Early rheumatoid-like synovial lesions in rabbits drinking cow's milk. I. Joint pathology.

Rheumatoid-like lesions developed in 9 of 25 (36%) Old English rabbits drinking cow's milk for 12 weeks. The incidence of lesions in male and female animals was similar. The majority of rabbits drinking cow's milk developed increased numbers of nucleated cells and raised percentages of T lymphocytes in their synovial fluids, compared to control rabbits. The cell counts and T cell percentages correlated with the severity of the histological lesions. No evidence of glomerulonephritis was observed in any of the experimental animals.