Organisms That Can Cause the Disease

Tests to Detect It and the Tell-tale Signs

  These following symptoms can be seen with encephalitis as well as with other neurological diseases. The combination of symptoms can give your veterinarian clues as to whether encephalitis is a likely cause and how advanced it might be:

 - Seizures: partial or complete loss of consciousness, stupor, falling over, biting at the air or chewing motions, frothing, paddling with the limbs

 - Head tilt: cocked at an angle

 - Head turn: head and neck arching toward one side of body

 - Circling

 - Eye abnormalities

 - Blindness: usually sudden

 - Pupils of different sizes

 - Rapid eye movement: up, down, side to side or in circles

 - Displaced eye position

 - Elevation of third eyelids

 - Dullness: depression, less responsive to stimulus

 - Abnormal behavior: disorientation, erratic howling or barking

 - Loss of appetite

 - Stiffness: especially in the neck

 - Abnormal gait: uncoordinated, stumbling, knuckling over or dragging feet

A definitive diagnosis of encephalitis often requires ruling out other diseases first. In addition to an MRI scan, veterinarians usually run a sequence of these other tests, tailored to each client's budget:

BLOOD WORK, INCLUDING:

 - A complete blood count to check for system-wide infection or anemia.

 - A chemistry panel to assess general organ function, including liver and kidneys.

 - Titers of various diseases transmit¬ted by ticks like Lyme disease, ehrlichiosis and Rocky Mountain Spotted Fever.

 - Toxin/Metabolic panels to check for abnormal levels of metabolic waste products like ammonia or bile acids. The presence of heavy metals like lead, mercury and zinc may also cause neurological disease.

 - Urinalysis to check for abnormal levels of metabolic products.

 - CSF tap: Veterinarians can draw cerebrospinal fluid by placing a needle in the back of the neck between two vertebrae to test for the presence of white blood cells and viral, fungal and bacterial organisms. The procedure requires anesthesia.

These organisms can cause encephalitis in a number of species, including dogs:

    VIRUSES

 - Canine Distemper Virus: A vaccine given every one or every three years after puppy boosters can prevent it.

 - Rabies: A vaccine protects against the disease, which is 100 percent fatal and transmissible to humans. It's spread by contact with other infected animals — usually raccoons, skunks, bats and other wildlife. Immediately report any suspicion of exposure to your veterinarian and local animal control facility.

BACTERIAL AND PROTOZOAL ORGANISMS

 - Toxoplasma gondii: Acquired by ingestion of infected meat or cat feces. Toxoplasma in cat feces also poses a risk of infection for pregnant women.

 - Neospora caninum: Similar to toxoplasma but not contagious to humans.

 - Rocky Mountain Spotted Fever: Caused by Rickettsia rickettsii, transmitted by ticks in the some Midwestern states.

 - Ehrlichia Canis and Equi:
Causes Ehrlichiosis, a tick-borne disease seen worldwide. It's transmissible through the
brown dog tick.

FUNGUSES AND THEIR ENVIRONMENT

 - Aspergillus: Found in soil and environmental products like hay and wood chips.

 - Blastomyces: Soil.

 - Histoplasmosis: Soil.

 - Coccidiomycosis: In the soil but limited to the Southwest, Mexico, Central and South America.

 - Cryptococcus: Soil and pigeon droppings.

FROM: CUMMINGS SCHOOL OF VETERINARY MEDICINE AT TUFTS UNIVERSITY