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.
Sugar O.Reports of pathologic investigations as to the cause of intermittent claudication in horses were made in France in October, 1831, by veterinarian Jean-François Bouley. Obstructive clots in the femoral arteries were found to be responsible for the muscular changes causing limping. Bouley's work in the horse was used by Charcot in 1858 to understand the mechanism of claudication in the case of a soldier with gunshot wound in whom a traumatic aneurysm, clotting, and ischemia of the legs developed. This was not, however, the first medically reported case of human claudication from vascular occlus...
Hoberg EP, Miller S, Brown MA.We report the first documented case of autochthonous echinococcosis in a horse of North American origin. Three fully mature and viable unilocular hydatid cysts of Echinococcus granulosus (Batsch, 1786) were an incidental finding at necropsy in the liver of a 14-yr-old gelding thoroughbred that had been foaled in Virginia and raised in Maryland. Protoscolices were armed with 2 rows of 28-37 rostellar hooks; small hooks measured 23-30 microns; large hooks measured 26-33 microns. Morphologically, these were compatible with rostellar armature considered typical for the equine strain of E. granulos...
Jang SS, Hirsh DC.During the years from 1984 through 1991, 1,067 specimens from canine, equine, exotic, feline, porcine, and ruminant animal sources were found to contain members of the genus Fusobacterium: The most common sites or conditions from which members of this genus were isolated were abscesses, the respiratory tract, and pleural and peritoneal cavities. Most specimens contained a single Fusobacterium species. The most commonly isolated species was Fusobacterium necrophorum. Almost all of the specimens contained other obligate anaerobes together with facultative and obligate aerobes. The identities of ...
McClure JR, Chapman MR, Klei TR.Since 1978, 20 surgical implantations of either Strongylus vulgaris or Strongylus edentatus have been performed in our laboratory for the purpose of obtaining single species cultures of these parasites. Following surgical implantation peak EPG values of 13-327 (S. vulgaris) and 363-1284 (S. edentatus) generally occurred during the first 3 weeks post-implantation. Duration of infections was as long as 5 years. Successful outcome of such surgeries appears to be related to the total number of parasites used (> or = 38) and the ratio of female to male worms implanted (1:1 or 2:1).
Tanaka S, Kaji Y, Taniyama H, Matsukawa K, Ochiai K, Itakura C.Typical Pneumocystis carinii pneumonia was found in a male thoroughbred foal (46 days old) suffering from diarrhea and hypogammaglobulinemia after birth. The characteristics of the organisms were demonstrated by Grocott methenamine silver staining, and scanning and transmission electron microscopy. The present focal had no histological lesions suggesting immunodeficiency. However, he could not get adequate colostrum from his dam, because she died of hemorrhagic shock due to immuno-mediated thrombocytopenia at delivery. This condition was considered to have predisposed the foal to the pneumonia...
Zimmermann W, Dürrwald R, Ludwig H.Borna disease virus in naturally infected horses, a donkey and sheep was detected for the first time by amplification of viral RNA using PCR. In contrast to a control group of healthy horses, brain tissue was positive by this assay in all animals with neurological symptoms. The use of a second round of PCR with nested primers following Southern hybridization confirmed the specificity and increased the sensitivity of the test. Comparison with conventional methods recommends this technique for monitoring of BDV infections at a molecular level.
McD○ LA, Dart AJ, Schiffman P, Parrot JJ.Enterolithiasis, as a cause of colic, was diagnosed and treated during surgical intervention in 2 Grant's zebras (Equus burchelli bohmi). The zebras were part of a wild herd in a zoo in the western United States. The clinical signs of enterolithiasis in both zebras were similar to those reported for horses. Analysis of the enterolith from 1 zebra revealed a composition identical to enteroliths that have been analyzed from horses. Three other zebras from this herd had enteroliths at necropsy. Enterolithiasis should be considered as a differential diagnosis for zebras with low-grade obstructive ...
Shams Eldin HE, Kirchhoff H.Tracheal swabs were taken from 25 horses with respiratory diseases and investigated for mycoplasmas using three different media. Mycoplasmas could be isolated from 5 horses. The isolates were characterized by serological and biochemical methods. Four isolates could be identified as Mycoplasma equirhinis. The fifth isolate could not be typed. It did not react with antisera against mycoplasmas found in the respiratory tract of horses and its biochemical characteristics were different from the mycoplasmas described so far. It may represent a new species.
