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.
Larsen AB, Moon HW, Merkal RS.The susceptibility of horses to Mycobacterium paratuberculosis was studied. A total of 8 colts was used: 2 colts were exposed intravenously and 1 colt used as a contact control was placed with them; 2 colts were exposed intragastrically; 1 colt was administered killed M. paratuberculosis intravenously; and the remaining 2 colts were used as normal controls and were housed separately. Colts administered live bacilli intravenously began losing weight 84 days after exposure, and shortly thereafter they had clinical signs of disease, consisting of loss of body weight and rough coat. The exposed co...
Nishi S, Watabe H, Hirai H.The production of antibody to homologous alpha fetoprotein (AFP) in rabbits, rats, and horses by immunication with human AFP is reported. The antigens were administered subcutaneously 5 times at intervals of 7-10 days. Rabbits and dogs received 1 mg of human AFP/ml of the homologous pooled newborn serum with each injection while the rats received 1/2 of the dose. The horses received 5 mg/ml/injection. 2 weeks after the last injection, antisera were collected and immunologic assays were performed by the Ouchterlony method and the reversed version of the Mancini method. High titered antibodies w...
Fong CK, Hsiung GD.Development of equine herpesvirus strain 82A was studied in cells from primary horse kidney (HOK) cultures and an equine dermis (ED) cell strain. HOK and ED cells are equally susceptible to the 82A virus infection and yield about the same amount of infectious virus. Intranuclear inclusions were present in both cell systems, but a ring-shaped syncytial formation was observed only in infected ED cells. Ultrastructural studies revealed the presence of dense granules 30 nm in diameter and characteristic star-like clusters of granules in the infected HOK cells, but these granules were rarely seen i...
Carrier SP, Bannister GL, Boulanger P.Twenty-nine lots of acetone-ether extracted liquid antigen were prepared from the pulp of 11 spleens collected from horses at the acute phase of experimental infection. The lots prepared from the highly reactive pulp resulted in general in a liquid antigen of greater activity than those extracted from weakly reactive pulps. Some variations in activity between lots of antigen prepared from the same spleen were also observed. No matter what the results, given a wide enough variation, all results were reproducible. The procedure permitted production of a greater number of antigen test doses from ...
Nakajima H, Norcross NL, Coggins L.Antigenic relationship between purified equine infectious anemia (EIA) virus and spleen-derived antigen from EIA-infected horses was examined by immunodiffusion. Identical antigenicity of these two antigens has been proven because precipitation lines formed between the two antigens and EIA antiserum connected with each other. The results indicate that the antigenic substance derived from infected spleen is a component of EIA virus.
Chiewsilp D, McCown JM.Repeated clot formation in mouse ascitic fluids containing antiviral antibody was eliminated by acid precipitation of the fibrinogen.
Selected equine cutaneous diseases for which there is strong evidence of an immunological aetiology are discussed in this section. The reactive disorders of urticaria, Culicoides hypersensitivity, erythema multiforme, drug eruptions and systemic granulomatous disease are included. The autoimmune diseases of the horse with cutaneous manifestations (pemphigus foliaceus, pemphigus vulgaris, bullous pemphigoid and cutaneous lupus erythematosus) are discussed. The clinical signs and diagnostic features of these immunologically induced equine dermatoses are defined, and the challenges in making a de...
Equine lentivirus receptor-1 (ELR1) has been characterized as the specific functional receptor that mediates equine infectious anemia virus (EIAV) entrance to horse macrophages. This receptor is tumor necrosis factor receptor superfamily member 14 (TNFRSF14). The aim of this study was to investigate the occurrence of allelic variants in the coding sequence of equine TNFRSF14 gene by screening for single-nucleotide polymorphisms (SNPs) in different equine populations. Forty seven horse samples were randomly selected from a reservoir of EIAV-seropositive and seronegative samples collected from d...
