CLINICAL RECOVERY AND LIMITED CURE IN CANINE VISCERAL LEISHMANIASIS TREATED WITH AMINOSIDINE (PAROMOMYCIN)

Three groups of three, six, and 12 dogs with parasitologically proven clinical visceral leishmaniasis (Leishmania chagasi infection) were tr eated with intramuscular aminosidine sulfate at doses of 20 mg/kg/day for 15 days; 80 mg/kg/day for 20 days, and 40 mg/kg/day for 30 days, r espectively. Follow-up was by parasitologic examination of bone marrow and skin, serology using the indirect immunofluorescent antibody test , and clinical examination for signs of visceral leishmaniasis or adve rse effects of treatment. In animals treated with 20 mg/kg/day, for 15 days, there was dramatic clinical improvement with disappearance of c onjunctivitis, increase in appetite, weight gain, and recovery of norm al skin condition and a healthy coat, but parasitologic relapse occurr ed between 50 and 100 days after initiation of treatment. Adverse effe cts were seen with treatment with 80 mg/kg/day for 20 days; three dogs died during or just after treatment, two showed temporary recovery, a nd one showed total clinical and parasitologic cure that was maintaine d for four years. Although adverse effects and relapses were seen in s ome dogs treated with 40 mg/kg/day for 30 days, three of 12 dogs showe d complete parasitologic and clinical cure that was sustained for at l east four years. Aminosidine treatment cannot be recommended as an alt ernative to the humane destruction of dogs for the control of canine v isceral leishmaniasis because ineffective treatment may prolong carrie r status or encourage development of drug resistance. This drug may be a therapeutic option if there is no danger of a dog acting as a reser voir of infection. Achievement of clinical recovery and limited cure w ith aminosidine suggests that further trials would be of value, possib ly in combination with other anti-leishmanial drugs and with supportiv e measures to reduce adverse effects.