Kuwamura M, Iwaki M, Yamate J, Kotani T, Sakuma S, Yamashita A.A 9-year-old male horse showed emaciation, weakness and trembling and was euthanatized. Histopathological examinations revealed loss, swelling and chromatolysis of motor neurons throughout the spinal ventral horns, axonal degeneration of the ventral spinal roots. Eosinophilic cytoplasmic inclusions were distributed in degenerated spinal ventral neurons. Ultrastructurally, the inclusions consisted of aggregations of granular dense material and a few vesicles. They reacted positively with polyclonal antibody against ubiquitin. The present case was diagnosed as equine motor neuron disease, which ...
Van Duijkeren E, Vulto AG, Van Miert AS.The indications for use, side-effects, and pharmacokinetic parameters of trimethoprim, sulfonamides and their combinations in the horse are reviewed. Trimethoprim/sulfonamide (TMPS) combinations are used for the treatment of various diseases caused by gram-positive and gram-negative bacteria, including infections of the respiratory tract, urogenital tract, alimentary tract, skin joints and wounds. TMPS combinations can be administered orally, since absorption from the gastrointestinal tract is relatively good. However, peak serum concentrations can vary significantly between individual horses....
van Gorkom LP, van Wessum R, van den Hoven R.A major part of the residing horses and ponies of a riding school in Noord-Holland became affected by a febrile disorder that included anorexia, depression, conjunctivitis, urticaria, edema of the legs and laborious locomotion. All remaining horses fell ill within one week. Based on the clinical symptoms the disorder was diagnosed as vasculitis. With serology the causative agent of the disorder appeared to be equine arteritis virus.
Zapf F, Schein E.The development of the piroplasm Babesia equi was studied by light microscopy in the gut and the haemolymph of three different Hyalomma species during and after the nymphs had engorged on parasitaemic horses. The stock of B. equi used was isolated from a horse imported from Turkmenistan (CIS) in 1991. The existence of gamogony was identified by the occurrence of gamonts and gametes in the gut contents of the nymphs at between 3 and 4 days after infestation of the nymphs, before the ticks dropped off the experimentally infected horses. Zygotes and kinetes were observed in the intestinal cells f...
Xiao L, Herd RP.Diarrhoea is one of the most important diseases of foals and
7040% are affected within the first 6 months of life (Palmer
1985). Although the cause is multifactorial and changes in the
physiology and nutrition of foals are sometimes responsible,
diarrhoea is frequently the result of infection by enteropathogens
such as bacteria, viruses and nematodes (Palmer 1985; Tzipori
1985). There is increasing evidence that Cryptosporidium
infection can also cause diarrhoea in foals (Austin et a/. 1990;
Kim 1990).
Cryptosporidiosis in horses is caused by Cryptosporidium
parvum, a coccidial paras...
Peters SE, Wakefield AE, Whitwell KE, Hopkin JM.Genetically distinct forms of Pneumocystis carinii infect several mammalian hosts. We report the amplification of P. carinii DNA from samples of two infected thoroughbred foal lungs by using primers designed from the sequence of a P. carinii mitochondrial rRNA gene; these primers also prime the amplification of P. carinii DNA from other hosts. The nucleotide sequence of part of the mitochondrial rRNA gene amplified from P. carinii infecting one of the foals was determined and found to be distinct from that of published rat-, rabbit-, ferret-, and human-derived P. carinii sequences.
Ghram A, Chabchoub A, Turki I, Boussetta M, Ibn Amor H, Ghorbel A.A seroepidemiological survey was realized in the Nord-Est Tunisia to study the prevalence of complement fixing and neutralizing antibodies to equine rhinopneumonitis and viral arteritis of horse, respectively. Four hundred sera were tested, using complement fixation reaction and seroneutralization test. The results show that 8.75% of sera have antibodies to viral arteritis and only 1.25% are positive for equine rhinopneumonitis.
Spiers S, May SA, Harrison LJ, Bennett D, Edwards GB.Significant amounts of collagenase and caseinase activity were detected in infected synovial fluid samples. Partial characterisation of the enzymes by gel filtration suggested that synovial fluid from cases of infectious arthritis may contain enzymes from both the synovial cells and neutrophils. This finding was also supported by analysis of sequential synovial fluid samples from 4 infected joints. In 3 joints the concentration of caseinase and in 1 joint collagenase paralleled the decline in total nucleated cell count. However, in 3 joints the concentration of collagenase remained high after ...
