Leptospirosis

First Described: Heidelberg, Germany, 1886 (Adolf Weil). Cause: Leptospira spp. (a spirochete bacterial pathogen, phylum Spirochaetes). Affected Hosts: Dogs, rarely cats, more than 150 other mammalian species. Geographic Distribution: Worldwide. Major Clinical Signs: Fever, lethargy, reluctance to move, anorexia, polyuria and polydipsia, vomiting, diarrhea, icterus, abnormal respiratory function. Major Differential Diagnoses: Nephrotoxicoses (e.g., NSAIDs, grapes and raisins, ethylene glycol), Lyme nephritis, acute glomerulonephritides, bacterial pyelonephritis, cholangiohepatitis, acute pancreatitis, canine monocytic ehrlichiosis, Rocky Mountain spotted fever, bacterial sepsis, leishmaniosis. Human Health Significance: Zoonosis. Human infection results from direct or indirect contact with contaminated urine. Mild influenza-like illness to severe illness with multiorgan failure (Weil’s disease) have the potential to occur.