Disclosed are an expandable network system and a redundant method applied to the system. The transfer computer includes: a plurality of first transfer computers for executing the transfer of the data; and a second transfer computer for taking over, when a fault occurs in any one of the plurality of first transfer computers. The strut may have side holes through which a therapeutic agent may pass and through which the radiopaque particles are incapable of passing. The cartridge further includes a bowl shaped application area that may be used to conveniently apply the styptic to the animal during or after clipping. Information tracked using the sensing device can be compared to the thresholds. The dispensing system is configured to selectively control the passage of the first and second fluids from each one of the at least two pumps to the at least one dispensing nozzle.