Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: Neurological signs in puppies and young dogs can come from infections like distemper, congenital conditions like hydrocephalus or liver shunts, low blood sugar in toy breeds, toxins, injuries, and inherited disorders. Idiopathic epilepsy often starts between about 6 months and 6 years. Any seizure, wobbliness, tremors, or behavior change in a young dog should be checked.
Common causes
- Low blood sugar: in toy-breed puppies that skip meals, causing weakness, trembling, and seizures
- Canine distemper: in unvaccinated puppies, causing respiratory signs followed by twitching and seizures
- Portosystemic shunt: an abnormal liver blood vessel causing confusion or seizures, often after meals
- Hydrocephalus: fluid on the brain, more common in toy and flat-faced breeds
- Idiopathic epilepsy: recurring seizures with no other cause
- Toxins: such as chocolate, xylitol, marijuana, or insecticides
- Head or spinal injuries
- Inherited conditions in some breeds
Emergencies
- A seizure lasting more than 5 minutes or repeated seizures
- A toy puppy that is weak, cold, or trembling (rub a little corn syrup on the gums if conscious and go to a vet)
- Possible toxin exposure
Prevention
- Complete puppy vaccinations
- Frequent meals for toy breeds
- Puppy-proof your home
Sources
- Merck Veterinary Manual: Nervous system disorders in dogs
- Berendt M, et al. International Veterinary Epilepsy Task Force consensus report on epilepsy definition, classification and terminology in companion animals. BMC Vet Res. 2015
- Merck Veterinary Manual: Canine distemper
- Merck Veterinary Manual: Portosystemic shunts
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.