More Dogs Likely Infected, But Without Life-threatening Illness
A pet dog from Chicago that had been experiencing respiratory symptoms since early January recently tested positive for SARS-CoV-2, the virus that causes COVID-19 in people.
The initial test was conducted by Dr. Ying Fang, a veterinary virologist, and her research team at the College of Veterinary Medicine at the University of Illinois Urbana-Champaign. (See Expert Viewpoint interview with Dr. Fang.) The canine sample was sent to her lab by Dr. Drew Sullivan, the dog’s veterinarian and the director of the Medical District Veterinary Clinic in Chicago, which is part of the veterinary college.
The positive diagnosis has been confirmed by the National Veterinary Services Laboratory in Ames, Iowa, part of the USDA Animal Plant and Health Inspection Service.
While the virus has been detected in Illinois cats, this case is the first in an Illinois dog. Dogs and cats in other states have previously tested positive, as reported on this USDA dashboard.
Dog Exposed Over New Year’s Holiday
“The dog is overall doing well, but he continues to have nasal congestion and clinical signs,” said Dr. Sullivan. “The source of infection appears to be a person who was caring for him over the New Year’s holiday while his owners were away. The caretaker became very ill with COVID while caring for the dog.”
The dog’s owners had not been ill with COVID, so it is unlikely that they infected the dog. The owners have also not become infected while living with the infected dog. There is no evidence of COVID infections passing from pets to people.
“The dog developed signs of respiratory illness about one week after the exposure. Initially, I suspected common canine respiratory pathogens. However, because the dog was not improving, I became suspicious of something else,” said Dr. Sullivan.
“Dr. Fang has a NIH project to develop novel diagnostic assays for detecting SARS-CoV-2 infection in animals,” he said, “so I worked with her to see if this dog’s problems might be caused by the coronavirus circulating in people.”
Other Suspected Cases in Chicago
Dr. Sullivan has seen a number of canine patients with respiratory signs that are somewhat unusual and are not consistent with classic infectious tracheobronchitis (kennel cough).
“These dogs appear to have more nasal congestion and suspected postnasal drip, leading to sneezing, reverse sneezing, and gag-like cough,” he said. “Although none of these patients has had severe illness, a few have been more ill, with possible co-infections by opportunistic bacteria.”
From speaking with the dogs’ owners, Dr. Sullivan learned that in about three-quarters of these suspected SARS-CoV-2 cases the dogs’ symptoms began around the same time that people living in the household with the dog tested positive for COVID-19.
“At this time, it appears that it’s possible there have been more dogs infected with SARS-CoV-2 than previously suspected. Luckily, these infections rarely cause severe disease in dogs,” said Dr. Sullivan.
The treatment for dogs infected with SARS-CoV-2 is supportive care. Dr. Sullivan said that dogs with lingering symptoms have appeared to benefit from steroidal medications.
Dr. Fang, who has been working on SARS-CoV-related viruses (arteriviruses and coronaviruses) since 1998, is a professor in the Department of Pathobiology. Dr. Sullivan is a faculty member in the Department of Veterinary Clinical Medicine. The University of Illinois College of Veterinary Medicine is the only veterinary college in Illinois and one of only 34 in the United States.