A Sonographic Reticulonodular Pattern Is Likely a Normal Finding in Kitten Spleens Using a High-Frequency Linear Transducer

Abstract

A sonographic reticulonodular splenic pattern is characterized by numerous hypoechoic nodules throughout the parenchyma and is commonly associated with benign, neoplastic, or infectious etiologies. However, this has been described as a normal age-related variant in children and puppies up to 1 year old. The purpose of this study was to determine whether the ultrasonographic appearance of the spleens of healthy kittens mimics that of normal puppies. This was a prospective, descriptive study design. Sixty-seven spleens and 50 healthy kittens (13 repeat kittens) were included. Apparently healthy kittens between the ages of 0 months and 1.5 years were scanned using a high-frequency linear transducer. Ultrasonographic patterns of the spleen were graded as follows: grade 1, homogeneous echotexture; grade 2, faint nodules <10% of the parenchyma; grade 3, larger ill-defined nodules involving 10%-25% of the spleen; and grade 4, large well-defined nodules involving >25% of the spleen. A reticulonodular pattern was present in 62 spleens (92%), with grade 2 most common. The grades were highest on average between 0 and 4 months old. Unexpectedly, young cats up to at least 1.5 years old were often noted to have a reticulonodular pattern. After 4 months old, there was a negative association with age and the grade of the spleen. This overall negative association persisted even among kittens that were enrolled serially. The findings of this study suggest that a reticulonodular pattern in young cats and kittens may be a normal finding and should not be mistaken for pathology.

Keywords: cat; feline; heterogeneous; mottled; ultrasound.