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.
Kobluk CN, Ducharme NG, Lumsden JH, Pascoe PJ, Livesey MA, Hurtig M, Horney FD, Arighi M.From May 1, 1983 to April 1, 1985, 142 operations were performed on horses with signs of acute abdominal pain (colic), using a ventral midline incision. Seventy-eight horses lived for at least 15 days after surgery or had acute dehiscence and were included in the study. Seventy horses had surgery once, and 8 horses had surgery 2 or more times. Six-month follow-up evaluation was obtained for 66 horses that had 1 surgery and for 6 horses that had multiple surgeries. Incisional complications included drainage (including infection), acute dehiscence, hernia, and suture sinus formation. The effects...
Grundy FJ, Baumann RP, O'Callaghan DJ.The immediate early (IE) proteins of herpesviruses are important regulatory factors which control the expression of genes at the transcriptional level. We report the DNA sequence of the immediate early gene of the alphaherpesvirus equine herpesvirus type 1 (EHV-1). This sequence is shown to be extremely rich in guanine and cytosine, resulting in a highly biased codon usage. The IE gene region possesses 38 open reading frames (ORFs) greater than 300 bp in length, 11 of which have coding regions of at least 100 amino acids (aa) following potential translation initiator codons. The largest ORF co...
Gray WL, Yalamanchili R, Raengsakulrach B, Baumann RP, Staczek J, O'Callaghan DJ.Equine herpesvirus type 1 (EHV-1) preparations enriched in defective interfering particles (DIPs) have previously been demonstrated to mediate the coestablishment of persistent infection and oncogenic transformation in primary hamster embryo fibroblasts. In this study, it was demonstrated that infection of a rabbit kidney (RK) cell line with EHV-1 DIP-enriched preparations also results in the establishment of persistent infection. Viral transcription was characterized in RK cells infected with DIP-enriched stocks and compared to viral transcription in RK cells infected with standard (STD) EHV-...
Young DR, Divers TJ, Benson CE.Clinical septicemia developed in 2 clinically normal horses after both were administered a portion of an amino acid solution IV. Serratia marcescens was subsequently isolated from blood of both horses. The isolates were shown to be identical on the basis of antibiograms and plasmid biochemistry, incriminating the infusate as the source of bacterial infection. The horses recovered after supportive and antimicrobial treatment.
Slocombe JO, Cote JF, McMillan I.Twenty-eight horses with a residual burden of strongyle eggs in the faces after treatment with mebendazole (MBZ) paste were treated with a suspension of either MBZ or oxibendazole (OBZ). Fecal samples were collected before and 14 days after these treatments. The number of strongyle eggs/g (epg) of feces for each horse was estimated using the Cornell-McMaster dilution and the Cornell-Wisconsin double centrifugation procedures. The epg for each horse was transformed using log (x + 1) and in an analysis of variance of the reduction in egg count for each horse on the logarithmic scale, there was a...
Higashi T, Harasawa R.The three equine adenovirus strains isolated in different locations showed a similar cleavage pattern with HindIII and the DNA homology among the strains was confirmed by Southern blot hybridization. The three strains revealed differences in cleavage patterns with BamHI, EcoRI and PstI, suggesting the presence of DNA polymorphisms among equine adenoviruses.
Monos DS, Wolf B, Radka SF, Rifat S, Donawick WJ, Soma LR, Zmijewski CM, Kamoun M.Six mouse and 13 rat monoclonal antibodies (mAb) recognizing HLA-DR, DQ and DP antigens were used for the detection of cell surface class II MHC antigens of equine lymphocytes. The monoclonal antibodies were tested against peripheral blood lymphocytes (PBL) from a panel of thoroughbred horses, using two-color fluorescence flow cytometry. Seven of these mAbs reacted with both surface immunoglobulin positive (sIg+) and surface immunoglobulin negative (sIg-) lymphocytes. sIg+ cells stained consistently brighter than sIg- cells. The fluorescence pattern did not vary from donor to donor for each of...
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.
