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.
Breathnach CC, Soboll G, Suresh M, Lunn DP.A commercial bovine IFN-gamma-specific monoclonal antibody was used to measure antigen-specific IFN-gamma production by equine lymphocytes. Paired PBMC samples were collected from six ponies prior to and 10 days after challenge infection with equine herpesvirus-1 (EHV-1). Each sample was stimulated in vitro with EHV-1, virus-free medium, or PMA and ionomycin, and labelled with monoclonal antibodies specific for various equine lymphocyte subset markers. Following fixation, intracellular IFN-gamma was detected using a FITC-conjugated bovine IFN-gamma-specific monoclonal antibody. In vitro restim...
Rossano MG, Schott HC, Murphy AJ, Kaneene JB, Sellon DC, Hines MT, Hochstatter T, Bell JA, Mansfield LS.Equine protozoal myeloencephalitis (EPM) is a serious neurological disease of horses in Americans. Most cases are attributed to infection of the central nervous system with Sarcocystis neurona. Parasitemia has not been demonstrated in immunocompetent horses, but has been documented in one immunocompromised foal. The objective of this study was to isolate viable S. neurona from the blood of immunocompetent horses. Horses used in this study received orally administered S. neurona sporocysts (strain SN 37-R) daily for 112 days at the following doses: 100/day for 28 days, followed by 500/day for 2...
Alber J, El-Sayed A, Lämmler C, Hassan AA, Weiss R, Zschöck M.The closely related streptococcal species Streptococcus equi subsp. zooepidemicus and S. equi subsp. equi were identified by polymerase chain reaction using oligonucleotide primers designed according to species-specific parts of the superoxide dismutase A encoding gene sodA. A further differentiation of both subspecies could be performed by amplification of the genes seeH and seeI encoding the exotoxins SeeH and SeeI, respectively, which could be detected for S. equi subsp. equi but not for S. equi subsp. zooepidemicus. A further simplification of the identification and differentiation of both...
Chacon SC, Faccini JL, Bittencourt VR.The host relationships for most species of the genus Amblyomma are poorly known in Brazil. The ability of A. pseudoconcolor and A. cooperi to successfully feed on horses was investigated during ongoing research on the life cycle of these two species, which are primarily associated with wildlife. Results of these experiments suggest that horses are potential hosts for the adult stages of both species.
Silva LA, Fioravanti MC, Oliveira KS, Atayde IB, Andrade MA, Jayme VS, Rabelo RE, Romani AF, Araújo EG.The effectiveness of combining metacresolsufonic acid with streptomycin in the treatment of actinomycosis, diagnosed either clinically or in the laboratory, was evaluated in 12 bovines and 2 equines. Eighty-seven percent of treated animals were considered clinically cured and did not show any signs of relapse after a six-month follow-up period. Therapeutic diagnosis by clinical observation was the procedure of choice when it was not possible to obtain laboratory diagnosis.
Oxford JS, Lambkin R, Sefton A, Daniels R, Elliot A, Brown R, Gill D.The Great Influenza Pandemic of 1918-1919 was a cataclysmic outbreak of infection wherein over 50 million people died worldwide within 18 months. The question of the origin is important because most influenza surveillance at present is focussed on S.E. Asia. Two later pandemic viruses in 1957 and 1968 arose in this region. However we present evidence that early outbreaks of a new disease with rapid onset and spreadability, high mortality in young soldiers in the British base camp at Etaples in Northern France in the winter of 1917 is, at least to date, the most likely focus of origin of the pa...
Howe L, Craigo JK, Issel CJ, Montelaro RC.It has been previously reported that transient corticosteroid immune suppression of ponies experimentally infected with a highly neutralization resistant envelope variant of equine infectious anemia virus (EIAV), designated EIAV(DeltaPND), resulted in the appearance of type-specific serum antibodies to the infecting EIAV(DeltaPND) virus. The current study was designed to determine if this induction of serum neutralizing antibodies was associated with changes in the specificity of envelope determinants targeted by serum antibodies or caused by changes in the nature of the antibodies targeted to...
Ruszczyk A, Cywinska A, Banbura MW.The prevalence of Equine herpesvirus 2 (EHV-2) infections in the horse populations in Poland was investigated. Peripheral blood leukocytes (PBLs) of 139 horses were tested. The animals were divided into four groups: clinically healthy horses, horses suffering from respiratory disorders, mares with a recent abortion and horses with diagnosed ataxia. Thirty-four virus isolates were obtained from leukocytes of the tested animals by cocultivation with equine dermal cells and were identified as EHV-2 by PCR using primers for the gB gene of EHV-2 and/or primers for the sequence located upstream of t...
