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.
Hartley CA, Wilks CR, Studdert MJ, Gilkerson JR.To compare methods of detecting equine herpesvirus type 1 (EHV1)- and EHV4-specific antibodies in horse sera. Methods: 33 acute and convalescent serum samples from experimentally or naturally infected horses after confirmed EHV1 or EHV4 infection. Methods: For each sample, serum antibody titers against EHV1 and EHV4 were determined by use of virus neutralization (VN) and complement fixation (CF) assays. The ELISA absorbance values for each serum sample were determined against the EHV1 and EHV4 recombinant ELISA antigens. Values obtained for acute and convalescent sera in each assay were compar...
Rossano MG, Schott HC, Kaneene JB, Murphy AJ, Kruttlin EA, Hines MT, Sellon DC, Patterson JS, Elsheikha HM, Dubey JP, Mansfield LS.To determine whether daily administration of pyrantel tartrate can prevent infection in horses experimentally challenged with Sarcocystis neurona. Methods: 24 mixed-breed specific-pathogen-free weanling horses, 10 adult horses, 1 opossum, and 6 mice. Methods: Sarcocystis neurona-naïve weanling horses were randomly allocated to 2 groups. Group A received pyrantel tartrate at the labeled dose, and group B received a nonmedicated pellet. Both groups were orally inoculated with 100 sporocysts/d for 28 days, 500 sporocysts/d for 28 days, and 1000 sporocysts/d for 56 days. Blood samples were collec...
Mencke N, Larsen KS, Eydal M, Sigurethsson H.Lice infestations in horses caused by the chewing louse Werneckiella (Damalinia) equi are observed worldwide. In the present study, the efficacy of 10% imidacloprid was tested on horses naturally infested with lice. Two groups of animals received a double application of 4 ml and 8 ml Advantage 10% spot-on on day 0 and 28 either. Horses, presenting dermatological signs with negative lice counts, were also included in this investigation. 40.86% of the horses presented positive lice counts and 84.21% of these animals showed clinical dermatologic signs. 65.45% of the lice-negative horses also show...
Ward MP, Couëtil LL.To estimate the association between climate and airborne pollen and fungal factors and chronic obstructive pulmonary disease (COPD) in horses. Methods: Data from 1,444 horses with a diagnosis of COPD. Methods: The Veterinary Medical Database was used to identify records of horses admitted to veterinary teaching hospitals in the United States and Canada between 1990 and 1999. Rainfall, mean minimum and maximum temperature, and maximum monthly pollen and fungal spore (mold) counts recorded at the city closest to where the hospital is located were identified for each month data were reported to t...
Szeredi L, Hornyák A, Pálfi V, Molnár T, Glávits R, Dénes B.The occurrence of equine arteritis virus (EAV) induced equine abortions was studied with different laboratory methods during a 3-year period. Tissue samples from 96 aborted equine foetuses or newborn foals were collected from 57 farms located in different parts of Hungary. Virus isolation, polymerase chain reaction (PCR), immunohistochemistry and serology were used for the detection of EAV infection. The overall seroprevalence of EAV infection in mares was 65%. EAV induced abortion was diagnosed in eight (8.3%) cases from six (10.5%) herds. Abortion was sporadic in all herds except for one, wh...
Paillot R, Daly JM, Juillard V, Minke JM, Hannant D, Kydd JH.Equine cytotoxic T lymphocyte (CTL) responses to equine herpesvirus-1 (EHV-1) are well characterised but little is known about the cytokine response after infection or vaccination. EHV-1 is common in horses and infects lymphocytes in vivo. This virus was used as a model to measure the synthesis of interferon gamma (IFN-gamma) by equine peripheral blood mononuclear cells (PBMC) after in vivo infection and/or in vitro stimulation with EHV-1. Both flow cytometry and ELISPOT assays were used to quantify equine IFN-gamma using a mouse anti-bovine IFN-gamma monoclonal antibody (clone CC302; shown to...
