Barking dog sound clips are available at WavSource.com, SoundBible.com and WavList.com. The sites offer barking dog clips featuring little dogs, big dogs, multiple dogs. and dogs growling and barking in the same clip.
Both WavSource.com and WavList.com offer dog barking clips as Wav file downloads. SoundBible.com offers clips in either Wav format or MP3. SoundBible.com dog barking clips have different permission licenses, including public domain, personal use only and attribution 3.0.
Dog barking sounds on WavList.com are not intended for use in public, whether for free or for profit. WavSource.com allows use of dog barking sounds on individual websites as long as the files are not linked directly from WavSource.com's bandwidth.