Organic-bred, free range chicken, with cachexia, inflammation at the level of the tarsal joints, scabs on the comb and dermatitis, especially in the dorsal area.

Pathologic examination of the animal allowed to observe different types of lesion without any apparent link between them :

  • The skin of the back had a multifocal ulcerative bacterial dermatitis, heterophilic and crusty, moderate and chronic with abundant intralesional bacteria.
  • The examination of the lesions in the tarsus revealed a viral arthritis with bilateral rupture of the gastrocnemius tendon and severe chronic tenosynovitis. This lesion is characteristic of avian reovirus infection.
  • Lesions on the comb corresponded to a hyperplastic and ulcerative severe, multifocal to diffuse dermatitis with intranuclear inclusion bodies. This type of lesion is indicative of a viral etiology. Although the inclusion bodies were positive to immunohistochemistry for papillomavirus, its presence could not be confirmed by electron microscopy.
The comb had confluent multifocal areas of hyperplasia, ulceration and crust, of between 0.5 to 1 cm in diameter.

The comb had confluent multifocal areas of hyperplasia, ulceration and crust, of between 0.5 to 1 cm in diameter.

Histological image (top) of the comb epithelium with basophilic intranuclear inclusions that stain positive (bottom) for immunohistochemistry against papillomavirus. Arrows indicate the inclusion bodies.

Histological image (top) of the comb epithelium with basophilic intranuclear inclusions that stain positive (bottom) for immunohistochemistry against papillomavirus. Arrows indicate the inclusion bodies.

Haematomas at the level of the tarsal joints. Complete rupture of the left and partialy right  gastrocnemius tendon.

Haematomas at the level of the tarsal joints. Complete rupture of the left and right partial gastrocnemius tendon.