Prevent Blackhead Disease (Histomoniasis)

Keep turkeys strictly separated from chickens and from ground where chickens have ranged. Blackhead disease is caused by the protozoan Histomonas meleagridis, transmitted via cecal worm eggs (Heterakis gallinarum) commonly carried by chickens. Turkeys suffer mortality rates of 70-100% in untreated flocks, while chickens often carry the parasite asymptomatically.

Why It Works

Chickens shed cecal worm eggs containing H. meleagridis into soil, where earthworms ingest them and remain infective for years. Housing turkeys on land free of chicken contamination and preventing shared ranging breaks the transmission cycle entirely. No approved drug treatment exists for blackhead in the U.S., making prevention the only viable strategy.

Tips

• Rotate turkey pastures annually and avoid land used by chickens within the past 3 years
• Control earthworm exposure in turkey runs, as earthworms serve as transport hosts for the parasite
• Watch for sulphur-yellow droppings and darkened, swollen head — signs that demand immediate bird isolation