Pneumonia in horses is a respiratory condition characterized by inflammation of the lungs, often caused by bacterial, viral, or fungal infections. It can affect horses of all ages, though young and immunocompromised animals are more susceptible. Clinical signs of pneumonia in horses may include coughing, nasal discharge, fever, and labored breathing. Diagnosis typically involves a combination of clinical examination, imaging techniques such as radiography or ultrasonography, and laboratory tests including blood work and microbial cultures. Treatment strategies vary depending on the underlying cause and may involve antimicrobial therapy, supportive care, and environmental management. This page compiles peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment of pneumonia in equine populations.
Prescott JF, Nicholson VM, Patterson MC, Zandona Meleiro MC, Caterino de Araujo A, Yager JA, Holmes MA.To evaluate use of the virulence-associated protein of Rhodococcus equi in immunizing foals against R equi pneumonia. Methods: Eight (experimental group) and 6 (controls) mares with their foals. Methods: Virulence-associated protein extracted from R equi was used to prepare an acetone-precipitated. Triton X-extracted (APTX) antigen. After determination of the efficacy of passive immunization, in untreated foals or in foals given plasma from a horse vaccinated with APTX antigen or from a nonvaccinated horse, a field trial was done to evaluate the efficacy of vaccination of 8 mares, twice with A...
Raidal SL, Taplin RH, Bailey GD, Love DN.To evaluate the administration of procaine penicillin prior to or during confinement with head elevation as a means of reducing the associated accumulation of inflammatory lower respiratory tract secretions and increased numbers of bacteria within the lower respiratory tract of confined horses. Methods: Two experiments were conducted to evaluate the efficacy of different dose rates and dosing frequencies. In experiment A a single low dose (15,000 IU/kg) of procaine penicillin was administered to four horses immediately prior to confinement with head elevation for 48 hours. The systemic leucocy...
Carrasco L, Mendez A, Jensen HE.An atypical case of chronic equine bronchopulmonary aspergillosis with an unusual hyphal morphology was diagnosed in a horse with Cushing's syndrome. Because of the hyphal localization in chronic ectatic bronchi and bronchioles, and juxtabronchiolar processes, the observed type of aspergillosis is similar to 'saprophytic bronchopulmonary aspergillosis' or 'semi-invasive pulmonary aspergillosis' in humans. The aetiological diagnosis of aspergillosis was accomplished by the application of a panel of monospecific polyclonal and monoclonal antibodies in immunohistochemical techniques.
Bell KS, Philp JC, Christofi N, Aw DW.Two regions in the gene coding for 16S rRNA in Rhodococcus equi were selected as species-specific primer sequences for the polymerase chain reaction (PCR). PCR using these primers was tested against 10 strains of R. equi (including the type strain) and gave positive results for all but was negative for all other tested species of Rhodococcus; representatives of the most closely related genera and a number of other bacterial species. This method could therefore be used to identify this species which can infect the lungs or other organs of horses, pigs, humans and other animals.
Guglick MA, MacAllister CG, Breazile JE.An 18-month-old Quarter Horse gelding was examined because of weight loss and dysphagia of 1 month's duration. Clinical signs included lethargy, dehydration, ptyalism, and probable aspiration pneumonia. Severe dyspnea and cyanosis were evident after mild exercise. Endoscopy revealed laryngospasm and pharyngospasm. Because clinical signs and endoscopic findings were suggestive of hyperkalemic periodic paralysis (HPP), acetazolamide treatment was instituted. Marked improvement was observed within 48 hours. The horse was determined to be homozygous for HPP. It is likely that this horse's dysphagi...
Vullo V, Mastroianni CM, Lichtner M, Mengoni F, Chiappini E, D'Agostino C, Delia S.Thirty healthy blood donors, 15 workers from horse-breeding farms, 69 human immunodeficiency virus (HIV)-negative persons at risk for HIV infection, 125 HIV-infected subjects without Rhodococcus equi infection, and nine HIV-infected patients with Rhodococcus equi pneumonia were evaluated in order to detect serum antibodies to Rhodococcus equi precipitate-soluble antigen by an enzyme immunoassay (EIA). Whereas EIA values for healthy donors, horse farm workers, individuals at risk for HIV infection, and HIV-positive subjects without Rhodococcus equi infection were comparable, HIV-infected patien...