Wolfman EF.Operations for intestinal ischemia are frequently done by veterinarians. In equine surgery those conditions commonly producing ischemia are intussusception, volvulus, bowel obstructions, and incarcerated hernias. In an attempt to predict intraoperative bowel viability after the restoration of circulation, a variety of adjuvant methods have been investigated. There is little question that of the techniques currently available, sodium fluorescein injected intravenously approaches the ideal in predicting nonviability in humans and in most animal models. Furthermore, it is safe, takes little opera...
Bertone AL.With large colon resection and anastomosis, up to 95 per cent of the length of the large colon has been successfully removed. A hand-sewn end-to-end anastomosis is effective for lesions in the left dorsal colon and pelvic flexure. Transection and a side-to-side anastomosis with stapling equipment is most effective for extensive resections (greater than 50 per cent). Horses with extensive colon resection (95 per cent) have permanent deficiencies of water absorption and digestion of cellulose and protein. Fermentative capacity is reduced, owing to decreased particulate matter retention time in t...
Ross MW.Cecal impaction and cecal perforation, the two most common equine cecal diseases, are thought to develop after slowing or interruption of a single progressive motility pattern, which begins in a pacemaker area near the apex, occurs once every 3 minutes, and propels ingesta from the cecum to the right ventral colon. Rectal examination in horses with cecal impaction is the most useful technique to grade the severity of the condition. Medical treatment is undertaken if the impaction is judged to be mild to moderate. Surgical correction of cecal impaction in severe cases requires a ventral midline...
McManus DP, Rishi AK.A segment of the ribosomal RNA gene of Schistosoma mansoni and a DNA fragment specific to Echinococcus granulosus, cloned in plasmids, have been used as DNA probes to assess the extent of genetic variability within E. granulosus and some distinct strains have been identified. The DNA analysis, involving restriction endonuclease digestion and Southern blot hybridization with the probes, did not demonstrate any significant genetic variation within the U.K. horse/dog or sheep/dog strains but confirmed the distinctiveness of the two strains shown in previous studies. The sheep/dog strain was shown...
Morris DD, Harmon BG, Moore JN.A study was performed to determine whether equine antiserum to core lipopolysaccharide (LPS) would enhance phagocytosis of smooth gram-negative (GN) organisms by equine macrophages. Five healthy adult horses (group A) were immunized with a bacterin prepared from the J-5 mutant of Escherichia coli 0111:B4 and Salmonella minnesota R595 to produce antibodies to core LPS. Five horses (group B) served as nonimmunized controls and were given physiologic saline solution instead of the rough mutant bacterin. Serum antibody titers to core LPS and to smooth E coli 0111:B4 were determined by indirect ELI...
Bailey M, Martin SC, Lloyd S.Immunologic and hematologic responses were examined in 4 ponies with experimentally induced Strongylus vulgaris infection and in 5 helminth-free ponies. Two ponies were inoculated with 200 larvae and 2 were inoculated with 700 larvae of S vulgaris and then were reinoculated with the same numbers of larvae 34 weeks later. Initial response of the ponies inoculated with S vulgaris was S vulgaris antigen-induced lymphocyte response that developed 1.5 to 3 weeks after inoculation and did not persist. Development of antigen-reactive lymphocytes was followed sequentially by a biphasic complement-fixi...
Edington N, Bridges CG, Griffiths L.When 23 ponies were infected with equid herpesvirus-1 or -4 (EHV-1 or EHV-4), nasal shedding of interferon (IFN) correlated closely with the duration of viral excretion. Equine interferon (EqIFN) was detected in the serum only from animals infected with the EHV-1 virus, and here high levels correlated with clinical symptoms of locomotor disorder and indicated a poor prognosis. Low levels of IFN were detected in explanted mononuclear cells from ponies infected with either virus.
van der Kolk JH, Sloet van Oldruitenborgh-Oosterbaan MM, Gruys E.A six-year-old pregnant Haflinger mare of 510 kilograms died from bilateral pleurisy following a hospitalisation period of ten days, during which she was treated with various antibiotics. At necropsy a bilateral fibrinopurulent pleurisy accompanied by an ulceration of the cardia of the stomach measuring once cm2 was found. In the wall of the oesophagus, close to the cardia, there was a fistula harbouring a 3rd stage Gasterophilus larva. The epithelial layer at this site was unimpaired and no gross connection between the fistula and the ulceration of the cardia was observed. The fistula was in ...
