What causes this? For young Yorkshire Terrier puppies, often it is stress (moving to a new home, being introduced to too many new environments, stimulants or situations in a short amount of time) or a fast change in
food
that often happens during the transition from breeder to new owner.
This is not to say that a puppy should not be introduced to new things - socialization is a very important part of healthy development and leads to a well behaved dog! However, puppies can become overwhelmed and may need to go at a slower pace if an owner is a bit too enthusiastic.
In regard to food, the golden rule is that switching over to a new food should take 4 weeks, with gradual changes made every 7 days.
Lastly, long periods of time without food can cause this and for this reason, we always recommend free feeding up to 3 months old, 3 meals from that point on and at least 2 meals (plus snacks) per day even for adults. Never mind that other breeds can eat once per day; most toy breeds including the Yorkie should have at least 2 healthy meals.
When Hypoglycemia sets in, a dog will shake, shiver and tremble, in a very similar way as if the Yorkie was very cold. It will be an uncontrollable shivering that takes hold of the entire body.
Other signs - which may occur at the same time or soon after - are weakness, dizziness, trouble walking. Left untreated, a dog can slip into a coma and then the final stage is fatal if not treated.
How to Prevent / Treat This - All owners of toy breed dogs should have honey on hand. Have it at your house and have a small amount on you if you are out and about with your Yorkie.
Some sources recommend Karo syrup - yet we must warn against this. Why? Because it can act as a laxative! And this is the last thing that a dog needs when already shaking and trembling due to low blood sugar!
So, honey is the #1 step in this. It is best to rub a small amount directly onto the gums of the puppy. This should stabilize him/her enough in order to be brought to the closest veterinarian or animal hospital.
Why not just treat this at home? Because you don't want to take a chance - In moderate to severe cases (which owners cannot diagnose from home) a dog will need an IV solution to stabilize blood sugar levels. When treated in this way, most Yorkies are just fine afterward.