Kaps S, Richter M, Philipp M, Bart M, Eule C, Spiess BM.A 12-year-old Haflinger gelding was presented to the veterinary medical teaching hospital of the University of Zurich with a light-pink raised mass on the temporal limbus and conjunctiva of the left eye. Squamous cell carcinoma was confirmed histologically after keratectomy and cryotherapy. Seven months later, a smooth pink, progressively enlarging mass was observed within the cornea of the left eye. Ultrasonographically, the mass was not only infiltrating the corneal stroma but seemed to protrude into the anterior chamber. The globe was surgically removed and submitted for pathology. A histol...
Meana A, Pato NF, Martín R, Mateos A, Pérez-García J, Luzón M.An epidemiological study on equine cestodosis was carried out in central Spain. A total of 372 digestive tracts from equids slaughtered in abattoirs located in central Spain were studied from November 2001 to May 2004. Anoplocephala perfoliata was detected in 24% of the animals and Anoplocephala magna in 18%. Individual tapeworm burden was from 1 to 491 tapeworms for A. perfoliata and from 1 to 64 tapeworms for A. magna. Low tapeworm burdens (less than 30 cestodes) predominated significantly (p<0.01) in all seasons for both species. Seasonal prevalence of infection by A. perfoliata was signifi...
Zdovc I, Ocepek M, Gruntar I, Pate M, Klobucar I, Krt B.The prevalence of Taylorella equigenitalis infection in Slovenia is unknown and methods used to refine identification in these stallions are required. Objective: In diagnosis of T. equigenitalis, polymerase chain reaction (PCR) would have advantages over culture methods, especially in cases where small numbers of causal agent or intensive contamination of genital swabs are involved. Methods: Culture method and PCR were used to examine a total of 980 genital swabs from the urethra and fossa urethralis of 245 stallions for the presence of the contagious equine metritis organism. Results: Among 2...
Wood JL, Newton JR, Chanter N, Mumford JA.Respiratory disease is important in young Thoroughbred racehorses, but the variation in the rates of occurrence between different ages and training groups has not been characterised. Objective: To determine the rates of respiratory disease, particularly inflammatory airway disease (IAD), as well as evidence of infection, and their variation between age and group. Methods: Horses were examined monthly in 7 British flat training yards over a 3 year period. IAD was defined as increased mucus in the trachea with increased proportions of neutrophils in tracheal wash samples. Frequencies of disease ...
Keller RL, Hendrix DV.Bacterial ulcerative keratitis is a common and often vision-threatening problem in horses. Emerging bacterial resistance to commonly used topical antibiotics has been demonstrated. Previous antibiotic use may alter the antimicrobial susceptibility of bacterial isolates. Objective: To document aerobic bacterial isolates and associated bacterial susceptibilities from horses with ulcerative keratitis treated at the University of Tennessee between January 1993 and May 2004 and determine whether prior antibiotic therapy affected antimicrobial susceptibility of the isolates. Methods: Medical records...
Raymond SL, Smith TK, Swamy HV.An experiment was conducted to determine the effect of feeding blends of grains naturally contaminated with Fusarium mycotoxins to mature, exercised horses, and to test the efficacy of a polymeric glucomannan mycotoxin adsorbent (GM polymer) in preventing Fusarium mycotoxicoses. Six mature, mixed-breed mares with an average BW of 530 kg were assigned to one of three dietary treatments for 21 d in a replicated 3 x 3 Latin square design. Feed consumed each day was a combination of up to 3.5 kg of concentrates and 5.0 kg of mixed timothy/alfalfa hay (as-fed basis). The concentrates fed included 1...
Cook RF, Cook SJ, Bolin PS, Howe LJ, Zhou W, Montelaro RC, Issel CJ.In the context of DNA vaccines the native equine infectious anemia virus (EIAV)-envelope gene has proven to be an extremely weak immunogen in horses probably because the RNA transcripts are poorly expressed owing to an unusual codon-usage bias, the possession of multiple RNA splice sites and potential adenosine-rich RNA instability elements. To overcome these problems a synthetic version of sequences encoding the EIAV surface unit (SU) envelope glycoprotein was produced (SYNSU) in which the codon-usage bias was modified to conform to that of highly expressed horse and human genes. In transfect...