Hoffman AM, Viel L, Staempfli HR, Muckle CA, Yager JA.One indication for referral of horses to veterinary hospitals is for diagnosis of the microbiologic cause of pneumonia, particularly when the initial treatment fails. Although endoscopic methods have long been available for microbiologic sample collection, accuracy of these methods under these conditions have not been studied in detail. We compared the bacteria isolated from samples obtained by bronchoalveolar lavage (BAL) with those obtained by protected catheter brush (PCB) from foals with unilateral pneumonia induced by inoculation with Klebsiella pneumoniae. As part of previously described...
Richard EA, Pitel PH, Lemaitre L, Jas D, Lekeux P, Pronost S, Fortier G.The aim of this study was to investigate neutrophil stimulation following experimentally-induced airway inflammation in healthy horses. Six horses received dexamethasone and four were then inoculated with equid herpesvirus-2 (EHV-2). Significant neutrophilia was detected in tracheal wash and bronchoalveolar lavage fluid for up to 6 days. Concentrations of neutrophil elastase (NE) and myeloperoxidase (MPO) were significantly increased compared to baseline for up to 14 days in tracheal washes and both markers were significantly correlated with neutrophil counts. Serum levels of surfactant protei...
Liu L, Castillo-Olivares J, Davis-Poynter NJ, Baule C, Xia H, Belák S.Samples from horses experimentally infected with the "large plaque variant (LP3A+)" of equine arteritis virus were analysed. These included 182 nasal swabs collected from day 1 to 14 post-infection (p.i.), and 21 virus isolates obtained from white blood cells of animals that showed a prolonged viraemia between days 30 to 72 p.i. In order to determine the genetic stability of the virus and particularly to characterise the genetic variants found during the prolonged viraemia, partial sequences of open reading frame 5 (ORF5) encoding glycoprotein 5 (GP5) were generated. Viruses with amino acid su...
Furniss C, Carstens A, Cilliers I.A 12-year-old, grey, crossbred pony mare was presented with a swelling in the neck over the area of the 2nd cervical vertebra (C2), which was found to be painful on palpation. The neck was held stiffly. Radiography of the cervical region showed a focal area of increased radio-opacity over the dorsal, caudal and lateral aspect of the dorsal spinous process of C2. Ultrasound confirmed the presence of a hypoechoic area approximately 15 cm in diameter superimposed over the dorsal spinous process of C2. An aspirate was taken of the mass, which revealed purulent exudate confirming the diagnosis of a...
Drudge JH, Lyons ET, Tolliver SC.In 1973-1974, 4 controlled tests were performed in pony foals (n = 17) raised parasite-free and experimentally infected with Strongyloides westeri. Administration of infective larvae by stomach tube in 1 test resulted in low-grade infections and tended to invalidate the test. Intraoral and percutaneous (intra-aural) administration of larvae resulted in suitable test infections for 1 and 2 tests, respectively. A paste formulation of dichlorvos at 36.3 mg/kg of body weight removal from 4 ponies. Treatment of 4 the dosage rate of 44 mg/kg was consistently effective (greater than 99% to 100%) for ...
Sander J, Terhardt M, Janzen N.In horses, congenital defects of energy production from long-chain fatty acids have not been described so far. In contrast, inhibition of fatty acid degradation caused by the toxins hypoglycin A and methylenecyclopropylglycine from various maple species are observed frequently. These non-proteinogenic aminoacids are passed on placentally to fetuses or with collostrum or milk to newborn foals. Nevertheless, newborn foals become very rarely symptomatic. Vertical transmission apparently is not sufficient to induce clinical disease without a particular genetic constellation being present. One of t...
Dinev D, Koĭchev K, Kolev K, Gerganova E.A total of 24 horses and 42 cattle with a variety of local suppurative processes (wounds, abscesses, phlegmons, tendovaginitis, etc.) were studied under conditions of the clinic with regard to the most commonly found microbial species and the opportunity to work out antibioticogrammes in terms of the effectiveness of 11 of the chemotherapeutic agents widely used in the practice. It was found that prevailing in horses were staphylococci and streptococci. In cattle Corynebacterium pyogenes was predominantly established. Besides, there was a rising trend in the part played by representative agent...