Murray RC, Gaughan EM, Debowes RM, Huston LC, Cooper VL, Welsh T.A 4-month Arabian filly presented for abdominal pain of 30 hours duration was found to have tachycardia, tachypnea, congested mucous membranes and gross abdominal distension. Further examination disclosed gastric reflux and small intestinal distension. Dehydration, prerenal azotemia, electrolyte abnormalities and metabolic alkalemia were observed. There was a progressive nonresponse to analgesic medication and deterioration in the foal's physiologic condition consistent with a small intestinal strangulating obstruction. Surgical exploration was declined. Necropsy examination revealed incarcera...
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...
Sahu SP, Alstad AD, Pedersen DD, Pearson JE.Immunoglobulin M (IgM) and G (IgG) capture enzyme-linked immunosorbent assays (ELISAs) were used as possible adjuncts to hemagglutination inhibition (HI) and virus neutralization (VN) tests to differentiate between reaction to recent exposure to eastern equine encephalomyelitis (EEE) virus and those due to prior vaccination. Serum samples were evaluated by the IgM-capture ELISA, and the results were compared with those of HI and VN tests. Of 381 serum samples, 51% (195 samples) were positive by HI test (> or = 1:40) and 54% (205 samples) were positive by VN test (> or = 1:10), but only 3...
Bonass WA, Hudson WA, Elton DM, Killington RA, Halliburton IW.Restriction enzyme digests of DNA from 22 unselected isolates of EHV-1 were analysed by hybridization with cloned DNA fragments covering the genome. In addition to a small amount of inter-strain variation, heterogeneity within strains was observed, caused by loss of specific restriction endonuclease sites in the DNA of a proportion of the virus particles of any one stock. Fifteen strains demonstrated the same intra-strain variation involving loss of the BamHI L-M site which was shown to lie within coding sequence for the large subunit of ribonucleotide reductase. This particular mutation may t...
van Nieuwstadt RA, Kalsbeek HC.In a horse with chronic unilateral nasal discharge guttural pouch mycosis caused by Aspergillus fumigatus was diagnosed. A percutaneous indwelling catheter was surgically installed in the left guttural pouch. Initial treatment with a povidone iodine solution proved to be unsatisfactory. Treatment was continued by administering enilconazole by ways of an indwelling through-the-nose-catheter. The latter treatment resulted in complete recovery.
Bemis DA, Bryant MJ, Kania SA, Newman SJ.Based on the scarcity of reports in veterinary medicine literature, it appears that Arcanobacterium spp. are rarely isolated from horses. Recently, a single isolate from vaginal discharge in a mare was characterized as a new species, Arcanobacterium hippocoleae. The present report describes a case of necrosuppurative placentitis and stillbirth in an American Quarterhorse mare. Numerous colonies of irregular, Gram-positive, rod-shaped bacteria were observed by histological examination within fibrin lattice associated with placental lesions. Arcanobacterium hippocoleae was isolated in large numb...
Leonel JAF, Tannihão B, Arantes JA, Vioti G, Benassi JC, Brandi RA, Ferreira HL, Keid LB, Soares RM, Oliveira TMFS.Visceral leishmaniasis (VL) is a neglected tropical disease caused by the Leishmania infantum parasite. The protozoan is able to infect several domestic and wild mammals. Since the first report on Leishmania spp. infection in horses in South America, leishmaniasis in equids has been highlighted in Brazil. A molecular epidemiological survey was carried out to verify the occurrence of Leishmania spp. DNA in horses and donkeys, in leishmaniases endemic areas in Sao Paulo State, Brazil. To this end, blood samples were obtained from 107 horses and 36 donkeys and subjected to DNA extraction followed...
Adeppa J, Ananda KJ, Krishna Murthy CM, Satheesha GM.A study was conducted to ascertain the incidence of gastrointestinal parasites in horses of Shimoga region, to generate the data regarding status of parasitic infections of equines in Karnataka state due to paucity of information. A total of 100 fresh fecal samples of equines were collected and examined by direct and sedimentation method for the detection of parasitic egg/ova. Among 100 samples examined, 84 (84.0 %) were found positive for various gastrointestinal helminths. Out of 84 positive cases, 44 (52.38 %) were found positive for Strongylus spp. eggs, 09 (10.71 %) showed Parascaris e...
Spier S, Carlson GP, Nyland TG, Snyder JR, Fischer PE.An 8-year-old gelding with a 3-month history of anorexia and weight loss was found to have a massive subcapsular splenic hematoma. At flank laparotomy, 36 L of fluid was removed from the hematoma. The horse's condition improved after drainage. Fifteen months later, the horse became depressed and febrile. A splenic abscess containing Bacteroides ruminicola and Clostridium sporogenes was found at necropsy.
