Final answer:
Basophils in cats have large, dark blue to purple staining granules and a two-lobed nucleus that may be obscured by the dense granules. They are smaller than other granular leukocytes and are least common among the leukocytes.
Step-by-step explanation:
The characteristic appearance of a basophil in a cat is described as having large granules that stain dark blue to purple and a two-lobed nucleus. However, the granules in basophils can be so abundant and large that they often obscure the view of the nucleus, making it difficult to discern its two-lobed structure. Basophils are a type of granular leukocyte, and they are part of the body's immune response.
Besides the distinctively large and dark-staining granules, basophils are smaller than other granular leukocytes like neutrophils and eosinophils. Their granules stain most effectively with basic (alkaline) stains, and they are typically less than one percent of the total leukocyte count.