Vandenabeele SI, White SD, Affolter VK, Kass PH, Ihrke PJ.Twenty horses with pemphigus foliaceus were seen over a period of 15 years in a veterinary medical teaching hospital. Breeds seen were seven quarterhorses, five thoroughbreds, three cross-bred horses, two Arabians and one of each of the following: standardbred, Tennessee walker and warmblood. There was no breed, age or sex predisposition. Nine were mares, ten were geldings and one was a stallion. Ages ranged from 2.5 months to 25 years, with a mean of 8.6 years. Sixteen (80%) of the pemphigus foliaceus horses first exhibited signs between September and February. There was a statistically signi...
Ameni G, Terefe W.A cross-sectional study was conducted to determine the prevalence of epizootic lymphangitis (EL) in 309 cart-mules (cart-pulling mules) in Bako and Ejaji towns, Western Ethiopia using clinical and microbiological examinations, between November 2002 and April 2003. The overall prevalence was 21% (CI=16.6-26%). The clinical, histological and mycological characteristics of EL in a cart-mule were similar with those in a horse. There was significant (chi2=133.5, P=0.001) association between tick infestation and EL lesions in study cart-mules. Amblyoma coherence and Boophilus genera were the ticks c...
Paré J, Simard C.The purpose of this study was to estimate the performance characteristics (accuracy, detection limit, and precision) of commercially available enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion (AGID) kits in comparison with a reference AGID kit for the detection of equine infectious anemia (EIA) antibodies in horses for regulatory use in Canada. A total of 285 positive and 315 negative samples by the reference AGID were tested blindly on 2 other AGID and 4 ELISA kits. Commercially available AGID kits for the serodiagnosis of EIA were found equivalent. The 3 ELISAs directed...
Galvin N, Collins D.: This report presented a brief overview of the literature on the perinatal asphyxia syndrome (PAS) in foals as a prelude to a description of the investigation and treatment of acute onset seizures in a 24-hour-old Thoroughbred colt foal.PAS can cause a wide variety of clinical abnormalities, of which seizures due to encephalopathy are the most significant. The structural and biochemical components of CNS neurones are disrupted by the shift from oxidative to anaerobic metabolism, with a resultant deficit in cellular energy. The cells succumb to the combined effects of acidosis, neurotoxic acti...
Spyrou V, Papanastassopoulou M, Koumbati M, Nikolakaki SV, Koptopoulos G.Molecular analysis of the regulatory and structurally important genetic segments of equine infectious anemia virus (EIAV) in mules is presented. We have previously reported clinicopathological and laboratory findings in mules infected with EIAV, both naturally and after experimental inoculation. In this study the fragment coding for integrase, gp90, tat and the fusion domain of gp45 of the proviral genome from these animals was sequenced and compared with one another and with that of EIAV strains already published in the literature. Significant variations were observed mainly in the sequences ...
Davidson AJ, Hodgkinson JE, Proudman CJ, Matthews JB.To investigate cytokine responses in cyathostomin infection, we quantified mucosal interleukin-4 (IL-4), interleukin-10 (IL-10), tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma by reverse transcriptase-competitive polymerase chain reaction. The analysis was performed on large intestinal wall samples obtained from six anatomical sites spanning the caecum and colon of 17 naturally exposed horses. The numbers of developing larvae (DL) and early third stage larvae (EL3) were ascertained using transmural illumination and pepsin digestion techniques, respectively. Levels of each cytoki...
Karlström A, Jacobsson K, Flock M, Flock JI, Guss B.Strangles is a serious disease in horses caused by Streptococcus equi subspecies equi. In this study, genes encoding putative extracellular proteins in this subspecies have been identified using signal sequence phage display. Among these, one showed similarities to the SclB protein, a member of the collagen-like proteins of Streptococcus pyogenes. The novel gene denoted sclC encodes a protein, SclC, of 302 amino acids, containing typical features found in cell wall-anchored proteins in Gram-positive bacteria. Based on similarities to the S. pyogenes collagen-like proteins the mature SclC prote...
