Canine leishmaniasis: clinical, parasitological and entomological follow-up after chemotherapy

Six naturally infected dogs [two with no signs of leishmaniasis ('asymptomatic'), two with a few signs ('oligosymptomatic') and two with many signs ('polysymptomatic')] were studied before and after chemotherapy. Another two, non-infected dogs were kept as controls. The dogs were studied clinically, haematologically and parasitologically five times over 11 months and their infectivity to sandflies was evaluated before and after the treatment. The 'asymptomatic' dogs were as infective to sandflies as the 'symptomatic' before treatment but all dogs were un-infective for at least a few months following chemotherapy. Treatment led to a temporary improvement in the clinical and biochemical condition of most of the dogs, the symptomatic dogs becoming asymptomatic, but parasitological cure was uncommon after 10 months' follow-up. There was often no correlation between clinical condition, parasitological condition and infectivity to sandflies. Some dogs from both the 'asymptomatic' and 'symptomatic' groups became infective to sandflies several months post-treatment.