COVID-19 Information Center

Idexx offers SARS-CoV-2 test for pets, bucking official stance
Published: April 21, 2020
Jennifer Fiala

Photo by Annette Aispuro
Opie developed a hacking cough about the same time that his owner, Jonathan Grimm, developed body aches, chills and a fever, in mid-March. Grimm later learned he had COVID-19. When he and his veterinarian tried to get Opie tested for SARS-CoV-2, the virus that causes COVID-19, they were stymied for weeks.

Idexx Laboratories is making its test for novel coronavirus commercially available to veterinarians, as new evidence emerges that the disease is sickening pets, and they're apparently catching it from their owners. 

The company is asking practitioners to first consult with public health authorities and rule out other possible causes of disease before ordering the PCR test — a diagnostic test that involves a technique called polymerase chain reaction — for SARS-CoV-2, the virus that causes COVID-19.

"We have continued to monitor the rapidly evolving public health crisis worldwide, paying special attention to the effects on pets," Jay Mazelsky, Idexx president and chief executive officer, said Monday in a news release. "While there is currently no evidence that dogs or cats play a role in transmitting the disease to humans, it became clear offering the test was the right thing to do when we saw clinical evidence that pets — especially cats and ferrets — can in rare cases be at risk for infection. And, we heard from our customers around the globe that veterinarians needed a testing option."

Antech Diagnostics, which rolled out its own test for SARS-CoV-2 at the same time as Idexx, isn't following suit. For weeks, both laboratory chains have conducted surveillance testing for SARS-CoV-2 on samples sent in for routine gastrointestinal or respiratory panels. In the surveillance testing, which is not targeted to pets in COVID-19-positive households, the laboratories have had no positive results. (Since this article's publication, Zoetis Reference Labs also has developed a test for novel coronavirus, which is available to veterinarians.)

Explaining Antech's decision not to offer SARS-CoV-2 tests on request, Dr. Jennifer Ogeer, Antech vice president for medical affairs and commercial marketing, said Monday by email: "Human and animal health organizations worldwide continue to advise that widespread testing of pets for SARS-CoV-2 ... is not indicated at this time. Should the guidance from these organizations change, Antech will be ready with a commercially available test for the veterinary community."

Idexx's move bucks recommendations from federal agencies that discourage the routine testing of animals for COVID-19. Among them are the U.S. Centers for Disease Control and Prevention and U.S. Department of Agriculture, as well as professional organizations such as the American Association of Veterinary Laboratory Diagnosticians and National Association of State Public Health Veterinarians.

"Veterinarians who believe an animal should be tested will contact state animal health officials, who will work with public and animal health authorities to decide whether samples should be collected and tested," guidance from USDA says. 

In the five months that the novel coronavirus has spread from Wuhan, China, to sicken millions of people around the world and kill more than 169,000, authorities have reported that two dogs and two cats have tested positive for the pathogen. Of those, one cat, in Belgium, reportedly had clinical signs consistent with COVID-19.

On Sunday, the International Society for Infectious Diseases announced on its ProMed website that two cats in New York — the first pets in the United States — reportedly tested positive for SARS-CoV-2. "Both had owners who were COVID-19 positive, and both animals were reportedly exhibiting respiratory signs. Additional samples are (reportedly) being sent to NVSL (National Veterinary Services Laboratories) for confirmation," the report said.

Dr. J. Scott Weese, an expert in infectious diseases and a professor at the University of Guelph's Ontario Veterinary College, said on his popular Worms and Germs blog that he was surprised that the news was shared before results were confirmed.

What's not surprising, he added, is that there are positive cats in households with positive people, because cats are known to be susceptible. "The risk posed by cats isn't any greater than it was prior to this report, although some people are bound to freak out," he wrote.

Testing quagmire 

The understanding that pets can catch the novel coronavirus from people with COVID-19 represents an evolution in the government's characterization of the virus's impact on companion animals. CDC officials first said there was no evidence that pets could be infected by the virus. Then they said animals couldn't get sick. With that now disproven, officials still aren't recommending testing animals. 