Marques SM, Scroferneker ML.The objective of this study was to determine the occurrence of Onchocerca cervicalis in 1200 adult horses from rural areas of Rio Grande do Sul, Brazil. Umbilical skin specimens measuring 2 x 2 cm were minced, suspended in 10 ml of distilled water and incubated at room temperature overnight. The liquid volume was centrifuged and the sediment was screened for microfilariae. The ligamentum nuchae were totally removed, preserved in ice and dissected for the detection of adult forms of Onchocerca cervicalis. Microfilariae of Onchocerca cervicalis were detected in midventral skin biopsy samples in ...
Wang X, Rikihisa Y, Lai TH, Kumagai Y, Zhi N, Reed SM.Anaplasma phagocytophilum immunodominant polymorphic major surface protein P44s have been hypothesized to go through antigenic variation, but the within-host dynamics of p44 expression has not been demonstrated. In the present study we investigated the composition and changes of p44 transcripts in the blood during the acute phase of well-defined laboratory A. phagocytophilum infections in naive equine hosts. Three traveling waves of sequential population changeovers of the p44 transcript species were observed within a single peak of rickettsemia of less than 1 month. During the logarithmic inc...
Patton KM, McGuire TC, Fraser DG, Hines SA.The goal of this research was to examine the role of cytotoxic T lymphocytes (CTL) in the control of Rhodococcus equi and specifically to determine if R. equi-specific CD8+ CTL occurred in the blood of immune horses. Equine peripheral blood mononuclear cells stimulated with antigen-presenting cells either infected with R. equi or exposed to soluble R. equi antigen lysed R. equi-infected target cells. Lysis was decreased to background by depletion of either CD2+ or CD3+ cells, indicating that the effector cell had a T-lymphocyte, but not NK cell, phenotype. Stimulation induced an increased perc...
Zevenhoven-Dobbe JC, Greve S, van Tol H, Spaan WJM, Snijder EJ.Equine arteritis virus (EAV) contains seven structural proteins that are all required to produce infectious progeny. Alphavirus-based expression vectors have been generated for each of these proteins to explore the possibilities for their constitutive expression in cell lines. This approach was successful for minor glycoproteins GP(2b), GP(3) and GP(4) and for the E protein. Subsequently, it was demonstrated that cell lines expressing these proteins could rescue EAV mutants that were disabled in the expression of the corresponding gene, resulting in the production of virus particles carrying t...
Dunkel B, Shokek AB, Wilkins PA.A neonatal foal with signs of rectal bleeding was diagnosed with an intraluminal rectal mass and intussusception on surgical exploration of the abdomen. Histologically, the mass consisted of cystic spaces lined by simple columnar epithelium with numerous goblet cells and was surrounded by thin bands of smooth muscle in a myxomatous stroma. Although the mass shared similarities with retrorectal cystic hamartoma (tailgut cyst) and juvenile polyps, described in human medicine, location and histologic findings were not entirely consistent with either condition.
Ibrahim el SM, Pagmajav O, Yamaguchi T, Matsumura T, Fukushi H.Nucleotide sequences of the intergenic region between ORF 62 and ORF 63 of equine herpesvirus 1 (EHV-1) isolates were analyzed. The sequences of this region consisted of variable and conserved domains among EHV-1 isolates. An EHV-1 mutant, Ab4-GFP, was constructed by inserting a green fluorescent protein (GFP) expression cassette flanked by lox P at both ends into the intergenic region between ORF 62 and ORF 63. Another mutant, Ab4-loxP, which contains one lox P site, was constructed by excision of the GFP cassette from the Ab4-GFP virus genome by cre enzyme. The recombinant Ab4-GFP formed sma...
Tydén E, Olsén L, Tallkvist J, Larsson P, Tjälve H.The intestinal enterocytes provide the initial site for cytochrome P450 (CYP)-mediated metabolism of orally absorbed xenobiotics. In man and some animal species, the CYP3A subfamily is highly expressed in the intestines and considered to be important in the first-pass metabolism of drugs and other xenobiotics. The aim of the present study was to investigate the mRNA expression, immunohistochemical localization and catalytic activity of CYP3A in the intestines of horse. Real-time RT-PCR analyses showed that the highest CYP3A mRNA expression was present in the duodenum with a decreasing level to...
