FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / J Vet Intern Med / An updated description of bacterial pneumonia in adult horse...
Journal of veterinary internal medicine2024; doi: 10.1111/jvim.17141

An updated description of bacterial pneumonia in adult horses and factors associated with death.

Abstract: Available descriptive studies on equine pneumonia are outdated or focus on specific horse or bacterial populations. Objective: To describe the clinical presentation and bacterial isolates of adult horses with bacterial pneumonia and identify factors associated with death. Methods: One hundred sixteen horses >2 years old with bacterial pneumonia. Methods: Retrospective case series. Data regarding history, physical examination, clinicopathologic features, treatment, bacterial culture and sensitivity, and outcome were collected and analyzed retrospectively. Results: Historical risk factors were present for 60% of cases, whereas abnormal vital signs on intake were present for <50%. Most horses (58%) underwent at least 1 change of antimicrobial treatment, and 67% received the highest-priority critically important antimicrobials. Streptococcus zooepidemicus was the most isolated bacteria (44%), followed by Escherichia coli (19%), Klebsiella spp. (18%), other Streptococcus species (17%), and Bacillus spp. (13%). Fusobacterium spp. were the most common anaerobic isolates (11%). Antimicrobial susceptibility varied widely. Survival to discharge was 73%. Heart rate at presentation (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.008-1.17, P = .03) and higher creatinine (OR 14.1, 95% CI 1.56-127.6, P = .02) increased the risk of death. Higher lymphocyte count (OR 0.27, 95% CI 0.08-0.94, P = .04) reduced risk. Conclusions: Contrasting older literature, Fusobacterium spp. were the most common anaerobes. Streptococcus zooepidemicus remained the most common isolate and was predictably susceptible to penicillin. Antimicrobial susceptibility was otherwise variable and broad applicability is limited as this was a single-center study. Increased risk of death associated with tachycardia and abnormally high serum creatinine concentration is consistent with previous studies.
© 2024 The Author(s). Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.
Get Full Text
Publication Date: 2024-07-15 PubMed ID: 39005215DOI: 10.1111/jvim.17141Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research paper offers an updated view of bacterial pneumonia in adult horses, highlighting the associated risk factors, bacterial causes, and correlations with mortality.

Objective and Methodology

The study aimed to understand the clinical profile of adult horses suffering from bacterial pneumonia and to identify any factors linked with death. The researchers launched a retrospective study using data from 116 horses aged over 2 years with bacterial pneumonia. Information concerning the horses’ medical history, physical examination results, clinical and pathological features, treatment processes, bacterial culture and sensitivity, and final outcomes were collected and assessed.

Historical and Clinical Background

  • The study observed that more than half of the examined cases (60%) were linked with a certain historical risk factor.
  • However, fewer than 50% of the horses had shown any abnormal vital signs during their intake.

Microbial Causes and Antimicrobial Treatments

  • Almost 58% of the horses underwent a change in antimicrobial treatment at least once, and 67% were administered the highest-priority critically important antimicrobials.
  • The most frequently encountered bacteria was Streptococcus zooepidemicus (44% of cases) and followed by Escherichia coli (19%), Klebsiella spp. (18%), other Streptococcus species (17%), and Bacillus spp. (13%).
  • Fusobacterium spp., an anaerobic bacteria type, was the most prevalent anaerobic isolate in 11% of the cases.
  • The susceptibility to the various antimicrobial drugs varied extensively between the individual horses.

Results and Risk Variables

  • The survival rate to discharge was 73%, signifying that a considerable number of horses managed to recover.
  • Certain factors increased the risk of death: a higher heart rate at presentation (with an odds ratio [OR] of 1.08) and elevated levels of creatinine (OR 14.1).
  • Horses with higher quantities of lymphocytes had a decreased risk of death (OR 0.27).

Conclusion

The researchers found several key departures from the existing literature on equine pneumonia, noting the prevalence of Fusobacterium spp., an anaerobic bacteria. While Streptococcus zooepidemicus remained the most isolated bacteria, it consistently responded well to penicillin. The study also reaffirmed the findings of previous research, demonstrating a link between increased mortality risk and elevated heart rates and high serum creatinine concentrations. As this was a single-center study, the broad applicability of these findings is limited.

Cite This Article

APA
Hallowell KL, Hepworth-Warren KL, Dembek K. (2024). An updated description of bacterial pneumonia in adult horses and factors associated with death. J Vet Intern Med. https://doi.org/10.1111/jvim.17141

Publication

Journal of veterinary internal medicine
ISSN: 1939-1676
NlmUniqueID: 8708660
Country: United States
Language: English

Researcher Affiliations

Hallowell, Kimberly L
  • Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.
Hepworth-Warren, Kate L
  • Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.
Dembek, Katarzyna
  • Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.