Mair TS, Taylor FG, Pinsent PJ.Fever of unknown origin (FUO) is a syndrome characterised by prolonged, unexplained fever associated with non-specific signs of illness such as lethargy, inappetence and weight loss. This paper reviews the details of 63 horses affected by FUO. The cause was found to be infection in 43 per cent of the cases, neoplasia in 22 per cent, immune-mediated diseases in 6.5 per cent and miscellaneous diseases in 19 per cent; the cause remained undiagnosed in 9.5 per cent.
Spier SJ, Lavoie JP, Cullor JS, Smith BP, Snyder JR, Sischo WM.Thirty-two horses with clinicopathologic evidence of endotoxic shock were randomly selected for a double-blind trial of hyperimmune lipopolysaccharide (LPS) core antigen plasma. Horses were suffering from acute toxic enteritis (n = 15), 360 degrees volvulus of the large colon (n = 9), proximal jejunitis/duodenitis (n = 6), or strangulating obstruction of the small intestine (n = 2). Plasma was harvested from suitable equine plasma donors (preimmune plasma) and horses were immunized with a whole-cell bacterin of an Rc mutant E. coli (J5). Plasma was again harvested from these horses when IgG EL...
Hannant D, Mumford JA.Cytotoxic cell precursors and/or cytotoxic memory cells were demonstrated in the peripheral blood of ponies after aerosol infection with influenza A/equine/Newmarket/79 (H3N8). In order to reveal their cytotoxic potential, peripheral blood mononuclear cells required a secondary antigenic stimulation. In vitro induced cytotoxic cells showed activity against influenza infected target cells in a 3-4 h 51Cr-release assay. The reactivity of cytotoxic cells was markedly influenced by the conditions of the secondary induction culture. If high concentrations of exogenous crude equine IL-2 were used, v...
van den Ingh TS, Hartman EG, Bercovich Z.A Leptospira interrogans serogroup australis serovar lora infection in a stud farm is reported. During three successive years (1984-1986) clinical leptospirosis with a severe often rapid, fatal course was seen in 12 foals. Clinical examination revealed severe respiratory distress, depression and pyrexia. Other symptoms were diarrhea (2), jaundice (1), and an unsteady gait (1). Morphological characteristics of the disease were massive pulmonary haemorrhage and haemorrhagic-thrombotic or extracapillary glomerulonephritis with tubulonephrosis and interstitial oedema. In most foals high or increas...
Saikku A, Koskinen E, Sandholm M.IgG levels and tryptic inhibition were investigated in sequentially collected mare's colostrum and milk, foal serum and urine. The colostral trypsin-inhibitor was "transfused" to the newborn foal by the colostral intestinal route in parallel with IgG. However, the trypsin-inhibitor as a small molecular weight inhibitor became excreted into urine peaking at about 20 hours. The physiological proteinuria in foals during the first 2 days is mostly due to immunoglobulin fragments and colostral-derived trypsin-inhibitor. Analysis of urine for IgG light chains or trypsin inhibitor will therefore reve...
Martens RJ, Martens JG, Fiske RA, Hietala SK.The immunoprophylactic capacity of specific immune plasma was evaluated in pony foals infected experimentally with Rhodococcus equi. Immune plasma, produced by repeated parenteral administration of viable R. equi to adult horses, was harvested and frozen. Group I (six control foals) and Group II (six principal foals) received lactated Ringers solution and immune plasma respectively at three and five days of age. R. equi were aerosolised into a caudal lung lobe of all foals at seven days of age. Clinical signs, haematological alterations, immune responses, thoracic radiographs and technetium99m...
Reef VB, Collatos C, Spencer PA, Orsini JA, Sepesy LM.Infection of umbilical arteries, umbilical vein, and/or urachus was diagnosed ultrasonographically in 33 foals 1 to 90 days old (mean, 17.7 +/- 17.3 days). In these foals, the most common initial problems were umbilical abnormalities, septic arthritis, and/or neonatal septicemia. In 16 foals, abnormalities of the external umbilical stalk were noticed on admission. Abnormalities of the internal umbilical structures were identified when enlargement and echogenic material (fluid and/or gas) were imaged ultrasonographically within these structures. Multiple structures were affected in 23 foals, wi...
