Veterinarians skeptical canine circovirus alone is sickening dogs

Practitioners with suspect cases urged to contact state officials

Published: September 10, 2013
By Jennifer Fiala

Photos courtesy of Dr. Melania Butera
Dr. Melanie Butera, a practitioner in Canal Fulton, Ohio, recently treated a Shar-Pei mix named Lexi for vasculitis, which caused the skin on her back to slough off. After the tissue was kept moist and sterile for approximately 30 days, the dog's skin regrew. Butera removed Lexi's sutures on Sept. 7. The photos shows Lexi's wound at day one (top left), day 10 (top right) and nearly healed (above).

It might look like circovirus and act like circovirus … and still not be circovirus.

That’s what scientists investigating the mysterious illness that's sickening and killing dogs in Ohio and elsewhere say after diagnostic tests of some infected samples came back positive for Dog Circovirus, or DogCV.

Dr. Patricia Pesavento is an associate professor of pathology, microbiology and immunology at the University of California, Davis, School of Veterinary Medicine. In the wake of reports that dogs in Ohio were dying of a mysterious toxicant or virus, she received samples from three of the infected animals, only one of which tested positive for DogCV.

The dogs' clinical signs included bloody diarrhea and vomiting, extreme lethargy, neurological problems and lack of appetite. Severe hemorrhagic gastroenteritis and vasculitis are associated with DogCV. Treatment guidelines do not exist apart from supportive care.

“Understanding the pathogenesis of DogCV is in its infancy," Pesavento explained by email. Pointing to previous research she conducted on DogCV, Pesavento said, "We have identified 10 animals retrospectively that are infected with DogCV and that have vascular-based disease, but there is a large burden of proof for causality."

By phone, she added: "My bottom line: Circovirus is part of this; we don’t know if it’s the same agent killing all of these animals.”

The Ohio Department of Agriculture, which is organizing the investigation, is asking veterinarians to consult the agency's Division of Animal Health at (614) 728-6220 if they see suspected cases. Concerned pet owners are encouraged to talk to their veterinarians.

Researchers at The Ohio State University (OSU) also are testing samples from sickened dogs. Melissa Weber, director of communications for the veterinary college, confirmed that one dog was sent to OSU for necropsy.

She stated that OSU does not have the ability to test for DogCV. "Everything else they've tested for has come back negative," she said.
"Circovirus is interesting, but that doesn't mean it's causing these deaths."

Even so, mainstream media have run with the idea that dogs are dying after contracting circovirus. "It's a scary new disease that can kill your dog," an Ohio news agency reported.

A press release issued last week by State Veterinarian Dr. Tony Forshey is less definitive.

“The laboratory confirmation is important because the virus is newly isolated, however we are not prepared at this time to confirm that canine circovirus is the cause of the dog illnesses,” he said. “Because the symptoms being exhibited can also be linked to other known illnesses, additional analysis and information is needed to determine if this virus is alone or in co-infection.”

DogCV is newly isolated and there is very little information available about the virus, where it came from and how it spreads, the Ohio Department of Agriculture press release stated. "The limited research available shows that canine circovirus can cause vasculitis and hemorrhaging in infected dogs."

Porcine Circovirus, the only other known mammalian circovirus, can cause vasculitis in swine.

Dr. Melanie Butera in Canal Fulton, 18 miles south of Akron, is one of a handful of practitioners in Ohio who’ve treated dogs infected with the novel virus. “I had two dogs come in on the same day with these odd and very severe signs,” said Butera of the first of her patients that presented with signs of the disease on Aug. 24. “These dogs had been sick such a short period of time with normal blood work. I immediately thought there was no way this was a virus. It worked too quickly for the viral diseases we are used to seeing.”

One of the two dogs died. It was then that Butera learned several dogs recently had become ill and three died after visiting a boarding facility in Norwood, north of Cincinnati.

Despite extensive testing of the facility, no bacterial agent or toxicant was found to have caused the cases, which sounded a lot like what Butera was seeing in her own practice. Butera turned to the Veterinary Information Network (VIN), an online community for the profession, where she consulted colleagues about what she was witnessing.

“What has really stood out to me in these cases is the acute profound lethargy/weakness/depression, and the sinus tachycardia,” she wrote in a VIN discussion. By phone, she added: “The big thing was how sick these dogs were in such a short time period. They had fluid coming out of their gums. They weren’t passing bloody diarrhea, they were passing blood and clear fluid.”

Another dog Butera treated with similar clinical signs is on the mend after vasculitis caused the skin on its back to slough off. She's now collecting reports from veterinarians in the area who've seen patients with similar conditions and has warned her clients about what she says are "sporadic cases."

“It was one of my patients that tested positive for circovirus,” Butera said. “But I’ve said this repeatedly: Just because they found the virus does not mean it caused the disease.”

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