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PDE: Just the Facts!

Pug Dog Encephalitis (PDE) is probably a Pug owners greatest concern and worst fear. Unfortunately, very little is known about this disease, however what is known, for certain, is presented here for the benefit of Pug owners and those considering Pugs as their breed of choice. Please note that this article serves only as an introduction to, and general description of PDE. For information on PDE in greater detail, consult veterinary sources found in your local library or on reputable internet sites.

What we do know about PDE is that it is an inflammation of the brain that strikes adolescent Pugs usually between the ages of 2 and 3. What causes this inflammation, in Pugs, and at this age range in particular is all unknown to this date.


Seizures are the primary symptom of PDE, however it is vitally important to understand and remember that seizure activity in Pugs does not necessarily indicate PDE is the cause. Pugs may also suffer seizures from Epilepsy, exposure to toxic chemicals or gasses and for unknown and unexplained reasons.

Lethargy and loss of muscle coordination are two symptoms that do, but don’t always precede seizure activity caused by PDE. Similar to the presence of seizure activity, neither of these two symptoms together or apart definitively indicates PDE is the cause. Lethargy is a symptom to nearly all illnesses that can strike a dog ranging from a common infection to something more serious. A loss of muscle coordination likewise can indicate other problems such as neurological issues and a side effective to convulsive activity brought out by inner ear disturbances such as Vestibular Disease or ruptured ear drums.

Pacing in circles before or between seizures is a fairly common symptom of PDE. The Pug will pace in a circular motion over and over again for a prolonged period. Head pressing against objects such as walls or furniture is another symptom seen with PDE. This pressing activity normally occurs frequently and for a prolonged period of time. Pugs suffering from PDE may also exhibit signs of agitation and/or aggression whereby the Pug appears disturbed for no apparent reason or aggression that is uncharacteristic of our Pugs and comes on suddenly also for no apparent reason.

Two Classifications of PDE:

Slow Progressive: This classification of PDE features seizure activity and sometimes the additional symptoms preceding the seizure activity. The seizures will strike, last anywhere from just a few seconds to a few minutes and then recur in a matter of days or weeks. In between these seizures, the Pug will return to normal and demonstrate no symptomatic characteristics associated with PDE.

Rapid Progression: This classification of PDE features seizure activity that is often more frequent, but not always. In between the seizure activity however, the Pug does not return to normal but instead does demonstrate symptomatic characteristics associated with PDE. These characteristics between seizures are commonly depression, bewilderment, disorientation and signs of lacking muscular coordination such as having difficulty walking.

The end result of either classification of PDE unfortunately is the same. Whether it strikes in the slow progressive or the rapid progressive form, PDE will eventually kill the Pug. Those Pugs that have been diagnosed with PDE and said to have survived are widely believed to have been misdiagnosed, or not diagnosed conclusively.

Difficulty of Learning More About PDE:

Broad Symptoms: Understanding the way seizure activity, lethargy and a lack of muscular coordination can indicate any number of health issues explains the difficulty veterinarians often have diagnosing PDE. While a favoring of one leg while running is a tell tale sign of Luxating Patella, or a crater in the cornea a sure sign of a corneal ulcer, the symptoms of PDE can span a wide range of possible causes making this disease difficult to diagnose.

Sudden Death: PDE normally strikes quickly, and frequently either kills the Pug or results in the owner agreeing to put his/her dog to sleep. This leaves little or no time to run tests such as CAT scans or MRI’s that might possibly help veterinary research learn more about this disease. Autopsies and tissue donation to veterinary research helps to provide some means of examination into PDE, however the speed at which PDE strikes and results in death surely makes researching the disease all the more difficult.

Pug Specific: Were this a disease to strike dogs of all or many breeds, more urgency would exist to research PDE so that a cause and cure could be found. But this is, after all, Pug Dog Encephalitis, not Pug/Poodle/Pomeranian/Pit Bull Dog Encephalitis and thus the urgency simply does not exist.

For better or worse however, with the increasing popularity of Pugs has come an increase in the veterinary research activity into PDE. This is though a bittersweet situation as this increase in the Pugs’ popularity has also resulted in an increase in the frequency of PDE, something that has led to support the already present belief that there is a genetic component to the disease.