Lateralization of bladder function in normal female canines.

This study aimed to identify potential lateralization of bladder function. Electrical stimulation of spinal roots or the pelvic nerve's anterior vesical branch was performed bilaterally in female dogs. The percent difference between the left and right stimulation-induced increased detrusor pressure was determined. Bladders were considered left or right-sided if differences were greater or less than 25% or 10%. Based on differences of 25%, upon stimulation of spinal roots, bladders were left-sided in 17/44 (38.6%), right-sided in 12/44 (27.2%) and bilateral in 15/44 (34.2%). Using ± 10%, 48% had left side dominance (n = 21/44), 39% had right side dominance (n = 17/44), and 14% were bilateral (n = 6/44). With stimulation of the pelvic nerve's anterior vesical branch in 19 dogs, bladders were left-sided in 8 (42.1%), right-sided in 6 (31.6%) and bilateral in 5 (26.3%) using 25% differences and left side dominance in 8 (43%), right sided in 7 (37%) and bilateral in 4 (21%) using 10% differences. These data suggest lateralization of innervation of the female dog bladder with left- and right-sided lateralization occurring at similar rates. Lateralization often varied at different spinal cord levels within the same animal.