Nordengrahn A, Rusvai M, Merza M, Ekström J, Morein B, Belák S.Equine herpesvirus type 2 (EHV-2), a member of the Gammaherpesvirinae subfamily, was studied in a two-phase respiratory disease complex of young foals as a predisposing factor for the secondary bacterial invasion of lungs with Rhodococcus equi (R. equi). Foals were immunized against EHV-2 on a farm where R. equi pneumonia regularly occurred during the last years. The immunizations were performed by using a subunit vaccine which selectively presents envelope glycoproteins of EHV-2 in a multimeric form of immunostimulating complexes (iscoms). The etiological role of EHV-2 was estimated by observ...
Dickinson CE, Traub-Dargatz JL, Dargatz DA, Bennett DG, Knight AP.To determine the clinical manifestations, morbidity, mortality, and treatment methods for rattlesnake venom poisoning in horses. Methods: Retrospective analysis of medical records. Methods: 27 horses with acute venom poisoning attributable to prairie rattlesnakes, and 5 with chronic problems subsequent to a rattlesnake bite. Results: Most horses were bitten on or near the muzzle while on pasture, resulting in head swelling, dyspnea, and epistaxis. Additional manifestations of acute poisoning included fever, tachycardia, tachypnea, cardiac arrhythmia, hemolytic anemia, thrombocytopenia, hemorrh...
Madarame H, Takai S, Morisawa N, Fujii M, Hidaka D, Tsubaki S, Hasegawa Y.Rhodococcus equi was isolated from the lungs of six foals with bronchopneumonia. All isolates expressed 15-17-kd antigens by immunoblot analysis and contained a virulence-associated plasmid of 85 or 90 kb. Immunohistochemically, R. equi from all pulmonary lesions showed the expression of 15-17-kd antigens mainly in the phagocytic cells. The specific monoclonal antibody to 15-17-kd antigens of R. equi (MAb 10G5) may be an aid in the diagnosis of R. equi-induced pneumonia.
Seltzer KL, Byars TD.To determine the percentage of Thoroughbred racehorses that would be capable of racing performance after recovery from infectious pleuropneumonia. Methods: Retrospective case series. Methods: 70 Thoroughbred horses that had recovered from pleuropneumonia. Only horses 5 years old known to be in race training at the time of illness were included in the study. Results: Forty-three of the 70 (61%) horses raced after recovery, and 24 of the 43 (56%) won at least 1 race. Horses that required placement of an indwelling thoracic drain apparently did not have a worse prognosis than did horses that did...
Raisis AL, Hodgson JL, Hodgson DR.Equine neonatal septicaemia was confirmed in 24 foals hospitalised at the Rural Veterinary Centre between 1989 and 1992 with suspected septicaemia. Septicaemia was confirmed by culture of bacteria from blood of live foals and tissues obtained at necropsy of foals that died or were euthanased. Pathogenic bacteria isolated were predominantly Enterobacteriaceae (including Escherichia coli and Salmonella serovars) and Actinobacillus equuli. Clinical manifestations of septicaemia included signs of depression, dehydration, abnormalities in body temperature and manifestations of localised infection i...
Mair TS.Three horses developed severe pulmonary infections while being treated with systemic corticosteroids for other diseases. Two of them had an immune-mediated skin disease, compatible with a diagnosis of pemphigus foliaceus, and one had severe chronic obstructive pulmonary disease. Case 1 developed diffuse pneumonia from which Streptococcus zooepidemicus and Bacteroides melaninogenicus were isolated, and it responded to antibiotic therapy. Case 2 developed septicaemia, pulmonary thrombosis and pneumonia associated with Escherichia coli, and died during a peracute illness with signs of disseminate...
De La Peña-Moctezuma A, Prescott JF, Goodfellow M.Four isolates of Rhodococcus equi, from pneumonic foals, and containing the 85 kb virulence plasmid, a porcine isolate containing an 80 kb plasmid, and their plasmid cured derivatives, were examined for 239 phenotypic properties in an attempt to find characters other than the virulence-associated protein (VapA) which might be encoded by the virulence plasmid in organisms grown at 37 degrees C. Tests chosen included those which have previously given variable results for R. equi isolates, since such variability might be attributed to plasmid curing, and characteristics which have been described ...
