What is Pug Dog Encephalitis (PDE)?

Hi! This is Payton’s mom, Christy. I’ve taken over the blog today so I can start to share Payton’s battle with PDE, to put a face on this devastating disease.


There is hope! Payton is thriving at 8 years old despite being diagnosed with PDE at age 3 1/2!

But first, here’s some general information about the disease for those of you that aren’t familiar with it (I am paraphrasing from on-line resources)…

Clinically, Pug Dog Encephalitis (PDE) is described as a Necrotizing Meningoencephalitis (NME) – and the terms PDE and NME can be used interchangeably. 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. 

PDE/NME is one of three inflammatory central nervous system diseases that affect the brain and/or spinal cord in the absence of an (apparent) infectious cause.  Granulomatous Meningeoncephalomyelitis (GME) and Necrotizing Encephalitis (NE) are the others.  The differences in the disease are a bit too technical for me to fully understand, but from what I’ve read, they differ in the way the disease presents itself on imaging (lesion patterns) and in the areas of the nervous system that are affected. Typically the symptoms are the same and since positively distinguishing the different inflammatory diseases can be complicated, thankfully similar treatments are prescribed; although usually, it is important to be more aggressive with medications and dosages when PDE/NME is suspected.  I found these articles, both by a doctor from UC Davis, to be good resources, http://veterinarycalendar.dvm360.com/inflammatory-brain-disorders-dogs-gme-nme-ne-and-srma-proceedings?rel=canonical and http://www.veterinaryteambrief.com/sites/default/files/sites/cliniciansbrief.com/files/IdiopathicCNSDisease.pdf. 

The cause of PDE is unknown. Although infectious disorders are known to cause other forms of encephalitis, infection is apparently not the cause of PDE. Recent studies suggest that an abnormal response by the body's immune system may play a role in the development of the disorder. It is believed to be a genetic condition, as littermates and closely related dogs are often affected. PDE most often affects young fawn females, but pugs of all ages, colors, and genders have been documented as having it.  PDE is not even exclusive to pug dogs, other small breeds have been diagnosed.

MRI and spinal tap are the common investigative tools, but there is still no definitive diagnostic test and only analysis of the brain after death can confirm suspicions of the disease.  However, ongoing research projects have discovered some of the genetic markers of the disease that has lead to a susceptibility test (available from UC Davis) that designed to identify the risk of a pug developing PDE in their lifetime.  Right now there is no cure, but because of genetic research, new treatment regimens have been developed that are becoming successful.  Read about the possibilities in my Treatment Guide.

PDE is typically manifested through seizures.  Other common symptoms include: muscle spasms, pressing of the head against something, a staggering walk, abnormal gait, walking in circles, apparent blindness, lethargy, depression, staring off into space, and neck or back pain. 

When Payton first got sick, she did not display the entire classic profile for PDE so do not assume that the list of symptoms (like those I listed above) found in on-line resources is accurate or complete. Ok, so now that we’ve got some background, tomorrow’s post will focus on Payton’s story – her diagnosis.

Love,
Christy (and Payton)