagnosed in each case by clinical examination, endoscopy and echographic examination of the retropharyngeal region. The infected retropharyngeal lymph node of each horse was punctured with a spinal needle under ultrasound guidance. Pus was aspirated from four of the horses, and ...
Kawamura Y, Fujimoto Y, Kutsuna R, Tomida J, Yamamoto KI, Miyoshi-Akiyama T, Okuno M, Ogura Y, Matsuoka M, Kawaguchi T, Tsutsuki H, Sawa T.A Gram-stain-negative, spiral bacterium (PAGU 1991T) was isolated from the blood of a patient with diffuse large B-cell lymphoma. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate was very closely related to Helicobacter equorum LMG 23362T (99.1 % similarity), originally isolated from a faecal sample from a healthy horse. PAGU 1991T was also very closely related to PAGU 1750 in our strain library (=CCUG 41437) with 99.7 % similarity. Additional phylogenetic analyses based on the 23S rRNA gene sequence and GyrA amino acid sequence further supported the close rel...
Bridges CG, Ledger N, Edington N.Ponies, without evidence of previous exposure to Equine herpes virus-1 (EHV-1), were experimentally infected with EHV-1 subtype 2 and investigated for lymphocyte transformation to virus-infected cell polypeptides, as shown by separation with gel electrophoresis. Animals made significant responses to Western blot fractions that corresponded to molecular weights of approximately 30,000, 40,000-45,000, 60,000-65,000, 80,000-95,000 and 100,000-140,000 MW. These molecular weight ranges correlated with the positions of major EHV-1 subtype 2 glycoproteins that were found at migration distances approx...
Lee SK, Choi J, Yoon J, Jung J, Park JY, Park J, Kim Y, Park JY, Park D.Equine adenovirus 1 (EAdV-1) can cause upper respiratory disease in horses and has been reported worldwide. In this study, and for the first time in Korea, the prevalence of EAdV-1 in equine nasal swabs was investigated using a PCR to identify potential risk factors and examine the genetic diversity of its DNA sequences by a comparison with foreign strains. Nasal swabs collected from 359 horses reared at Korea Racing Authority facilities were tested using an EAdV-1 hexon-specific PCR and the associations between EAdV-1 infection and sex, age, region, breed, and activity were analyzed. Five sam...
Fu ZF, Denby L, Lien DH, Robinson AJ.An indirect enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies against equine herpesvirus type 2 (EHV-2) in equine sera. The optimal conditions of antigen concentration, and serum and conjugate dilutions were established by chequerboard titrations. When the standard ELISA test was used for titration of test sera, it was found to give titres approximately 1500 times higher than those obtained in the virus neutralization (VN) test, and a correlation coefficient of 0.815 was obtained between these two tests on 42 equine sera. All the positive serum samples by ...
Hubbert WR.1. Better results in the production of diphtheria antitoxin can be obtained with greater experience in the selection of the most suitable type of horses to be used. Young animals are usually to be preferred. Over one-half of all such horses can be made to yield 300-unit serum, while a third will yield (5)oo-unit serum. 2. High-test horses require a shorter time to immunize and will yield a potent serum for a longer period than will low-test horses. 3. The period of usefulness of an antitoxin horse is short, and on an average endures only a few months. 4. A horse having attained a maximal antit...
Stros K, Krivanec K, Komárek J, Malinský B.There is a description of equine dermatophytosis enzootic, caused by the microscopic fungus Trichophyton equinum. The disease affected 32 horses, mostly young, all in the same herd (74.4%). The diseased horses were successfully treated with the preparation Fenoform forte, applied superficially at the concentration of 0.5% of the active substance. The authors made an attempt to determine the criteria for clinical differentiation of fully developed trichophytosis and microsporosis of horses. Trichophytosis (T. equinum) is characterized as typical numerous small and round patches, covered by smal...
Kendrick JW, Stevenson W.A band of 23 pregnant mares on a Thoroughbred breeding farm all had serum virus-neutralizing antibody titres to equine herpesvirus 1 (EHV-1). Antibody was not transferred to their foals in utero. All foals received antibody from colostrum and developed antibody titres similar to their dams. The serum virus-neutralizing antibody titres were observed in 10 of these foals for 1 year. Decay of passive immunity occurred at the rate of 3.25 two-fold dilutions in 100 days and reached zero at the mean time of 180 days. The foals were exposed to EHV-1 twice. Foals with a geometric mean titre of 1 : 25 ...
Bartak M, Chodkowski M, Słońska A, Bańbura MW, Cymerys J.In the present study, the influence of the infection with equine herpesvirus type 1 (non-neuro-pathogenic and neuropathogenic strains of EHV-1) on the morphology and distribution of mitochondrial network in equine dermal cell line was investigated. Our results indicate that EHV-1-infection caused changes in the mitochondrial morphology manifested mostly by fission and reactive oxygen species generation.
Pang H, Kong XG, Sentsui H, Kono Y, Sugiura T, Hasegawa A, Akashi H.Six strains of equine infectious anemia virus (EIAV) were recovered from febrile and non-febrile stages of a horse experimentally infected with the P337-V70 strain given once to a horse. The env gp90 genes of the isolates, the P337-V70 and P337-V26, avirulent virus derived from the P337-V70 strain, were sequenced. A comparison of the gp90 gene sequences revealed that amino acid variations among the viruses tested showed as high as 8.2 to 11.5%. In addition, the comparison also indicated that the isolates that recovered from the non-febrile stage were contained in nucleotide insertions in the p...
