Tropical Fowl Mite Infestation

The tropical fowl mite, Ornithonyssus bursa is a common ectoparasite of chickens and wild nesting birds (such as pigeons, starlings, and sparrows) living in subtropical and tropical regions worldwide. It looks very similar to the Northern fowl mite.

Clinical Signs of Tropical Fowl Mites in Chickens

Tropical fowl mites cause irritation (excessive itching), painful dermatitis, feather loss, and anemia in chickens. The mites are most commonly found in the vent area and accumulate in masses on just a few feathers. Tropical fowl mites can also spread from the birds to humans---resulting in avian mite dermatitis (also referred to as gamasoidosis or acariasis), characterized by prolonged itching, welts, and painful dermatitis.

The tropical fowl mite is known for inhabiting abandoned nests of wild nesting birds. They may also become a pest to humans in areas of high bird populations or where wild birds are allowed to roost on roofs and around the eaves of homes. The life cycle of the tropical fowl mite is similar to that of the Northern fowl mite. It lays its eggs on the birds or in the nests, which take 3 days to hatch. They will almost immediately begin feeding off the blood of the birds and increase in their numbers rapidly. Without a blood meal from a bird host, they usually will die within 3 weeks.