This puppy is too young to play around too long with something like this. Neurological problems at such an early age can indicate serious congenital problems, and need to be addressed by a veterinarian ASAP.
How long have you had your puppy? If you have had her for more than a week, her breeder let her go from the litter way too early. With larger breeds, puppies need to stay with their litters at LEAST through their eighth week to learn important social skills such as bite inhibition. But toy breeds should be kept with their litters much longer, and should not be sent off to their forever homes until somewhere between the 14th and 16th week of age.
In any case, unless the puppy sustained an injury at your home that is responsible for the neurological tic, you need to contact the puppy's breeder and let them know what is going on. In a puppy this young, it would indicate that there has been a problem since birth that is just now manifesting itself, and ethically, if not legally, the breeder is responsible for whatever veterinary treatment this puppy needs. They SHOULD offer to replace her with a healthy puppy and assume the veterinary treatment themselves, or at least OFFER to replace her. I realize that you're probably already horribly attached to her, I know I would be, but neurological problems can come with devastating medical bills, and you should not be made to pay if the puppy was ill, unbeknownst to you, when you purchased her.
In any case, she DOES need to be seen by a vet ASAP. Call the breeder and tell them what you are doing, and then make the appointment with the vet. Once you get your diagnosis, you can take it from there. The problem here, though, might be that there will be many expensive diagnostics necessary to determine what the cause is, and if that's the case, you need to decide whether you want to pay the bill yourself or whether you want to make the breeder take the puppy back and treat the puppy themselves, and replace her with a healthy puppy for you. You would not be letting the puppy down by doing that. Unless you were told otherwise, I'm sure you were under the impression that you were purchasing a healthy Yorkie puppy, so you are completely within your rights to ask for another puppy. If the breeder refuses, or otherwise gives you a hard time, report them to the Yorkshire Terrier Club of America, which is the parent club for the breed. They may not be able to force the breeder to do anything, but they can certainly steer others away from purchasing puppies from that breeder, making it unprovitable for them to continue breeding, and hopefully putting a stop to an unethical breeder.
Do not let the breeder tell you that they are not responsible. If they try that, I would not only report them to the parent club, I would take them to small claims court for the veterinary bills. I realize I'm getting WAY ahead of myself here, but I just want you to know about everything that could possibly get thrown your way in a situation such as this. Forewarned is forearmed, y'know? Best of luck to you, and PLEASE come back to the forum and let us know what happens.
Ghilly
My 2 year old Yorkie has been shivering for about 4 days and acting lethargic and ill, but eating fine, etc... Today I took her to the vet and it seems like a neurological tic in her neck and head which goes on and on. I am very concerned about this and would like to hear what could cause this and cure it.
Lexie Yorkie and owner
I don't know for sue what might cause this, but all I can say is if it happened to my dog, and more than once, I would definitely take her to the vet for checks. (Unless you can think of some other trigger for this....a fly/wasp/something stuck in his teeth/water on his face/some sore spot on his face or muzzle/ear problem.....etc)