Although there are differences, there remain more similarities between human fighters/fighting and the sport of dogs than there are differences.

Think about human swimmers for a minute and they're all in decent shape, but nothing compared to boxing shape. It is also very hard to cut down to lowest weight while in the water.

Regarding the most basic of basic principles, the number 1 thing any boxer needs is LEG STAMINA while forever moving forward, lateral, backward etc. WHILE ON THE GROUND ... and he simply cannot condition for this while swimming, where his feet never once touch the ground, or carry his weight, ever. Thus IMO swimming is "false conditioning" for a fighter. In other words, yes swimming builds a general "muscular endurance" (while treading water) ... but to condition a fighter, really building the stabilizer muscles in the legs for constantly carrying his weight is the primary goal, which is why the king of all exercises for a fighter is some kind of ROADWORK.

Therefore, rather than spend a ton of money trying to build a swimtank for a dog, I would be spending my money on a match dog that doesn't need to be swum as a workaround, because he does his roadwork like a champ.

Cheers,

Jack