[ChibiLuv]

So lately my eldest yorkie, Chibi (4yrs) has been increasingly getting agry at people and other dogs while out on walks. He has always barked at people carrying things and kids but now he barks at everyone. He's not barking meanly though. He also barks a lot at big dogs, especailly if they are unruley but today while walking him and Molli they both started barking at this basset hound(molli barking playfully) and thier leashes got tangled up and I dropped Chibi's leash and he went charging at the basset hound who was cowering and shaking in fear! Luckily he didnt hurt him but he was being very aggressive and barking and biting at the poor basset. I have never seen him act like this before, especially to a dog who was just minding his own buisness. I am worried his aggresion towards people and dogs while out on walks is increasing and I'm not sure what to do to make it stop. Help?