Alternative therapies called best long-term hope for blackhead disease in turkeys

Alternative treatments may be the only long-term hope for managing blackhead in turkeys, said Robert Beckstead, PhD, turkey health specialist, North Carolina State University.

For now, however, biosecurity is the only available option for preventing the disease, he told Poultry Health Today.

Blackhead disease is caused by the protozoan parasite Histomonas meleagridis and usually causes mortality between 70% and 100%. The last medication licensed for treating the disease, nitrasone, was removed from the market at the end of 2015.

No figures are officially kept on the number of turkeys that have blackhead disease, which tends to be sporadic, but some years are worse than others. In 2015 — the same year avian influenza affected the turkey industry — the losses due to blackhead disease were particularly high, Beckstead said.

He does not foresee a new drug ever becoming available to treat blackhead disease and said many companies are testing alternative products to see if they have the ability to prevent transmission of the disease.

“Our lab is really busy at the moment, running through a lot of these different feed additives, essential oils [and] plant extracts to see if they have anti-histomonal activity, and whether actually they can be used in the turkeys to prevent the disease,” Beckstead said.

Because biosecurity is currently the only line of defense against the disease, producers must make sure that contaminated mechanical vectors, such as farm equipment, vehicles or workers’ boot, don’t bring the disease onto their farms, he said.

On a positive note, Beckstead said the avian influenza outbreak prompted the turkey industry to initiate better biosecurity measures, which will also help prevent blackhead disease.