Determination of the number of mast cells in lymph node, bone marrow, and buffy coat cytologic specimens from dogs.

Cytologic samples of popliteal lymph node, proximal femoral bone marrow, and the buffy coat fraction of blood were obtained from 56 dogs. The number of mast cells on 1 slide of each sample was determined by microscopic examination. Eleven of 46 slides of lymph node aspirate contained mast cells (range, 1 to 16; mean, 6.4; median, 5 mast cells/slide). Fifty-one bone marrow aspirate slides were evaluated. Two of these contained a single mast cell. None of the 53 buffy coat smear slides examined contained any mast cells. These results indicated that in clinically normal dogs, a few to several mast cells may be encountered in smears of lymph node aspirate, mast cells are rare in smears of bone marrow aspirate, and mast cells are absent from smears of buffy coat.

Focal spinal muscular atrophy in two German shepherd pups.

Focal spinal muscular atrophy evolved rapidly in two German Shepherd pups 2 weeks after birth. By 1 month, the male and female littermates had developed a valgus deformity of the right forelimb, a flexed carpus, and arm and forearm muscle weakness and atrophy. In the male, less severe left forelimb weakness and wasting also occurred, and bilateral forelimb denervation potentials were recorded. Postmortem study of the male revealed asymmetric loss and degeneration of motoneurons in the cervical spinal cord intumescence. Degenerating neurons appeared vacuolated or chromatolytic. Chromatolysis was often peripheral and resulted from dispersion and loss of the free and attached ribosomes which normally from Nissl bodies. Although this focal neuronopathy was unlike motoneuron diseases described previously in animals, it resembled the asymmetric and unilateral, benign spinal muscular atrophies found in humans.