Seeking clarification on exactly why commercial testing of pets is discouraged, VIN News attempted for weeks to reach numerous officials within federal and state public health agencies, without much success. Ed Curlett, director of public affairs for USDA Animal and Plant Health Inspection Service, responded by email with advice from the agency's website:

"USDA and CDC are not recommending routine testing of animals for COVID-19. Public and animal health officials may decide to test certain animals that are showing signs and that are known to have been exposed to the virus.

"If you think your animal could have COVID-19, the best thing to do is to consult your veterinarian. Make sure to tell your veterinarian if your animal was exposed to the virus that causes COVID-19, and if your animal is experiencing or displaying any clinical signs."

On Sunday, the American Veterinary Medical Association updated its COVID-19 information page to reiterate that the "routine testing of animals for COVID-19 is NOT recommended" by the USDA, CDC, Animal Association of Veterinary Laboratory Diagnosticians and National Association of State Public Health Veterinarians.

"The decision to test an animal should be made collaboratively between the attending veterinarian and local, state, and/or federal public health and animal health officials after careful and deliberate consideration of available guidance ..." the AVMA continued. "... [I]t will be necessary to coordinate that testing with these individuals." 

Officials' reluctance to test pets is raising eyebrows among people who believe that testing can help further understanding of the nature of the pandemic.

"Based on the messaging so far, it seems the USDA and CDC just don't want to know how widespread coronavirus is in dogs and cats, or they're unprepared to deal with it," mused a veterinarian and industry expert who spoke on condition of anonymity due to job constraints. "Pet owners want this test — they want it for their own well-being as well as their pets' well-being. Maybe our government agencies recognize the potential chaos that could ensue if we find out that people can give the virus to their pets, and their pets can spread it."   

Another insider who requested anonymity due to government ties pondered the same: "It's like they don't want to acknowledge what is happening."

Even so, there are plenty of reasons to discourage the sporadic testing of animals, said Weese, the infectious disease expert: Decisions about testing should be made by considering the risks and benefits. Knowing for the sake of knowing isn't reason enough to test; a test should either change the treatment, management or prognosis.

In a blog post, Weese explained: "Sporadic clinical testing might sometimes be useful, but it can also be a waste of time and effort, and can actually cause more problems if things haven’t been thought through properly."

By phone, he elaborated: "We want to keep pets of people with COVID-19 in the house unless they have to leave for urgent medical care. Testing requires someone to get the pet and take it to a clinic, where multiple people need to handle it. 

"It's a safety hazard for anyone sampling possible SARS-CoV-2-positive animals, and right now, a positive or negative result is unlikely to change the course of treatment," which is supportive care.

However, Weese indicates that surveillance testing designed to answer questions about how often pets are infected or get sick after exposure is important to help understand the virus. For that reason, he is part of an informal team of animal- and public-health experts in Canada who are trying to organize the surveillance of SARS-CoV-19 in pets by sampling households with active disease. The hope, he said, is to figure out the transmission rate of infection between humans and other animals; what characteristics can help identify risk; and how long animals shed the virus.

Amassing that kind of data is a huge endeavor, logistically. So far, only a handful of animals have been tested. None has been positive.

"It's been slow, getting into households with COVID-19," he said. "To get good information, we have to go into households while people are infected. The longer we wait, the more likely they'll burn off [the virus]." 

Seeking straight answers

Courtesy of Jonathan Grimm
Opie’s lingering cough led his owner and veterinarian to suspect he might have caught COVID-19. However, diagnostic testing came back positive for feline calicivirus and, ultimately, negative for the virus that causes COVID-19. The cat is fully recovered now.

Cat owner Jonathan Grimm recalls that the body aches, chills and fevers began on March 13. The following week, he started having breathing trouble and his chest felt "like it was in a vice." It was around that time, Grimm says, that his two domestic longhaired cats, a 1-year-old named Opie and a 10-year-old named Mickey, began to "hack, like they had a hairball," but without producing anything.

Grimm, fearing he had contracted the novel coronavirus, got tested for it. While awaiting the results, his cats continued to cough and were seen by a colleague of Dr. Julio Lopez, an internal medicine specialist in Los Angeles. Doxycycline was prescribed. Grimm declined radiographs, having not yet made the connection that cats could contract the same coronavirus causing a global pandemic. 