Jin S, Issel CJ, Montelaro RC.We recently reported a highly protective attenuated live virus vaccine for equine infectious anemia virus (EIAV) based on a proviral construct (EIAVUKDeltaS2) with a genetically engineered mutation in the viral S2 gene that eliminates expression of this accessory protein. While the EIAVUKDeltaS2 vaccine provides protection from detectable infection by experimental challenge with highly virulent virus, the potential for commercial application of this vaccine is complicated by the fact that horses inoculated with the EIAVUKDeltaS2 vaccine strain become seropositive in various reference diagnosti...
Crouch CF, Daly J, Hannant D, Wilkins J, Francis MJ.Protective responses generated by vaccination with an immuno-stimulating complex (ISCOM)-based vaccine for equine influenza (EQUIP F), containing a new 'American lineage' H3N8 virus, were studied. Seven ponies in the vaccine group received two intramuscular injections of EQUIP F given 6 weeks apart. Aerosol challenge with an A/eq/Newmarket/1/93 reference strain 4 weeks after booster vaccination resulted in clinical signs of infection and viral shedding in 7 influenza-naive control animals whereas the vaccinated ponies were significantly protected from both clinical signs and virus excretion. I...
Cauchard J, Sevin C, Ballet JJ, Taouji S.The aim of this study was to evaluate serum IgG antibody levels and opsonizing activity in foals from pregnant mares immunized with either proteins from an R. equi strain containing virulence-associated protein A (VapA), an immunodominant surface-expressed lipoprotein encoded by a virulence plasmid crucial for virulence in foals, or a whole killed virulent R. equi preparation. Forty-eight pregnant mares were distributed into three groups, i.e. 24 immunized with R. equi VapA protein antigen associated with a water-based nanoparticle adjuvant (Montanide IMS 3012), 8 immunized with whole killed R...
Konishi E, Shoda M, Ajiro N, Kondo T.Antibodies to Japanese encephalitis virus (JEV) nonstructural 1 (NS1) protein constitute a marker of natural JEV infection among populations vaccinated with inactivated JE vaccine. In Japan, with few recent human JE cases, the natural infection rate is critical to evaluate the necessity of continuing JE vaccination. A sensitive immunochemical staining method for detecting NS1 antibodies in individuals naturally and subclinically infected with JEV was previously established. Here, an enzyme-linked immunosorbent assay (ELISA) to detect NS1 antibodies in equine sera was developed and evaluated as...
Gudmundsdottir KB, Svansson V, Aalbaek B, Gunnarsson E, Sigurdarson S.Twenty isolates of Listeria monocytogenes associated with five confirmed and four suspected incidents of listeriosis in horses in Iceland were characterised by serotyping, pulsed-field gel electrophoresis and ribotyping. Semiquantitative estimates of the numbers of L monocytogenes were made on faeces from horses with clinical signs of listeriosis and on grass silage fed to them. Large numbers of L monocytogenes were often found in the faeces of horses with severe signs of disease. The 20 isolates could be divided into six genotypes, each incident involving only one genotype. One serovar 1/2a g...
Bender JB, Tsukayama DT.Infectious agents are insidious, often changing to adapt to host defenses or treatment advances. Because these challenges will continue, the need to apply standard and transmission-based precautions is important not only in the human hospital setting but in the veterinary clinic setting. In addition, to prevent human infection and potential liability, clinics need to establish program algorithms to prevent disease spread for specific agents or planned procedures to respond to potential nosocomial and zoonotic disease events. These need to be done proactively. Furthermore, more money needs to b...
Kondratjeva J, Julien F, Coutelier C, Humeau L, Moog F, Combarros D, Fourquaux I, Pressanti C, Delverdier M, Moore PF, Cadiergues MC.Cutaneous epitheliotropic T-cell lymphoma is a malignant tumour of the skin already reported in humans, dogs, cats, horses, and other species, but not previously in donkeys. The standard diagnosis is based on clinical, morphological and immunophenotypic data. Differentiation of malignant versus benign proliferation of lymphocytes is crucial; in ambiguous cases T-cell receptor gamma (TRG) molecular clonality should be tested. In the present paper, we report a case of mycosis fungoides diagnosed in a donkey whose diagnosis was based on clinical, histological and immunohistochemical aspects and a...
