Diagnosis of Potomac horse fever (syn. equine neorickettsiosis) in 2 foals in southwestern Ontario.
Abstract: Potomac horse fever (PHF) is characterized by fever, depression, anorexia, ileus, diarrhea, and occasionally, laminitis. The disease is caused by infection with and/or . Equids of all ages may be affected; however, the condition has not been well-characterized in foals. This report describes clinical signs, laboratory findings, and treatment of 2 foals diagnosed with PHF in southwestern Ontario. Feces submitted for an equine PCR panel tested positive for spp. and were subsequently confirmed to be (Case 1) and (Case 2). Both foals recovered following hospitalization and intensive care. Key clinical message: The purpose of this report is to make veterinarians aware that foals may develop PHF. During summer (July to September), when encountering foals in endemic areas with clinical signs compatible with PHF, veterinarians should consider PHF as a diagnostic rule-out. For confirmation of the diagnosis, blood and feces should be submitted for PCR testing for spp. . La fièvre équine du Potomac (PHF) se caractérise par de la fièvre, une dépression, de l’anorexie, un iléus, de la diarrhée et, occasionnellement, une fourbure. La maladie est causée par une infection par et/ou . Les équidés de tous âges peuvent être atteints; cependant, cette pathologie n’a pas été bien caractérisée chez les poulains. Ce rapport décrit les signes cliniques, les résultats de laboratoire et le traitement de 2 poulains diagnostiqués avec PHF dans le sud-ouest de l’Ontario. Les matières fécales soumises à un panel PCR équin se sont révélées positives pour spp. et ont ensuite été confirmées comme étant positives pour (cas 1) et (cas 2). Les deux poulains se sont rétablis après une hospitalisation et des soins intensifs.Message clinique clé :Le but de ce rapport est de sensibiliser les vétérinaires au fait que les poulains peuvent développer une PHF. Pendant l’été (juillet à septembre), lorsqu’ils rencontrent des poulains dans des zones d’endémie présentant des signes cliniques compatibles avec le PHF, les vétérinaires doivent considérer le PHF comme une exclusion diagnostique. Pour confirmer le diagnostic, du sang et des selles doivent être soumis à un test PCR pour spp.(Traduit par D Serge Messier).
Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.
Publication Date: 2023-12-04 PubMed ID: 38046433PubMed Central: PMC10637704 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.
- Case Reports
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.
This research article reports two cases of Potomac horse fever amongst foals in southwestern Ontario in an effort to alert veterinarians about the possibility of this ailment in young horses.
Plain Language Overview
Potomac horse fever (PHF) is a disease that is usually found in equines like horses and donkeys. Although this infection can affect equids of all ages, it has not been adequately studied in young horses, specifically foals. This paper discusses two instances of PHF in foals in Ontario’s southwestern region, including their symptoms, laboratory results, and treatment. The findings suggest that veterinarians should consider PHF when examining foals in regions where the disease is common, especially during the summer months.
Potomac Horse Fever (PHF)
- PHF is marked by a number of symptoms such as fever, depression, loss of appetite, cessation of bowel movements, diarrhea, and at times, inflammation of the laminae in the feet leading to severe pain and changes in gait.
- The disease is triggered by specific bacterial infections, namingly Neorickettsia spp.. The paper indicates that the particular species found in the two foals were N. risticii and N. sennetsu.
PHF in Foals in Southwestern Ontario
- The researchers present the clinical signs and laboratory findings alongside the treatments used for the two PHF diagnosed foals.
- Both of the foals’ conditions improved following a period of intensive care in a clinic.
Key Clinical Message
- The main aim of this report is to increase awareness amongst veterinarians about the possibility of foals developing PHF.
- Veterinarians are advised to consider PHF as a potential diagnosis when examining foals showing signs of the disease from July to September, in regions where the condition is already prevalent.
- The paper highlights the importance of blood and fecal samples for a conclusive diagnosis of PHF through Polymerase Chain Reaction (PCR) testing for the presence of Neorickettsia spp..
Cite This Article
APA
Fortin-Trahan R, Sjolin E, Lack A, de Arbina CL, McFadden-Bennett A, Wang L, Baird JD, Rikihisa Y, Arroyo LG.
(2023).
Diagnosis of Potomac horse fever (syn. equine neorickettsiosis) in 2 foals in southwestern Ontario.