References

This article includes 57 references
  1. Racklyeft D, Raidal S, Love D. Towards an understanding of equine pleuropneumonia: factors relevant for control.. Aust Vet J 2000;78(5):334‐338.
    doi: 10.1111/j.1751‐0813.2000.tb11788.xgoogle scholar: lookup
  2. Center for Epidemiology and Animal Health. Equine mortality in the United States, 2015.. 2015.
  3. Carvallo FR, Uzal FA, Diab SS, Hill AE, Arthur RM. Retrospective study of fatal pneumonia in racehorses.. J Vet Diagn Invest 2017;29(4):450‐456.
    doi: 10.1177/1040638717717290google scholar: lookup
  4. Wood JLN, Newton JR, Chanter N, Mumford JA. Association between respiratory disease and bacterial and viral infections in British racehorses.. J Clin Microbiol 2005;43(1):120‐126.
    doi: 10.1128/jcm.43.1.120‐126.2005google scholar: lookup
  5. Sweeney C. Aerobic and anaerobic bacterial isolates from horses with pneumonia or pleuropneumonia and antimicrobial susceptibility patterns of the aerobes.. J Am Vet Med Assoc 1991;198(5):839‐842.
  6. Tomlinson JE, Reef VB, Boston RC, Johnson AL. The association of fibrinous pleural effusion with survival and complications in horses with pleuropneumonia (2002–2012): 74 cases.. J Vet Intern Med 2015;29(5):1410‐1417.
    doi: 10.1111/jvim.13591google scholar: lookup
  7. Arroyo MG, Slovis NM, Moore GE, Taylor SD. Factors associated with survival in 97 horses with septic pleuropneumonia.. J Vet Intern Med 2017;31(3):894‐900.
    doi: 10.1111/jvim.14679google scholar: lookup
  8. Estell KE, Young A, Kozikowski T. Pneumonia caused by Klebsiella spp. in 46 horses.. J Vet Intern Med 2016;30(1):314‐321.
    doi: 10.1111/jvim.13653google scholar: lookup
  9. Reimer J. Ultrasonography as a diagnostic aid in horses with anaerobic bacterial pleuropneumonia and/or pulmonary abscessation: 27 cases (1984‐1986).. J Am Vet Med Assoc 1989;194(2):278‐282.
  10. Seltzer K. Prognosis for return to racing after recovery from infectious pleuropneumonia in thoroughbred racehorses: 70 cases (1984‐1989).. J Am Vet Med Assoc 1996;208(8):1300‐1301.
  11. Raphel C. Pleuritis secondary to pneumonia or lung abscessation in 90 horses.. J Am Vet Med Assoc 1982;181(8):808‐810.
  12. Byars TD, Becht JL. Pleuropneumonia.. Vet Clin North Am Equine Pract 1991;7(1):63‐78.
    doi: 10.1016/s0749‐0739(17)30516‐3google scholar: lookup
  13. Sweeney C. Anaerobic bacteria in 21 horses with pleuropneumonia.. J Am Vet Med Assoc 1985;187(7):721‐724.
  14. Hepworth‐Warren KL, Estell K, Cowles B, Amodie D, Crisman M. Utility of serum amyloid A in monitoring clinical response to antimicrobial treatment in horses with bacterial pneumonia.. J Vet Intern Med 2023;37(5):1917‐1922.
    doi: 10.1111/jvim.16818google scholar: lookup
  15. Racklyeft D, Love D. Bacterial infection of the lower respiratory tract in 34 horses.. Aust Vet J 2000;78(8):549‐559.
    doi: 10.1111/j.1751‐0813.2000.tb11901.xgoogle scholar: lookup
  16. Austin S. Case‐control study of risk factors for development of pleuropneumonia in horses.. J Am Vet Med Assoc 1995;207(3):325‐328.
  17. Raidal SL, Love DN, Bailey G. Inflammation and increased numbers of bacteria in the lower respiratory tract of horses within 6 to 12 hours of confinement with the head elevated.. Aust Vet J 1995;72(2):45‐50.
    doi: 10.1111/j.1751‐0813.1995.tb15328.xgoogle scholar: lookup
  18. Raidal S, Bailey G, Love D. Effect of transportation on lower respiratory tract contamination and peripheral blood neutrophil function.. Aust Vet J 1997;75(6):433‐438.
    doi: 10.1111/j.1751‐0813.1997.tb14349.xgoogle scholar: lookup
  19. Hepworth‐Warren KL, Wilgenbusch CM, Wong DM, Fales‐Williams AJ, Wiechert SA, Sponseller BA. Intrathoracic oesophageal perforation and secondary pleuropneumonia: five cases: pleuropneumonia secondary to oesophageal perforation.. Equine Vet Educ 2015;27(6):283‐290.
    doi: 10.1111/eve.12279google scholar: lookup
  20. Cohen ND. Neurologic evaluation of the equine head and neurogenic dysphagia.. Vet Clin North Am Equine Pract 1993;9(1):199‐212.
    doi: 10.1016/s0749‐0739(17)30424‐8google scholar: lookup
  21. Christley RM, Hodgson DR, Rose RJ. A case‐control study of respiratory disease in Thoroughbred racehorses in Sydney, Australia.. Equine Vet J 2010;33(3):256‐264.
    doi: 10.2746/042516401776249796google scholar: lookup
