Depluming mites (Knemidocoptes gallinae, Neocnemidocoptes gallinae) are found worldwide and are related to the scaly leg mite (Knemidocoptes mutans). Depluming mites prefer feathered portions of the body while scaly-leg mites infest the non-feathered regions. Both mites spend their entire lives on the bird and do not survive long in the environment.
The depluming mite burrows into the basal shafts and feathers of the epidermis of birds which results in irritation and inflammation. The feathers break easily and are often pulled out by the bird resulting in bare patches on the back (Figure 1) which may spread to the wings, neck, and head. These mites are very small, burrow into the skin, and are difficult to see without magnification.
Various treatments have been prescribed which include sulfur baths, malathion, carbaryl dust, and ivermectin topical application (not licensed for chickens). Since the mite is somewhat protected by its location in burrows of the skin, multiple applications may be necessary.
For more information about TVMDL’s test catalog, visit tvmdl.tamu.edu or call 1.888.646.5623.
REFERENCES
Hinkle NC and Corrigan RM. External Parasites and Poultry Pests (Depluming Mites) in Diseases of Poultry, 13thedition, Wiley-Blackwell, ed. Swayne, DE et al. pp. 1101-1102, 2013.