An experiment on gentamicin toxicosis was carried out in 11 dogs. Ten dogs received 10 mg/kg intramuscularly 3 times a day for 14 days and another dog the same dosage for 10 days. All dogs were euthanatized and necropsied at the 11th, 15th-19th, 21th, 27th, and 37th day of the experiment. Main clinical signs were: loss of appetite, apathy, polyuria, polydpsia, diarrhea, vomit and oliguria. Laboratory findings included enzymuria, cylindruria, azotemia and isosthenuria. Gross lesions were restricted to the kidneys, these were pallid, swollen and soft. Two dogs developed mild perirenal edema. Histologically, tubular necrosis, restricted to the proximal convoluted tubules, was observed in the kidneys of 10 dogs. In the kidneys of all dogs there was regeneration of epithelial cells of those tubules; this change occurred mainly in the external cortex, varied from minimal to marked, and was associated to marked tubule dilation. At the 37th day of the experrment, the kidneys have their normal morphology restored. Neither glomerular lesions nor extrarenal lesions related to uremia were observed. It is concluded that gentamicin was toxic to dogs when administered in the dosis and frequency stated above and induced acute renal tubular necrosis with subsequent variable degrees of regeneration.
toxic nephrosis; gentamicin; diseases of dogs