  22. Carr EA, Carlson GP, Wilson WD, Read DH. Acute hemorrhagic pulmonary infarction and necrotizing pneumonia in horses: 21 cases (1967‐1993).. J Am Vet Med Assoc 1997;210(12):1774‐1778.
  23. Ferrucci F, Zucca E, Croci C, Di Fabio V, Martino PA, Ferro E. Bacterial pneumonia and pleuropneumonia in sport horses: 17 cases (2001–2003).. Equine Vet Educ 2008;20(10):526‐531.
    doi: 10.2746/095777308x354255google scholar: lookup
  24. Bianchi MV, Mello LS, Ribeiro PR. Causes and pathology of equine pneumonia and pleuritis in Southern Brazil.. J Comp Pathol 2020;179:65‐73.
    doi: 10.1016/j.jcpa.2020.07.006google scholar: lookup
  25. Oikawa M, Kamada M, Yoshikawa Y, Yoshikawa T. Pathology of equine pneumonia associated with transport and isolation of Streptococcus equi subsp. zooepidemicus.. J Comp Pathol 1994;111(2):205‐212.
    doi: 10.1016/s0021‐9975(05)80052‐0google scholar: lookup
  26. Reuss SM, Giguère S. Update on bacterial pneumonia and pleuropneumonia in the adult horse.. Vet Clin North Am Equine Pract 2015;31(1):105‐120.
    doi: 10.1016/j.cveq.2014.11.002google scholar: lookup
  27. Toombs‐Ruane LJ, Riley CB, Kendall AT, Bolwell CF, Benschop J, Rosanowski SM. Antimicrobial susceptibilities of aerobic isolates from respiratory samples of young New Zealand horses.. J Vet Intern Med 2015;29(6):1700‐1706.
    doi: 10.1111/jvim.13600google scholar: lookup
  28. Weese JS, Giguère S, Guardabassi L. ACVIM consensus statement on therapeutic antimicrobial use in animals and antimicrobial resistance.. J Vet Intern Med 2015;29(2):487‐498.
    doi: 10.1111/jvim.12562google scholar: lookup
  29. Centers for Disease Control and Prevention (U.S.). Antibiotic Resistance Threats in the United States, 2019.. Centers for Disease Control and Prevention (U.S.) 2019.
    doi: 10.15620/cdc:82532google scholar: lookup
  30. Wilson A, Mair T, Williams N, McGowan C, Pinchbeck G. Antimicrobial prescribing and antimicrobial resistance surveillance in equine practice.. Equine Vet J 2023;55(3):494‐505.
    doi: 10.1111/evj.13587google scholar: lookup
  31. Miagkoff L, Archambault M, Bonilla AG. Antimicrobial susceptibility patterns of bacterial isolates cultured from synovial fluid samples from horses with suspected septic synovitis: 108 cases (2008–2017).. J Am Vet Med Assoc 2020;256(7):800‐807.
    doi: 10.2460/javma.256.7.800google scholar: lookup
  32. Theelen MJP, Wilson WD, Byrne BA. Differences in isolation rate and antimicrobial susceptibility of bacteria isolated from foals with sepsis at admission and after ≥48 hours of hospitalization.. J Vet Intern Med 2020;34(2):955‐963.
    doi: 10.1111/jvim.15692google scholar: lookup
  33. Theelen MJP, Wilson WD, Edman JM, Magdesian KG, Kass PH. Temporal trends in in vitro antimicrobial susceptibility patterns of bacteria isolated from foals with sepsis: 1979‐2010: foal sepsis: temporal trends in in vitro antimicrobial susceptibility patterns.. Equine Vet J 2014;46(2):161‐168.
    doi: 10.1111/evj.12130google scholar: lookup
  34. Chipangura JK, Chetty T, Kgoete M, Naidoo V. Prevalence of antimicrobial resistance from bacterial culture and susceptibility records from horse samples in South Africa.. Prev Vet Med 2017;148:37‐43.
    doi: 10.1016/j.prevetmed.2017.10.004google scholar: lookup
  35. Potier JFN, Durham AE. Antimicrobial susceptibility of bacterial isolates from ambulatory practice and from a referral hospital.. J Vet Intern Med 2020;34(1):300‐306.
    doi: 10.1111/jvim.15685google scholar: lookup
  36. World Health Organization. Critically Important Antimicrobials for Human Medicine. 6th rev. ed.. World Health Organization 2019.
  37. Sanchez LC, Giguère S, Lester GD. Factors associated with survival of neonatal foals with bacteremia and racing performance of surviving Thoroughbreds: 423 cases (1982–2007).. J Am Vet Med Assoc 2008;233(9):1446‐1452.
    doi: 10.2460/javma.233.9.1446google scholar: lookup
  38. Gomez DE, Leclere M, Arroyo LG. Acute diarrhea in horses: a multicenter Canadian retrospective study (2015 to 2019).. Can Vet J 2022;63:1033‐1042.
  39. Bertin FR, Reising A, Slovis NM, Constable PD, Taylor SD. Clinical and clinicopathological factors associated with survival in 44 horses with equine neorickettsiosis (Potomac horse Fever).. J Vet Intern Med 2013;27(6):1528‐1534.
    doi: 10.1111/jvim.12209google scholar: lookup
  40. Nikvand AA, Jalali SM, Ghadrdan Mashhadi A, Razi Jalali M, Hassanpour AS. Clinical, hematologic, hemostatic, and serum biochemical findings related to survival in Arabian horses with colic.. Vet Clin Pathol 2019;48(3):441‐448.
