Could not find a good loud/aggressive dog barking sound in existing Alexa Skills, so I built this one for my own house protection. Hope it is useful to you as well.
It plays immediate loud dog barking sound for several minutes to scare off any potential intruders. No initial Alexa interaction or confirmation needed. To start, just say "Alexa, start Loud Bark" or "Alexa, launch Loud Bark". It is also a good idea to integrate with outdoor security cameras or motion sensors to get the skill triggered automatically through a Alexa Routine. You can also set your Echo speaker volume to max in the routine before starting the Loud Bark Skill to get best results.