Granulomatous Disease in Dogs

Granulomatous disease is an inflammatory condition of the central nervous system. Granulomatous meningoencephalomyelitis (GME) is also known under the names of inflammatory reticulosis, granulomatous reticulosis, neoplastic reticulosis and histiocytic encephalitis. Mononuclear cells accumulate in the meninges, in the brain (encephalo) and/or the spinal cord (myelitis).

GME in Canines

Focal GME causes the formation of a granuloma while disseminated GME spreads through the entire central nervous system. Ocular GME is very rare and causes optic neuritis and blindness in both eyes.

This condition occurs a lot more often in dogs than in cats. Middle aged dogs are more predisposed to GME and females are more at risk than males. The incidence of the disease is higher in small breed dogs.

The causes of granulomatous disease are not known. Immune and infectious causes as well as cancerous cells are suspected to contribute.

The prognosis of granulomatous disease in dogs is poor; most dogs do not survive more than one year with this disease. The disease has a rapid onset and the treatment consists mostly of symptom management.

There is a chronic form of granulomatous meningoencephalitis known as necrotizing meningoencephalitis. This is a condition that might be inherited in Pugs, Maltese dogs, Yorkshire terriers, Chihuahuas and Shih Tzus. This causes more tissue damage than other types of GME causing rapid onset of dementia and seizures.

Symptoms of Granulomatous Disease in Dog

The symptoms may vary, depending on the area of the brain or spine affected by the disease.

If the forebrain is affected, the dog will display:

• Seizures
• Pacing and circling
• The dog is pressing his head with his paws
• The dog stumbles often even though his gait is otherwise normal
• Blindness

If the disease affects the hindbrain (brainstem and/ or cerebellum), expect to see symptoms such as:

• Frequent falling
• Rolling on one side
• Inability to blink and facial paralysis
• Spastic gait
• Depression
• Tremors
• If the spinal cord is involved, the disease will manifest through :
• Spinal pain (back pain)
• Fever
• Weakness or paralysis of limbs

Diagnosis of Granulomatous Disease in Dogs

As microscopical examination of central nervous system tissue is not practical, your veterinarian will perform some other tests for a clear diagnosis:

• CBC (complete blood count/hemogram)
• Serum chemistry analysis
• Urinalysis

After these preliminary tests, you could also have to take your dog for additional tests:

• Serological tests of blood
• Neuroimaging (CT/MRI)
• Cerebrospinal fluid analysis
• Bacterial and viral culture of the cerebrospinal fluid
• Electroencephalogram

Treatment of Granulomatous Disease

If your dog is diagnosed with granulomatous meningoencephalomyelitis, all you can do for him is prolong his life and reduce discomfort and pain. The treatment is meant to relieve the symptoms:

• Phenobarbital or other anticonvulsants, to treat seizures
• Prednisone or dexamethazone or other corticosteroids, to prevent further destruction of brain tissue by the immune system
• Radiation therapy, used in focal GME, can extend the dog's life
• IV fluids