Spencer JA, Deinnocentes P, Moyana EM, Guarino AJ, Ellison SE, Bird RC, Blagburn BL.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome seen in horses from the Americas and is mainly caused by Sarcocystis neurona. Recently, a 29-kDa surface antigen from S. neurona merozoites was identified as being highly immunodominant on a Western blot. This antigen has been sequenced and cloned, and the expressed protein has been named SnSAG1. In a previous study, cell-mediated immune responses to SnSAG1 were shown to be statistically significantly reduced in horses with EPM in comparison to EPM-negative control horses. It therefore appears as though the parasite is able to i...
Morgan ER, Hetzel N, Povah C, Coles GC.Parasites were extracted from the stomach and small intestine of 118 horses at slaughter. The most abundant species was the tapeworm Anoplocephala perfoliata. Maximum likelihood analysis was used to investigate the relationship between the number of worms and their total weight, and the ability of an antibody-based elisa to diagnose the level of infection. The total weight of tapeworms increased towards a maximum as the number of worms increased, suggesting a population density-dependent constraint on the weight. The number of A perfoliata present could be predicted approximately from the resu...
Chang YF, Ku YW, Chang CF, Chang CD, McDonough SP, Divers T, Pough M, Torres A.The objective of this study is to determine whether doxycycline, ceftiofur or tetracycline could be effectively used to treat equine Lyme disease. Ponies experimentally infected with Borrelia burgdorferi by tick exposure were treated with doxycycline, ceftiofur or tetracycline for 4 weeks (28 days). Doxycyline and ceftiofur treatment were inconsistent in eliminating persistent infection in this experimental model. However, tetracycline treatment seems to eliminate persistent infection. Although serum antibody levels to B. burgdorferi in all ponies declined gradually after antibiotic treatment,...
Ludwig A, Gatineau S, Reynaud MC, Cadoré JL, Bourdoiseau G.This aetiological study of guttural pouch mycosis (GPM) in the horse was based on the retrospective study of 21 horses brought into the National Veterinary School of Lyon (France) between 1998 and 2002. Biopsies were taken from the lesions caused by GPM during endoscopic examination. In 87% of the cases, direct examination gave positive results, whereas 43% of the cultures were found to be negative. The main fungi observed were Aspergillus fumigatus (in three cases), A. versicolor (in two cases, together with other fungi), and A. nidulans and A. niger (one case each). In six cases, the Aspergi...
Rivera JA, McGuire TC.To determine if equine monocyte-derived dendritic cells (DC) were susceptible to equine infectious anemia virus (EIAV) infection, ex vivo-generated DC were infected with virus in vitro. EIAV antigen was detected by immunofluorescence 3 days post-infection with maximum antigen being detected on day 4, whereas there was no antigen detected in DC incubated with the same amount of heat-inactivated EIAV. No cytolytic activity was observed after EIAV(WSU5) infection of DC. These monocyte-derived DC were more effective than macrophages and B cells in stimulating allogenic T lymphocytes. Both infected...
Thirion-Delalande C, Guillot J, Jensen HE, Crespeau FL, Bernex F.A 6-year-old female pony died after 2 days of prostration. Clinical signs included hyperthermia and abnormal pulmonary auscultation sounds. Necropsy revealed diffuse severe necrohaemorrhagic colitis and splenitis, multiple visceral ecchymoses, petechial haemorrhages in the brain and lungs. Microscopical examination showed acute necrohaemorrhagic colitis, encephalitis, pneumonia and splenitis associated with fibrinoid vasculitis, thrombosis and fungal hyphae within and around vessels. Immunohistologically, concomitant aspergillosis (caused by Aspergillus fumigatus) and mucormycosis (causde by A...
Traversa D, Otranto D, Iorio R, Giangaspero A.Equine thelaziosis caused by the eyeworm Thelazia lacrymalis is a parasitic disease transmitted by muscid flies. Although equine thelaziosis is known to have worldwide distribution, information on the epidemiology and presence of the intermediate hosts of T. lacrymalis is lacking. In the present work, a PCR-RFLP based assay on the first and/or second internal transcribed spacer (ITS1 and ITS2) of ribosomal DNA was developed for the detection of T. lacrymalis DNA in its putative vector(s). The sensitivity of the technique was also assessed. The restriction patterns obtained readily differentiat...
