I can understand the use of a shock collar...but a Taser? They are designed and metered specifically for an instantaneous, non-lethal effect on a human being. While I could imagine an officer on a call who was being attacked by a dog employing his Taser (I'd think a sidearm would be a better choice in that situation), I really doubt canine training was given any consideration in the Taser's design. I can't imagine a K9 unit's veterinarian sanctioning its use, and given the cost of these dogs, it is, if nothing else, taking a big risk with the tax-payer's dollars.
Keep in mind that by the time these dogs go to a department and start working, they've already been through extensive familiarization and training elsewhere with their handlers. Any training done at the department is sustainment or recertification training, and normally, any dog that won't let up with voice command alone should probably have long since been weeded out.
Don’t discount the possibility that a reporter translates shock collar into “taser” much like they translate gun into “submachinegun”. Coulda been a cattle prod for that matter and they’d still probably call it a taser.