Egri B, Sárközy P, Bánhidy G.From 14 to 17 April 1990 and from 12 to 21 May 1993 a total of 136 Caucasian (Donish, Karabakh, Kabardin, local halfbred) and 26 thoroughbred stud-horses were examined for ectoparasites in studs of Stawropol County, Russia. A total of 4054 botfly larvae were identified from 9700 faecal samples collected during a period of 3-4 days after oral treatment with Eqvalan (MSD), Strongid Plus (Pfizer) and Vermitan Plus (Sanofi-Chinoin). The species distribution was: Gasterophilus intestinalis 84.53%, G. nasalis 10.41%, G. haemorrhoidalis 3.62%, G. inermis 1.41%. Gasterophilus nasalis and G. inermis ha...
Gardner RB, Nydam DV, Luna JA, Bicalho ML, Matychak MB, Flaminio MJ.Phagocytic activity of neonatal foals has been reported to be similar to that of adult horses, but serum opsonization capacity develops with age and may be further altered when opsonins are consumed during infection. Objective: Phagocytosis, oxidative burst activity, and serum opsonization capacity in neonatal foals admitted to an intensive care unit are reduced in comparison with control foals. Methods: Blood samples were collected from hospitalized neonatal foals and from control foals. Hospitalized foals were characterized as sick or septic on the basis of a sepsis score and received intrav...
Di Francesco A, Donati M, Mattioli L, Naldi M, Salvatore D, Poglayen G, Cevenini R, Baldelli R.We tested 731 sera from apparently healthy light horses against Chlamydophila pneumoniae, by a microimmuno-fluorescence (MIF) test. To verify cross-reactions with other species of chlamvdiae, all sera with an antibody titre > or = 32 to C. pneumoniae were tested against both C. psittaci and C. abortus. Antibodies to C. pneumoniae were detected in 194 out of 731 (26.5%) samples tested, with antibody titres ranging from 32 to 1024. No antibody titre > or = 32 was detected in sera to C. abortus. Only few sera with a high antibody titre to C. pneumoniae reacted weakly with C. psittaci at the dilut...
Wong DM, Ruby RE, Eatroff A, Yaeger MJ.A newborn foal was presented because it was unresponsive and in cardiopulmonary arrest. Aggressive cardiopulmonary cerebral resuscitation was administered to the foal, which revived the foal; however, acute renal failure developed. Fluid retention and azotemia occurred although the foal was alert and able to suckle. A 6-hour renal replacement therapy session using hemodiafiltration and a continuous renal replacement therapy machine was administered to the foal at 3 days of age which lowered the foal's azotemia and facilitated removal of some of the excess body fluid. Despite therapy, the foal ...
Kinoshita Y, Takechi M, Uchida-Fujii E, Miyazawa K, Nukada T, Niwa H.Bacterial placentitis in horses commonly results in abortion, premature birth or compromised neonatal foal health. Although mycobacterial infections are generally uncommon in horses, 10 equine abortion cases caused by Mycobacterium avium subsp. hominissuis (MAH) infections occurred between 2018 and 2019 in Japan. They occurred on seven Thoroughbred horse farms in the Hidaka district of Hokkaido, but direct contact among the mares on different farms was not recorded. Most cases were characterized by extensive pathological lesions of the placenta, which are not typical in cases of common pathoge...
Smiet E, Haritova A, Heil BA, Fink-Gremmels J, Wijnberg ID.To compare the pharmacokinetics of the fourth generation cephalosporin, cefquinome, in neonatal foals, 6-week-old foals and mature New Forest ponies in order to recommend appropriate dosage regimens for use of this drug. Methods: Cefquinome was administered i.v. at 1 mg/kg bwt twice a day (q. 12 h), 1 mg/kg bwt 3 times a day (q. 8 h) or 4.5 mg/kg bwt q. 12 h to each age group (n = 6). Plasma cefquinome concentrations were analysed using high-performance liquid chromatography combined with electrospray tandem mass spectrometry. Results: Both foal age groups had comparable pharmacokinetic data e...
Booth TM, Abbot J, Clements A, Singer ER, Clegg PD.To describe and evaluate a technique for radical resection of the entire intrathecal component of the common digital extensor tendon (CDET) in horses. Methods: Prospective clinical study. Methods: Seven client-owned horses. Methods: Seven horses with wounds that resulted in septic tenosynovitis of the CDET sheath were treated by complete surgical resection of the affected tendon and ablation of the tendon sheath; 5 had previous surgery that was unsuccessful. Time from initial injury to complete resection was 1-22 weeks. In 6 horses, the wound was closed primarily using a closed suction (4 hors...