Mukaratirwa S, Munjere IF, Takawira M, Chingwena G.Gastrodiscosis outbreaks due to Gastrodiscus aegyptiacus were recorded in horses in the vicinity of Harare, Zimbabwe, in the absence of Bulinus forskalii, B. senegalensis and Cleopatra sp. which are considered to be the only intermediate host snails. This suggested the possibility of other snail species acting as intermediate hosts in the life cycle of the trematode. A study was carried out to determine the susceptibility of 7 freshwater snail species to infection with G. aegyptiacus. First generation (F-1) of 5 freshwater pulmonate snail species, Bulinus tropicus, Bulinus globosus, Biomphalar...
Shibahara T, Kuwano A, Ueno T, Katayama Y, Ohya T, Taharaguchi S, Yamamoto S, Umemura T, Ishikawa Y, Kadota K.Studies of equine intestinal spirochetes have long focused on intestinal contents alone, but intestinal spirochetosis has been reported recently in a 21-month-old Thoroughbred colt in Japan. To define the clinical and pathological significances of intestinal spirochetosis in several horses, an epizootiologic survey with histologic, immunohistochemical, and ultrastructural methods was conducted for Brachyspira antigen-containing intestinal spirochetes in 12 diseased or injured Thoroughbred horses, aged from 35 days to 17 years. Brachyspira antigen-containing spirochetes were found in 7 of 12 ho...
Ward MP, Alinovi CA, Couëtil LL, Wu CC.The diagnostic accuracy of a PCR used to identify horses shedding Salmonella spp. in their feces during hospitalization was estimated, relative to bacterial culture of serially collected fecal samples, using longitudinal data. Five or more fecal samples were collected from each of 116 horses admitted as inpatients, for reasons other than gastrointestinal disease, between July 26, 2001 and October 25, 2002. All 873 fecal samples collected were tested with a PCR based on oligonucleotide primers defining a highly conserved segment of the histidine transport operon gene of Salmonella typhimurium, ...
Trapp S, von Einem J, Hofmann H, Köstler J, Wild J, Wagner R, Beer M, Osterrieder N.Key problems using viral vectors for vaccination and gene therapy are antivector immunity, low transduction efficiencies, acute toxicity, and limited capacity to package foreign genetic information. It could be demonstrated that animal and human cells were efficiently transduced with equine herpesvirus 1 (EHV-1) reconstituted from viral DNA maintained and manipulated in Escherichia coli. Between 13 and 23% of primary human CD3+, CD4+, CD8+, CD11b+, and CD19+ cells and more than 70% of CD4+ MT4 cells or various human tumor cell lines (MeWo, Huh7, HeLa, 293T, or H1299) could be transduced with o...
Franzén P, Aspan A, Egenvall A, Gunnarsson A, Aberg L, Pringle J.Six horses were experimentally infected by administration of horse blood containing a Swedish strain of Anaplasma phagocytophilum. The polymerase chain reaction (PCR) signal was consistently detected 2-3 days before appearance of clinical signs and persisted 4-9 days beyond abatement of clinical signs, whereas diagnostic inclusion bodies were 1st noted on average 2.6 +/- 1.5 (SD) days after onset of fever. Clinical signs and hematologic changes were largely indistinguishable from those previously reported for diseases caused by A phagocytophilum (formerly Ehrlichia equi--"Californian agent") a...
Alhassan A, Pumidonming W, Okamura M, Hirata H, Battsetseg B, Fujisaki K, Yokoyama N, Igarashi I.With the aim of developing more simple diagnostic alternatives, a differential single-round and multiplex polymerase chain reaction (PCR) method was designed for the simultaneous detection of Babesia caballi and Babesia equi, by targeting 18S ribosomal RNA genes. The multiplex PCR amplified DNA fragments of 540 and 392 bp from B. caballi and B. equi, respectively, in one reaction. The PCR method evaluated on 39 blood samples collected from domestic horses in Mongolia yielded similar results to those obtained from confirmative PCR methods that had been established earlier. Thus, the single-roun...