Vacek JR, Macharg MA, Phillips TN, Foerner JJ, Everett KA.A 3-month-old Thoroughbred colt was presented with signs of colic. Findings from physical examination, abdominal paracentesis, abdominal radiographs and clinical pathology revealed uroperitoneum secondary to a calculus obstructing the urethra and causing subsequent urinary bladder rupture. Analysis of the calculus demonstrated a tissue center with outer concretions composed primarily of struvite.
Kamphues J, Meyer H, Liebler EM, Johannsen A.Anamnesis and clinical signs of horses form five different stables after ingestion of ionophores are reported and techniques of feed examination are described. Within a few hours or days after feeding of new types or batches of concentrates horses fell ill. They showed colic-like symptoms with intense sweating and ataxia. Most of the sick animals died within a short time span. Samples of the concentrates were analysed and different types and amounts of ionophores were detected. In four cases contamination by monensin in concentrations of less than 5 mg to 679 mg/kg feed were found. One feed sa...
Eysker M, Vercruysse J.The epidemiology, chemotherapy and control of strongylus infections in the horse are discussed. The annual cycle of various species are stated. In addition the anthelmintics available for treatment and control and the occurrence of anthelmintic resistance are referred to. Finally the options for control under various management conditions (little if any grazing; extensive grazing; intensive grazing) are discussed.
Kumar R, Sethi K, Gaur DK, Goyal SK, Kumar S, Jain S, Kumar S.Serodiagnosis of surra, caused by Trypanosoma evansi, is still based on native antigens purified from bloodstream form of T. evansi grown in rodents. In order to investigate prospective diagnostic possibilities as an alternative for native antigens, we cloned, expressed 26 kDa calflagin protein containing 218 amino acids from T. evansi (Indian Strain) in Escherichia coli. The potential of recombinant calflagin (rCLF) protein as diagnostic antigen was evaluated in immunoblot and indirect ELISA using experimentally infected equine serum samples from 0 to 84 days post infection. The antibodies a...
Anna M, Łukasz M, Adam O, Chełmońska-Soyta A.The aim of the study was to investigate the mechanisms leading to immunization through the use of a multicomponent bacterial immunomodulator and to find out the relationship between the TLR 4 receptor with selected parameters of innate immunity and to acquire immunity. The study was conducted on 18 Polish Pony Horses foals divided into two study groups: control (n = 9) and experimental (n = 9). Foals from the experimental group received intramuscular duplicate injection of 5 ml of multi-component bacterial immunomodular at 35 and 40 days of age. RNA isolated from venous blood was use...
Becht JL, Page EH, Morter RL, Boon GD, Thacker HL.Serological evidence with or without clinical signs of neonatal isoerythrolysis was experimentally produced in 6 of 8 foals born to mares allo-immunized with washed erythrocytes from the stallion. Blood group antigens were determined in all mares, stallions and foals, and the incompatible antigenic factor(s) responsible for the disease were defined. In 5 of 8 foals born to alloimmunized mares, a single antigenic factor difference accounted for the erythrocyte incompatibility between mare and foal. The erythrocyte antigen suspected as the most responsible for isoerythrolysis observed was A1. Ag...
Atwill ER, Mohammed HO, Lopez JW, McCulloch CE, Dubovi EJ.To locate counties within New York state with a high seroprevalence among the equine population, to determine host, management, and environmental factors that were associated with seropositivity to Ehrlichia risticii, and to determine evidence for arthropod- or helminth-mediated transmission of E risticii to horses. Methods: Cross-sectional study. Methods: A random sample of 3,000 of the 39,000 equine operations in New York state was selected, and 2,587 horses from 511 operations were tested. Methods: Blood samples were collected from horses and tested for seropositivity, using the indirect fl...