French DD, Klei TR, Taylor HW, Chapman MR.Twenty-one mixed-breed pony foals, reared and maintained under parasite-free conditions, were used to test the efficacy of ivermectin in oral drench and paste formulations (200 micrograms/kg) against 11-day-old migrating larvae of Parascaris equorum. Three replicates of 4 foals and 3 replicates of 3 foals were formed on the basis of age. Foals in replicates of 4 were randomly allocated to be indicators, or to receive vehicle (control) or ivermectin paste or ivermectin liquid. Foals in replicates of 3 were randomly allocated to receive vehicle or ivermectin paste or ivermectin liquid. The recov...
Kohn CW, Knight D, Hueston W, Jacobs R, Reed SM.Immunoglobulin G, IgM, and IgA concentrations were measured in serum collected from 36 Standardbred mares within 12 hours of foaling, in colostrum collected within 6 hours of foaling, and in serum collected from foals 24 to 48 hours after birth. In serum collected from mares after parturition, mean concentrations of IgG, IgM, and IgA were 2,463.9 +/- 1,337.3 mg/dl, 136.4 +/- 218 mg/dl, and 305.2 +/- 237.5 mg/dl, respectively. In serum from foals, mean concentrations of IgG, IgM, and IgA were 1,953.3 +/- 1,635 mg/dl, 33.8 +/- 30.4 mg/dl, and 58.4 +/- 42.2 mg/dl, respectively. In colostrum, mean...
Van Camp SD, Mahler J, Roberts MC, Tate LP, Whitacre MD.An ovarian adenocarcinoma with teratomatous elements was removed from a 9-year-old mare. Although no other lesions were detected at ovariectomy, multifocal metastatic masses led to cachexia and euthanasia 2 months later. This case reaffirms the need to exercise caution when removing ovarian masses to prevent seeding of the abdomen. This report includes discussion of the WHO system of classification of ovarian tumors.
Wilson DG, Mays MB, Colahan PT.Seven horses with canker had radical surgical debridement and various irritant substances applied to the wounds. Four of the horses were clinically normal in (mean) 3.6 months, 1 mare was lame, and 2 horses were euthanatized because of complications of their treatments. Seven horses that had minor surgical debridement and antimicrobial agents used systemically and topically were clinically normal in (mean) 1.4 months. Seemingly, canker in horses should be managed using minor surgical debridement and appropriate antimicrobial therapy.
Sconza S, Di Cesare A, Iorio R, Bartolini R, Paoletti B, Traversa D.Cyathostomins, or 'small strongyles', are the most important equine helminths because of their worldwide distribution, spread of anthelmintic‑resistant populations, and pathogenic impact. The so‑called 'selective treatment' of those animals exceeding a certain faecal egg count (FEC) has recently been proposed to implement cyathostomin control programmes. The present study evaluated the extent of egg shedding in 475 horses living in 12 farms from 3 regions of Italy. All examined farms and 224 horses (47.6%...
Pascoe JR, Ellenburg TV, Culbertson MR, Meagher DM.A 360-degree torsion of the left spermatic cord was diagnosed in a 2 1/2-year-old Quarter Horse colt. Clinical signs included abdominal discomfort, with slight elevations in heart and respiratory rates. The scrotum on the left side was moist and edematous. The left testicle was enlarged, firm, and retracted slightly toward the abdominal cavity. The colt resented palpation of the testicle. On rectal palpation, the left vaginal ring and the structures passing through the ring were edematous and painful to pressure. Surgical correction was achieved by emasculation. The tail of the epididymis and ...