Kyvsgaard NC, Lindbom J, Andreasen LL, Luna-Olivares LA, Nielsen MK, Monrad J.Horses, mules and donkeys are indispensable farming and working animals in many developing countries, and their health status is important to the farmers. Strongyle parasites are ubiquitous in grazing horses world-wide and are known to constitute a threat to equine health. This study determined the prevalence of strongyle infection, the efficacy of ivermectin and fenbendazole treatment, and strongyle re-infection rates of working horses during the dry months in Nicaragua. One hundred and five horses used by farmers for transport of people and goods were randomly allocated into three treatment ...
McChesney SL, England JJ, McChesney AE.An agent lethal to embryonated chicken eggs was isolated from lung tissues of a quarter horse mare with a fatal respiratory disease. The lesions induced in embryonated chicken eggs, the tinctoral properties, the ultrastructural morphology, the resistance of the organism to sodium sulfadiazine, and the presence of a chlamydial complement fixing antigen, identify this isolate as a member of the family Chlamydiaceae and suggest the agent to be Chlamydia psittaci. Two Shetland ponies experimentally infected with the isolated agent developed subclinical infection as demonstrated by an increase in c...
Sudan V, Jaiswal AK, Shanker D, Verma AK.Rotat 1.2 variant surface glycoprotein (VSG) is considered to be an important VSG expressed in most of the isolates of Trypanosoma evansi. This makes the molecule an important candidate for both molecular- and serological-based detection of surra. There are ample reports of existence of this gene in isolates from cattle, buffalo, and camel across the world. Of late, there are reports of its absence from a fewer isolates of T. evansi of murine and wildlife origin. Search of literature revealed no reports from horses. The present communication presents the first report of molecular cloning and c...
Gunnarsdottir H, Van der Stede Y, De Vlamynck C, Muurling F, De Clercq D, van Loon G, Vlaminck L.The aim of the study was to determine if horses with large colon impaction were more severely affected by oral pathology than control cases and to relate faecal particle size distribution to dental pathology in both study groups. A prospective study included 39 horses with large colon impaction and 72 control horses from a hospital-based population. An oral pathology score (OPscore) and periodontal disease index (PDI) were assigned to all horses and faecal samples were collected for estimating faecal particle size and analysis of particle size distribution. Horses with large colon impactions w...
Takai S, Yoda A, Sasaki Y, Kakuda T, Suzuki Y, Oikawa M.Tracheal washing fluid was collected from 170 foals at 28 and 35 d old from February to July in a foaling season on horse-breeding farms with sporadic rhodococcosis in Japan and was investigated by quantitative culture. The history of the 170 foals followed up for the next few months. The proportion of R. equi-positive foals at 28 and 35 d old was significantly increased according to the birth month. Furthermore, the mean number of R. equi in the tracheal washing fluid of each month group increased according to their birth month with the rise in outside temperature. During the follow-up observ...
Walter J, Seeh C, Fey K, Bleul U, Osterrieder N.Equine herpesvirus myeloencephalopathy (EHM) is a severe manifestation of equine herpesvirus 1 (EHV-1) infection. Prevention and treatment of EHM during EHV-1 outbreaks is critical, but no reliable and tested specific medication is available. Due to the thromboischemic nature of EHM and due to the fact that EHV-1 entry in cells is blocked by heparin, it was hypothesized that this compound may be useful in reduction of EHM incidence and severity. Therefore, during an acute EHV-1 outbreak with the neuropathogenic G/D Pol variant, metaphylactic treatment with heparin to prevent EHM was initiated....
Valberg SJ, McKinnon AO.Five horses with fatal clostridial cellulitis are described. The characteristic findings were the rapid development of a crepitant swelling with an associated toxemia, which in four cases followed intramuscular injections. The clinical features, diagnostic techniques and pathogenesis are discussed. The importance of an early diagnosis is emphasized.
Ensink JM, Bosch G, van Duijkeren E.Tissue chambers, implanted subcutaneously in the neck in six ponies, were inoculated with Streptococcus equi subsp. zooepidemicus in order to determine the clinical efficacy of prophylactic administration of trimethoprim/sulfadiazine (TMP/SDZ) against this infection. The TMP/SDZ treatment consisted of one intravenous (i.v.) injection of 5 mg/kg TMP and 25 mg/kg SDZ and the same dose of TMP/SDZ per os (p.o.), both given 3 h before inoculation. The oral dose was then repeated every 12 h for 5 days. TMP/SDZ concentrations in tissue chamber fluid (TCF) were above 10 times MIC at the moment of inoc...