Marble SL, Edens LM, Shiroma JT, Savage CJ.A 16-hour-old foal was examined because of subcutaneous emphysema, which began developing 3 hours after a routine delivery. Physical examination did not reveal soft-tissue or musculoskeletal trauma, and there were no skin injuries to explain the subcutaneous accumulation of air. Results of CBC and serum biochemical analysis were within reference limits, and findings on endoscopy of the pharyngeal area, trachea, and esophagus were within normal limits other than observation of dorsal pharyngeal compression. A pulmonary bulla, pneumomediastinum, and pneumothorax were detected on thoracic radiogr...
Hurley JR, Begg AP.A trial was conducted on a Thoroughbred stud to determine whether or not the administration of anti-Rhodococcus equi hyperimmune plasma would reduce the prevalence of R equi pneumonia (rattles) in foals born in the 1992 horse breeding season. Hyperimmune plasma was administered to 34 foals; another 57 foals were untreated. There was no significant difference in the number of transfused foals developing R equi pneumonia compared with the untreated foals. The time required for recovery from pneumonia between the 2 groups was not significantly different.
Tate LP, Blikslager AT, Little ED.Guttural pouch tympanites was diagnosed in eight foals with respiratory stridor and tympanic swelling in the parotid region. Three foals were treated by transendoscopic neodymium:yttrium aluminum garnet (Nd:YAG) laser fenestration of the median septum between the guttural pouches. One foal died of pneumonia, and the other two foals recovered completely, although the fenestration later closed in one foal. Five foals were treated by creating a salpingopharyngeal fistula using transendoscopic laser irradiation; complete resolution of the tympanites occurred. Transendoscopic laser surgery in stand...
Austin SM, Foreman JH, Hungerford LL.Risk factors for development of pleuropneumonia were determined by reviewing medical records of 45 horses with pleuropneumonia and 180 control horses examined between Jan 1, 1980 and Jan 1, 1990. Factors considered included age, breed, sex, occupation, transport farther than 500 miles within the previous week, racing within the previous 48 hours, viral respiratory tract infection or exposure to horses with viral respiratory tract disease within the previous 2 weeks, and vaccination against influenza or rhinopneumonitis within the previous 6 months. Results indicated that Thoroughbreds were at ...
Kanaly ST, Hines SA, Palmer GH.Rhodococcus equi, a facultative intracellular bacterium, causes chronic, often fatal granulomatous pneumonia in young horses and in humans with AIDS. The inability of host alveolar macrophages to kill intracellular R. equi results in the development of granulomas and progressive loss of pulmonary parenchyma. Clearance of the organism from the lung requires functional CD4+ T cells. The purpose of this study was to identify the cytokine effector mechanisms that mediate clearance of R. equi from the lung. Mice were treated with monoclonal antibodies (MAbs) to either gamma interferon (IFN-gamma) o...
Oikawa M, Takagi S, Anzai R, Yoshikawa H, Yoshikawa T.Eight young thoroughbred horses, taken 1858 km by road (travelling time, 41 h), were examined to assess the pathological nature of respiratory disease associated with transport. Three of the horses showed clinical abnormalities including pyrexia, coughing, leucocytosis and neutrophilia after the first 20 h of transportation. Endoscopical examination of the trachea revealed exacerbation of airway inflammation as a result of transport in two of the three affected horses. A consistent finding in the affected horses was focal serous neutrophilic pneumonia affecting the cranio-ventral portion of th...
Schlocker N, Gerber-Bretscher R, von Fellenberg R.In a search of viral agents in pulmonary macrophages of horses with chronic pulmonary disease, equine herpesvirus 2 was found to be unique. In 8 of 9 horses with chronic pulmonary disease, antigens of equine herpesvirus 2 were detected by indirect immunofluorescence staining of scattered foamy macrophages immediately after harvesting by bronchoalveolar lavage and fractionation on metrizamide gradients. In a healthy horse, antigens were not found. After 1 week of cultivation of bronchoalveolar lavage cells from a second group of 9 horses with chronic pulmonary disease, viral antigens were detec...
Raidal SL.Pleuropneumonia is a clinically important equine disease, predisposed by a number of identifiable factors. Successful management is largely dependent on early identification and prompt initiation of appropriate treatment strategies. Rapid resolution of the disease process is associated with appropriate treatment commenced within 48 h of the causative insult. Lower airway contamination by oropharyngeal organisms and subsequent extension into the pulmonary parenchyma results in respiratory dysfunction and systemic toxaemia. Acute disease is associated with the isolation of facultatively anaerobi...
