Fig 1: Immunohistochemistry (IHC) of CFB and RND1 on bovine foot skin from the site of BDD lesions. Low power images accompanied with high power inserts. Images shown are representatives of three independent experimental replicates (n = 3) for each tissue lesion type (no BDD, acute BDD, chronic BDD). (A–C) IHC for CFB. (A) No BDD. Labeling of lymphocytes and plasma cells at the dermal-epidermal junction (×20), with insert confirming identification of labeled mononuclear cells (×100). (B) Acute BDD. Intense labeling of the most superficial keratinocytes (×20), with insert showing intense cytoplasmic and membranous labeling of the most superficial keratinocytes (×x400). (C) Chronic BDD lesion (×20, ×400) exhibiting similar findings to (B). (D–F) IHC for RND1. (D) No BDD. Multifocally, the stratum corneum has granular background labeling of the stratum corneum keratinocytes (×20, ×100). (E) Acute BDD. Multifocally, there are intensely labeled keratinocytes near to ulcerated regions (×20), with insert highlighting view of intense labeling (×400). (F) Chronic BDD. Multifocal mild granular labeling of the stratum corneum keratinocytes similar to (D); however, note most of the thickened stratum corneum is not labeled (20). Insert shows background labeling of some stratum corneum keratinocytes (400).