Can Vet J, 64(12), 1129-1132.
Publication
Researcher Affiliations
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario N1G 2W1 (Fortin-Trahan, Sjolin, Lack, Baird, Arroyo); 1165 Highway 8, Sheffield, Ontario L0R 1Z0 (Lopez de Arbina); 455 Dobbie Drive, Unit 2, Cambridge, Ontario N1T 1T1 (McFadden-Bennett); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA (Wang, Rikihisa).
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario N1G 2W1 (Fortin-Trahan, Sjolin, Lack, Baird, Arroyo); 1165 Highway 8, Sheffield, Ontario L0R 1Z0 (Lopez de Arbina); 455 Dobbie Drive, Unit 2, Cambridge, Ontario N1T 1T1 (McFadden-Bennett); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA (Wang, Rikihisa).
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario N1G 2W1 (Fortin-Trahan, Sjolin, Lack, Baird, Arroyo); 1165 Highway 8, Sheffield, Ontario L0R 1Z0 (Lopez de Arbina); 455 Dobbie Drive, Unit 2, Cambridge, Ontario N1T 1T1 (McFadden-Bennett); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA (Wang, Rikihisa).
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario N1G 2W1 (Fortin-Trahan, Sjolin, Lack, Baird, Arroyo); 1165 Highway 8, Sheffield, Ontario L0R 1Z0 (Lopez de Arbina); 455 Dobbie Drive, Unit 2, Cambridge, Ontario N1T 1T1 (McFadden-Bennett); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA (Wang, Rikihisa).
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario N1G 2W1 (Fortin-Trahan, Sjolin, Lack, Baird, Arroyo); 1165 Highway 8, Sheffield, Ontario L0R 1Z0 (Lopez de Arbina); 455 Dobbie Drive, Unit 2, Cambridge, Ontario N1T 1T1 (McFadden-Bennett); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA (Wang, Rikihisa).
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario N1G 2W1 (Fortin-Trahan, Sjolin, Lack, Baird, Arroyo); 1165 Highway 8, Sheffield, Ontario L0R 1Z0 (Lopez de Arbina); 455 Dobbie Drive, Unit 2, Cambridge, Ontario N1T 1T1 (McFadden-Bennett); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA (Wang, Rikihisa).
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario N1G 2W1 (Fortin-Trahan, Sjolin, Lack, Baird, Arroyo); 1165 Highway 8, Sheffield, Ontario L0R 1Z0 (Lopez de Arbina); 455 Dobbie Drive, Unit 2, Cambridge, Ontario N1T 1T1 (McFadden-Bennett); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA (Wang, Rikihisa).
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario N1G 2W1 (Fortin-Trahan, Sjolin, Lack, Baird, Arroyo); 1165 Highway 8, Sheffield, Ontario L0R 1Z0 (Lopez de Arbina); 455 Dobbie Drive, Unit 2, Cambridge, Ontario N1T 1T1 (McFadden-Bennett); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA (Wang, Rikihisa).
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario N1G 2W1 (Fortin-Trahan, Sjolin, Lack, Baird, Arroyo); 1165 Highway 8, Sheffield, Ontario L0R 1Z0 (Lopez de Arbina); 455 Dobbie Drive, Unit 2, Cambridge, Ontario N1T 1T1 (McFadden-Bennett); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA (Wang, Rikihisa).
MeSH Terms
- Horses
- Animals
- Ontario
- Anaplasmataceae Infections / diagnosis
- Anaplasmataceae Infections / veterinary
- Anaplasmataceae Infections / microbiology
- Horse Diseases / diagnosis
- Horse Diseases / microbiology
- Neorickettsia risticii / genetics
- Polymerase Chain Reaction / veterinary
- Gastrointestinal Diseases / veterinary
References
This article includes 22 references
- Elfenbein JR, Sanchez LC. Prevalence of gastric and duodenal ulceration in 691 nonsurviving foals (1995u20132006) Equine Vet J Suppl. 2012;41:76u201379.
- Budachetri K, Lin M, Yan Q, et al. Real-time PCR differential detection of Neorickettsia findlayensis and N. risticii in cases of Potomac Horse Fever. J Clin Microbiol. 2022;60:e00250u201322.
