Seizures in Yorkies are usually an indication of an underlying health problem. Because of their small size, Yorkies are more at risk for a few health problems than are other breeds, and these disorders have the potential to develop especially quickly. If your Yorkie has a seizure, contact your veterinarian immediately regardless of what you may suspect the seizure's cause to be.
As explained on Yorkshire-terrier.com, hypoglycaemia or low blood sugar, can occur if your Yorkie goes too long without eating or because of the liver's failure to properly dispense sugar into the blood. Because Yorkies are so small, their bodies store less sugar than a larger dog's. Puppies between 2 and 4 months old are at especially high risk because they are even smaller and the energy-hungry brain makes up a larger portion of their bodies than it does in adults. The brain is also completely reliant on energy carried as sugar in the blood and is therefore one of the first areas to show symptoms of hypoglycaemia. A seizure is a symptom of severe hypoglycaemia and is usually preceded by weakness, confusion, drooling and abnormally pale gums. Yorkshire-terrier.com recommends feeding at least four times a day to avoid hypoglycaemia and feeding a mixture of Gatorade and honey if your dog is having an attack.
Yorkshire terriers and other small breeds are especially likely to develop liver shunts, according to the Canine Epilepsy website. While in the womb, puppies have no need to filter their own blood, so a vein bypasses their liver. If this bypass vein fails to grow shut after birth, blood may be allowed past the liver without being filtered. Unfiltered blood may cause seizures as well as excessive thirst, vomiting, lack of coordination and stunted growth. Diagnosis of a liver shunt is made by an ammonia tolerance test and X-ray and must be treated surgically.
While not more likely in Yorkshire terriers than other dogs, epilepsy occurs in 2 to 3 per cent of all dogs. Seizures in dogs are broken up into three stages. According to Vet Info, the first stage, called prodome, may cause your Yorkie to behave erratically. The second, or aura, stage causes nervousness and whining and is followed closely by the actual seizure, or ictus stage. A variety of health problems could be the root cause of canine epilepsy or the cause could remain unknown. Your veterinarian may be able to medically control your Yorkie's seizures.
Lyme Disease or Rocky Mountain Spotted Fever
Both diseases are carried by ticks. The most obvious symptom of Lyme disease is arthritis, but it could cause seizures in severe cases. Dogs are unlikely to contract Lyme disease, especially if you remove any ticks within 24 hours. Check your Yorkie frequently for ticks.
Tumours or Brain Injury
Brain tumours, even if not cancerous or malignant, could cause enough pressure to give your Yorkie seizures. Brain trauma caused by a head injury may also cause seizures, though they may not occur for weeks or even months.