Days later, Grimm called the veterinary clinic back to say he'd tested positive for COVID-19, and that, while Mickey was recovering, Opie's condition had worsened. Grimm was now suspicious that his cats might have it, too, given the timing of the illnesses and the trio's close quarters in a studio apartment. Lopez, now on the case, said he found himself in an unusual situation. Like the federal government, state public health authorities were discouraging testing animals for SARS-CoV-2, and there were no protocols in place for testing.

Authorities with Los Angeles Veterinary Public Health — one of few public health agencies in the country solely devoted to veterinary medicine — encouraged Lopez to find another avenue for testing. He turned to Idexx. 

At the time, the laboratory chain wasn't allowing veterinarians to directly order PCR tests for SARS-CoV-2, owing to the government's cautionary stance. Instead, Idexx randomly selected samples sent in for respiratory or gastrointestinal panels, testing for SARS-CoV-2.

Idexx didn't promise to test Opie's sample for SARS-CoV-2 but suggested that Lopez submit it to the lab for a feline upper respiratory panel and label it "COVID-19 exposure."

On Sunday, March 29, Opie was swabbed, and the sample sent to Idexx. On April 1, Idexx said the cat tested positive for feline calicivirus, a common respiratory virus that can result in pneumonia with coughing and dyspnea in some cats. "Because of this," Lopez told VIN News, "they considered the matter closed."

But Lopez didn't. On April 5, the organization that operates the Bronx Zoo reported that one tiger had tested positive for the novel coronavirus. The feline, a Malayan tiger named Nadia, was presumed to have contracted the virus from an asymptomatic zookeeper. Like Nadia, three other tigers and three lions in the zoo had dry coughs. The other tigers and the lions were not tested, however, because they were not as sick as Nadia, and the zoo did not want to anesthetize them all in order to obtain samples for testing, according to a report by Reuters.

The case prompted Lopez to push to get Opie's sample tested for the coronavirus. While calicivirus commonly causes upper respiratory infection in cats, Lopez was not convinced it could cause the type of coughing the cats presented. He went back to the Los Angeles veterinary public health authorities on April 8. "… Calicivirus infection is not an alternate diagnosis for this case," he said in an email. "Calicivirus causes upper respiratory signs and only in kittens in shelters have a cough and pneumonia been noted. I would like to have Opie tested for SARS-CoV-2, how can we proceed?"

Lopez said the agency advocated for testing, but the California State Public Health Veterinarian's office resisted.

VIN News tried to reach state public health agencies, as well as the Los Angeles Department of Public Health, to clarify their stance on testing animals for the virus. No one responded.

Behind the scenes, Lopez said, some agency officials admitted that they simply don't want to find positive samples and alarm the public. "That's not a good reason not to test," he told VIN News. "We are scientists dealing with a novel virus. We need this kind of information."

In a letter dated April 8 to California Public Health Veterinarian Dr. Charles Franz, Lopez asked for permission to test Opie's pharyngeal sample for SARS-CoV-2. 

"If a tiger in the Bronx Zoo who does not have access to the public was tested due to exposure from an asymptomatic zoo employee, I think Opie deserves testing given the confirmed positive owner," Lopez wrote. "The results will help us gather more information on this novel virus and inform the millions of pet owners out there. … I please ask that you request Idexx to test the pharyngeal swab samples they have in their possession or to have them forward the samples to the USDA for testing."

The agency rejected Lopez's request.

Meanwhile, Idexx had selected Opie's sample for SARS-CoV-2 screening. "I received news of the negative result Friday, April 10th, after having my request denied by California public health," Lopez said.

He doesn't regret the lengths he went to with state authorities to try to obtain an officially sanctioned test. "I still think the negative result is useful information given the close contact the owner maintained with his cats. [It] shows it may be difficult to transmit it to cats outside of a laboratory setting."

Editor's note: This article was amended to attribute a statement by Antech to Dr. Jennifer Ogeer, vice president for medical affairs and commercial marketing, and include new information about Zoetis Reference Labs.