Give 1mg of Benadryl per pound such that if your dog weighs 30 pounds, you should give it 30 mg of Benadryl. Talk your veterinarian - while antihistamines are generally safe, there are the potential for side effects particularly if your dog has chronic organ failure (renal failure, liver failure, congestive heart failure, etc.).
1 Encephalitis is inflammation of the brain. 2  Meningitis is inflammation of the membranes (called meninges) that surround the brain and spinal cord.  Both encephalitis and meningitis can be caused by bacteria or viruses, and rarely a fungus, or be noninfectious.
encephalomyelitis. acute disseminated encephalomyelitis inflammation of the brain and spinal cord after infection (especially measles) or, formerly, rabies vaccination.quine encephalomyelitis a type of encephalomyelitis in horses and mules, caused by an alphavirus and spread to humans by mosquitoes; it occurs in summer epizootics in the Western Hemisphere. Three forms are recognized: eastern, western, and Venezuelan. Called also equine encephalitis.