Encephalitis in Dogs: Symptoms and Prevention

When reading about encephalitis, you may come across related medical terms such as meningitis or myelitis. 

While these terms can be confusing, they’re helpful because they describe where inflammation is occurring, and these conditions often occur together. 

The “-itis” terms help veterinarians pinpoint the areas of your dog’s body affected: 

• Encephalitis: inflammation of the brain 

• Myelitis: inflammation of the spinal cord 

• Meningitis: inflammation of the tissues surrounding the brain and spinal cord 

For example, encephalomyelitis means there is inflammation affecting both the brain and spinal cord. 

When inflammation affects the brain or surrounding structures, dogs can develop a wide range of neurological, vision, and motor abnormalities, depending on which areas of the brain are involved. 

What Is Encephalitis in Dogs?

Encephalitis in dogs is the inflammation of a canine’s brain.

Because inflammation of the brain can progress rapidly, all cases of encephalitis are considered serious and require immediate veterinary care.

If your dog develops signs of encephalitis, seek emergency treatment immediately. 

Symptoms of Encephalitis in Dogs

Symptoms of encephalitis in dogs include: 

• Seizures 

• Head pressing 

• Circling 

• Lethargy 

• Blindness or vision changes 

• Head tilt 

• Stumbling or loss of coordination (ataxia) 

• Sudden behavior changes, like sudden aggression or sluggishness  

Causes of Encephalitis in Dogs

Encephalitis in dogs is broadly classified as infectious or idiopathic. 

Infectious encephalitis occurs when an underlying infection triggers inflammation of the brain. Dogs who are unvaccinated, spend a lot of time outdoors, or are not on regular heartworm, flea and tick prevention are at higher risk of contracting infectious disease that leads to encephalitis. 

Common infectious causes of encephalitis in dogs include: 

• Viruses, such as rabies and canine distemper virus 

• Bacteria, including Ehrlichia, Borrelia (Lyme disease), Anaplasma, Leptospira, and Streptococcus. Many of the bacteria that cause encephalitis in dogs are spread by ticks. 

• Fungal organisms, such as Cryptococcus, Coccidioides (Valley Fever), and Blastomyces 

• Parasites, including Cuterebra and Baylisascaris. Neospora is a protozoal parasite that can also cause encephalitis. 

Idiopathic encephalitis refers to conditions where the cause isn’t fully understood. Many of these cases are believed to be immune-mediated, meaning the dog’s immune system mistakenly attacks itself. 

These conditions are more often seen in small-breed dogs. Examples of encephalitis in dogs where the cause is unknown include: 

• Granulomatous meningoencephalomyelitis (GME). This causes widespread inflammatory disease of the brain and spinal cord. 

• Necrotizing meningoencephalitis (NME). This causes inflammation and tissue damage, which affects the brain and its coverings. 

• Necrotizing leukoencephalitis (NLE). This is an inflammatory disease primarily affecting the brain’s white matter. 

• Shaker syndrome. This is a neurological condition characterized by tremors, most often in small white-haired dogs. 

How Veterinarians Diagnose Encephalitis in Dogs

To diagnose encephalitis, your vet will start by doing a thorough full body and neurological exam. They will typically perform blood work and may take X-rays to rule out underlying organ disease. 

Additional testing may include specialized blood tests to screen for infectious causes. Blood samples may be sent out to be analyzed for antibodies or PCR testing (which detects genetic material from infectious organisms). 

Advanced imaging, such as CT scans and MRI, is often very helpful for diagnosing encephalitis and determining which areas of the brain are affected. 

A cerebrospinal fluid (CSF) tap is another valuable diagnostic tool. During this procedure, fluid is collected from around the spinal cord under sterile conditions while your dog is under anesthesia; it’s then sent to a lab for analysis. The results can help identify inflammation, infection, or abnormal cell types. 

Treatment of Encephalitis in Dogs

Steroids are an important part of treating encephalitis in dogs. 

Steroid medications, such as prednisone, help reduce brain swelling and ease the symptoms your dog may be experiencing. 

Typically, steroids are prescribed using a tapering schedule. This means starting by giving your dog a higher dose, more frequently, and gradually reducing it over time. Be sure to follow all instructions from your veterinarian and the medication label. Some pet parents find it helpful to write tapering dates on a calendar to keep track of the dosing schedule. 

If your dog is diagnosed with a bacterial infection, they may be prescribed an antibiotic such as doxycycline or sulfamethoxazole/trimethoprim. 

These medications are typically given with food, and it’s important to complete the entire course as prescribed. Avoid missing doses or stopping treatment early. 

If your dog is diagnosed with a systemic fungal infection, an antifungal medication such as fluconazole may be prescribed. 

Dogs experiencing seizures may also be prescribed anticonvulsant medications, such as phenobarbital or levetiracetam. 

If you notice side effects from any prescribed medication, such as vomiting or diarrhea, pause the medication and contact your vet right away for guidance. 

Recovery and Management of Encephalitis in Dogs

Some dogs affected by encephalitis can make a full recovery, but that may take several months. In some cases, prolonged hospitalization is necessary. 

For pups experiencing unsteadiness and disorientation, nonslip mats (like the Allisandro Waterproof & Non-Slip Dog & Cat Crate Mat) in the crate and throughout the home can help improve traction, and toe grips (like Dr. Buzby's ToeGrips Dog Nail Grips) may help your dog better manage slippery hardwood floors. 

A support sling (such as the Labra Plush Dog Support Sling) can also help when taking your dog outdoors if their balance and coordination are affected. 

Prevention of Encephalitis in Dogs

Regular preventative care can reduce your dog’s risk of developing several diseases associated with encephalitis. 

Rabies and canine distemper are considered core vaccines and are recommended as part of every dog’s routine wellness care. 

Monthly prevention for internal and external parasites can also protect dogs from many tick-borne illnesses linked to encephalitis. 

Your vet may recommend products like NexGard Plus or Simparica Trio to help keep your dog parasite-free. 

After walks in wooded or high-risk areas, bathe your dog if needed and check carefully for ticks, quickly removing any you find.