Mealey RH, Kappmeyer LS, Ueti MW, Wagner B, Knowles DP.Theileria equi immune plasma was infused into young horses (foals) with severe combined immunodeficiency. Although all foals became infected following intravenous challenge with homologous T. equi merozoite stabilate, delayed time to peak parasitemia occurred. Protective effects were associated with a predominance of passively transferred merozoite-specific IgG3.
McQueary CA, Worley DE, Catlin JE.Of 22 foals from 4 localities in southwestern Montana, 59% were found to be infected with Eimeria leuckarti. Oocysts collected from feces of 4 positive horses were sporulated and subsequently administered to a 5- to 6-month-old foal. The prepatent period was 31 days and the patent period was between 5 and 10 days.
Tu YB, Zhou T, Yuan XF, Qiu HJ, Xue F, Sun CQ, Wang L, Wu DL, Peng JM, Kong XG, Tong GZ.The long terminal repeats (LTRs) of equine infectious anemia virus donkey leukocyte-attenuated virus (EIAV-DLA) were substituted with those of the wild-type EIAV-L (wt EIAV-L, the parent virus of EIAV-DLA). The resulting chimeric plasmid was designated pOK-LTR DLA/L. Purified pOK-LTR DLA/L was transfected into monocyte-derived macrophage (MDM) cultures prepared from EIAV-negative, heparinized whole blood from a donkey. Eighth-passage cell cultures developed the typical cytopathogenic effects (CPE) of EIAV infection, and virions with typical EIAV profiles were observed with an electron microsco...
Coloe PJ, Ireland L, Vaudrey JC.We record a fatal case of gas-oedema disease (malignant oedema) in a 5-year-old horse. The nature of the lesion is consistent with a gas-oedema type infection due to a Clostridium spp. The causative organism was isolated and identified by conventional biochemical tests and by gas-liquid chromatographic analysis of its metabolic products as Clostridium fallax, but significant variations in the reported biochemical characteristics of Cl. fallax were detected. We believe that this is the first reported case of Cl. fallax infection in a horse.
van der Kolk JH, Bernadina WE, Visser IJ.A four year old Dutch warmblooded mare was born and raised in the province of North-Brabant, the Netherlands. On May 16, 1989, she showed signs of colic, anorexia, depression, ileus, severe dehydration and leukopenia. When the mare collapsed, euthanasia was carried out. Acute colitis and cytoplasmic inclusion bodies in macrophages were observed at autopsy. When an indirect immunofluorescence assay was performed, the Ehrlichia risticii titre of the serum was found to be 1:640.
de Linde Henriksen M, Andersen PH, Thomsen PD, Plummer CE, Mangan B, Heegaard S, Toft N, Brooks DE.To study the equine deep stromal abscesses (DSA) with focus on the duration of the corneal disease, medical treatment, season of presentation, clinical appearance, and the degree of corneal vascularization. Methods: Equine DSA diagnosed, biopsied, and surgically treated at the University of Florida Veterinary Medical Center (UFVMC) from 2004 to 2009 were identified. The medical record, clinical photographic images, and microbiology results for each case were evaluated. Frequency and prevalence calculation as well as qualitative data analysis was performed for clinical and microbiological data....
Debarbat F, Mollaret HH, Mailloux M.Bovine leptospirosis is a typical form in the island of Reunion. It appears during the second part of the rain season. The clinical picture of equine leptospirosis is acute hepatonephritis. About 10 serogroups are found in bovines, with greater frequency for Sejroë and Hebdomadis. In horses, the prevailing serogroups are Autumnalis, Ballum, Icterohaemorrhagiae, Australis, Grippotyphosa.
Pellegrini-Masini A, Dolente BA, Habecker PL, Jesty SA.A 5-year-old Quarter Horse mare was referred for evaluation of oral ulcers, limb edema, weight loss, and weakness. There was marked diffuse swelling extending from the stifle region to the tarsal region of the left hind limb, and the horse had a left hind limb lameness. Firm swellings ranging from 2 to 15 cm in diameter and consisting of nodules, plaques, and discrete masses were palpated on both sides of the neck, over the right shoulder region, over the left elbow region, and over the left caudoventral aspect of the abdomen. Laboratory abnormalities included hypoproteinemia, neutrophilia, an...
