Pug Dog Encephalitis
Pug Dog Encephalitis is an inflammatory disease of the brain affecting Pug dogs of either sex. The disease is considered unique to the Pug breed. Similar symptoms have been reported recently in Maltese, Pekingese and Yorkshire Terrier breeds but do not seem to be the same disease.
PDE is an invariably fatal disease in the Pug which generally affect Pugs between 6 months and 7 years; however, the majority of Pugs affected are between 9 and 19 months of age. Clinically, the disease is described as a necrotizing meningoencephalitis. This means that the brain and the layer of tissues surrounding the brain are abnormally inflamed. The term "necrotizing" describes the clinical way in which portions of the brain are literally dying. Although these portions may be very small, they are numerous and cause severe and progressive neurologic symptoms. Specific symptoms of PDE include: seizures, pressing of the head against a wall or furniture, a staggering walk, apparent blindness, lethargy, depression, and neck pain. When first presenting symptoms, most pugs simply quit jumping on or off furniture as they once did casually and they appear to have a "stiff neck".
Pug dog encephalitis is one of the inflammatory diseases of the central nervous system (CNS) which cause seizures in dogs: canine distemper, rabies, toxoplasmosis, Rocky Mountain spotted fever and several other diseases. If a dog of less than 1 or greater than 5 years of age suffers persistent seizures, it should be thoroughly examined and tested for these neurological disorders.
Pug dog encephalitis can last from several days to 6 months or more and usually starts in its acute, rapidly progressing form. Symptoms include seizures, depression, abnormal gait, blindness, staring off into space, pressing head against the wall or furniture, ataxia (a staggering walk), and intermittent screaming. What causes this disease is still unknown. It is believed to be a genetic condition, as littermates and closely related dogs are often affected, but it also occurs in Pugs born from non-related lines. The disease has no cure.
Pug dog encephalitis is difficult to diagnose since its symptoms often relate to other CNS diseases. Seizures may be caused by many other underlying conditions such as hypoglycemia, canine distemper, rabies, toad poisoning, chemicals and toxic plants ingestion. Sometimes it is possible to make the correct diagnosis using the magnetic resonance imaging of the brain (MRI), or analyzing the white blood cells in the spinal fluid. But most often the disease is diagnosed after the dog dies.
Although PDE is always terminal, treatment may control seizures and reduce the inflammatory process in the brain for a short period of time. A veterinarian may prescribe medication which will make the Pug feel more comfortable, but there is currently no known cure for PDE nor are there medications to alleviate all the symptoms.
What causes PDE?
Many years of research have been dedicated to diagnosing and defining PDE. From this research, it has been determined that PDE is a very distinct, breed specific syndrome; however, the etiology of the disease has not been determined. Recent research on PDE strongly suggests a genetic component to its occurrence as the affected dogs seem to have common lines of ancestors. This does not mean if your Pug is not related it cannot get PDE! Simply that research is narrowing down the possibilities.
There have been suggestions that a viral infection may lead to PDE, but no one has been able to isolate viral particles from affected dogs. The most recent research has verified that there are no viral components in pugs affected with PDE. Lastly, an autoimmune reaction has been suggested due to results from one affected Pug, but no further evidence of autoimmune reaction has been demonstrated in other Pugs.
The most recent research information on the disease tends to be found on the home page of the Pug Dog Club of America as they are the primary funding underwriter for the ongoing studies of PDE.
How can I prevent PDE in my Pugs?
Since we do not know the cause of PDE, no one knows how to prevent it. If it turns out that PDE is a genetically inherited disease, then Pugs are born with it and the only prevention will be not to breed the parents who are carriers of the disease.