Siedek EM, Whelan M, Edington N, Hamblin A.Equine herpesvirus type 1 (EHV-1) causes respiratory disease, abortion and myeloencephalopathy in horses. As with other herpesviruses, cell-mediated immunity is considered important for both recovery and protection. Although virus-specific T-cell proliferation and cytotoxicity can be detected following in vivo infection, little is known about the role of antigen presenting cells such as dendritic cells (DCs) in these processes. Peripheral blood DCs were shown to express the viral glycoprotein gB perinuclearly following exposure to EHV-1 in vitro, demonstrating EHV-1 replication within them. Co...
Orsini JA, Nunamaker DN.A 4-year-old Standardbred stallion sustained a severely comminuted fracture involving the second, third, and fourth metacarpal bones. The fracture was repaired using two 14-hole broad dynamic compression plates positioned at 90 degrees to one another, allowing one plate to protect the other in the bending mode. An autologous cancellous bone graft obtained from the tuber coxae was added at the site of the defect in the mid- to upper third of the third metacarpal bone. Complications associated with the fixation included a Staphylococcus aureus infection 5 months after surgery, laminitis that dev...
Obi TU, Taylor WP.Serum samples collected from 1,197 goats, 586 sheep, 254, cattle, 55 dogs and 44 horses were examined for antibodies to adenovirus by the agar-gel precipitation test. Results show that 17.7% of the goats, 18.4% of the sheep, 4.3% of the cattle, and 4.5% of the horses had precipitating antibodies. None of the dog sera examined was positive. The results seem to indicate a moderate level of previous exposure to adenovirus infection especially among goats and sheep in Nigeria.
Perillo A, Passantino G, Passantino L, Cianciotta A, Mastrosimini AM, Lacovazzi P, Venezia P, Jirillo E, Troncone A.Among 622 slaughtered horses from eastern Europe, 156 thyroid glands were selected on the basis of macroscopic alterations (e.g., determination of volume and weight). In the 80% of these thyroids, microscopic alterations consistent with a diagnosis of Hashimoto thyroiditis-like disease were found. In particular, a subverted architecture of the thyroid gland with colloid rarefaction, lymphocytic infiltration, and fibrosis was noted. The confirmation of the histopathological diagnosis of an equine Hashimoto thyroiditis-like disease was provided by the increased serum concentration of thyroglobul...
Gilliam LL, Ownby CL, McFarlane D, Canida A, Holbrook TC, Payton ME, Krehbiel CR.Rattlesnake bites in horses are not uncommon and the clinical outcomes are widely variable. Treatment of horses with anti-venom is often cost prohibitive and could have negative consequences; therefore, the development of a quantitative test to determine if anti-venom therapy is indicated would be valuable. The objective of this study was to develop an ELISA to detect rattlesnake venom in biological samples from clinically bitten horses. Nineteen horses were enrolled in the study. Urine was available from 19 horses and bite site samples were available from 9 horses. A double sandwich fluoresce...
English AW.The seasonal changes in longevity on herbage of the infective larvae of strongylid nematodes of the horse were studied. During the summer months, 1% of the larvae survived on herbage for 2-3 weeks, with 0.2% still viable for a further 2-3 weeks. Equivalent survival periods in winter were 7-11 weeks and over 11 weeks respectively. During spring and autumn, larvae survived for periods varying from 3-8 weeks. On Rhodes grass (Chloris gayana) growing vigorously in the summer of 1976, the majority of larvae remained in the lowest layers of the pasture, within 10 cm of the soil surface. Very few rea...
Bolin DC, Donahue JM, Vickers ML, Harrison L, Sells S, Giles RC, Hong CB, Poonacha KB, Roberts J, Sebastian MM, Swerczek TW, Tramontin R, Williams NM.During the spring and summer of 2001 and in association with the mare reproductive loss syndrome, 22 terminal and 12 clinical cases of equine pericarditis were diagnosed in central Kentucky. Actinobacillus species were the principal isolates from 8 of 10 nontreated, terminally affected and 3 of 10 clinically affected horses. Enterococcus faecalis and Streptococcus zooepidemicus were cultured from the remaining 2 nontreated terminal cases. No viruses were isolated in tissue culture. Nucleic acid of equine herpesvirus-2 was detected in pericardial and tracheal wash fluids of 3 and 1 individuals,...
