In cats, diseases involving caudal areas such as the lower urinary tract, perineum, or hind limb can cause lymphadenopathy at intra-abdominal caudal abdomen. Due to less sensitivity of radiographs and lymph node location that may be difficult to detect by ultrasonogram. Computed tomography (CT) can provide much more information; however, there is no information of normal appearance of feline caudal abdominal lymph node.
Therefore, the aim of this study was to investigate the appearance of caudal abdominal lymph nodes in healthy cats.
Abdominal pre- and post-contrast enhanced CT images were performed in 15 healthy cats, which divided into 3 groups; kitten, mature, and senile cats. Then, the appearance, location, and size (width, length, and height) derived from multiplanar reconstruction were evaluated.
Among 15 cats, internal iliac lymph node was detected only in 5 cats with average size of 2.4 x 4.2 x 2.3 mm. In contrast, medial iliac and sacral lymph nodes were distinct on post-contrast CT images with average size of 4.1 x 11.8 x 3.2 and 3.5 x 6.9 x 3.6 mm, respectively. In addition, age of cats has an effect on lymph node size. The result showed that kittens have significantly larger size of medial iliac lymph node than other groups (p=0.0013).
In summary, in healthy cats, internal iliac lymph node is hard to be detected and the age of the cat would affect the size of the lymph nodes. This information would be applied as reference values prior to detecting lymph node abnormalities in clinical practice.