Fey K, Schmid P.Using a broth microdilution technique, the in vitro susceptibility of bacterial isolates from the equine respiratory tract to trimethoprim, sulfadoxine, sulfadimethoxine, and combinations of these compounds was determined. The bacterial strains (n = 88) isolated recently from horses with respiratory symptoms belonged to the following species: Streptococcus equi subsp. zooepidemicus (n = 34), Streptococcus equi subsp. equi (n = 22), Staphylococcus aureus (n = 9), Klebsiella pneumoniae (n = 7), Rhodococcus equi (n = 4), Pseudomonas spp. (n = 3) and Escherichia coli (n = 3). In addition, two isol...
Blunden AS, Smith KC, Binns MM, Zhang L, Gower SM, Mumford JA.Equid herpesvirus 4 (EHV-4) infection was diagnosed as the cause of interstitial pneumonia in a 6-week-old conventionally reared Welsh pony foal, by cocultivation and immunolabelling with specific monoclonal antibodies, EHV-4 specific amplification of viral DNA, and immunohistological examination of infected tissues. The case was novel in that replication of the EHV-4 isolate in endothelial cells and in the synovial epithelium was a feature. Restriction digests of this isolate were compared with those of seven respiratory and one abortigenic EHV-4 isolate, and no differences in restriction pat...
Raidal SL, Love DN, Bailey GD.Confinement of horses with their heads elevated for periods up to 24 hours was used to evaluate the extent and the effects of bacterial contamination of the equine lower respiratory tract. Significant (P < 0.05) increases in bacterial numbers (up to 10(9) colony forming units/mL in transtracheal aspirate derived samples) occurred within 6 or 12 hours in most horses. Pasteurella/Actinobacillus spp and Streptococcus spp were most commonly isolated. Lowering of the head for 30 minutes every 6 hours to facilitate postural drainage did not prevent multiplication of organisms to levels equivalent...
Boldur I, Cohen A, Tamarin-Landau R, Sompolinsky D.The lungs of 139 calves presented for autopsy and 29 healthy slaughtered calves were examined for Legionella by culture and by direct immunofluorescence (DIF) with fluorescein-conjugated antisera. About 17% of the cadaver lungs and 4% of lungs from slaughtered animals were positive by DIF. Legionella organisms were only isolated from the lungs of two cadavers (L. pneumophila, serogroup 1). In a prevalence study of antibodies to Legionella in domestic and wild animals of various species, titers of greater than or equal to 64 were demonstrated by indirect immunofluorescence in sera of 10% of dai...
Fey K, Schmid P.Using a broth microdilution technique, the in vitro susceptibility of bacterial isolates from the equine respiratory tract to trimethoprim, sulfadoxine, sulfadimethoxine, and combinations of these compounds was determined. The bacterial strains (n = 88) isolated recently from horses with respiratory symptoms belonged to the following species: Streptococcus equi subsp. zooepidemicus (n = 34), Streptococcus equi subsp. equi (n = 22), Staphylococcus aureus (n = 9), Klebsiella pneumoniae (n = 7), Rhodococcus equi (n = 4), Pseudomonas spp. (n = 3) and Escherichia coli (n = 3). In addition, two isol...
Raidal SL, Taplin RH, Bailey GD, Love DN.To evaluate the administration of procaine penicillin prior to or during confinement with head elevation as a means of reducing the associated accumulation of inflammatory lower respiratory tract secretions and increased numbers of bacteria within the lower respiratory tract of confined horses. Methods: Two experiments were conducted to evaluate the efficacy of different dose rates and dosing frequencies. In experiment A a single low dose (15,000 IU/kg) of procaine penicillin was administered to four horses immediately prior to confinement with head elevation for 48 hours. The systemic leucocy...
Rahman A, Uzal FA, Hassebroek AM, Carvallo FR.Pneumonia is a significant disease of horses. Although pneumonia has traditionally been studied in racehorses, little information is available for non-racing horses. Non-racing horses that died with pulmonary lesions ( = 156) were available from cases submitted for autopsy from January 2015 to June 2020. Bronchopneumonia (35%), interstitial pneumonia (29%), embolic pneumonia (21%), granulomatous pneumonia (13%), and pleuritis (2%) were observed in the examined horses. Seventy-four horses died or were euthanized because of pulmonary diseases, and 82 horses died or were euthanized because of...
