Endemic Canine Leishmaniasis

Leishmaniasis of man is an endemic, sporadic infection in Central and South America, Africa, Southern Europe, Asia and the Orient [8]. The discovery of cutaneous leishmaniasis in a person in south Texas, whose foreign travel extended only to the border states of Mexico, was reported in 1968 [ 1 I]. Recently, the finding of two more cases of human dermal leishmaniasis in south central Texas suggested the disease is endemic [lo]. Seven cases of canine leishmaniasis in the United States have been reported [4-7, 9, 12, 131. All were in dogs with a history of travel in Greece for extended periods. A fox in a zoo probably acquired leishmania1 infection in Northern Africa [3]. We report the discovery of an endemic focus of canine leishmaniasis in north central Oklahoma. A 7-year-old female American Foxhound dog, had had alopecia of 90% of its body for about a year and Demodex mites had been found repeatedly in skin scrapings. It had come from a kennel of 17 Foxhounds, about half of which had dermatitis characterized by dry hair coat, scaliness, moderate to severe randomly distributed alopecia, moderate erythema, some pruritis and ulceration with exudation. The dog was anemic (packed cell volume, 28.0%) and had a slightly elevated leukocyte count (18,100 WBC/mm3) and neutrophilia (90%). Total serum proteins were 9.5 gm/dl. Blood urea nitrogen, serum glutamic pyruvic transaminase, and glucose were within normal limits. Serum electrophoresis revealed hypoalbuminemia ( I . 16 g/dl), hyperglobulinemia (7.84 g/dl) and an albumin/globulin ratio of 0.15. The dog was killed and necropsied. It was thin with prominent bony structure and generalized muscle atrophy. There was complete generalized hair loss except on the dorsal midline. Multiple scabs and areas of ulceration with exudation were on the face, neck and about the ears. The popliteal, prescapular, and superficial inguinal lymph nodes were enlarged. Bone marrow was deep red and wet. The lungs contained several irregular, slightly elevated pale areas, about 1 centimeter at greatest width, that extended slightly into the parenchyma. There was serous atrophy of fat associated with joints and heart. Impression smears of a prescapular lymph node and bone marrow taken at necropsy had numerous leishmania within macrophages (fig. 1). Organisms were found in sections of hilar, mesenteric, popliteal and prescapular lymph nodes. Cortical and medullary areas contained diffuse, often dense, accumulations of macrophages which contained many organisms. Accumulations of plasma cells were associated with reticuloendothelial proliferation. Organisms also were in macrophages associated with diffuse septa1 thickening and multifocal areas of plasma cells and histiocytes in lung. Macrophages in the red pulp of the spleen, Kupffer cells and periportal macrophages of the liver, macrophages in the lamina propria and submucosa of stomach, duodenum, jejunum, ileum, and colon all contained leishmania. A few macrophages with organisms were in connective tissue of the right and left atrium and of the inner renal medulla. All sections of skin contained numerous organisms in macrophages throughout the superficial and deep dermis. Organisms were within and without areas of