Ragle CA, de Mira MC, Pearson LK, Coelho JC.A 2-year-old Quarter Horse was evaluated because of a progressive left-sided facial deformity and unilateral nasal and ocular discharge. Results: Physical examination revealed convexity of the left frontonasal region, left-sided nasal and ocular discharge, and decreased air flow through the left nares. Radiography and computed tomography revealed an extensively mineralized mass occupying most of the left paranasal sinuses. Results: The mass was surgically debulked, but complete removal was precluded because the mass was tightly adhered to the frontal and maxillary bones. Results of histologic ...
Neill SD, O'Brien JJ, McMurray CH, Blanchflower WJ.Cellular fatty acid compositions of contagious equine metritis isolates and three reference Haemophilus equigenitalis cultures were determined by gas chromatography. The chromatographic data were standardised and normalised fatty acid methyl ester (FAME) profiles were produced. The profiles were compared visually and similarity indices were determined using a computer peak matching method. There was little difference between the profiles of the three reference strains, each strain being characterised by three major fatty acids; C 18:1, C 16:0 and 30H-C 14:0. Variations in cultural conditions h...
Minato E, Aoshima K, Kobayashi A, Ohnishi N, Sasaki N, Kimura T.Equine herpesvirus 1 (EHV-1) uses equine major histocompatibility complex class I (MHC class I) as an entry receptor. Exogenous expression of equine MHC class I genes in murine cell lines confers susceptibility to EHV-1 infection. To examine the in vivo role of equine MHC class I as an entry receptor for EHV-1, we generated transgenic (Tg) mice expressing equine MHC class I under the control of the CAG promoter. Equine MHC class I protein was expressed in the liver, spleen, lung, and brain of Tg mice, which was confirmed by Western blot. However, equine MHC class I antigen was only detected in...
Voermans M, Butler CM, van der Velden MA, Sloet van Oldruitenborgh-Oosterbaan MM.Umbilical hernias are common in foals. This article provides a review of the literature and presents a case of an 1.5-year-old Friesian mare with an incarcerated umbilical hernia. After reposition of the incarcerated intestine (with a lot of effort), the practising veterinarian referred the mare to the Department of Equine Sciences. Preperforative peritonitis was diagnosed, presumed to be caused by necrotic bowel. After laparotomy, this tentative diagnosis was confirmed. The necrotic part of the small intestine was resected and intensive medical treatment was started. Initially, the mare recov...
Ernst NS, Freeman DE, Mackay RJ.A 6-year-old Appaloosa mare was examined because of inappetance, difficulty eating, and swelling and mucopurulent discharge in the right eye. Results: Results of a CBC and serum bio-chemical analysis revealed no important findings. Ophthalmologic examination revealed scarring and ulceration of the superficial layers of the cornea. Endoscopic examination of the upper portion of the respiratory tract and auditory tube diverticula (guttural pouches) revealed abnormal thickness of the right stylohyoid bone and a plaque suggestive of mycotic growth on the left internal carotid artery. Radiographic ...
Estrada R, Gutiérrez JM, Alvarado J, Robles A, Avila C, González N.The development of antibody response against phospholipase A2 activity of Bothrops asper venom was studied in a group of adult and healthy horses used in the production of the polyvalent antivenom at the Instituto Clodomiro Picado. Simultaneously, the general condition of the animals during the immunization schedule was also studied. There was a great individual variability in the immune response, although most of the horses studied reached the highest neutralizing titer after injection of doses of venom of 30 mg and 50 mg. On the other hand, in horses that had been previously immunized and we...
Sauer FJ, Verhaar N, Geburek F.To describe the treatment and outcome of a foal with a fresh allogenic cancellous bone graft after surgical debridement of a traumatic septic osteitis. Methods: A neonatal Quarter Horse foal. Methods: Case report. Methods: The foal sustained a traumatic laceration exposing the proximal third metatarsal bone. One week after surgical debridement and closure, radiographic signs of septic osteitis were noted along the physeal scar. The lesion was debrided, and antimicrobial therapy was implemented. The infection resolved but left a large defect in the metaphysis and epiphysis. Grafting was indic...