    doi: 10.1111/vcp.12779google scholar: lookup
  41. Lilliehöök I, Bröjer J, Nostell K. Hematologic, prostaglandin F2α‐metabolite, serum amyloid A, and serum iron changes in horses with experimentally induced endotoxemia.. Vet Clin Pathol 2020;49(2):319‐325.
    doi: 10.1111/vcp.12870google scholar: lookup
  42. Collins MB, Hodgson DR, Hutchins DR. Pleural effusion associated with acute and chronic pleuropneumonia and pleuritis secondary to thoracic wounds in horses: 43 cases (1982‐1992).. J Am Vet Med Assoc 1994;205(12):1753‐1758.
  43. Chiavaccini L, Hassel DM. Clinical features and prognostic variables in 109 horses with esophageal obstruction (1992‐2009): esophageal obstruction in horses.. J Vet Intern Med 2010;24(5):1147‐1152.
    doi: 10.1111/j.1939‐1676.2010.0573.xgoogle scholar: lookup
  44. Wood JLN, Newton JR, Chanter N, Mumford JA. Inflammatory airway disease, nasal discharge and respiratory infections in young British racehorses.. Equine Vet J 2010;37(3):236‐242.
    doi: 10.2746/0425164054530579google scholar: lookup
  45. Hepworth‐Warren KL, Nelson N, Dembek KA, Young KAS. Comparison of thoracic ultrasonography and thoracic radiography between healthy adult horses and horses with bacterial pneumonia using a novel, objective ultrasonographic scoring system.. Front Vet Sci 2022;9:991634.
    doi: 10.3389/fvets.2022.991634google scholar: lookup
  46. Ayala J, Quesada A, Vadillo S, Criado J, Píriz S. Penicillin‐binding proteins of Bacteroides fragilis and their role in the resistance to imipenem of clinical isolates.. J Med Microbiol 2005;54(11):1055‐1064.
    doi: 10.1099/jmm.0.45930‐0google scholar: lookup
  47. Fultz L, Giguère S, Berghaus LJ, Grover GS, Merritt DA. Pulmonary pharmacokinetics of desfuroylceftiofur acetamide after nebulisation or intramuscular administration of ceftiofur sodium to weanling foals: nebulised ceftiofur sodium in foals.. Equine Vet J 2015;47(4):473‐477.
    doi: 10.1111/evj.12316google scholar: lookup
  48. McKenzie Iii HC, Murray MJ. Concentrations of gentamicin in serum and bronchial lavage fluid after once‐daily aerosol administration to horses for seven days.. Am J Vet Res 2004;65(2):173‐178.
    doi: 10.2460/ajvr.2004.65.173google scholar: lookup
  49. McKenzie Iii HC, Murray MJ. Concentrations of gentamicin in serum and bronchial lavage fluid after intravenous and aerosol administration of gentamicin to horses.. Am J Vet Res 2000;61(10):1185‐1190.
    doi: 10.2460/ajvr.2000.61.1185google scholar: lookup
  50. Hardefeldt LY, Browning GF, Thursky K. Antimicrobials used for surgical prophylaxis by equine veterinary practitioners in Australia.. Equine Vet J 2018;50(1):65‐72.
    doi: 10.1111/evj.12709google scholar: lookup
  51. Mair TS, Parkin TD. Audit of antimicrobial use in eleven equine practices over a five‐year period (2014–2018).. Equine Vet Educ 2022;34(8):404‐408.
    doi: 10.1111/eve.13438google scholar: lookup
  52. Sprayberry KA, Byars TD. Equine pleuropneumonia.. Equine Vet Educ 1999;11(6):290‐293.
    doi: 10.1111/j.2042‐3292.1999.tb01557.xgoogle scholar: lookup
  53. Rendle D, Armstrong S, Hughes K. Combination fibrinolytic therapy in the treatment of chronic septic pleuropneumonia in a Thoroughbred gelding.. Aust Vet J 2012;90(9):358‐362.
    doi: 10.1111/j.1751‐0813.2012.00962.xgoogle scholar: lookup
  54. Hilton H, Pusterla N. Intrapleural fibrinolytic therapy in the management of septic pleuropneumonia in a horse.. Vet Rec 2009;164(18):558‐559.
    doi: 10.1136/vr.164.18.558google scholar: lookup
  55. Gilbertie JM, Schaer TP, Schubert AG. Platelet‐rich plasma lysate displays antibiofilm properties and restores antimicrobial activity against synovial fluid biofilms in vitro.. J Orthop Res 2020;38(6):1365‐1374.
    doi: 10.1002/jor.24584google scholar: lookup
  56. Tomlinson JE, Byrne E, Pusterla N. The use of recombinant tissue plasminogen activator (rTPA) in the treatment of fibrinous pleuropneumonia in horses: 25 cases (2007–2012).. J Vet Intern Med 2015;29(5):1403‐1409.
    doi: 10.1111/jvim.13594google scholar: lookup
  57. Blasi F, Page C, Rossolini GM. The effect of N ‐acetylcysteine on biofilms: implications for the treatment of respiratory tract infections.. Respir Med 2016;117:190‐197.
    doi: 10.1016/j.rmed.2016.06.015google scholar: lookup

