Alanis Morissette -- I'm Afraid My Dog Will Be Kidnapped and Held for Ransom

Alanis Morissette wants her dog back in the worst way ... and now fears all of the publicity surrounding the alleged dognapping by her former "house manager" has made her dog a target for ransom.

TMZ broke the story ... Alanis claims her former housekeeper took her dog and refused to give it back after she was fired. The housekeeper says Alanis abandoned the pooch because it was crapping all over the house.

Alanis and her hubby Mario Treadway filed a lawsuit trying to get the dog back, but now she says there's a red alert -- the singer is afraid the bad guys out there now know how much Circus means to her and she's afraid they'll take the dog and hold it for a king's ransom.

Alanis' hubby filed new legal docs, in which he says Circus "is not merely a piece of property. He is living and breathing," adding each day he's separated from the dog, "[my] heart suffers more and more."

Treadway says the house manager is ultimately motivated by money and not love. He says because both he and Alanis are well-known singers, the price tag for Circus goes up and the maid thinks she can score $25K easily ... or so he says.

Treadway points to a video posted online by the former housekeeper ... which he says has made Circus more recognizable to potential dognappers.