May CE, Schulman ML, Howell PG, Lourens CW, Gouws J, Joone C, Monyai MS, le Grange M, Bezuidt OK, Harper CK, Guthrie AJ.Taylorella equigenitalis is the causative agent of contagious equine metritis (CEM), a sexually transmitted infection of horses. We report here the genome sequence of T. equigenitalis strain ERC_G2224, isolated in 2015 from a semen sample collected in 1996 from a Lipizzaner stallion in South Africa.
Goebel WF, Staub AM.1. The immunization of horses with the colicinogenic bacillus E. coli K235 L + O(m) stimulates antibodies which precipitate and neutralize colicine K and neutralize the heterologous colicine I as well. 2. Unlike rabbits, horses evoke predpitating antibodies for the sialic acid-containing polysaccharide colominic acid.
Barber SM.A three year old Thoroughbred filly was examined because of bilateral nasal discharge and external swelling of the left laryngeal area. Endoscopy revealed an enlarged left arytenoid cartilage, left laryngeal hemiplegia and drainage of purulent material into the lumen of the larynx. Radiographs showed a large fluid and gas filled cavity overlying the caudal larynx and cranial trachea. Surgical drainage and debridement of the abscess led to complete healing by secondary intention. Laryngeal ventriculectomy was performed as a treatment for left laryngeal hemiplegia, but a grave prognosis for resp...
Rousseaux CG, Futcher KG, Clark EG, Naylor JM.Two cases of cauda equina neuritis are compared and contrasted. Neurological deficits of the tail and perineum were noted and functional deficits were seen in gait, urination, defecation and cranial nerve function. Lesions consisted of nonsuppurative inflammation of the nerve trunks and proliferation of the perineurium of the cauda equina. Cranial nerve involvement in one case supported a diagnosis of polyneuritis equi rather than cauda equina neuritis. The possible etiologies and pathogenesis of this disease are discussed.
Etana D.Samples were collected from clinically infected carthorses in Awassa. Fungus species affecting the carthorses were identified. Eight genera of fungal groups were isolated from swabs and skin scrapes taken from symptomatic horses. These included Aspergillus spp., Histoplasma spp., Penicillium spp., Microsporum spp., Trichophyton spp., yeast cells of Candida spp., Cryptococcus spp. and Geotrichum spp. The most frequent isolates were from the genera Aspergillus (48%), Penicillium (39.2%) and Trichophyton (31.6%). Clinical findings are reported, the economic, zoonotic and pathogenetic importance o...
Soza-Ossandón P, Rivera D, Allel K, González-Rocha G, Quezada-Aguiluz M, San Martin I, García P, Moreno-Switt AI.Healthcare-associated infections caused by Staphylococcus, particularly Staphylococcus aureus, represent a high risk for human and animal health. Staphylococcus can be easily transmitted through direct contact with individual carriers or fomites, such as medical and non-medical equipment. The risk increases if S. aureus strains carry antibiotic resistance genes and show a phenotypic multidrug resistance behavior. The aim of the study was to identify and characterize methicillin resistant coagulase-positive staphylococci (MRSA) and coagulase-negative staphylococci (MRCoNS) in equine patients an...
Horner GW, Hunter R.Two serologically unrelated adenoviruses were isolated from ill-thrifty young horses on a thoroughbred stud. The viruses differed in their cytopathic effects in cell culture and in their haemagglutination properties. A serological survey of horses in the northern half of the North Island showed the prevalence of precipitating antibodies against equine adenoviruses to be 39%.
Wauters J, Martens A, Pille F, Dumoulin M, Gasthuys F, Sys S, Meyer E.Synovial fluid samples from culture-confirmed infected joints (n=13), joints with pronounced non-infectious synovitis (n=11) and healthy joints (n=14) were collected from 24 equine patients and seven slaughterhouse horses. The samples from the joints with non-infectious synovitis and healthy joints served as negative controls. After isolation, counting and identification of neutrophils, the percentage viability, and the proportion apoptotic and necrotic neutrophils were determined by flow cytometry. Viability was significantly higher in infected samples compared to the controls. A significant ...
Bowman DD, Cummings JF, Davis SW, deLahunta A, Dubey JP, Suter MM, Rowland PH, Conner DL.Morphological information is presented for syntype material of the etiologic agent of equine protozoal myeloencephalitis, Sarcocystis neurona. A clinical description of the horse from which the organism was isolated and the methodology used to immunosuppress the horse in an attempt to increase parasite numbers are also given. The description includes microscopic details observed both with light and transmission electron microscopy. Mainly stages from tissue are illustrated, but information is also presented on the development of the organism after inoculation onto monolayers of bovine monocyte...