Fultz L, Giguère S, Berghaus LJ, Davis JL.Current labelling for the use of ceftiofur crystalline free acid (CCFA) in horses states that 2 i.m. doses must be administered 4 days apart to provide 10 days of therapeutic coverage. A 10 day treatment regimen is not sufficient for the long-term treatment of horses with severe lung consolidation or pleuropneumonia. There are currently no data to guide an appropriate dosing interval when a longer treatment regimen is warranted. Objective: To determine steady-state plasma and pulmonary epithelial lining fluid (PELF) concentrations of desfuroylceftiofur acetamide (DCA) after weekly i.m. adminis...
Martens RJ, Martens JG, Renshaw HW, Hietala SK.The opsonic capacity of serum containing R. equi-specific antibody was compared with antibody-deficient sera using luminol-dependent chemilumenscence (LDCL) and bactericidal assays. These assays incorporated peripheral blood polymorphonuclear neutrophilic leukocytes (PMNL) exposed to R. equi opsonized with neonatal equine pre-colostral serum (control) or serum from foals with R. equi infections (principal). All sera were complement inactivated at 56 degrees C for 30 min. Bacteria were obtained from the lung of a foal with R. equi pneumonia. Neutrophils were obtained from one adult horse for LD...
Zúñiga MP, Badillo E, Abalos P, Valencia ED, Marín P, Escudero E, Galecio JS.Rhodococcus equi is responsible for foal pneumonia worldwide, with a significant economic impact on the production and breeding of horses. In Chile, the first case was reported in 2000, and since then, its incidence has been increasing. Distinctive characteristics of R. equi as an intracellular pathogen in macrophages, emergence of virulence plasmids encoding surface lipoprotein antigens, and appearance of antibiotic resistance against macrolides and rifampicin have significantly complicated the treatment of R. equi pneumonia in foals. Therefore, in vitro susceptibility studies of first-line a...
Cho SN, Collins MT, Reif JS, McChesney AE.Attempts to infect horses with Legionella pneumophila were undertaken to determine pathogenicity and to evaluate the possibility that horses serve as a reservoir for the organism. A previous study showed that the prevalence of antibodies to L pneumophila in the equine population exceeded 30% of over 600 sera examined. Horses were infected experimentally with the Philadelphia 1 or Bloomington 2 strain of L pneumophila IV or by aerosolization. Signs of clinical illness were restricted to a transient febrile response. A transient decrease in circulating lymphocytes occurred 2 days after inoculati...
Hance SR, Robertson JT.A 5-year-old Thoroughbred gelding was examined because of a small axillary wound sustained 5 days earlier and had resulted in extensive subcutaneous emphysema. Three days after admission, the horse's respiratory rate had increased to 72 breaths/min, and the horse appeared anxious and distressed. Thoracic radiography revealed pneumomediastinum and severe bilateral pneumothorax. Tube thoracostomy was performed on both hemithoraxes. The drains were connected to one-way suction valves and suction devices to decompress the thorax. A nasopharyngeal catheter was inserted, and oxygen insufflation was ...
Javsicas LH, Giguère S, Womble AY.The objectives of this study were to determine the serum and pulmonary disposition of telithromycin in foals and to determine the minimum inhibitory concentration (MIC) of telithromycin against macrolide-susceptible and macrolide-resistant Rhodococcus equi isolates. A single dose of telithromycin (15 mg/kg of body weight) was administered to six healthy 6-10-week-old foals by the intragastric route. Activity of telithromycin was measured in serum, pulmonary epithelial lining fluid (PELF), and bronchoalveolar lavage (BAL) cells using a microbiological assay. The broth macrodilution method was u...
Hoffman AM, Viel L, Juniper E, Prescott JF.Respiratory tract infections are prevalent in foals, yet the frequency with which the distal airways are affected in clinical episodes of respiratory tract disease has not been evaluated to our knowledge. The objective of the study was to determine the incidence of distal respiratory tract infection (DRTI) in foals on a sample of Thoroughbred breeding farms (n = 10) in Ontario. In a pilot study, clinical criteria commonly used to select foals for antimicrobial treatment (detection of abnormal lung sounds, plus nasal discharge, cough, fever, tachypnea, and/or lethargy) were found to segregate f...
