Two main causes of infectious anemia occur in the United States, Anaplasma marginale and Theileria orientalis particularly the Ikeda genotype. This dashboard is available to share distribution data, current best practices, and research. This page will include a dashboard for pathogen distribution, risk maps, niche modeling, contact information, and current best practices and recent research.
Comprehensive Comparison Profile
If you need a quick-reference guide to print or share with your team, this master matrix breaks down the critical biological and operational differences:
| Feature | Theileria orientalis (Ikeda) | Anaplasma marginale |
|---|---|---|
| Common Name | Bovine Infectious Anemia / Theileriosis | Bovine Anaplasmosis |
| Pathogen Type | Protozoan parasite (piroplasm) | Obligate intracellular bacterium |
| Primary Target | Red blood cells (erythrocytes) & lymphocytes | Mature red blood cells exclusively |
| Main Vector | Asian longhorned tick (Haemaphysalis longicornis) | Rocky Mountain Wood tick (Dermacentor andersoni), D. variabilis, and biting flies |
| Mechanical Spread | Highly contagious via reused needles, ear-notchers, and dehorning equipment as well as biting insects | Highly contagious via blood-contaminated equipment and biting stable/horse flies |
| Primary Age Affected | Severe in calves (2-6 months old) and late-gestation pregnant cows | Severe/fatal in adult cattle (>2 years old); calves show mild or no signs |
| Key Clinical Signs | Pale/jaundiced mucous membranes, lethargy, high abortion rates in naïve animals, sudden milk drop | Severe icterus (yellowing), aggressive behavior (due to brain hypoxia), sudden death |
| FDA-Approved Cure | None (Supportive care and stress reduction only) | Chlortetracycline (CTC) via medicated feed (requires a VFD) or injectable Oxytetracycline |
| Carrier Status | Lifelong persistent carrier | Lifelong persistent carrier |
Actionable Biosecurity Checklist
To prevent the introduction or spread of either blood parasite within your herd, execute the following three-phase protocol:
Phase 1: Vector Control & Pasture Management
- Acaricide Treatment: Apply approved topical pyrethroid pours or insecticide ear tags during peak tick seasons (spring through autumn).
- Pasture Grooming (potentially): Keep pastures mowed short near tree lines. The Asian longhorned tick thrives in tall, unmanaged brush and thick thatch.
- Wildlife Exclusion: Where possible, limit cattle access to deep wooded patches where deer and other wildlife continuously reintroduce tick populations.
Phase 2: Strict Equipment Hygiene
- Single-Use Needles: Change needles between every single animal during routine vaccinations or antibiotic treatments. Reusing a needle is the fastest way to turn a single carrier into a herd-wide outbreak.
- Tool Disinfection: Submerge dehorners, castrators, and ear-notching tools in an approved disinfectant solution (like a 1:32 bleach-to-water dilution or Nolvasan) between every animal.
Phase 3: Diagnostic Diagnostics & Sourcing
- Isolation Strategy: Isolate all incoming stock (purchased bulls, replacement heifers) for at least 30 days in order to monitor for clinical disease
- PCR Screening: Coordinate with your veterinarian to submit whole blood samples (EDTA purple-top tubes) for a multiplex blood parasite PCR panel before mixing new arrivals with the main herd.