Holland RE, Grimes SD, Walker RD, Wilson RA.Hemolytic E. coli strain 807-13, O149:NM:K88(STb+, LT+), was isolated from the feces of a neonatal diarrheic foal. E. coli 807-13 was examined for adhesion to brush border membranes (BBM) from foals, adult horses and pigs, and its pathogenicity was assessed in neonatal foals and pigs. E. coli 807-13 did not adhere to equine BBM but adhered to pig BBM. It did not cause diarrhea nor did it colonize the intestinal epithelium of 3 colostrum-deprived and 3 suckled foals challenged at 24 h of age. Acute ulcerative gastritis and acute suppurative gastritis were observed in 2 colostrum-deprived challe...
Azarvandi A, Khosravi AR, Shokri H, Talebkhan Garoussi M, Gharahgouzlou F, Vahedi G, Sharifzadeh A.Yeasts are commensal organisms found in the reproductive and gastrointestinal tracts, and on the skin and other mucosa in mammals. Objective: The purpose of this study was to isolate and identify yeast flora in the caudal reproductive tract in healthy female horses. Methods: Longitudinal study. Methods: A total of 453 samples were collected using double-guarded swabs from the vestibule, clitoral fossa and vagina in 151 horses. All samples were cultured on Sabouraud 4% dextrose agar and incubated at 35°C for 7-10 days. Isolates were identified according to their morphological characteristics a...
Bak EJ, Jean YH, Woo GH.Four thoroughbred horses showing lameness, ataxia, circling, depression, recumbency, and seizures, were examined. The horses had gross, pale- to dark-red manifestations and foci in the central nervous system (CNS). Multifocal to coalescing eosinophilic necrotizing encephalomyelitis was observed histologically in the CNS along with intact or degenerated nematodes. Nematodes had polymyarian-coelomyarian musculature, a smooth thin cuticle, and intestines lined by multinucleated cells with microvilli. These traits suggested the nematodes belonged to the family Protostrongylidae, which includes Par...
Zakia LS, Arroyo LG, Gomez DE, Boerlin P, Surette MG, Lillie BN.Equine enterotyphlocolitis is an inflammatory process of the intestinal tract of horses that is associated with multiple etiologic agents and risk factors. Most clinical cases do not have an etiologic diagnosis. We describe here the pathogens detected and the histologic lesions found in horses with enterotyphlocolitis in Ontario that were submitted for postmortem examination, 2007-2019. We reviewed the medical records of 208 horses that fulfilled inclusion criteria. Cultures were positive in 67 of 208 (32%) equids for Clostridium perfringens, in 16 of 208 (8%) for Clostridioides difficile, and...
Di Pietro R, Arroyo LG, Leclere M, Costa M.Bacterial imbalances are observed in intestinal diseases and fecal microbiota transplantation (FMT) has been used to restore the intestinal microbiota of horses. However, there is evidence that the current methods proposed for FMT in horses have limited efficacy. The objective of this study was to concentrate the bacteria present in the donor stool by centrifugation, and to test the effect in horses with antibiotic-induced dysbiosis. One healthy 11-year-old horse was selected as a fecal donor and 9 horses were given trimethoprim sulfadiazine (TMS) for 5 days to induce dysbiosis. Horses receive...
Martin-Downum K, Yazwinski T, Tucker C, Fincher M, Ralph J, Hamilton J.Commercial preparations of fenbendazole (Safe-Guard, Intervet), ivermectin (Eqvalan, Merial) or moxidectin (Quest, Fort Dodge) were administered once to horses scheduled for routine parasiticide treatment. In total, 93 horses from six cooperating farms were used in the study. Computer generated, random allocation of horses to treatment group was conducted at each farm. Fecal egg counts were determined for all horses on trial days 0, 56, 84 and 112, with corresponding calendar dates that were unique to each farm. Only strongyle egg counts from animals which were positive at day 0 were used for ...
Madigan JE, Valberg SJ, Ragle C, Moody JL.Severe muscle cramping not associated with exercise was observed in 5 horses. Focal muscle groups in various regions underwent intermittent visible contraction. Intermittent prolapse of the third eyelid, sweating, pawing, muscle tremors, and muscle fasciculations also were observed. Clinical signs often were misconstrued as signs of colic. Percussion of muscle induced contraction of muscle groups. Concentrations of serum electrolytes and the acid-base balance were within reference limits, but activities of creatine kinase and aspartate transaminase were moderately high. Muscle biopsy revealed ...
