At least 12 dogs and 10 cats in the U.S. have been confirmed to be infected with the SARS-CoV-2 virus.
In July, pets in Arizona, California, Georgia, North Carolina, South Carolina, Texas, Utah, and Wisconsin became the most recent confirmed positive for the virus. All animals with confirmed infections so far were exposed to people with known or likely infections, according to the U.S. Department of Agriculture.
A veterinarian in California saw an 11-year-old male cat in late June for signs of respiratory difficulty and found the cat had hypertrophic cardiomyopathy. It died the following day, according to California Department of Health officials.
Agency officials provided a statement that they didn’t know why the veterinarian requested SARS-CoV-2 testing. A second cat lived in the same home without clinical signs of illness.
On July 16, officials at Clemson University in South Carolina announced that the USDA Animal and Plant Health Inspection Service had confirmed an infection in an 8- or 9-year-old shepherd mix that lived with a person who developed COVID-19. Dr. Boyd Parr, South Carolina state veterinarian and director of Clemson Livestock Poultry Health, said the dog’s owners consulted their veterinarian in March about respiratory disease, and signs recurred in June. The dog was hospitalized June 23 and euthanized because of the chronic respiratory condition July 2, he said.
The Texas Animal Health Commission reported a veterinarian requested testing of a 2-year-old dog for SARS-CoV-2 as a precaution because its owners had confirmed infections. The dog tested positive but was healthy as of July 8.
An announcement published July 1 by the Georgia Department of Public Health indicates the department found SARS-CoV-2 infection in a 6-year-old dog after it developed neurologic illness. It was euthanized days later.
“While the dog did test positive for SARS-CoV-2, the progressive neurological illness was caused by another condition,” the announcement states.
The Georgia dog’s owners had confirmed infections with SARS-CoV-2 prior to the dog’s illness, state officials said. A second dog from the same home lacked signs of illness, and health authorities were waiting for results of testing on that dog.
In a July 23 update to the World Organisation for Animal Health, APHIS officials said a dog in Arizona tested positive after showing signs of respiratory disease, but recovered. A cat in Texas was infected but did not have clinical signs; it was tested as part of surveillance testing of animals exposed to the virus, the report states.
The report also says that, in July, health authorities reported finding virus-neutralizing antibodies in four cats and two dogs in Utah, two dogs in Wisconsin, and one dog in North Carolina.
APHIS officials have been tracking infections in animals, starting with April’s infections among ill tigers and lions at the Bronx Zoo in New York City. The other infected animals were two cats and four dogs in New York state and one cat each in Illinois and Minnesota.
Dr. Ryan M. Wallace, veterinary epidemiologist for the Centers for Disease Control and Prevention and member of the agency’s One Health Working Group, said the CDC helped state agencies investigate reports this summer of SARS-CoV-2–infected pets with severe illness, and all of those animals had severe underlying conditions. The dog in Georgia with neurologic abnormalities, for example, had a brain tumor found during necropsy.
SARS-CoV-2 infections were not identified as the cause of death for those animals, although it’s difficult to determine whether the virus could have contributed to their illnesses.
Studies of experimental infections in dogs and cats so far have involved small sample sizes, typically comprised of young and healthy animals, Dr. Wallace said. But the infections in those studies tended to result in few clinical signs of illness.
Most pets with confirmed infections also have required little veterinarian intervention, he said.