Basophils Basophils Prototypical basophils of human blood are filled with small, round, dark purple granules. Similar basophils are found in some species but not in others. Canine basophils are difficult to recognize since many do not have readily apparent granules. The major identifying features of canine basophils are the long and folded nucleus, described as ribbon-like, and the unusual gray to lavender hue of the cytoplasm.
Some basophils contain a few purple granules.
Basophils are rare in blood of healthy dogs. Feline basophils are packed with small, slightly oval granules that are pale lavender rather than deep purple. The nucleus in many appears to have vacuoles, which are actually granules lying on top of the chromatin. Basophils are rare in blood of healthy cats. Basophils of horses and ruminants are similar to each other and to human basophils.