Leishmaniasis is caused by a protozoan in the Leishmania species. Skin
disease, polyarthritis (arthritis in multiple joints), mucosal disorders
(lumps on tongue, gums, etc.), damage to internal organs and possibly bleeding
disorders. It is diagnosed by examination of tissues from affected dogs
or by serology through antibody titers. I am not sure if there is a consistently
effective medical treatment for this condition since there appear to be
a lot of semi-effective medications listed in the veterinary literature.
The skin signs seen with this disease include loss of hair, scaling of the skin, ulceration of the skin on the limbs or ears, formation of nodules on the body and sometimes pustules.