Nervous System Disease Treated as an Infection

 Perhaps you have owned a dog or known of one with a disease of the nervous system called granulomatous meningoencephalitis (GMC).   Affected dogs may be un-coordinated, stagger, have neck stiffness, seem confused or have other signs indicating brain and/or spinal cord involvement.  Veterinary medical texts claim it is an autoimmune disease in which the body is destroying the nervous system and recommend sick dogs be treated with prednisolone or some other immune depressing drug to depress the immune response.  But this is only effective during treatment once that stops symptoms resume or the dog dies.

     Here in the Imperial Valley I encounter a case about once a month.  And true to the medical books’ prophecy therapy with immune depressing drugs has been unsatisfactory.  Could it be that the nervous system degeneration is the body’s aberrant response to some unknown virus infection?  To test this conjecture sick dogs are given an injection of a corticosteroid along with a human drug that inhibits virus infections.  Also, they receive a synthetic antibiotic to limit inflammation and a couple of vitamin-like compounds to facilitate metabolism of disease-damaged nerve cells.  With 30 days of treatment patients return to normal suggesting that virus infection may be the underlying cause of GMC and that the virus-inhibiting drug is effective. 

Congenital Heart Disease in a Young Dog

He was less than a year old. His shiny black coat indicated he had been well cared for and was ready for the good life Labrador Retrievers enjoy. But as he lay on the examination it was obvious he was very sick. He had become acutely ill and as he turned toward me his eyes seemed to say, “It’s no use, Doc”.

          With mouth halfway opened he gasped for breath, but there was no sound of rushing air. I could not feel the femoral pulse. Nor, could I hear the heart beat with a stethoscope. These two signs indicated the heart was not adequately pumping blood. However, the electrocardiogram was not unusual. It could not define the type of heart disease, and he was too ill to do chest radiographs that might be instructive. There were sounds of air movement in the lungs, vesicular sounds, detectable with the stethoscope but no rates or creptations. This and his gasping for breath suggested the lungs were filling with fluid escaping from his blood. This is called pulmonary edema. The dog was treated for dilated cardiomyopathy, a common form of heart failure. And, although he was not coughing he was also treated for influenza, a virus infection which can cause pulmonary edema even though heart failure was considered to be a more likely primary cause of his symptoms.

          He died during the night. The necropsy next morning showed his lungs were indeed edematous. Enough so that, it was obvious he had drowned in fluids that escaped into his lungs from blood vessels due to stasis of blood flow that complicated inadequate heart function. The heart disease was not dilated cardiomyopathy. Rather, it was hypertrophic cardiomyopathy; a condition in which heart muscle cells proliferate increasing heart wall thickness. Scar tissue may form further compromising cardiac contraction. Eventually these changes lead to heart failure and death of the victim. Rare in dogs, it is common in cats in which it is thought to be inherited. I was told litter mates of this dog all died suddenly but no diagnosis of cause of their deaths was rendered. These deaths suggest hypertrophic cardiomyopathy in this young litter was inherited. As a rule, therapy of dogs terminally ill with this disease is not effective. Management of the disease is by prevention. Avoid mating of known carriers. 

Periodontal Disease

She was brought to the hospital because she had been sneezing for a week and the owner wanted it stopped.  This was the first time I had seen Trixy, an old, overweight Miniature Poodle. At first I thought she might have a chronic infection somewhere in the nasal cavity that was causing her to sneeze or maybe cancer in the back part of the nasal cavity.  With these problems one often sees intermittent bleeding from the nostrils and there may be reverse sneezing as if there was exudate draining backward into the throat, but this hadn’t happened.  Then, when Trixy was put on the floor, she did a forward sneeze trying to clear something from the front of the nasal cavity.  That was different, not what I expected. The teeth were the cause of the problem!  I could see they were massively caked with a greenish-gray scale that had accumulated over years.  It was accompanied by periodontal disease and that infection had progressed down the teeth causing them to become loose and painful.  In Trixy’s case, infection around the roots of the large canine teeth had eroded into the nasal cavity creating fistulas (holes) so that pus drained into the nasal cavity, causing poor Trixy to sneeze.  To treat this condition one can administer antibiotics which may control the infection temporarily only to have it resume when the antibiotic treatment ceases.  Another way veterinarians solve Trixy’s problem is to stop the flow of pus by cleaning the teeth with ultrasound (brushing won’t do), extracting teeth that are loose or infected and then, surgically close the fistulas between the mouth and the nasal cavity. 

Prevention by routine tooth cleaning is the preferred management of this disease.  Twenty years ago many dogs had fistulas between the mouth and the nasal cavity that developed when canine teeth with severe periodontal disease fell out.  This condition was especially common in small lap dogs that lived indoors and ate human table food.  But over time owners of these small dogs have eliminated table food diets and fed nutritionally balanced commercial dog food which has prevented bone degeneration around the teeth from developing.  They also have had their pet’s teeth cleaned routinely by a veterinarian.

Treating Puppies with Parvo virus Infection; A Study

Start of the parvo virus season is just around the corner. It extends through fall, winter and spring and is most prevalent in low desert areas such as the Imperial Valley. Affected puppies vomit, and suffer from diarrhea. If neglected, pups can become very dehydrated and death is a common outcome. Some owners treat sick puppies themselves using over-the-counter remedies too often with disastrous results.  Years ago I learned that the drugs used to treat sick puppies were critical. Sometimes when one of the penicillin drugs was used for treatment the puppy would develop a severe Clostridium difficile diarrhea, a very undesirable consequence.

 I did some studies to see what might or might not work. During the 2016 parvo season 61 pups that had tested positive for parvo were treated. They all got the same regimen: a liquid oral prescription for the gastro-intestinal bacteria, a small injection of a broad spectrum-antibiotic for other bacteria in their bodies and an oral antivirus medicine used in people. Puppies were sent home with instructions to return the following day for further treatment. Most of the sick puppies were treated only once, and only one of them died. Perhaps the antivirus medicine was most helpful I am not certain that it was but I continue to rely on it.