The World Health Organization (WHO) was previously convinced that cats and dogs couldn't get infected by SARS-CoV-2, the new coronavirus that causes COVID-19. It even had that point listed on its myth-buster web page.

But now the agency isn't so sure after a report of a dog that tested positive in Hong Kong after remaining with its owners who had COVID-19. Fortunately for the dog, it didn't have any clinical signs of the disease. But meanwhile, pet health companies including Zoetis (NYSE:ZTS) and Heska (NASDAQ:HSKA) had been working on developing tests for companion animals that may be affected by COVID-19.

While the dog tested positive for the virus, it didn't have a measurable amount antibodies to the virus, but that may be because the virus was cleared so quickly that the dog's immune system didn't have a chance to develop an antibody response.

On its website, the WHO noted that "there is no evidence that a dog, cat or any pet can transmit COVID-19."

Veterinarian listening to a dog's heart

Image source: Getty Images.

Pet laboratory testing company IDEXX Laboratories (NASDAQ:IDXX) was developing a veterinary test for COVID-19. It checked thousands of samples from dogs and cats but didn't find any animals testing positive for the virus.

"Should leading health authorities determine it is clinically relevant to test pets for the COVID-19 virus, IDEXX will be ready to make the IDEXX SARS-CoV-2 (COVID-19) RealPCR Test available," said Jay Mazelsky, president and CEO of IDEXX.

IDEXX suggested that owners of dogs and cats with respiratory signs see their veterinarian, who can test the pets for more common respiratory pathogens.