Pille F, Martens A, Schouls LM, Peelman L, Gasthuys F, Schot CS, De Baere C, Desmet P, Vandenberghe F.Standard culturing techniques are often unrewarding in confirming diagnosis of synovial infection in the equine patient. Several human studies report the use of sensitive polymerase chain reaction (PCR) techniques for the detection of bacterial involvement in acute synovitis. However, successful extraction of bacterial DNA directly from clinical samples from horses without prior culture has not been reported yet. The goal of this study was to develop a sensitive and reliable method for molecular detection and identification of bacterial species in synovial fluid from horses with infectious syn...
Wondimagegnehu K, Leta S, Amenu K, Negussie H.Respiratory disease is the most common presenting complaint at veterinary clinics and a priority concern for equid owners and veterinary practitioners in Ethiopia. This study aimed to report the molecular detection of EHV-2 and EHV-5 and to assess the risk factors associated with infection in working equids in central Ethiopia. Nasopharyngeal swabs were collected from 58 horses and donkeys to detect EHV-2 and EHV-5 using PCR targeting the conserved region of glycoprotein B (gB) genes. From 58 equids, EHV-5 and EHV-2 were detected in 20 (34.5%) and 19 (32.8%) equids, respectively. Concurrent in...
Souto EPF, Maia LA, Olinda RG, Galiza GJN, Kommers GD, Miranda-Neto EG, Dantas AFM, Riet-Correa F.Two cases of nasal pythiosis are reported in horses from the semi-arid region of northeastern Brazil. From January 1986 to December 2015, the Laboratory of Animal Pathology, Federal University of Campina Grande received 830 equine samples, 156 (18.79%) of which were diagnosed with pythiosis. Of these, two horses (1.28%), a male and a female adult cross-breed, had lesions in the nasal cavity. Both horses had access to water reservoirs. Clinically, they had swelling in the rhinofacial region and a serosanguineous nasal discharge. Macroscopically, in case 1, the lesion affected the nasal vestibul...
Johnson AK, Roberts JF, Hagan A, Wilborn RR, Dujovne G, Sells SF, Donahue JM.A 25-year-old pregnant American Quarter Horse mare presented with a 1-week history of progressively worsening vaginal discharge. Transrectal ultrasound revealed increased thickness of the combined uterus and placenta with evidence of chorioallantoic edema but no placental separation. A thickened amnion was visible on transabdominal ultrasound. Abortion occurred 2 days after presentation despite medical treatment. At necropsy, the chorioallantois had variable but diffuse thickening with focally extensive browning of the chorionic surface in the right horn and adjacent body. There were fluid-fil...
Radalj A, Milic N, Stevanovic O, Nisavic J.Nasal swabs originating from 112 apparently clinically healthy and unvaccinated horses of different age, breed and from diverse rearing conditions from Serbia and Bosnia and Herzegovina were examined for the presence of equine herpesviruses 1, 4 and 5 using multiplex nested PCR (Mn‑PCR) and virus isolation. The detected viruses were subsequently characterised by gB gene nucleotide sequencing and their phylogenetic analysis was performed. The infections with EHV‑1, EHV‑4, and EHV‑5 in the examined horse populations are apparently chronic, subclinical and persistent, whilst the shedding ...
Dixon RJ, Hartley WJ, Hutchins DR, Lepherd EE, Feilen C, Jones RF, Love DN, Sabine M, Wells AL.An outbreak of perinatal foal mortality associated with a herpesvirus is described. Twenty two foals either were still-born, or died soon after birth, or were weak and soon developed severe respiratory signs, or were normal at birth and developed respiratory symptoms 18 to 24 hours later. Elevated temperatures, heart and respiratory rates were constant features. The animals were severely leucopaenic, and showed an absolute neutropaenia. At autopsy the lungs were enlarged, and showed varying degrees of aeration and moderate to severe oedema and congestion. Histopathology showed an acute focal n...
Vercruysse J, Eysker M, Demeulenaere D, Smets K, Dorny P.A controlled trial was carried out to evaluate the persistence of the effect against small strongyles of a 2 per cent moxidectin gel administered orally to foals at a dose rate of 0.4 mg/kg bodyweight. Five of nine helminth-free foals were treated on day 0, and the remaining four foals were used as controls. On days 0, 7, 14, 21 and 28 all nine foals were infected experimentally with 200,000 small strongyle larvae. Three treated and two control foals were necropsied on day 42 and the rest on day 43. Fourteen species of small or medium sized small strongyles were found in the control foals, 10 ...