Citations

This article has been cited 4 times.
  1. Junkkari R, Mykkänen A, Sulku P, Rantala M, Pohjanvirta T, Eklund M, Pelkonen S, Grönthal T. Occurrence, antibiotic susceptibility and genetic variation of Streptococcus zooepidemicus in Finnish weanling horses with and without respiratory infection. Acta Vet Scand 2026 Jan 27;68(1):7.
    doi: 10.1186/s13028-025-00839-0pubmed: 41593672google scholar: lookup
  2. Hardefeldt L, Thomas K, Page S, Norris J, Browning G, El Hage C, Stewart A, Gilkerson J, Muscatello G, Verwilghen D, van Galen G, Bauquier J, Cuming R, Reynolds B, Whittaker C, Wilkes E, Clulow J, Burden C, Begg L. Antimicrobial prescribing guidelines for horses in Australia. Aust Vet J 2025 Dec;103(12):781-889.
    doi: 10.1111/avj.70003pubmed: 40903020google scholar: lookup
  3. Hepworth-Warren KL, Love K. Survey of the approach to the diagnosis and management of bacterial pneumonia in adult horses by equine veterinarians. Front Vet Sci 2024;11:1484970.
    doi: 10.3389/fvets.2024.1484970pubmed: 39764370google scholar: lookup
  4. Kabir A, Lamichhane B, Habib T, Adams A, El-Sheikh Ali H, Slovis NM, Troedsson MHT, Helmy YA. Antimicrobial Resistance in Equines: A Growing Threat to Horse Health and Beyond-A Comprehensive Review. Antibiotics (Basel) 2024 Jul 29;13(8).
    doi: 10.3390/antibiotics13080713pubmed: 39200013google scholar: lookup
Subscribe to our newsletter
Join 99,075 horse owners like you who receive our email updates on horse health and nutrition.