Lurking Threat: Three Wyoming vets researching Canine Dysauntonomia
February 5, 2019
Three people in Wyoming are researching genomic sequences of suspected agents of a rare but usually deadly dog malady known as Canine Dysauntonomia.
One of the most determined among those researchers is Donal O'Toole, Pathologist at Wyoming State Vet Lab in Laramie. Born in Scotland, he practiced in England before becoming active with UW's veterinary brain trust.
"A relatively new disease, CD was first recognized in the United Kingdom around 1983," Dr. O'Toole explains. "Locally, a dog out of southeast Wyoming gave us our first good description, in 1991. We kind of assumed it was rare . . . then a vet in Torrington, who had worked at Colorado State University, contacted us with information confirming some CD around Goshen County.
"Dr. Brant Schumaker participates in our determined effort to get word to clinical practices across Wyoming what this disease looks like," Dr. O'Toole says. "Some vets who had been in Kansas, where the disease was studied, reported the clinical signs were very distinctive. Yet examining vets had been missing it, simply hadn't seen it.
“This disease is a big deal, the mortality is about 92 percent, and even if they survive they’re usually partially neurologically crippled, perhaps in swallowing, urination, elimination. Once destroyed, cells that control the autonomic nerve never come back, and only really determined owners can manage those dogs.” Donal O’Toole, Wyoming state Vet Lab pathologist
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"A vet in Torrington made a video of a dog suffering the disease, which we showed at several meetings of the Wyoming Veterinary Medical Association, in an effort to alert and inform. People do not like to watch that video, it isn't pleasant," Dr. O'Toole says. "This disease is a big deal, the mortality is about 92 percent, and even if they survive they're usually partially neurologically crippled, perhaps in swallowing, urination, elimination. Once destroyed, cells that control the autonomic nerve never come back, and only really determined owners can manage those dogs."
Dysautonomia is not dog specific. It has reportedly stricken cats, sheep, horses and humans. However, it is widely thought that the cause is not common amongst all species.
Dr. Brant Schumaker, Epidemiologist with WSLV, says, "Dysautonomia is currently considered to be rare; however the WSVL has been receiving an increasing number of canine cases over the past few years . . . concentrated east of the Continental divide."
The Wyoming State Vet Lab study identified some clinical signs of CD in December 2011 "including vomiting, regurgitation, diarrhea, prolapsed third eyelid, distended bladder, dilated pupils, megaesophagus, and low or absent anal tone. "The etiology of the disease is currently unknown; however it is commonly thought to be an environmental toxin of some type. Upon histologic evaluation, lesions are seen in the autonomic nervous system (mesenteric ganglia) as well as the brainstem. WSVL has started a serum bank for future study of this disease. If you feel you have a possible case of CD, we ask that you contact us and send serum samples for analysis. Also, if possible, a tissue block of the adrenal glands and surrounding tissue (i.e. mesenteric ganglia) would be referred so that diagnosis can be confirmed and recorded," the WSLV pleads.
"CD is a mind-boggling disease with an unknown cause." Dr. Schumaker says. "One of the missions of the WSVL and the University of Wyoming is to provide extension service to the surrounding community. The multi-disciplinary team at UW consists of eight researchers who are all admittedly dog lovers in their own right. Additionally, the suffering that these affected animals and owners undergo is heart-wrenching. Any owners who have symptoms should pursue immediately!
"I try to contact owners of dogs diagnosed with CD and give them a questionnaire. We look for clues in those, and if someone spots a good clue we can do a hypothesis," said Schumaker.
The researchers seek data on confirmed cases. The strongest evidence at this point indicates a toxin produced by microorganisms in disturbed soil, said Schumaker.
Dr. O'Toole says, "I once had 7 cases in 27 days, but only two in the last year."
Some properties have recurrent cases, possibly due to fungus bacterium exposure to soil. A clinical neurologist at the University of Missouri published a series of papers on the topic, indicating it could be caused by poisoning. "Victims are usually rural, frequently working dogs, usually in first year or two of life, but not always. There's even been an episode affecting a litter of puppies," he said.
Dr. Lindsey Sudbrink of Salt Creek Vet Clinic (SCVC) at Newcastle, Wyoming, says she ironically learned of CD by "finding and reading a several-year-old clipping Dr. Vorpahl had saved, when we first bought his practice."
Meeting her first case of CD while working in Rapid City over four years ago, she remembered that article, and recognized the described symptoms. She says, "Each time you see it you realize it sooner. It's often found in dogs 1 or 2 years old. Often found when they move to a new property. Yet one of my cases had lived on the same property for 11 years, then developed CD and died. I have treated two dogs at different times that were genetically related, yet that thread really doesn't bear out in a lot of cases, or lead anywhere. You look for similarities, some constant in symptoms or other factors, and this illness just doesn't give you a constant. It's tough, because when the owner contacts you the dog is just a little abnormal . . . and it progresses so fast."
Now Dr. Lindsey has seen her fifth CD case — Lisa Darlington's young stockworking Border Collie named Jet, brought to SCVC Jan. 20, after two days of illness. Following two days of treatment during which she continued to regurgitate, exploratory surgery found her stomach "filled with brown putrid fluid." After two more days of every known treatment that should've helped her, Jet underwent humane euthanasia.
Lisa says, "It was such a shock. It just came so fast." Her husband Jim Darlington said less than a week after Jet even displayed a slight lack of appetite, she was gone. He wondered if a case of Parvo when she was nine months old weakened her system.
Dr. Lindsey says, "The single and strongest common denominator I've recognized in CD is deep ground disturbance of some sort. The victims are usually ranch dogs, where there's always digging going on for some reason – water lines, building, repairs, roads, lots of reasons the ground gets disturbed."
Dr. Schumacher spoke also of that, and Dr. O'Toole has likewise recognized deep ground disturbance as a CD common denominator. However, he notes "CD has infected cats in closed pet colonies with no access to the outdoors. It could be micro toxins from underground that develop in sunshine, might be ag pesticide, might be contaminant in feeds," he ponders, shaking his head in frustration.