Barton MD, Embury DH.Pyogranulomatous pneumonia was induced in Thoroughbred foals by intranasal challenge with freeze-dried cultures of Rhodococcus equi (previously Corynebacterium equi). The incubation period was about 18 days and clinical signs were not seen for a further week. There were marked seasonal and individual foal differences in responses to infection. Elevations in serum caeruloplasmin oxidase activity and copper concentrations appeared to be sensitive indicators of infection. Serum zinc concentrations and serum alpha-mannosidase and alkaline phosphatase activities fell in the more severely infected f...
Berry CR, O'Brien TR, Madigan JE, Hager DA.Clinical records and thoracic radiographs of 19 horses with a confirmed pathologic diagnosis of silicosis were reviewed. These horses had histories of varying degrees of chronic weight loss, exercise intolerance, and respiratory distress. At the time of presentation, two horses were asymptomatic. Ten horses were geldings and nine were female. The mean age of the 19 horses was 10.7 +/- 5.5 years. Fourteen horses were identified as being from the Monterey-Carmel Peninsula of midcoastal California. An abnormal, structured interstitial pulmonary pattern was identified on thoracic radiographs in ea...
Rossi H, Raekallio M, Määttä M, Tapio H, Hanifeh M, Junnila J, Rajamäki MM, Mykkänen A.Pneumonia is one of the potential complications of general anaesthesia in horses. Anaesthesia is known to increase neutrophils in bronchoalveolar lavage fluid (BALF) of horses after lateral recumbency, but studies after dorsal recumbency are lacking. Our primary aim was to determine when lung inflammation reaches its maximum and how rapidly BALF cytology returns to baseline after anaesthesia in dorsal recumbency. A secondary aim was to investigate the possible effect of vatinoxan, a novel drug, on the BALF cytology results. Six healthy experimental horses were enrolled in this observational cr...
McClure S, Sibert G, Hallberg J, Bade D.The efficacy and safety of sustained release ceftiofur administered twice, 4 days apart, for treatment of horses with naturally acquired Streptococcus equi subsp. zooepidemicus (Strep. zoo.) pneumonia was evaluated in a multicenter, placebo-controlled, double-blinded, randomized clinical trial. The study included 373 horses (278 treated and 95 placebos) with naturally acquired pneumonia. Inclusion in the statistical analyses for treatment efficacy for Strep. zoo. required recovery of ≥10(4) CFU/mL of Strep. zoo. on the primary isolation plate which resulted in 201 cases (145 treated and 56 p...
Yager JA, Duder CK, Prescott JF, Zink MC.Polymorphonuclear neutrophil leukocytes (PMNL) from 8 healthy foals (2-14 weeks of age) and 2 foals with bacterial pneumonia were separated from whole blood using a 2 step Percoll gradient. Purified PMNL were tested for bactericidal function against Rhodococcus equi and Staphylococcus aureus in the presence of normal horse serum. The percentage uptake after a 15-min pre-incubation of PMNL and bacteria was also calculated. Ultrastructural examination of the interaction of R. equi and normal foal PMNL was performed after 15 min incubation. Results indicated that foal PMNL effectively phagocytose...
Singh BR.Sixty-nine vaginal swabs and 138 rectal swabs collected from 195 equids were analysed for the presence of thermotolerant bacteria, that is, bacteria surviving at 60+/-0.1 degrees C for one hour. Thermotolerant Escherichia coli, Enterobacter species, Klebsiella pneumoniae, Proteus species and Pseudomonas species were isolated from 41, 16, nine, three and three of the 138 rectal swabs, respectively; seven of the E coli and two of the Enterobacter species isolates survived pasteurisation at 63.8+/-0.1 degrees C for 30 minutes. All except three E coli, two Enterobacter species and one Proteus spec...
Phumoonna T, Muscatello G, Chicken C, Gilkerson JR, Browning GF, Barton MD, Heuzenroeder MW.A total of 227 field samples from naturally exposed foals aged between 3 weeks and 6 months were used in an evaluation of a peptide-based enzyme-linked immunosorbent assay (ELISA) for diagnosis of Rhodococcus equi infection. A biotinylated peptide derived from the virulence-associated protein A (VapA) of R. equi, a horse pathogen, was synthesized and designated as PN11-14. The peptide corresponds to the N-terminal B-cell epitope TSLNLQKDEPNGRASDTAGQ of the VapA protein. Based upon a serum immunoglobulin (Ig)G titre of 512 as a positive cut-off value for the R. equi infection, the ELISA provide...
