Experimental ampicillin glomerulonephropathy.

Eighteen dogs were given repeated doses (between 4 and 19) of ampicillin (7 mg per kg intramuscularly on 3 days a week). Fifteen of the dogs developed a subclinical glomerulonephropathy characterized by mesangial hypercellularity. While only 9 of the 18 dogs showed electron-dense deposits in the mesangium, 14 dogs had glomerular deposits of IgG and 11 of these had C3 deposits also.