Genetic tests being done on dog

March 5, 2020

Agriculture, Fisheries & Conservation Department Assistant Director (Inspection & Quarantine) Dr Thomas Sit: We discussed with other international experts in this field and we’re pretty sure that this dog has a low level of infection - it’s confirmed. From the first sample to our last sample tested, it’s already (been) six days. The dog’s nasal or oral mechanism, their secretion they should have - if contaminated - they should have a way to clean the virus, it would not stay for that long if it was just a contamination. I think it will take at least five or seven days for the blood results because it’s not an easy test, it’s not a quick test. We need to grow a virus and then neutralise the serum, so it takes some time. According to experts, it’s likely that humans infect dogs. We understand that viruses don’t read guidelines, they cross boundaries and sometimes animals infect humans, and sometimes it’s the other way round. This is called zoonotic disease and it’s been happening, it is not new. At this stage, we don’t have enough data to have a 100% answer as to whether it is infectious to other dogs or not. But if the dog’s owner is positive, it’s better to take precautionary measures to prevent onward transmission. For general hygiene, handwashing, wearing gloves and preventing the dog from licking around, I think that is important to prevent further infection. We know this coronavirus is an RNA virus. The basic virology is that all RNA viruses will mutate. It’s just a matter of time. That’s why I said the University of Hong Kong School of Public Health needs to do a genetic analysis to compare this dog’s genetic sequencing compared to the virus isolated from the patient so that they can compare. So if it’s totally identical, that means there’s no mutation. The testing is still ongoing.

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The Agriculture, Fisheries & Conservation Department today said genetic sequencing tests are being carried out on the pet dog of a confirmed COVID-19 patient which could reveal if the virus has mutated or not.

The department's Assistant Director (Inspection & Quarantine) Dr Thomas Sit told a press briefing this afternoon that the coronavirus is what is known as an RNA virus which eventually mutates.

“That is why the University of Hong Kong School of Public Health needs to do a genetic analysis to compare this dog’s genetic sequencing to the virus isolated from the patient so that they can compare. So if it is totally identical, then there is no mutation. The testing is still ongoing.”

Dr Sit reiterated that international experts agreed that the dog has a low level of infection, despite its blood tests not being ready yet.

“From the first sample to our last sample tested, it has already (been) six days. The dog’s nasal or oral mechanism, their secretion they should have - if contaminated - they should have a way to clean the virus, it would not stay for that long if it was just a contamination.

“I think it will take at least five or seven days for the blood results because it is not an easy test, it is not a quick test. We need to grow a virus and then neutralise the serum, so it takes some time.”

He added that it was too early to say whether animal-to-animal transmission was a possibility.

“At this stage, we do not have enough data to have a 100% answer as to whether it is infectious to other dogs or not. But if the dog’s owner is positive, it is better to take precautionary measures to prevent onward transmission.”

Dr Sit also advised dog owners to wash their hands, wear gloves and try to stop their dogs from licking their surroundings to prevent the virus from spreading further.