Pug Dog Encephalitis 

    An encephalitis was first recognized in the Pug in the 1960's in California. It now has been diagnosed throughout the Unites States, in Australia and in Europe. The microscopic features of this encephalitis differ from all the other known encephalitides of the dog. This makes it unique for this breed and the reason for the name:
Pug Dog Encephalitis.  In 1983 I described this disease in the second edition of my textbook Veterinary Neuroanatomy and Clinical Neurology. Those of us involved in veterinary neuropathology have shared our pathologic material and from this and our personal experience, we are all agreed that this is a unique disease in this breed of dogs. Although the disease has features that you would expect an infectious agent to cause, none has yet been identified.
    What clinical signs do you expect to see in these dogs and where do they occur? Our collective experience to date shows a range of onset of clinical signs from 9 months to 4 years. These signs can come on suddenly and progress rapidly to death in a few days or be more subtle and slowly progress over weeks and months. The most common sign is that of a seizure or convulsion. These vary in their form but most dogs will suddenly act strange, lose consciousness, have muscle tremors or spasms that rapidly spread over the body causing their limbs to stiffen, be unable to move, and the dog loses its balance and falls over. It often thrashes, sometimes violently for a few seconds, chews vigorously and salivates excessively. Sometimes it will defecate and urinate. All of this violent, uncontrolled activity usually lasts less than a minute and the dog will slowly or occasionally rapidly return to normal. Usually the dog is very depressed and sometimes blind for one to a few hours after the seizure before full recovery. Occasionally recovery does not occur and the dog will continue to seizure or have rapidly recurring seizures.
    The dog with the slowly progressive form of the disease will return to normal but will continue to have seizures at varying intervals from a few days to a few weeks. The dog with acute, rapidly progressive form of the disease will usually have an abnormal gait and posture that persists between seizures. The dog will have difficulty walking and be weak and incoordinated. It will often lose its balance and fall and may have its head tilted to one side. It will usually act pressed and bewildered. Sometimes partial blindness is evident. These same signs may occur with the slow form of this disease but at a slower rate of development and late in the course of the disease. Dr. Donald Cordy published his experiences with this disease in California pug dogs. In 1992 a similar disease in the Maltese terrier was published.
    Ultimately, with either form, the dog will become recumbent, be unable to ambulate, become comatose and die. Usually owners elect euthanasia before these terminal signs occur. There is no specific treatment for this disease. The seizures can sometimes be controlled initially by the anticonvulsant drug Phenobarbital but eventually, as the disease progresses, this will be ineffective.
    Many of us have had the experience of recognizing this disease in more than one animal in a litter. Usually the onset of signs is weeks to months apart in these littermates. This observation, plus the breed specification, makes a genetic predisposition a significant consideration. This may involve a genetically determined adnormality of their immune system that makes these dogs susceptible to an infectious agent such as a virus that normally does not cause disease or the agent may be an altered form of a known canine viral disease to which these dogs are especially susceptible. These are speculations that remain to be proven or disproven.
    The only way to better determine the possible genetic basis for this disease is to carefully document all the suspected cases and study their pedigrees.  The breed association should appoint an individual or group of individuals to be responsible for the pedigree studies. The only way to make a definitive diagnosis of this disease is by autopsy and microscopic examination of the nervous system. This must be done by individuals experienced in veterinary neuropathology, which usually means at a College of Veterinary Medicine.
  

  I am so sorry to inform you that Alexander de Lahunta  DVM, PhD has retired and their is no one at  New York State College of Veterinary Medicine at Cornell University  willing to provide this service.

    There has been no progress on our understanding of this disease but neither has there been any organized basic research study attempted..

Alexander de Lahunta DVM,PhD
E-Mail  shirrayne@nyc.rr.com

Thank you for the information you have been sending me on PDE. Please continue to end this to me.
Shirley Thomas, President
Pug Dog Club of Greater New York, Inc.