Knight AP.Dysphagia developed in a 2-year-old Quarter Horse filly following an incident in which it fell over backward while exercising on a mechanical horse walker. Hyperextension of the neck at this time apparently caused unilateral rupture of the longus capitis (rectus capitis ventralis major) and the rectus capitis ventralis minor muscles at their insertion. An existing mycotic lesion involving the dorsomedial wall of the left guttural pouch may have weakened the area of insertion of the involved muscles. Tearing of the tendinous insertion of these muscles caused damage to the IX, X, and XI cranial ...
Morris DD, Whitlock RH.Equine antiserum to core lipopolysaccharide (LPS) was evaluated in a double-blind prospective study for therapeutic benefit in suspected septicemia in neonatal foals. Forty foals younger than 7 days of age were included in the study by satisfaction of clinical and laboratory criteria, suggestive of gram-negative septicemia. Twenty-two foals were treated with core LPS antiserum (plasma produced from horses which were hyperimmunized with rough gram-negative mutant bacterin) and 18 foals received "nonimmune" plasma (from horses prior to immunization against core LPS). All foals received antimicro...
Tirosh-Levy S, Gürbilek SE, Tel OY, Keskin O, Steinman A.Rhodococcus equi is a common cause of pneumonia in foals and has extensive clinical, economic and possibly zoonotic consequences. This bacterium survives well in the environment and may be considered as normal flora of adult horses. Certain strains of this bacterium are extremely virulent in foals, and early identification and intervention is crucial for prognosis. Rhodococcus equi is endemic in many parts of the world and occasionally isolated in Israel. This study was designed to evaluate R. equi seroprevalence in adult horses in Israel to indirectly indicate the potential level of exposure ...
Eichentopf A, Snyder A, Recknagel S, Uhlig A, Waltl V, Schusser GF.A 20-year-old pony mare was presented to the equine hospital with a ten-day history of dysphagia, regurgitation and coughing. An obstruction of the oesophagus was excluded via endoscopy, but the proximal oesophagus appeared to be distended and circular contractions were missing. A guttural pouch endoscopy revealed a single, black-mottled plaque on the pharyngeal ramus of the vagus nerve in the left guttural pouch, causing a local swelling of this nerve. The pharyngeal ramus seemed to be atrophic distal to the lesion. A biopsy was taken from the lesion and histopathological findings proved the ...
da Silveira BP, Cohen ND, Lawhon SD, Watson RO, Bordin AI.Rhodococcus equi causes pyogranulomatous pneumonia in foals and immunocompromised people. Despite decades of research efforts, no vaccine is available against this common cause of disease and death in foals. The purpose of this narrative review is to summarise the current understanding of interactions between R. equi and the host innate immune system, to describe features of the immune response that are associated with resistance or susceptibility to R. equi infection, and help guide strategies for developing novel approaches for preventing R. equi infections. Virulence of R. equi in foals has...
Bohlman T, Waddell H, Schumaker B.The occurrence of zoonotic infections following an animal exposure continues to be an important consideration for all patients, especially those within agricultural communities. Streptococcus equi subspecies equi (S. equi subsp. equi) is a bacteria known to cause a common infection called 'Strangles' in horses. This article highlights a new case of pneumonia and bacteremia in a patient caused by S. equi subsp. equi following strangles exposure in a horse. Rarely has there been reported horse to human transmission of subsp. equi. Methods: A 70-year-old woman attended a rural emergency departmen...
Flaminio MJ, Rush BR, Cox JH, Moore WE.Decreased proportion of CD4+ and CD8+ T lymphocytes in peripheral blood likely contributed to susceptibility to Pneumocystis carinii in a foal. Cytological evaluation of bronchoalveolar lavage was required for identification of the pathogen and serial flow-cytometric analysis of peripheral blood lymphocytes documented transient low expression of CD4+ and CD8+ T lymphocytes. Although immunodeficiency is uncommon, it must be included in the differential diagnosis for patients suffering from chronic or opportunistic infections and may provide an indication for immunostimulant therapy.
