15 Apr 2020
However, University of Cambridge Department of Veterinary Medicine head debunks work and insists owners should not be concerned by findings.
James Westgate
Job Title
A new study has suggested the coronavirus pandemic could have been sparked by a stray dog eating bat meat.
Xuhua Xia from the University of Ottawa in Canada studied coronavirus signatures across different species and has claimed feral dogs are the most likely animal intermediate host for the virus, in a study published in Molecular Biology and Evolution.
Prof Xia hypothesised that the ancestor of the new coronavirus and its nearest relative – a bat coronavirus – infected the intestines of dogs, where it evolved before jumping to humans.
Humans and mammals can fight viruses through a key antiviral protein – the zinc finger antiviral protein – which prevents the infection from multiplying, while regions of DNA called CpG dinucleotides direct the immune system to attack the virus.
Single-strand coronaviruses can avoid the body’s natural defences, however, by reducing CpG, in a similar fashion to HIV.
In his study, Prof Xia analysed all 1,252 full-length betacoronavirus genomes deposited into the open access GenBank database.
He said SARS-CoV-2 and its closest known relative – a bat coronavirus (BatCoV RaTG13) sharing 96% sequence similarity – have the lowest amount of CpG among its close coronavirus relatives.
Only genomes from canine coronaviruses, which have already caused a highly contagious intestinal disease worldwide in dogs, have similar genomic values, according to the study.
However, the paper was criticised by University of Cambridge Department of Veterinary Medicine head and researcher in infection dynamics, James Wood.
Prof Wood said: “I find it difficult to understand how the author has been able to conclude anything from this study, or to hypothesise much, let alone that the virus causing COVID-19 may have evolved through dogs.
“There is far too much inference and far too little direct data. I do not see anything in this paper to support this supposition and am concerned this paper has been published in this journal.
“I do not believe any dog owners should be concerned as a result of this work.”
