Possible Clues:

• Sounds as if my unfashionable little dog will come up like a mushroom
• Mushrooms might grow from that terrier of mine, by the sound of it
• Is it my dog, by the sound of it, that you can get the mushrooms from?
• Sounds as if my little dog could make fun with Gus, perhaps
• Does this help the little dog I have to grow like a mushroom, by the sound of it?