Possible Clues:

• One might be dogged at short leg
• Second-rate resource
• Hound the fool appearing in a flutter
• Type of horn getting low note on time
• Back holding an animal: a dog
• Mongrel as best dog
• Gamble about 17 across for the same sort of creature as 12 across
• Are its short legs a confounded advanage?
• Sort of horn to summon a hound
• 'The Hound of the Baskervilles', first impression - something worth having