UPDATE, June 23, 2021 - The MSU VDL has received a recent increase in equine blood samples from horses infected with intragranulocytic bacterium morphologically consistent with Anaplasma phagocytophilum, a tick-borne disease associated with fever, lethargy, and icterus. While Anaplasma is not contagious horse-to-horse, it is transmitted by Ixodes ticks, which are common in Michigan and have grown in population size in recent years. Horses typically begin showing signs of disease (fever, etc.) 8–12 days after being bitten by the tick.
Anaplasma morulae (see photos) can be visually detected in neutrophils via blood smear examination, or infection can be assessed by PCR and IFA titers. The MSU VDL offers several tick-borne diagnostic options for veterinarians through submission of whole blood, serum, or ticks. With prompt and appropriate recognition and treatment, most infected horses have an excellent prognosis.
As always, if you have questions, need help ordering tests, or want more information on testing, please call the laboratory. In addition, the MSU Large Animal Clinic is available to see horses on emergency 24/7/365 and can be contacted for evaluation and treatment of infected horses.
Ticks and tick-borne diseases such as anaplasmosis, babesiosis, ehrlichiosis, Lyme disease, and Rocky Mountain spotted fever pose a health risk to humans and various species of livestock and companion animals. In recent years, the geographic ranges of these diseases have been shifting and expanding. Changing weather patterns and events are contributing factors. The ease of modern transportation also allows for movement of animals (and potentially insect/arachnid vectors) all over the globe. Veterinarians and pet owners should be aware of current trends in their area and locations where pets may have lived or traveled previously.
The MSU VDL closely monitors new and emerging tick-borne diseases to provide veterinarians with the best diagnostics to detect possible infections based on the type of tick and geographic region. For example, a new type of Borrelia, termed Borrelia mayonii, that has emerged in the western Great Lakes region can cause Lyme disease in humans and is found in the Ixodes scapularis ticks which also are carriers for Borrelia burgdorferi.
The MSU VDL offers several tick-borne diagnostic options for veterinarians through submission of whole blood, serum, or tick. Check our test catalog for more information. Specific diagnostic options include:
- Anaplasma phagocytophilum IFA
- Anaplasma spp PCR
- Babesia canis IFA
- Babesia gibsoni IFA
- Babesia spp PCR
- Ehrlichia canis IFA
- Ehrlichia spp PCR
- Equine Tick Core Panel
- Lyme IFA
- Lyme PCR
- Rickettsia rickettsii IFA
- Rickettsia PCR
- Tick-Borne Disease Antibody Screen
- Tick Identification
- Tick PCR
For More Information
- Tiny Arachnids with a Big Bite—Let’s Talk Ticks! (Summer 2020) provides detailed information for veterinary practitioners on tick-borne diseases and diagnostic testing strategies
- Ticks & Tick-Borne Diseases: Information for Pet Owners & Clinicians includes quick tick facts, resources for additional information, and resources specifically for our Michigan clients
- Michigan Emerging Disease Issues website includes information on vector-borne diseases in Michigan and the Michigan Zoonotic and Vector-Borne Disease Mapper
- Companion Animal Parasite Council offers tickborne disease prevalence maps, forecasts, and a subscription for disease alerts
- Centers for Disease Control and Prevention provides national data on tick-borne diseases
As always, if you have questions, need help ordering tests, or want more information on testing, please call the laboratory. We enjoy the opportunity to talk with our clients!