Splenic diffuse heterogeneous hypoechogenicity pattern of dogs and cats: A systematic review

This review summarized published data about the ultrasound image of the spleen in dogs and cats described as diffuse heterogeneous echogenicity pattern and its metaphorical terms honeycomb appearance, moth-eaten, lacy, marbled, and mottled. The following words were used to search the indexed articles: (Moth-eaten or mottled or marbled or reticulonodular or lacy) and (spleen or splenic) and (ultrasonography or ultrasound or ecography) and (cat or feline or dog or canine). In total, 36 articles were initially found, of which 19 were selected. The reticulonodular pattern can be seen in healthy puppies. Although patients with various morbidities may present the pattern of splenic diffuse heterogeneous echogenicity, the higher prevalence in the data collected from the papers included in this review were natural infection by Babesia canis 100% (72/72) or by Ehrlichia canis 100% (17/17) or caused by torsion of the spleen 73.3% (11/15). This pattern is also associated with neoplasia both in dogs and cats. The use of more precise descriptors, such as diffuse heterogeneous echogenicity pattern, reticular or reticular-nodular pattern, is preferred over metaphorical terms such as lacy, moth-eaten, mottled, or marbled pattern. Discrete diffuse heterogeneous splenic echogenicity patterns can be missed if ultrasonographic examinations are conducted with lower-frequency transducers. Although healthy puppies or patients with various morbidities may present the diffuse heterogeneous splenic echogenicity pattern, higher prevalences were reported in canine patients with natural infection by Babesia canis and Ehrlichia canis.