Grewar JD, Sergeant ES, Weyer CT, van Helden LS, Parker BJ, Anthony T, Thompson PN.An African horse sickness (AHS) outbreak occurred in South Africa's AHS controlled area in autumn 2016. A freedom from disease survey was performed to establish the likelihood of ongoing circulation of the associated virus during the same period the following year. A single-stage surveillance strategy was employed with a population-level design prevalence of 1% to establish a survey population sensitivity of 95% (probability that one or more positive horses would be detected if AHS was present at a prevalence greater than or equal to the design prevalence). In March 2017, a total of 262 random...
Anderson C, Baha H, Boghdeh N, Barrera M, Alem F, Narayanan A.Zoonotic pathogens that are vector-transmitted have and continue to contribute to several emerging infections globally. In recent years, spillover events of such zoonotic pathogens have increased in frequency as a result of direct contact with livestock, wildlife, and urbanization, forcing animals from their natural habitats. Equines serve as reservoir hosts for vector-transmitted zoonotic viruses that are also capable of infecting humans and causing disease. From a One Health perspective, equine viruses, therefore, pose major concerns for periodic outbreaks globally. Several equine viruses ha...
Eysker M, Boersema JH, Grinwis GC, Kooyman FN, Poot J.The efficacy of a 2% moxidectin equine gel at a dosage rate of 0.4 mg kg-1 was evaluated in a controlled trial at Utrecht University. Twelve yearling castrated male Shetland ponies grazed a pasture of 2 ha from May 1994 until housing in November. Six ponies were treated with moxidectin, whereas the others served as non-treated controls. Necropsy was carried out 35 days after treatment. Greater than 99% efficacy of moxidectin was observed on faecal egg output. No effect of moxidectin was observed on mucosal inhibited early cyathostome L3 (EL3) or on the total numbers of mucosal developing stage...
Sugimoto C, Isayama Y, Kashiwazaki M, Mitani K.The minimal inhibitory concentrations of 31 antimicrobial agents were determined for 99 isolates of Haemophilus equigenitalis by the agar dilution method. All the isolates showed good susceptibility to 26 antimicrobial agents tests, minimal inhibitory concentrations of which were less than 3.13 micrograms/ml for more than 90% of the isolates. Of these agents, 4 macrolides (erythromycin, oleandomycin, kitasamycin, tylosin), 3 tetracyclines (tetracycline, chlortetracycline, oxytetracycline), 1 peptide (colistin), 1 penicillin (ampicillin) and 1 pleuromutilin (tiamulin) were the most active agent...
Henson FM, Schofield PN, Jeffcott LB.This study describes the distribution pattern of transforming growth factor-beta 1 (TGF-beta 1) mRNA and protein in normal pre- and post natal growth cartilage and alterations present in lesions of dyschondroplasia (osteochondrosis). TGF-beta 1 expression and immunoreactivity have been investigated by in situ hybridisation and immunolocalisation in the articular/epiphyseal growth cartilage of the lateral trochlear ridge of the distal femur. Cartilage was obtained from 19 normal Thoroughbred horses (5 prenatal and 14 post natal horses) and 15 post natal horses with dyschondroplasia (DCP). TGF-b...
Tortschanoff M, Aurich C, Rosengarten R, Spergser J.Mycoplasma equigenitalium and Mycoplasma subdolum have been associated with infertility, endometritis, vulvitis and abortions in mares, and with reduced fertility and balanoposthitis in stallions. Despite their role in equine genital disorder, determinants of virulence and pathogenesis as well as factors provoking specific host immune responses have not been identified, so far. To establish the major immunogenic components of Mycoplasma (M.) equigenitalium and M. subdolum, antigen profiles of their type strains as well as 30 clinical isolates were compared by SDS-PAGE and immunoblot analysis u...
Robert MP, Stemmet GP, Smit Y.Bilateral paranasal sinus diseases are rarely reported in horses. Treatment using a bilateral frontonasal bone flap on a standing, regular-sized adult horse has not been described previously. A 13-year-old Thoroughbred gelding was evaluated for bilateral mucopurulent nasal discharge. Radiographic, endoscopic and computed tomographic examinations revealed bilateral sinus pathological changes consistent with an ethmoid haematoma involving the maxillary and frontal sinuses. A bilateral frontonasal bone flap was created under standing sedation and local anaesthesia. A tracheotomy was performed ini...
