Keep your dog indoors between the end of April and the end of October. Never allow your dog to rest or sleep outdoors at night, except on windy nights if you can be sure the wind does not drop.
Spray fly screens and the dog's indoor premises with Citronella and/or a solution of Stomoxin (permethrin) once a week. Dabbing the coat of the dog with this solution is also common practice but be careful to have adequate ventilation and avoid overdosage (dilute accurately) when doing this to your dog. Handle Stomoxin with care, keep away from fish tanks, food and avoid inhalation.
Use a Scalibor collar to increase protection.
Advantix (BAYER) and other drop on products are also effective against ticks and fleas.
The above methods do not guarantee 100% protection.
A guaranteed protection is operating a fan, ceiling or otherwise (even at lowest speed) over the dog's indoor area, especially where the dog sleeps.
You may have your dog's blood tested around the end of January of each year. Early detection enhances the chances of survival if your dog is infected.
Prevention is better than cure … but with regard to Leishmaniasis cure can never be guaranteed.