Rainger JE, Hughes KJ, Kessell A, Dart CM.A 3-year-old Thoroughbred colt was presented to the University Veterinary Centre Camden for evaluation of ataxia. The horse was anaesthetised to facilitate cervical radiography and myelographic examination of the spinal cord. Recovery from anaesthesia was uneventful. Five days after general anaesthesia the horse re-presented with pleuropneumonia. It was euthanased 24 hours after presentation on humane grounds. Necropsy revealed severe tracheal erosion over the middle third of the ventral surface of the trachea, pleuropneumonia and narrowing of the cervical cord between C4 and C6. It is postula...
DiPietro JA, Todd KS.The common anthelmintics used to treat parasitic infections of horses are described. Dosage, anthelmintic spectrum, formulation and administration, mode of action, toxicity contraindications, and resistance of parasites to anthelmintics are included.
Doherr MG, Carpenter TE, Wilson WD, Gardner IA.The objective of this study is to describe the design, application and validity of a self-administered (mailed) questionnaire to collect data on potential risk factors for Corynebacterium pseudotuberculosis infection in California horses. Horses admitted to the UC Davis Veterinary Medical Teaching Hospital (VMTH) between 1 July 1992 and 30 June 1994 served as the study base for case identification and simple random sampling of 800 control horses. A questionnaire was mailed to owners of the study horses, followed by a reminder postcard and a second copy of a questionnaire. Data were collected o...
Wright IM, Phillips TJ, Walmsley JP.A technique for evaluation of the navicular bursa using a 4 mm 25 degrees inclined view arthroscope is described. This allows examination of the palmar/plantar surface of the navicular bone, the insertions of the navicular suspensory, T and impar ligaments, the bursal synovium and the dorsal surface of the deep digital flexor tendon. The technique was used in 16 horses with punctures of the navicular bursa. Procedures facilitated by the technique were bursal lavage, removal of pannus, synovial resection and debridement of lesions on the palmar/plantar surface of the bone and in the deep digita...
Ghallab RS, El-Beskawy M, El-Shereif AA, Rashad AMA, Elbehiry MA.Equine endometritis is one of the most common causes of reproduction failure. To achieve better treatment outcomes, different diagnostic methods should be combined. In the current study, 39 repeat breeder mares were subjected to ultrasonography examination to detect excessive accumulation of intrauterine fluids and an abnormal oedema pattern, which revealed that 61.5% of mares were positive. Combined with endometrial cytology by low-volume uterine flush, 47.7% of smears contain neutrophils (more than 2-3 per HPF X100), and microbial culture. 92.3% of mares were infected with different bacteria...
Janicek JC, Kramer J, Coates JR, Lattimer JC, Lacarrubba AM, Messer NT.A 4-month-old Missouri Fox Trotter colt was examined for a 5-week history of head tilt after treatment for suspected pulmonary Rhodococcus equi infection. Results: Computed tomography revealed osteolysis of the occipital, temporal, and caudal portion of the parietal bones of the left side of the cranium. A soft tissue mass compressing the occipital region of the cerebral cortex and cerebellum was associated with the osteolytic bone. Results: A rostrotentorial-suboccipital craniectomy approach was performed to remove fragmented occipital bone, debulk the intracranial mass, and obtain tissue sam...
Perdrizet JA, Callihan DR, Rebhun WC, Shin SJ.The clinical course and successful therapeutic management of a horse with malignant edema caused by Clostridium septicum is described. This is believed to be the first report of a horse surviving malignant edema caused by C. septicum. A discussion of this disease syndrome, including etiology, pathogenesis, clinical signs, therapy, and diagnostic methods is presented.
Duncan JL, Abbott EM, Arundel JH, Eysker M, Klei TR, Krecek RC, Lyons ET, Reinemeyer C, Slocombe JO.These guidelines have been designed to assist in the planning, operation and interpretation of studies which would serve to assess the efficacy of drugs against internal parasites of horses. Although the term anthelmintic is used in the title and text, these guidelines include studies on drug efficacy against larvae of horse bot flies, Gasterophilus spp., which are non-helminth parasites commonly occurring in the stomach of horses. The advantages, disadvantages and application of critical and controlled tests are presented. Information is also provided on selection of animals, housing, feed, d...