Abdel-Gaber R, Al Quraishy S, Dkhil MA, Alghamdi J, Al-Shaebi E.Sarcocystosis is a parasitic disease caused by an intracellular protozoan parasite Sarcocystis belonging to the phylum Apicomplexa. These parasites have a requisite two-host life cycle. Recently, there are many Sarcocystis species that identified morphologically. In the present study, diaphragmatic muscle samples from the domestic horse (Equus caballus) were examined for Sarcocystis infection. The natural infection with sarcocysts was recorded to be 62·5% for only microcysts in the infected muscles. Molecular analysis using the 18S rRNA gene was conducted to swiftly and accurately identify th...
de Arruda Coutinho LC, de Jesus AL, de Paiva Fontes KF, Coimbra EC, Mariz FC, de Freitas AC, de Cássia Carvalho Maia R, de Castro RS.Equine Infectious Anemia (EIA) is a persistent lentivirus infection of horses which causes a chronic clinical condition with worldwide importance in veterinary medicine. The p26 protein is usually prepared for use as an antigen in serological tests for EIA diagnosis since it is a well-conserved gene sequence and very immunogenic. In view of the ability of yeast to make post-translational modifications of proteins, this study was carried out to allow Pichia pastoris to be used for the expression of a synthetic codon-optimized EIAV p26 gene. The gene was cloned into pPICZαA vector after appropr...
Wang J, Wen S, Zhao R, Qi J, Liu Z, Li W, An J, Wood C, Wang Y.The conjugation of small ubiquitin-like modifier (SUMO) to the target protein, namely, SUMOylation, is involved in the regulation of many important biological events including host-pathogen interaction. Some viruses have evolved to exploit the host SUMOylation machinery to modify their own protein. Retroviral Gag protein plays critical roles in the viral life cycle. The HIV-1 p6 and the Moloney murine leukemia virus CA have been reported to be conjugated with SUMO. In this study, we report for the first time, to our knowledge, the covalent conjugation of equine infectious anemia virus (EIAV) G...
Kranenburg LC, van Ree HE, Calis AN, de Pater M, Buter GJ, van Maanen C, Sloet van Oldruitenborgh-Oosterbaarn MM.Equine proliferative enteropathy caused by Lawsonia intracellularis is an emerging disease of weanling foals and affects their growth and development. The prevalence of Lawsonia intracellularis in The Netherlands is not known. The aim of the study was to investigate the seroprevalence of Lawsonia intracellularis in horses in The Netherlands. Blood samples were taken from healthy foals before and after weaning and from healthy yearlings and mature horses on farms throughout The Netherlands. These samples were analysed for the presence of Lawsonia intracellularis-specific antibodies with a block...
Salama SA, Dardiri AH, Awad FI, Soliman AM, Amin MM.African horsesickness virus was isolated from blood samples of street dogs in Aswan Province in Arab Republic of Egypt. Of six isolated "dog strain" African horsesickness viruses, three viruses designated D2, D6 and D10 have been identified as type 9 African horsesickness virus. Methods of isolation, tissue culture adaptation, serological indentification and typing are described. Horses experimentally infected with dog viruses showed febrile reaction and characteristic clinical and pathological signs of African horsesickness. Reisolation of African horsesickness virus type 9 was achieved from ...
Wilson WD, Baggot JD, Adamson PJ, Hirsh DC, Hietala SK.Sodium cefadroxil was administered as a single intravenous dose (25 mg/kg) to six healthy adult mares. Plasma samples were collected over a 24-h period and cefadroxil concentrations were measured by microbiological assay. The pharmacokinetic behavior of the drug was appropriately described in terms of a one-compartment open model. Values for the major pharmacokinetic terms were: extrapolated initial plasma concentration = 59.2 +/- 15.0 micrograms/ml; half-life = 46 +/- 20 min; apparent volume of distribution = 462 +/- 191 ml/kg; and body clearance = 7.0 +/- 0.6 ml/min.kg. In a subsequent study...
Rozario C, Martínez-Sobrido L, McSorley HJ, Chauché C.Influenza A viruses (IAVs) are important respiratory pathogens of horses and humans. Infected individuals develop typical respiratory disorders associated with the death of airway epithelial cells (AECs) in infected areas. Virulence and risk of secondary bacterial infections vary among IAV strains. The IAV non-structural proteins, NS1, PB1-F2, and PA-X are important virulence factors controlling AEC death and host immune responses to viral and bacterial infection. Polymorphism in these proteins impacts their function. Evidence from human and mouse studies indicates that upon IAV infection, the...
Tahoun A, Elnafarawy HK, Elmahallawy EK, Abdelhady A, Rizk AM, El-Sharkawy H, Youssef MA, El-Khodery S, Ibrahim HMM.Diagnosis and treatment of ocular fungal infection in equine seems very challenging for owners and clinicians. The present study aimed to identify and characterize fungal species isolated from the eyes of clinically healthy and diseased equines (N = 100) from Dakahlia Governorate, Egypt. The work also involved morphological and molecular characterization of the major fungal species. In addition, correlations between the occurrence of isolated fungi and some of the potential risk factors were also investigated. Interestingly, the prevalence rate of ocular mycosis in all examined equines in the ...
Santos AC, Nogueira CEW, Dos Santos Suñe Moraes B, Müller V, Mousquer MA, Leite FPL.Equine theileriosis, caused by the Theileria equi protozoan, is a disease of worldwide importance. T. equi expresses surface proteins, of which the EMA-2 protein is a promising antigen for vaccine use. The aim of this study was to evaluate the immune response of adult horses, pregnant mares, and foals to an experimental EMA-2 protein of recombinant T. equi vaccine. A total of 46 horses were used in this study for vaccine trials and challenges. Twelve geldings, 14 pregnant mares, and 14 foals were divided into vaccinated and control groups. Total serum specific anti-rEMA-2 IgG, IgG subclasses, ...