Beck A, Baird JD, Slavić D.This is the first report of the isolation of Actinomyces denticolens, an opportunistic pathogen, from a draining submandibular lymph node abscess in a horse in Ontario. Due to the similarity of the clinical signs with strangles, this pathogen should be included in the differential diagnosis of submandibular lymphadenopathy in the horse. Il s’agit du premier rapport d’isolement d’ un agent pathogène opportuniste, lors du drainage d’un abcès d’un ganglion lymphatique sous-maxillaire chez un cheval en Ontario. En raison de la similarité des signes cliniques avec ceux de la gourme, ...
Daniels SP, Proudman CJ.The ovicidal activity of benzimidazole (BZ) anthelmintics is unique and not seen in other drug classes. Such ovicidal efficacy is not widely reported for equine cyathostomins, nor has this activity been tested in the face of BZ resistance. Although the product label states that fenbendazole is for use against BZ-susceptible cyathostomins, susceptibility testing is rarely performed. In this field-based study, the ovicidal efficacy of fenbendazole in horses (n=39) harbouring BZ-resistant cyathostomins was compared when dosed at 7.5mg/kg body weight (BW) orally, as a single dose per os (n=21) or ...
Songsri J, Mala W, Wisessombat S, Siritham K, Cheha S, Noisa N, Wongtawan T, Klangbud WK. O157:H7 is enterohemorrhagic , which produces verocytotoxin or Shiga toxin. It is a well-known cause of severe diseases in humans worldwide. Cattle and other ruminants are the main reservoirs of this organism. Sports animals, such as fighting bulls, riding horses, and fighting cocks, are economic animals in Southern Thailand. This study aimed to identify O157:H7 from the rectal swabs of these sports animals and determine the antimicrobial susceptibility patterns of isolated bacteria. Unassigned: The rectal swabs were collected from 34 fighting bulls, 32 riding horses, and 31 fighting cocks. ...
Yamanaka T, Tsujimura K, Kondo T, Hobo S, Matsumura T.We investigated the efficacy of the oral administration of oseltamivir phosphate (OP) in horses experimentally infected with equine influenza A virus (H3N8). Nine horses were divided into three horses each of control, treatment and prophylaxis groups. An administration protocol for the treatment group (2 mg/kg of body weight, twice a day for five days) was started immediately after the onset of pyrexia (above 38.9 degrees C). An administration protocol for the prophylaxis group (2 mg/kg of body weight, once a day for five days) was started on a day before viral inoculation. In the treatment gr...
Sahu SP, Dardiri AH.Uterine, cervical, and clitoral specimens on swabs from pony mares infected with contagious equine equine metritis (CEM) bacteria were streaked on agar plates. Colonies of CEM bacteria were observed under CO2 incubation in 2 days on Eugon chocolate agar and Eugon blood agar plates. The diameter of the colonies varied from 0.2 mm to 1 mm in 2 days which increased to 0.3 mm to 2.0 mm on day 4. The colonies on Eugon chocolate agar plates on days 2 to 4 were shiny, brown, round, and convex, and easily glided when pushed with a loop. The diameter of the colonies on chocolate and blood agar plates m...
Posnett ES, Ambrosio RE.This report describes DNA probes for the identification of Babesia equi. A genomic library of B. equi was constructed in pUC13. Several clones were identified that hybridized strongly to B. equi DNA. Clone pBE33 hybridized specifically to B. equi DNA and did not hybridize to horse DNA nor to DNA from Babesia caballi, Babesia bovis or Babesia bigemina. Two subclones of pBE33 (pSB20 and pEH21) containing B. equi repetitive sequences, could detect 0.49 ng and 0.97 ng B. equi DNA, respectively.
Zhu C, Li Q, Guo W, Lu G, Yin X, Qi T, Xiang W, Ran D, Qu J.We report the complete genomic sequence of A/equine/Heilongjiang/1/2010, a strain of Florida sublineage clade 2 of H3N8 subtype equine influenza virus (EIV) isolated in northern China. This is the first announcement of a complete genomic sequence of EIV of such a clade in China.
