Respiratory symptoms got you breathless? Try our equine respiratory PCR panel -- we test for 7 respiratory bacteria and viruses from 1 swab.

Neurological symptoms got you down? Try our equine neurological PCR panel -- we test for 5 neurological diseases from 1 CSF or tissue sample.

Diarrhea got you on the run? Try our equine GI / diarrhea PCR panel -- we test for 4 GI diseases from 1 fecal or swab sample.

Oh baby! Our equine breeding/abortion PCR panel tests for 5 diseases affecting breeding success from 1 swab or semen sample.

* * *

For our international clients: Our DRY CARDS let you mail blood samples to Zoologix easily and cheaply from anywhere. Samples are small, light and stable at room temperature.

* * *

Zoologix performs equine PCR tests for...

African horse sickness

Anaplasma phagocytophilum





Borna virus

Borrelia burgdorferi

Burkholderia mallei and pseudomallei

Clostridium difficile

Clostridium species

Contagious equine metritis (CEM)




Eastern equine encephalitis (EEE)

E. coli O157:H7

E. coli panel

Equine adenoviruses

Equine arteritis virus (EAV)

Equine hepatitis virus

Equine herpesvirus
type 1

Equine herpesvirus
type 2

Equine herpesvirus
type 3

Equine herpesvirus
type 4

Equine herpesvirus
type 5

Equine infectious anemia (EIA)

Equine parvovirus

Equine piroplasmosis

Equine protozoal myeloencephalitis (EPM)





Horsepox virus

Influenza type A

Japanese encephalitis

Lawsonia intracellularis


Lyme disease


Neospora caninum

Neospora hughesi


Potomac horse fever


Rhodococcus equi


Sarcocystis neurona

St. Louis encephalitis

Strangles (Strep equi)

Streptococcus pneumoniae




Taylorella equigenitalis

Theileria equi

Toxoplasma gondii


Trypanosoma equiperdum

Trypanosoma evansi

Venezuelan equine encephalitis (VEE)

Vesicular stomatitis

West Nile virus (WNV)

Western Equine Encephalitis (WEE)

Yersinia enterocolitica

Yersinia pseudotuberculosis

Genetic tests for...

Hyperkalemic periodic paralysis

Potomac horse fever PCR test
equine assay data sheet

Potomac horse fever (Neorickettsia risticii, formerly known as Ehrlichia risticii; also know as equine monocytic ehrlichiosis)

Test code:
B0028 - Ultrasensitive qualitative detection of Neorickettsia risticii by real time polymerase chain reaction.

B0028 is included in P0015 - equine GI/diarrhea PCR panel


Ehrlichiosis is a disease caused by obligatory intracellular bacteria of the genus Ehrlichia that affects a variety of animals including humans. Several species are assigned to this genus; those for which the vectors are known are transmitted by ixodid ticks. Most Ehrlichia infect predominantly white blood cells of their vertebrate hosts; the one exception is Ehrlichia platys which infects blood platelets of dogs. The organisms appear in clusters known as morulae in the cytoplasm of infected cells.

Traditionally, these organisms were classified as agranulocytic or granulocytic based on the cells they infect. With the advent of molecular detection methods and RNA sequencing techniques, these organisms have been reclassified with different names. For example, Ehrlichia risticii is now classified as Neorickettsia risticii and Ehrlichia platys is now Anaplasma platys. Ehrlichia equi, Ehrlichia phagocytophila and human granulocytic Ehrlichial agent have now been confirmed to be the same species and have been reclassified as Anaplasma phagocytophila.

Neorickettsia risticii causes Potomac horse fever, also known as equine monocytic ehrlichiosis. Natural infections have also been reported in dogs, with symptoms resembling E. canis infection. N. risticii is very closely related to Ehrlichia sennetsu.

Potomac horse fever is prevalent in the Midwestern and Northeastern United States and has also been reported in Europe and India. Mode of transmission is unknown, but recent reports suggest oral transmission. Transplacental transmission of this agent has also been reported. Infections are more prevalent during summer months and have a 5 to 30% mortality rate. Clinical signs of infection are pyrexia, anorexia, enteritis, watery diarrhea, colic and laminitis. Hematological findings include thrombocytopenia and leucopenia.

Serological detection of E. risticii is not only insensitive but also not very specific because of cross-reactivity with other Ehrlichia organisms. Detection by culture is slow and also lacks sensitivity. Detection of the pathogen by PCR is sensitive and highly specific (Mott et al., 1997).


  • Help confirm the disease causing agent
  • Shorten the time required to confirm a clinical diagnosis of N. risticii infection.
  • Help ensure that horse populations are free of N. risticii
  • Early prevention of spread of this bacterium
  • Minimize personnel exposure to this bacterium
  • Safety monitoring of biological products that derive from horses

Mott, J., Rikihisa, Y., Zhang, Y., Reed, S.M. and Yu, C.Y. (1997) Comparison of PCR and culture to the indirect fluorescent-antibody test for diagnosis of Potomac horse fever. J Clin Microbiol. 35:2215-9.

Specimen requirements: 0.2 ml whole blood in EDTA (purple top) tube, or fecal swab or 0.2 ml feces.

Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time PCR

Normal range: Nondetected

2003-2023 Zoologix, Inc. • Email Zoologix • Phone (818) 717-8880