How illegal it is depends on how caught you get.
IIRC 15 minutes of barking violates noise ordinances. If you happen to decide not to shoot it mr vegan, then a quick phone call to the local police with a complaint will result in a cop stopping by to say “Hey we’ve been having complaints. Keep that mutt quiet.” That’s usually enough to wake up a shitty owner to their negligence.
It’s not that hard to keep dogs quiet. I’ve got a yappy little shit but if he ever starts “nuisance barking” I scream at him and cowers down and slinks away quietly. :tup: