October 15, 2013

 

 Investigation follows dog illnesses, deaths in Ohio


An unidentified disease may have sickened dozens of dogs, killing three, in two areas of Ohio. 
 
Erica Hawkins, a spokeswoman for the Ohio Department of Agriculture, said dogs brought to clinics in the Cincinnati and Akron areas in the three-week period ending Sept. 6 had clinical signs that included vomiting, bloody diarrhea, weight loss, and lethargy. Veterinarians reported to the department that the vomiting and diarrhea seemed to be related to vasculitis. 

“The suspicion is that there probably are more related cases,” she said Sept. 6. “That’s one of the reasons why we put out a news release today: to try to encourage veterinarians to be on the lookout for these symptoms and to report them if they have suspect cases that they think might be related.”

Ohio authorities have not heard reports of diseases with similar clinical signs in neighboring states, she said.

Dr. Tony M. Forshey, state veterinarian for Ohio, said the state’s investigation has eliminated many known bacterial and viral causes for this disease, and he thinks evidence indicates the outbreak is caused by a viral infection. It is believed to spread through oral-fecal contact, and other transmission methods are possible.

Dr. Forshey said the disease was notable for the unique lesions connected with vasculitis. For example, a 2-foot section along the back of a dog was sloughed during its illness.

The Ohio agriculture department is receiving samples from veterinarians who are treating ill pets, and the department will send those samples to laboratories at the University of California-Davis and Kansas State University as well as analyze them in the state’s own veterinary diagnostic laboratory, Dr. Forshey said.

Dr. Forshey said every pet owner would need to assess their pet’s disease risks, as would organizers of upcoming dog shows within Ohio.

Jack Advent, executive director of the Ohio VMA, said his organization wants people to take their pets to veterinarians if they see unusual signs, but he cautioned against undue fear.

A bulletin distributed by the OVMA indicates the Ohio Department of Agriculture asked veterinarians to help by contacting the department laboratory if they saw similar cases and by telling pet owners what signs to look for and how to protect their dogs against the spread of infectious disease.

The department was trying to determine whether the illnesses were connected with a novel circovirus that was identified in California and described in a scientific article this past spring. Dr. Patricia A. Pesavento, who is one of the researchers who identified the virus in dogs in California, said she is working with the Ohio authorities and is testing for the circovirus, which she said was not likely the only factor in the California illnesses.

The article, “Circovirus in tissues of dogs with vasculitis and hemorrhage” (Emerg Infect Dis 2013;19:534-541), indicates researchers characterized the genome of a novel circovirus that was found in the liver of a dog that had hemorrhagic gastroenteritis, necrotizing vasculitis, and granulomatous lymphadenitis. The virus should be considered a possible causative agent in dogs with unexplained vasculitis, the article states, but further study of the virus is needed to determine whether it causes disease.

Dr. Pesavento is one of the authors of the article and an associate professor of pathology, microbiology, and immunology at the University of California-Davis. She said that, among samples from four dogs from Ohio, one was positive for the circovirus and three were negative. She thinks the circovirus did not cause an outbreak in Ohio, although it could be a contributing factor.

“We have some new viruses in dogs; that includes a circovirus and a bocavirus, and we’re just trying to work out how they might be affecting dogs’ health,” she said. “In the case of the Ohio outbreak, it’s certainly not the simple answer to what’s going on with those dogs.”

She is involved in ongoing research on the circovirus.

The article in Emerging Infectious Diseases described the discovery of high quantities of the circovirus in lymph nodes and spleens of four dogs from California. Dr. Pesavento said of two dogs that became ill in 2012, one had hemorrhagic diarrhea and the second had neurologic signs. They, along with two dogs for which 2009 and 2010 records were retrospectively analyzed, had vasculitis and signs of vascular compromise such as bleeding or infarction, although the tissues involved differed among those dogs.

The article indicates the virus was found in tissue samples from 19 of 168, or 11 percent, of dogs with diarrhea and in 14 of 204, or 7 percent, of healthy dogs. Testing also found co-infections with other canine pathogens in two-thirds of dogs with diarrhea. The circovirus, “alone or in co-infection with other pathogens, might contribute to illness and death in dogs,” the article states.