Wallace KD, Selcer BA, Tyler DE, Brown J.Transrectal ultrasonography was performed on the cranial mesenteric artery and its major branches in 23 conscious adult horses. Ultrasonographically, 25 arterial segments were classified as either normal or abnormal. These ultrasonographic classifications were later compared with the gross and histologic evaluations of each artery following necropsy of each horse. In this study, transrectal ultrasonography as a diagnostic test for verminous arteritis had a 90% sensitivity for detecting normal arteries and an 86% specificity for detecting abnormal arteries, suggesting that ultrasonography may b...
Slocombe JO, Rendano VT, Owen RR, Pennock PW, McCraw BM.Radiographs of the aorta and abdominal arteries were obtained from a normal anesthetized pony following catheterization of a femoral artery for nonselective, semiselective or selective arteriography. The arteries had smooth borders and regular diameters and the branches of the cranial mesenteric artery could be followed distally on the angiogram through to the smaller branches proximal to the bowel wall. Following arteriography, the pony walked normally and there were minimal alterations of the levels of serum muscle enzymes and blood lactate. The procedures for arteriography were repeated in ...
Hay AN, Potter A, Kasmark L, Zhu J, Leeth CM.Varying susceptibility exists among mammalian species to the development of potentially fatal endotoxemia due to gram-negative bacteria molecular component, lipopolysaccharide (LPS). Toll-like receptor 4 (TLR4) is responsible for LPS-associated immune response and is expressed on numerous immune cells including B lymphocytes. TLR4 is expressed in a functional form on mouse B lymphocytes, a species much less susceptible to endotoxemia compared with humans who are highly sensitive to endotoxin. Humans possess B lymphocytes that are not responsive to LPS. Likewise, horses are highly susceptible t...
Kuroda T, Nagata SI, Tamura N, Kinoshita Y, Niwa H, Mita H, Minami T, Fukuda K, Hobo S, Kuwano A.To determine plasma pharmacokinetics of metronidazole and imipenem following administration of a single dose PO (metronidazole, 15 mg/kg) or IV (imipenem, 10 mg/kg) in healthy Thoroughbreds and simulate pleural fluid concentrations following multiple dose administration every 8 hours. Methods: 4 healthy Thoroughbreds. Methods: Metronidazole and imipenem were administered, and samples of plasma and pleural fluid were collected at predetermined time points. Minimum concentrations of metronidazole and imipenem that inhibited growth of 90% of isolates (MIC90), including 22 clinical Bacteroides iso...
Marley LK, Soffler C, Hackett ES.OBJECTIVE To describe clinical features, diagnostic methods, treatments, and outcomes associated with ingested wire foreign bodies in the abdomen of horses. DESIGN Retrospective case series. ANIMALS 16 client-owned horses with ingested wire in their abdomens that were evaluated at a veterinary teaching hospital between April 2002 and February 2013. PROCEDURES Data for each case were collected from medical records and owners and then reviewed. Differences in clinicopathologic variables between horses that did (survivors) or did not (nonsurvivors) survive to discharge from the hospital were asse...
Kilcoyne I, Nieto JE.For the equine veterinarian, orthopedic emergencies are a common occurrence in clinical practice, with traumatic wounds of the distal limb and penetrating injuries of the hoof being some of the most common medical conditions to affect horses. Intravenous regional limb perfusion is a technique widely used for the treatment of orthopedic infections in horses. The objectives of this review are to discuss some of the clinical applications for this treatment modality in the field and to review the technique for the practitioner.
Buening GM, Perryman LE, McGuire TC.Nasal washings and tears were collected from seven Arabian foals with combined immunodeficiency and nine normal foals. The major immunoglobulin in the external secretions of normal foals over 2 months of age was secretory immunoglobulin A, whereas foals with combined immunodeficiency lacked this immunoglobulin. The external secretions of both normal and immunodeficient foals contained free secretory component at birth.
