Comparison of renal ultrasonographic measurements between healthy cats of three cat breeds: Ragdoll, British Shorthair and Sphynx.

Healthy cats of three cat breeds -- Sphynx (n = 11), British Shorthair (n = 15) and Ragdoll (n = 15) -- were included in this study. All cats underwent an ultrasonographic examination to assess renal length, cortical thickness, medullary thickness and corticomedullary ratio. Of all ultrasonographic measurements, renal length showed the highest variation. For all ultrasonographic dimensions, individual and kidney side (left vs right) variation were much more pronounced than interbreed variation. Sphynx cats tended to have larger kidneys (4.09 ± 0.33 cm) than British Shorthair (3.77 ± 0.43 cm) and Ragdoll cats (3.87 ± 0.41 cm). British Shorthair cats, however, tended to have a thinner cortex (0.67 ± 0.13 cm) and medulla (0.76 ± 0.18 cm) than Sphynx (0.76 ± 0.14 cm and 0.90 ± 0.25 cm, respectively) and Ragdoll cats (0.75 ± 0.13 cm and 0.91 ± 0.22 cm, respectively). However, statistical tests did not reveal significant differences between these cat breeds. The corticomedullary ratio was similar for the three cat breeds (Sphynx: 0.93 ± 0.43; British Shorthair: 0.91 ± 0.26; Ragdoll: 0.88 ± 0.31). The left kidney (3.83 ± 0.42 cm) was significantly smaller than the right kidney (3.99 ± 0.40 cm) and showed a thicker medulla (left: 0.93 ± 0.21 cm, right: 0.79 ± 0.22 cm), and thus a lower corticomedullary ratio (left: 0.80 ± 0.23, right: 1.01 ± 0.32). For the cortical thickness, no significant difference was observed between the left (0.71 ± 0.14 cm) and right kidney (0.74 ± 0.14 cm).