Histopathological changes have been described in dogs receiving a single oral dose of bromethalin (6.25 mg/kg). Histologic lesions included diffuse white matter spongiosis, mild microgliosis, optic nerve vacuolization, mild thickening of Bowman’s capsule, and occasional splenic megakaryocytes. Ultramicroscopic examination of the mid brain stem revealed occasional swollen axons, intramyelinic vacuolization, and myelin splitting at the intraperiod line (Dorman et al., 1990c). Dorman et al. (1992) also reported histopathological changes in cats induced by bromethalin. In brief, ultrastructural changes include separation of myelin lamellae at the interperiod lines, with the formation of intramyelinic vacuoles (intramyelinic edema), rupture and coalescence of intramyelinic vacuoles into larger extracellular spaces (spongy change), and pronounced cytosolic edema of astrocytes and oligodendroglial cells. Histopathology of the brain and spinal cord of rodents receiving multiple low or sublethal doses of bromethalin revealed a spongy degeneration of the white matter that was shown upon ultramicroscopic examination to be intramyelinic edema (Van Lier and Cherry, 1988).
Diphenylamine
Diphenylamine is an organic compound with the formula (C6H5)2NH. The compound is a derivative of aniline, consisting of an amine bound to two phenyl groups. The compound is a colorless solid, but commercial samples are often yellow due to oxidized impurities.
