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Journal of veterinary internal medicine2013; 27(6); 1528-1534; doi: 10.1111/jvim.12209

Clinical and clinicopathological factors associated with survival in 44 horses with equine neorickettsiosis (Potomac horse Fever).

Abstract: The epidemiology of equine neorickettsiosis (EN) has been extensively studied but limited clinical and clinicopathological data are available concerning naturally infected horses. Objective: Factors predictive of survival will be identified in horses diagnosed with EN. Methods: Convenience sample of 44 horses with EN admitted to 2 referral institutions. Methods: A retrospective study was performed. A diagnosis of EN was based on the presence of positive blood or fecal PCR. Results: The most common clinical signs included diarrhea (66%), fever (50%), anorexia (45%), depression (39%), colic (39%), and lameness (18%). The median duration of hospitalization was 6 days and 73% of horses survived to discharge. Laminitis was present in 36% of horses, 88% of which were affected in all 4 feet. Serum creatinine and urea nitrogen concentrations, as well as RBC count, blood hemoglobin concentration, hematocrit, band neutrophils, serum AST activity, serum CK activity, and anion gap, were significantly (P < .05) higher in nonsurvivors. Serum chloride and sodium, concentrations as well as duration of hospitalization were significantly lower in nonsurvivors. The results of forward stepwise logistic regression indicated that blood hemoglobin concentration on admission and antimicrobial treatment with oxytetracycline were independent factors associated with survival. Conclusions: Severity of colitis as reflected by electrolyte loss, hemoconcentration, and prerenal azotemia were predictors of survival in horses diagnosed with EN. Treatment with oxytetracycline was associated with increased survival.
Publication Date: 2013-10-01 PubMed ID: 24118378DOI: 10.1111/jvim.12209Google Scholar: Lookup
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  • Journal Article

Summary

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The research article explores factors associated with survival in horses diagnosed with equine neorickettsiosis (EN), a disease commonly known as Potomac Horse Fever. The study finds that the severity of colitis, hemoconcentration, prerenal azotemia, and treatment with the antibiotic oxytetracycline are key predictors of survival.

Study Context and Methodology

  • The study acknowledges that while the epidemiology of Equine neorickettsiosis (Potomac horse Fever) has been extensively studied, there is limited data about how clinical and clinicopathological factors influence the survival of naturally infected horses.
  • The objective was to identify the factors that can predict survival in horses diagnosed with EN.
  • The research applied a retrospective approach and used a convenience sample of 44 horses with EN admitted to two referral institutions.
  • The diagnosis of EN was based on positive blood or fecal PCR (Polymerase chain reaction) – a method used to amplify the number of copies of a specific region of DNA, in order to produce enough DNA to be adequately tested.

Findings and Results

  • The study identified the most common clinical signs of EN to be diarrhea, followed by fever, anorexia, depression, colic, and lameness.
  • At the median, horses were hospitalized for 6 days, and 73% of them survived to be discharged.
  • About 36% of the horses developed laminitis, a painful condition affecting the horse’s feet, with 88% of them affected in all their 4 feet.
  • Nonsurvivors had significantly higher serum creatinine and urea nitrogen concentrations, red blood cell (RBC) count, blood hemoglobin concentration, hematocrit, band neutrophils, serum AST (Aspartate aminotransferase) activity, serum CK (Creatine Kinase) activity, and anion gap.
  • On the other hand, nonsurvivors had significantly lower serum chloride and sodium concentrations, as well as a shorter duration of hospitalization.
  • Analysis by logistic regression indicated independent factors associated with survival as blood hemoglobin concentration on admission and antimicrobial treatment with oxytetracycline.

Conclusions

  • The researchers concluded that severity of colitis, which is reflected by electrolyte loss, hemoconcentration (increase in blood components due to loss of fluid), and prerenal azotemia (a type of kidney failure where more nitrogenous wastes are released into the blood), are indicators of survival in horses diagnosed with EN.
  • Additionally, treatment with the antibiotic oxytetracycline was found to have a positive association with increased survival.