- Xiong Q, Bekebrede H, Sharma P, Arroyo LG, Baird JD, Rikihisa Y. An ecotype of Neorickettsia risticii causing Potomac Horse Fever in Canada. Appl Env Microbiol. 2016;82:6030u20136036.
- Teymournejad O, Lin M, Bekebrede H, et al. Isolation and molecular analysis of a novel Neorickettsia species that causes Potomac Horse Fever. mBio. 2020;11:e03429u201319.
- Teymournejad O, Lin M, Bekebrede H, et al. Erratum for Teymournejad et al., u201cIsolation and molecular analysis of a novel Neorickettsia species that causes Potomac Horse Feveru201d. mBio. 2020;11:e00774u201320.
- Arroyo LG, Moore A, Bedford S, et al. Potomac horse fever in Ontario: Clinical, geographic, and diagnostic aspects. Can Vet J. 2021;62:622u2013628.
- Oliver-Espinosa O. Foal diarrhea: Established and postulated causes, prevention, diagnostics, and treatments. Vet Clin North Am Equine Pract. 2018;34:55u201368.
- Palmer JE, Benson CE, Whitlock RH, Ziemer E. Potomac horse fever: Diagnostic criteria and recognition of endemic areas. Proc 2nd Symposium on Equine Colic Research ; 1986; pp. 157u2013160.
- Schofield FW. An investigation into an endemic disease of horses (occurring chiefly in Kent and Essex counties of the province of Ontario). Report of the Ontario Veterinary College 1924. Guelph, Ontario: OVC. 1925;49:41u201349.
- Baird JD, Arroyo LG. Historical aspects of Potomac horse fever in Ontario (1924u20132010) Can Vet J. 2013;54:565u2013572.
- Palmer JE. Potomac horse fever. In: Coetzer JAW, Tustin RC, editors. Infectious Diseases of Livestock. 2nd ed. I. Oxford, England: Oxford University Press; 2004. pp. 583u2013591.
- Madigan JE, Pusterla N, Johnson E, et al. Transmission of Ehrlichia risticii, the agent of Potomac horse fever, using naturally infected aquatic insects and helminth vectors: Preliminary report. Equine Vet J. 2000;32:275u2013279.
- Mott J, Muramatsu Y, Seaton E, Martin C, Reed S, Rikihisa Y. Molecular analysis of Neorickettsia risticii in adult aquatic insects in Pennsylvania, in horses infected by ingestion of insects, and isolated in cell culture. J Clin Microbiol. 2002;40:690u2013693.
- Greiman SE, Rikihisa Y, Cain J, Vaughan JA, Tkach VV. Germs within worms: Localization of Neorickettsia sp. within life cycle stages of the digenean Plagiorchis elegans. Appl Environ Microbiol. 2016;82:2356u20132362.
- Rikihisa Y, Perry BD, Cordes DO. Ultrastructural study of ehrlichial organisms in the large colons of ponies infected with Potomac horse fever. Infect Immun. 1985;49:505u2013512.
- Rikihisa Y, Johnson GC, Wang YZ, Reed SM, Fertel R, Cooke HJ. Loss of absorptive capacity for sodium and chloride in the colon causes diarrhoea in Potomac horse fever. Res Vet Sci. 1992;52:353u2013362.
- 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;27:1528u20131534.
- Slovis NM, Elam J, Estrada M, Leutenegger CM. Infectious agents associated with diarrhoea in neonatal foals in central Kentucky: A comprehensive molecular study. Equine Vet J. 2014;46:311u2013316.
- Mott J, Rikihisa Y, Zhang Y, Reed SM, Yu CY. Comparison of PCR and culture to the indirect fluorescent-antibody test for diagnosis of Potomac horse fever. J Clin Microbiol. 1997;35:2215u20132219.
- Palmer JE, Whitlock RH, Benson CE. Equine ehrlichial colitis: Effect of oxytetracycline treatment during the incubation period of Ehrlichia risticii infection in ponies. J Am Vet Med Assoc. 1988;192:343u2013345.
- Palmer JE, Benson CE, Whitlock RH. Effect of treatment with oxytetracycline during the acute stages of experimentally induced equine ehrlichial colitis in ponies. Am J Vet Res. 1992;53:2300u20132304.
- Dowling PM, Russell AM. Pharmacokinetics of a long-acting oxytetracycline-polyethylene glycol formulation in horses. J Vet Pharmacol Therap. 2000;23:107u2013110.