Yorkshire Terriers are expressive little dogs, so when yours starts acting off, you notice fast. The cause could be anything from low blood sugar (a common toy breed problem) to pain, anxiety, or age-related confusion. What matters is reading the specific behavior and matching it to what’s most likely going on.
Low Blood Sugar Is a Top Suspect
Yorkies are one of the breeds most vulnerable to hypoglycemia because of their tiny body mass. Clinical signs usually show up when blood sugar drops below about 40 to 50 mg/dL, and they can look genuinely strange: trembling, wobbliness, sudden sleepiness, nervousness, muscle twitching, or staring blankly. Some dogs vomit, refuse food, or seem restless and confused for no obvious reason. In severe cases, a Yorkie can collapse or have a seizure.
This is especially common in puppies and very small adults who haven’t eaten in several hours. Skipping a meal, playing too hard, or being stressed (like a vet visit or a long car ride) can all tip a Yorkie into hypoglycemia. If your dog seems weak, shaky, or “out of it” and hasn’t eaten recently, a small amount of sugar water or honey rubbed on the gums can help in the short term while you get to a vet.
Hidden Pain Changes Behavior
Dogs rarely cry out when they hurt. Instead, they get quiet, clingy, or irritable. In a Yorkie, pain often looks like reluctance to jump on furniture, stiffness when getting up, walking more slowly than usual, or holding the back slightly arched with the head low. Some dogs stop wanting to play or start snapping when picked up, which owners read as their dog “acting weird” rather than “being in pain.”
Dental problems are a major source of hidden pain in Yorkies specifically. The breed is prone to tooth decay and gum disease, which can make a dog drool, paw at the face, or suddenly refuse hard food. Back and neck injuries from jumping off high surfaces are another common culprit in toy breeds. If your Yorkie is moving differently, favoring a limb, or flinching when touched in a specific area, pain is the most likely explanation.
Anxiety and Stress Behaviors
Small dogs are more prone to anxiety-driven behaviors, and frequent punishment makes it worse. A stressed Yorkie might pace, pant, hide, destroy things, bark excessively, or have accidents in the house. Separation anxiety is one of the most common behavioral problems in dogs overall, and it shows up as destruction, whining, barking, or frantic behavior when you leave or even when you start getting ready to leave.
Dogs separated from their litter before 8 weeks of age, which is common in pet shop puppies, are more likely to develop these problems. Changes in your household can also trigger anxiety: a new baby, a move, a different work schedule, construction noise, or even rearranging furniture. If the weird behavior lines up with being left alone or with a specific environmental change, anxiety is worth considering.
Reverse Sneezing Looks Scarier Than It Is
If your Yorkie suddenly stands rigid with neck extended, head tilted back, elbows flared out, and makes rapid, loud snorting or honking sounds through the nose, that’s almost certainly reverse sneezing. It looks alarming, like the dog can’t breathe, but it’s actually a reflex that clears dust, allergens, or other irritants from the back of the nasal passages. Unlike a normal sneeze that pushes air out, a reverse sneeze pulls air in through the nose with the mouth closed.
Episodes typically last under a minute and resolve on their own. Your dog will act completely normal afterward. If it happens once in a while, it’s harmless. If it starts happening multiple times a day or lasts longer than usual, it could signal allergies, nasal mites, or a polyp that needs attention.
Tracheal Collapse in Yorkies
Yorkshire Terriers are one of the breeds most commonly affected by tracheal collapse, where the windpipe partially flattens during breathing. The hallmark sign is a dry, honking cough that gets worse with excitement, exercise, heat, humidity, or pressure on the neck from a collar. Over time, it can progress to wheezy breathing, and in severe episodes, the gums or tongue may turn blue or the dog may faint.
This condition develops gradually, so you might first notice your Yorkie coughing after getting excited at the door or pulling on the leash, then later struggling more with exercise or breathing loudly at rest. Switching from a collar to a harness reduces pressure on the trachea and helps immediately.
Liver Shunts and Strange Neurological Signs
Yorkies have a higher rate of portosystemic shunts than most breeds. This is a blood vessel defect, often present from birth, that lets blood bypass the liver. Without proper filtering, toxins build up and affect the brain. The resulting behaviors look distinctly “weird”: staring into space, walking in circles, pressing the head against a wall, seeming disoriented or confused, or having seizures. Affected dogs are often smaller than expected with poor muscle development.
These signs tend to appear in young dogs, usually within the first couple years of life, and they often get worse after meals because that’s when the most unfiltered blood reaches the brain. If your Yorkie is young, undersized, and doing things like zoning out, circling, or pressing its head against surfaces, a liver shunt is something your vet can test for with bloodwork and imaging.
Cognitive Decline in Older Yorkies
Yorkies live 12 to 16 years on average, which means many reach the age where canine cognitive dysfunction becomes a factor. This is essentially the dog version of dementia, and it creates behaviors that owners describe as weird because they don’t match the dog’s personality.
The signs include wandering aimlessly, getting stuck in corners or behind furniture, staring at walls, forgetting house training, sleeping more during the day and being restless at night, losing interest in food or walks, pacing in repetitive patterns, and not recognizing familiar people. Some dogs become more anxious or even aggressive. These changes tend to creep in gradually, with owners noticing one or two things at first and then more over weeks or months. If your Yorkie is over 10 and the personality shifts have been slow and progressive, cognitive decline is a strong possibility.
When the Behavior Needs Urgent Attention
Some “weird” behaviors are actually emergencies. Get to a vet immediately if your Yorkie is having a seizure or collapsing, struggling to breathe or choking, vomiting or having diarrhea repeatedly over several hours, showing a swollen or hard belly, bleeding from any opening, or has eaten something potentially toxic (chocolate, xylitol-sweetened gum, grapes, rat poison, or medications).
A healthy small dog at rest has a heart rate of 90 to 120 beats per minute, breathes 18 to 24 times per minute, and has a body temperature between 100 and 102.5°F. If you can check any of these and they fall significantly outside those ranges, that’s useful information to share when you call the vet. Persistently rapid breathing, a heart rate well above 120 at rest, or a temperature over 103°F all suggest something that needs same-day evaluation.