Canine encephalitis is an inflammation of the brain. It's most commonly caused by canine distemper, but is also caused by rabies and herpesvirus, which causes encephalitis in pups younger than 2 weeks. There are four types of encephalitis: bacterial, which is when bacteria enters the body through the circulatory system, fungal encephalitis, which is rare, and postvaccination encephalitis, which is uncommon today with modern vaccines. Lead encephalitis occurs in dogs who chew on items containing lead.
Aggression and Personality Changes
Dogs with encephalitis tend to act different from their normal behavior due to the infection going on in their brains. Personality change symptoms include depression, which can be characterized by the dog refusing to eat, play or do the things he used to love doing. Confusion and senility are also common symptoms of this condition. Sudden aggression toward people the dog normally is very gentle with is another sign of a brain inflammation.
Symptoms Resulting in Coma
Some of the more serious symptoms of canine encephalitis are high fever and an uncoordinated gait, or the dog tripping frequently while trying to walk. Another symptom is head tilting, brought on by inner ear problems creating dizziness or light-headedness. Stupor is a common symptom, characterized by the dog just lying still and staring without responding when his name is called. These symptoms become more noticeable as the disease progresses and are followed by seizures and coma.
Parts of the Brain Affected
When certain parts of the brain are infected in encephalitis the symptoms vary depending on what parts of the body that portion of the brain controls. Forebrain encephalitis creates blindness, behavior changes, seizures, mental depression and a peculiar symptom where the dog walks in circles. In brainstem encephalitis the head tilts to the side from dizziness, there is uncoordinated behavior and tremors in the muscles, along with facial paralysis that causes the features to droop.
Lead Induced Encephalitis
There are a lot of old buildings that still have lead paint on the walls. Dogs who chew on lead materials such as paint often develop central nervous system symptoms, such as seizures and personality changes, due to the lead altering the brain's metabolism. These symptoms usually follow the less serious gastric symptoms of vomiting, diarrhea and constipation. Paint eating is a common symptom of pica, an eating disorder where the animal eats non-food items.
- Ryan McVay/Photodisc/Getty Images