Haider W, Brehm W, Keller H.An apparently unilateral cryptorchid stallion was referred to the clinic with a history of colic. In the course of laparotomy an ileus caused by strangulation of the small intestine was found and the horse was euthanized because of poor prognosis. During autopsy strictures and ectasia of the jejunum were found as well as hermaphroditism along with male phenotype. The frequency of cryptorchidism in the case of intersexuality is discussed.
Scherbarth R, Pózvári M, Heilkenbrinker T, Mumme J.From 1972 to 1991, presecretion on an average of 183 stallions per year had been examined. Facultatively pathogenic germs were ascertained in 13.5% of the samples. However, the portion showed considerable annual fluctuation, as did the percentage of the different kinds of germs. In most of the cases, only minimal growth had been observed in culture. Except for the total percentage, these results are contradictory to those we found during the examination of cervical swabs of mares. In order to ascertain the importance of the respective results and to render possible a correct interpretation, th...
Denny HR.The current trends in equine fracture treatment are reviewed. Surgical approach, method of fixation, the advantages of Association for the Study of Internal Fixation (ASIF) implants and the complications of treatment are discussed with reference to 21 fracture cases. Normal limb function was restored in four horses with fractures of the olecranon and one with a mid shaft fracture of the tibia following stabilisation of the fracture with plates. A horse with a chip fracture of the distal radius and three other animals with fractures of the lateral condyle of the third metacarpal bone were also ...
Bacon Miller C, Wilson DA, Martin DD, Pace LW, Constantinescu GM.A 3-year-old Quarter Horse gelding was treated for left guttural pouch mycosis by ligation and balloon catheterization of the left internal carotid artery. Catheter advancement was shorter (10 cm) than the normally reported distance (13-15 cm), but was observed endoscopically during placement as it coursed within the internal carotid artery through the guttural pouch. The horse developed a persistently abnormal respiratory pattern after catheter placement, failed to gain consciousness, developed pulmonary edema, and died 5.5 hours postoperatively. Postmortem examination revealed an aberrant le...
Krpan MK.Transtracheal aspiration is used to obtain samples for culture and cytologic examination of respiratory tract secretions and exudates. A 15-cm-long area of the ventral midcervical region is surgically prepared, a small site infiltrated SC with 2-3 ml lidocaine, and a stab incision made in the skin. A trocar with cannula is inserted through the incision and annular ligament into the trachea and the trocar removed. An 8-Fr polypropylene catheter is inserted about 35-40 cm down the trachea and attached to a 30-ml syringe, containing 20 ml sterile saline, with a 3-way stopcock . The saline is rapi...
Wright L, Puchalski SM, Kristoffersen M, Lindegaard C.To develop arthroscopic approaches to the atlanto-occipital (A-O) and describe associated arthroscopic anatomy. Methods: Experimental ex vivo study and clinical case report. Methods: Ten equine cadaver joints and 1 clinical case. Methods: CT arthrograms of 8 A-O joints were performed to determine the placement of an arthroscopic portal. Arthroscopy was performed via dorsal and/or ventral approaches (dorsal or ventral to the longissimus capitis tendon) in 10 cadaveric A-O joints and the A-O joint of a 2-week-old foal with septic arthritis. Accessible cartilage was debrided in 3 cadaver joints. ...
Doyle AJ, Saab ME, Lewis KM, McClure JT.An alcohol-based rub has been confirmed effective at reducing bacterial counts on equine skin. Skin sites with expected high bacterial burden have not been tested or has a comparison to a common protocol been performed. Objective: To determine if ethanol-based antisepsis reduces bacterial counts on the equine distal limb comparable to a current chlorhexidine scrub method and determine the most effective application technique for the product. Methods: Randomised trial. Methods: Forty-one horses were used in the study. By horse, each limb was randomly assigned to a treatment group: 5min scrub us...