Cite This Article

APA
Bertin FR, Reising A, Slovis NM, Constable PD, Taylor SD. (2013). Clinical and clinicopathological factors associated with survival in 44 horses with equine neorickettsiosis (Potomac horse Fever). J Vet Intern Med, 27(6), 1528-1534. https://doi.org/10.1111/jvim.12209

Publication

ISSN: 1939-1676
NlmUniqueID: 8708660
Country: United States
Language: English
Volume: 27
Issue: 6
Pages: 1528-1534

Researcher Affiliations

Bertin, F R
  • Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN.
Reising, A
    Slovis, N M
      Constable, P D
        Taylor, S D

          MeSH Terms

          • Acid-Base Equilibrium / immunology
          • Animals
          • Aspartate Aminotransferases / blood
          • Blood Urea Nitrogen
          • Chlorides / blood
          • Creatine Kinase / blood
          • Creatinine / blood
          • Ehrlichia / immunology
          • Erythrocyte Count / veterinary
          • Female
          • Hematocrit / veterinary
          • Hemoglobins / analysis
          • Horse Diseases / immunology
          • Horse Diseases / microbiology
          • Horses
          • Logistic Models
          • Male
          • Retrospective Studies
          • Rickettsia Infections / immunology
          • Rickettsia Infections / microbiology
          • Rickettsia Infections / veterinary
          • Sodium / blood

