Noga E J, Wright J F, Pasarell L
Department of Companion Animal and Special Species Medicine, College of Veterinary Medicine, North Carolina State University, Raleigh 27606.
J Comp Pathol. 1990 Apr;102(3):335-44. doi: 10.1016/s0021-9975(08)80022-9.
Adult, aquarium-reared Oreochromis mossambicus (Tilapia mossambica), which were naturally infected with Mycobacterium marinum, displayed non-healing skin ulcers and other clinical signs considered to be typical of piscine mycobacteriosis. However, in addition, they frequently had melanotic foci in the skin and spleen, due to the presence of pigment cells surrounding the cutaneous and splenic inflammation. Such melanotic foci have never been reported in response to mycobacteriosis. All fish also have variable numbers of melanomacrophages which appeared to replace pancreatic acini. The relationship of the pancreatic melanomacrophages to the pathogenesis of mycobacteriosis is uncertain, but such lesions may have contributed to the chronic cachexia associated with this case.
