Killer disease afflicts pets and baffles vets (very scary sounding)!!
http://seattletimes.nwsource.com/htm...24_dogs18.html
Monday, October 18, 2004 - Page updated at 12:00 A.M.
Killer disease afflicts pets and baffles vets
KANSAS CITY, Mo. — The disease that killed Alexi has a lot of veterinarians baffled.
The frisky boxer puppy had been a snuggly delight to her owner, Amber Putnam, 17, of Paola, Kan. But when Alexi became ill last winter, her condition deteriorated with alarming speed: She stopped eating, she had trouble urinating, her eyes turned glassy and her nose became dry and crusty.
"It was instant. Just one thing after the other," Putnam said. "I think we were all in denial. We thought she would turn around."
Alexi was struck down by dysautonomia, a mysterious animal disease that attacks the nervous system and is almost always fatal within weeks.
Veterinarians don't know what causes dysautonomia. And there is no cure, just palliative care to make animals less uncomfortable in their final days. Researchers have just begun to look for its cause.
What makes dysautonomia more mystifying is that since it appeared in the United States 18 years ago, it has remained localized in the Midwest and Rocky Mountain states. Western Missouri and eastern Kansas have been the hot spot of the disease.
Floyd the cat felled in 1986
Veterinarians estimate hundreds of dogs in the region die from dysautonomia every year, and the disease shows no sign of going away.
"You kind of get a gut feeling about it, and in our neck of the woods, this is a fairly common disease," said Dennis O'Brien, a veterinarian at the University of Missouri, Columbia. As more veterinarians learn about the disease, he said, more cases are being correctly diagnosed.
O'Brien, a specialist in neurology, is recognized as one of the leading U.S. experts on dysautonomia. He has been tracking the disease since 1986, when it made its first U.S. appearance in a Kansas City house cat named Floyd.
A few other cats developed dysautonomia after Floyd died, but by 1988, the disease had started affecting dogs. First there was a case in southern Missouri, followed by others in Colorado and Wyoming.
"After that, it kind of exploded," O'Brien said. "The calls we got from [veterinary] general practitioners were, 'I've never seen anything like this.' "
Dysautonomia is rare in humans. It was first recognized in horses about 100 years ago in Scotland. Local residents called it grass sickness, believing horses became ill grazing in certain pastures.
Beginning in 1982, there was an epidemic among cats across northern Europe. Hundreds of cats and a small number of dogs died. "By the late 1980s, it faded away and pretty much disappeared," O'Brien said. "It certainly hasn't abated here."
"A spectacular disease"
In dysautonomia, nerve cells called neurons are quickly annihilated throughout the autonomic nervous system. This portion of the nervous system controls many vital functions, such as regulating the heartbeat, stimulating muscle contractions of the bladder and intestines to eliminate wastes, causing glands in the eyes to make tears and making the pupils of the eyes expand and contract with changes in light.
"It's a spectacular disease," said Gayle Johnson, a veterinary pathologist at the University of Missouri who has examined under a microscope the nervous systems of dogs with dysautonomia. "Every place you look, there are dead or dying neurons or an absence of neurons. Everything from the brain and spinal column to the intestinal wall is affected."
As dysautonomia progresses, dogs can walk and use their muscles normally. And they maintain their mental faculties, so they are acutely aware of their declining condition.
"They're miserable; that's the best word for it," O'Brien said. "Their sensory functions are fine. They know their bladder is blown up like a balloon and they can't go. They know their stomach is full and they can't do anything about it. They're absolutely miserable."
Tough to diagnose
Because dysautonomia has so many symptoms, it can be hard for veterinarians to diagnose — at first.
"For every case we see, there's probably five times the number of cases that go undiagnosed," said veterinary neurologist Brian Cellio in Overland Park, Kan.
Although in rare cases dogs with dysautonomia live through their illness, Cellio generally recommends that the animals be euthanized. Dogs that survive run the risk of recurring pneumonia and digestive disorders.
"You have to weigh what's best for your patients and their owners," Cellio said.
When O'Brien and other researchers analyzed data on 42 Missouri dogs with dysautonomia, they discovered definite patterns: The disease appears to be seasonal, occurring most often in late winter and early spring and becoming less frequent by late summer. It is more common in younger dogs; the average age is about 18 months.
Most dogs with dysautonomia come from rural areas, where they are allowed to roam. That makes it difficult to identify a cause of the disease.
"It's usually dogs roaming the countryside. They eat anything. They roll on anything. They sniff anything, swim through anything," O'Brien said.
A theory
His theory is that dysautonomia is an autoimmune disease, like multiple sclerosis, in which the body's immune system attacks the nervous system.
Even if that theory proves true, researchers need to figure out what sets off the immune system of dogs. Scientists think autoimmune reactions could be initiated by certain things in the environment, such as viruses.
"There's something in this area that is triggering an autoimmune disease," O'Brien said. "That's the real puzzler here: What is the difference between Missouri, Kansas, Oklahoma and the Northern Plains, and the Northeast and the Southeast United States?"
Not every dysautonomia researcher shares O'Brien's autoimmune hypothesis.
Kenneth Harkin, a veterinarian at Kansas State University, suspects some kinds of bacteria could produce a toxin that poisons the nervous system of dogs with dysautonomia.
If that's the case, why would the disease be limited to the Midwest? "It may be just that the conditions are right here for the bacteria to produce the toxin," Harkin said. "But we really don't know the answer."