Johnson PJ, Mrad DR, Schwartz AJ, Kellam L.Outcome and complications associated with administration of moxidectin gel to 3 foals < 4 months old are described. Two foals became comatose but survived following supportive treatment. One foal died following loss of consciousness associated with moxidectin administration. Risk of moxidectin overdose exists, because horse owners often fail to read or comprehend the package insert instructions pertaining to use of the syringe-locking mechanism. In addition, moxidectin should not be administered to foals < 4 months old, because it is likely that treated foals will become comatose.
Seahorn TL, Carter GK, Martens JG, Crandell RA, Martin MT, Scrutchfield WL, Cummins JM, Martens RJ.The immunotherapeutic effect of low-dose human alpha interferon on viral shedding and clinical disease was evaluated in horses inoculated with equine herpesvirus-1 (EHV-1). Eighteen clinically healthy weanling horses, 5 to 7 months old, were allotted to 3 equal groups. Two groups were treated orally with human alpha-2a interferon (0.22 or 2.2 U/kg of body weight), on days 2 and 1 before inoculation with EHV-1, the day of inoculation, and again on postinoculation day 1. The horses of the remaining group were given a placebo orally on the same days. The horses were monitored daily for changes in...
Kumanomido T, Kamada M, Wada R, Kenemaru T, Sugiura T, Akiyama Y.Sagiyama virus is a member of the Getah virus group. Its pathogenicity for horses was examined. All the horses infected with the original 4 strains of Sagiyama virus (M6/Mag 33, Mag 121, Mag 132 and Mag 258) developed pyrexia ranging from 39.0 to 40.0 degrees C. Other clinical signs, characterized by eruptions, edema in the hind legs, enlargement of the submandibular lymph node and mild leukopenia, were also manifested. Viremia occurred 1-4 days post-inoculation (p.i.). Virus was recovered from spleen, liver, lung and various lymph nodes of a horse autopsied on Day 4 p.i. The maximum titer of ...
Katila T, Lock TF, Hoffmann WE, Smith AR.A study was conducted to 1) determine differences in the inflammatory response following bacterial challenge between normal mares and mares with chronic endometritis and 2) to determine if enzyme activity in uterine fluid can be used to evaluate degree of inflammation in the equine uterus. Six normal mares (Group 1) and four mares with chronic endometritis (Group 2) received an intrauterine infusion of beta-hemolytic streptococci on the second day of estrus. Neutrophil concentration as well as lysozyme and alkaline phosphatase activity were determined in uterine secretions obtained by placing ...
Klingeborn B, Dinter Z.Antibody to equid herpesvirus 1, which mediates single radial hemolysis, is that responsible for neutralization. Hemagglutination inhibition antibody is not necessarily involved in neutralization or hemolysis.
Shimizu A, Kawano J, Ozaki J, Sasaki N, Kimura S, Kamada M, Anzai S, Saito H, Sato H.Seventy-six Staphylococcus aureus strains isolated from various lesions of horses were characterized. All of the 76 strains were identified as biotypes B (38.2%) and C (61.8%). Of 55 strains tested, 42 (76.4%) were differentiated into 7 coagulase types. Coagulase types V and VII were predominant in the metritis strains. Coagulase type II was found most frequently in the strains from phlegmon, dermatitis, sinusitis, empyema sinus, and nasal catarrh. Forty-two (55.3%) of the 76 strains were differentiated into 24 phage patterns. Twenty (58.8%) of 34 typable strains from metritis were lysed by th...
De Cock HE, Labelle P, Magdesian KG.The clinical, gross morphological, histological and immunohistochemical characteristics of an ameloblastic carcinoma in a 30-year-old Quarter Horse mare are reported. This tumour was fast growing, locally invasive and destructive. Histologically, it showed an infiltrative pattern of large islands, broad sheets and, at the periphery, small cords of moderately pleomorphic round, oval to spindle-shaped cells. Immunohistochemical evaluation revealed positive labelling for vimentin, cytokeratin 5/6 and cytokeratin 14. In the oral cavity of human beings, this immunolabelling pattern is unique for th...
