Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2024 Jun 13;11(6):269.
doi: 10.3390/vetsci11060269.

Equine Granulocytic Anaplasmosis: A Systematic Review and Meta-Analysis on Clinico-Pathological Findings, Diagnosis, and Therapeutic Management

Andreea Monica Bogdan  1 , Ioan Liviu Mitrea  1 , Mariana Ionita  1
Affiliations
Review

Equine Granulocytic Anaplasmosis: A Systematic Review and Meta-Analysis on Clinico-Pathological Findings, Diagnosis, and Therapeutic Management

Andreea Monica Bogdan et al. Vet Sci. .

Abstract

Equine granulocytic anaplasmosis (EGA) is a tick-borne disease affecting horses worldwide, caused by Anaplasma phagocytophilum. The disease ranges from non-specific clinical signs to fatal outcomes. This paper aimed to analyze EGA cases reported in peer-reviewed journals, particularly on clinico-pathological findings, diagnosis, and therapeutic management. Overall, 189 clinical cases from 31 publications were included in the study. Extensive symptomatology for the EGA cases was reported, of which mostly was fever (90.30%), followed by limb edema (48.51%), anorexia (41.79%), depression (32.84%), icterus (22.39%), ataxia (17.91), tachycardia (16.42%), and lethargy (15.67%). Laboratory tests revealed thrombocytopenia (90.32%), anemia (75%), decreased hematocrit (70.59%), leukopenia (55.88%), lymphopenia (58.14%), and neutropenia (41.67%) as the most common hematological abnormalities. For a subset of tested animals, hyperbilirubinemia (20/29), hyperfibrinogenemia (13/15), and hyponatremia (10/10) were also reported. The diagnosis was established by microscopic identification of morulae (in 153 cases), and/or PCR (120 cases), isolation (1 case), or serology (56 cases). For treatment, oxytetracycline was used in the majority (52.24%) of EGA cases, but recovery without antibiotherapy (10.34%) was also noted. In conclusion, the variety of clinical and pathological findings and the challenging therapeutic approaches reported suggest that EGA should be included in the differential diagnosis when fever occurs.

Keywords: Anaplasma phagocytophilum; clinico-pathology; diagnosis and treatment; equine granulocytic anaplasmosis.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Prisma flow chart for selecting eligible articles for clinical equine granulocytic anaplasmosis (EGA).
Figure 2
Figure 2
(a) Number of published articles per year reporting equine granulocytic anaplasmosis cases. (b) Map with the countries where the equine granulocytic anaplasmosis (EGA) reported cases (n = 189) originated from.
See this image and copyright information in PMC

References

    1. Rymaszewska A., Grenda S. Bacteria of the genus Anaplasma—Characteristics of Anaplasma and their vectors: A review. Vet. Med. 2008;53:573–584. doi: 10.17221/1861-VETMED. - DOI
    1. Silaghi C., Santos A.S., Gomes J., Christova I., Matei I.A., Walder G., Domingos A., Bell-Sakyi L., Sprong H., Von Loewenich F.D., et al. Guidelines for the Direct Detection of Anaplasma spp. in Diagnosis and Epidemiological Studies. Vector Borne Zoonotic Dis. 2017;17:12–22. doi: 10.1089/vbz.2016.1960. - DOI - PubMed
    1. Slivinska K., Víchová B., Werszko J., Szewczyk T., Wróblewski Z., Pet’ko B., Ragač O., Demeshkant V., Karbowiak G. Molecular surveillance of Theileria equi and Anaplasma phagocytophilum infections in horses from Ukraine, Poland and Slovakia. Vet. Parasitol. 2016;215:35–37. doi: 10.1016/j.vetpar.2015.10.025. - DOI - PubMed
    1. Dumler J.S., Barbet A.F., Bekker C.P., Dasch G.A., Palmer G.H., Ray S.C., Rikihisa Y., Rurangirwa F.R. Reorganization of genera in the families Rickettsiaceae and Anaplasmataceae in the order Rickettsiales: Unification of some species of Ehrlichia with Anaplasma, Cowdria with Ehrlichia and Ehrlichia with Neorickettsia, descriptions of six new species combinations and designation of Ehrlichia equi and ‘HGE agent’ as subjective synonyms of Ehrlichia phagocytophila. Pt 6Int. J. Syst. Evol. Microbiol. 2001;51:2145–2165. doi: 10.1099/00207713-51-6-2145. - DOI - PubMed
    1. Burgess H., Chilton N.B., Krakowetz C.N., Williams C., Lohmann K. Granulocytic anaplasmosis in a horse from Saskatchewan. Can. Vet. J. 2012;53:886–888. - PMC - PubMed

LinkOut - more resources