Lymph node hyperplasia in infected sheep. Photograph of popliteal lymph nodes ipsilateral and contralateral to inflamed limb collected from a clinically lame animal (a). Mean lymph node size (each lymph node represented as proportion (%) of combined weight) in control animals (left and right prescapular and popliteal lymph nodes) and animals affected by unilateral hindlimb (popliteal lymph nodes) and forelimb (prescapular lymph nodes) lameness on day 0 prior to treatment, and 3 days post-treatment (b). Data are presented as mean values; s.e.d. represents the standard error of the difference. a, b, c Means with disparate letters are significantly different (p < 0.001).