Meier HP.In 1828, the Society of Swiss Veterinarians (GST) raised a prize question in regard to the symptoms, etiology and prophylaxis of polyarthritis in the foal. The treatise of Matthias Anker on this subject was treated with distinction and published in 1830. His statements answered both the questions to the clinical aspects and referred also to epidemiological, pathological, economical and ethical issues as well as husbandry and relations with the breeders. The comprehensive article of Anker in a lucid language and obliging views still finds great interest today, as the septicemia is one of the bi...
Materniak-Kornas M, Rożek W, Rola J, Osiński Z, Löchelt M, Kuźmak J.Equine foamy virus (EFVeca) is a foamy virus of non-primate origin and among the least-studied members of this retroviral subfamily. By sequence comparison, EFVeca shows the highest similarity to bovine foamy virus. In contrast to simian, bovine or feline foamy viruses, knowledge about the epidemiology of EFVeca is still limited. Since preliminary studies suggested EFVeca infections among horses in Poland, we aimed to expand the diagnostics of EFVeca infections by developing specific diagnostic tools and apply them to investigate its prevalence. An ELISA test based on recombinant EFVeca Gag pr...
Steuer AE, Scoggin K, Stewart JC, Barker VD, Adams AA, Loynachan AT, Nielsen MK.This study aimed to collect information on local and systemic inflammatory responses, and goblet cell-associated components, following anthelmintic treatment with moxidectin and ivermectin in horses naturally infected with cyathostomin parasites. Thirty-six horses aged 2-5 years of age were randomly allocated to three groups. Group 1 received ivermectin/praziquantel (0.2 mg/kg), Group 2 received moxidectin/praziquantel (0.4 mg/kg) and Group 3 were untreated controls. Tissue samples from the Cecum, Dorsal and Ventral Colons were used for histopathological evaluation and preserved for RNA is...
Odenkirchen S, Huskamp B.Casuistics of 200 patients with acute diarrhea (72 horses with salmonellosis, 55 horses with typhlocolitis, 73 horses with unspecific diarrhea) have been analyzed. It was shown, that horses with salmonellosis have been fallen ill with a primary disease for a longer period of time before the beginning of diarrhea than those with typhlocolitis and that in cases of salmonellosis antibiotics very often were used during the preliminary treatment. Frequently a primary illness of the colon was seen with typhlocolitis. Besides the frequent use of butylscopolamin during the pretreatment was noticed. Th...
Spier SJ, Meagher DM.Rational perioperative management improves the success rate of abdominal surgery. Important aspects of management are discussed, including principles of fluid therapy, nutrition, intravenous catheterization, antimicrobial prophylaxis, and the use of nonsteroidal anti-inflammatory medication. Current advances in the area of immunotherapy are mentioned.
Milnes E, Delnatte P, Dutton CJ, Brouwer E, Cai HY, Smith DA, Peregrine AS.A 23-yr-old captive-born Przewalski's horse mare ( Equus przewalskii) was euthanized at a Canadian zoo because of severe colic resulting from rupture of a jejunal pseudodiverticulum. An incidental finding of an encysted larval cestode within a hepatic granuloma was diagnosed on histopathology. Gel-based polymerase chain reaction (PCR) on liver tissue was positive for Echinococcus granulosus sensu lato, and deoxyribonucleic acid sequencing of the PCR product was 100% homologous with Echinococcus equinus. This appears to be the first molecular confirmation of E. equinus in North America, and the...
Thurston CC, Stefanovski D, MacKinnon MC, Chapman HS, Richardson DW, Levine DG.The objective of this study was to determine the diagnostic ability of serum amyloid A (SAA) and fibrinogen for early detection of surgical site infection (SSI) after equine internal fixation. Horses undergoing internal fixation for fracture, arthrodesis, or osteotomy with internal fixation for limb deformity were included in the study. SAA and fibrinogen were measured on blood samples preoperatively and on days 1, 3, 5, 7, 10, and 14 postoperatively. Statistical analysis included use of Spearman's rank correlation, logistic regression, and calculating the area under the receiver operating cha...