          Citations

          This article has been cited 21 times.
          1. Pinn-Woodcock TL, Aprea MS, Lejeune M, Tomlinson JE. Molecular detection of pathogens in an equine fever diagnostic panel: 2019-2023. Equine Vet J 2026 Mar;58(2):486-496.
            doi: 10.1111/evj.14527pubmed: 40384355google scholar: lookup
          2. Urgibl-Bauer A, Lorch A, Badura D, Zablotski Y, Constable PD, Trefz FM. Retrospective evaluation of acid-base imbalances, clinicopathologic alterations, and prognostic factors in hospitalized calves with Eimeria-associated diarrhea. Front Vet Sci 2024;11:1467583.
            doi: 10.3389/fvets.2024.1467583pubmed: 39834917google scholar: lookup
          3. Haywood LMB, Sheahan BJ. A Review of Epithelial Ion Transporters and Their Roles in Equine Infectious Colitis. Vet Sci 2024 Oct 7;11(10).
            doi: 10.3390/vetsci11100480pubmed: 39453072google scholar: lookup
          4. Hallowell KL, Hepworth-Warren KL, Dembek K. An updated description of bacterial pneumonia in adult horses and factors associated with death. J Vet Intern Med 2024 Sep-Oct;38(5):2766-2775.
            doi: 10.1111/jvim.17141pubmed: 39005215google scholar: lookup
          5. Fortin-Trahan R, Sjolin E, Lack A, de Arbina CL, McFadden-Bennett A, Wang L, Baird JD, Rikihisa Y, Arroyo LG. Diagnosis of Potomac horse fever (syn. equine neorickettsiosis) in 2 foals in southwestern Ontario. Can Vet J 2023 Dec;64(12):1129-1132.
            pubmed: 38046433
          6. Taylor SD, Hart KA, Vaughn S, Giancola SC, Serpa PBS, Santos AP. Effects of intravenous administration of ascorbic acid (vitamin C) on oxidative status in healthy adult horses. J Vet Intern Med 2024 Jan-Feb;38(1):460-468.
            doi: 10.1111/jvim.16934pubmed: 37948618google scholar: lookup
          7. Giraldo AF, Carballo R, Serrenho RC, Tran V, Valverde A, Renaud DL, Gomez DE. Association of the type of metabolic acidosis and non-survival of horses with colitis. Can Vet J 2023 Nov;64(11):1044-1050.
            pubmed: 37915775
          8. Thirumalapura NR, Livengood J, Beeby J, Wang W, Goodrich EL, Goodman LB, Erol E, Tewari D. Improved molecular detection of Neorickettsia risticii with a duplex real-time PCR assay in the diagnosis of Potomac horse fever. J Vet Diagn Invest 2023 Jan;35(1):62-66.
            doi: 10.1177/10406387221135184pubmed: 36373552google scholar: lookup
          9. Gomez DE, Leclere M, Arroyo LG, Li L, John E, Afonso T, Payette F, Darby S. Acute diarrhea in horses: A multicenter Canadian retrospective study (2015 to 2019). Can Vet J 2022 Oct;63(10):1033-1042.
            pubmed: 36185796
          10. Uzal FA, Arroyo LG, Navarro MA, Gomez DE, Asín J, Henderson E. Bacterial and viral enterocolitis in horses: a review. J Vet Diagn Invest 2022 May;34(3):354-375.
            doi: 10.1177/10406387211057469pubmed: 34763560google scholar: lookup
          11. Arroyo LG, Moore A, Bedford S, Gomez DE, Teymournejad O, Xiong Q, Budachetri K, Bekebrede H, Rikihisa Y, Baird JD. Potomac horse fever in Ontario: Clinical, geographic, and diagnostic aspects. Can Vet J 2021 Jun;62(6):622-628.
            pubmed: 34219771
          12. Luethy D, Feldman R, Stefanovski D, Aitken MR. Risk factors for laminitis and nonsurvival in acute colitis: Retrospective study of 85 hospitalized horses (2011-2019). J Vet Intern Med 2021 Jul;35(4):2019-2025.
            doi: 10.1111/jvim.16147pubmed: 33938584google scholar: lookup
          13. Constable PD, Trefz FM, Sen I, Berchtold J, Nouri M, Smith G, Grünberg W. Intravenous and Oral Fluid Therapy in Neonatal Calves With Diarrhea or Sepsis and in Adult Cattle. Front Vet Sci 2020;7:603358.
            doi: 10.3389/fvets.2020.603358pubmed: 33585594google scholar: lookup
          14. Taylor S. A review of equine sepsis. Equine Vet Educ 2015 Feb;27(2):99-109.
            doi: 10.1111/eve.12290pubmed: 32313390google scholar: lookup
          15. DeNotta SL, Divers TJ. Clinical Pathology in the Adult Sick Horse: The Gastrointestinal System and Liver. Vet Clin North Am Equine Pract 2020 Apr;36(1):105-120.
            doi: 10.1016/j.cveq.2019.11.004pubmed: 31982231google scholar: lookup
          16. Savage VL, Marr CM, Bailey M, Smith S. Prevalence of acute kidney injury in a population of hospitalized horses. J Vet Intern Med 2019 Sep;33(5):2294-2301.
            doi: 10.1111/jvim.15569pubmed: 31436910google scholar: lookup
          17. McKenzie HC, Funk RA, Trager L, Werre SR, Crisman M. Immunogenicity of Potomac horse fever vaccine when simultaneously co-administered with rabies vaccine in a multivalent vaccine or as two monovalent vaccines at separate sites. Equine Vet J 2019 Nov;51(6):774-778.
            doi: 10.1111/evj.13096pubmed: 30859618google scholar: lookup
          18. Bertin FR, Ruffin-Taylor D, Stewart AJ. Insulin dysregulation in horses with systemic inflammatory response syndrome. J Vet Intern Med 2018 Jul;32(4):1420-1427.
            doi: 10.1111/jvim.15138pubmed: 29749643google scholar: lookup
          19. Shaw SD, Stämpfli H. Diagnosis and Treatment of Undifferentiated and Infectious Acute Diarrhea in the Adult Horse. Vet Clin North Am Equine Pract 2018 Apr;34(1):39-53.
            doi: 10.1016/j.cveq.2017.11.002pubmed: 29426709google scholar: lookup
          20. Arroyo MG, Slovis NM, Moore GE, Taylor SD. Factors Associated with Survival in 97 Horses with Septic Pleuropneumonia. J Vet Intern Med 2017 May;31(3):894-900.
            doi: 10.1111/jvim.14679pubmed: 28271546google scholar: lookup
          21. Uzal FA, Diab SS. Gastritis, Enteritis, and Colitis in Horses. Vet Clin North Am Equine Pract 2015 Aug;31(2):337-58.
            doi: 10.1016/j.cveq.2015.04.006pubmed: 26048413google scholar: lookup