A five-year old crossbreed dog that lived in a household with three adults who had been diagnosed with Covid-19 was diagnosed with the same infection in August last year. The dog exhibited flu-like symptoms – which included a dry hacking cough, mild dyspnea (shortness of breath) and lack of appetite.
The case of this dog is told in an academic paper titled “Near-complete Genome of SARS-CoV-2 Delta Variant of Concern Identified in a Symptomatic Dog (Canis lupus familiaris) in Botswana” that was put together by multiple researchers, some based here at home and others based abroad. The local research team included Dr. Kereng Masupu who was the Chairperson of the now-disbanded Presidential COVID-19 Taskforce and Dr. Sikhulile Moyo, the Research Laboratory Director at the Botswana Harvard AIDS Institute Partnership (BHP) who gained international fame last year after discovering the Omnicron, a Covid-19 variant. Moyo was himself a member of the Presidential COVID-19 Taskforce.
The discovery of the dog with Covid-19 was part of SARS-CoV-2 genomic surveillance in response to the State of Emergency, for which parliament had to convene a special session to debate the Emergency Powers Regulations that guided national response to the pandemic. The dog lived in a household with three adults who, beginning August 2 last year, were under a 10-day quarantine for Covid-19 infection. The paper notes that the dog “was at high risk of getting infected as it was being hand-fed and cared for by everyone in the household during their quarantine.” For four days, the dog had been coughing – which would mean that the coughing started on July 31. On August 3, a day after the human residents of the household in question had tested positive for Covid-19 and had been placed under quarantine, the dog’s case was reported to the Botswana National Veterinary Laboratory in Gaborone.
Upon clinical examination of the dog two days later, the dog was found to be “mildly depressed and had lost appetite.” The dog’s vaccination records showed that while it was protected from rabies, it had waning protection for rabies itself as well as canine distemper, respiratory disease, canine parvovirus and infectious canine hepatitis on account of the time lapse.
“In-contact neighbourhood dogs had no symptoms of the highly infectious kennel cough despite being in direct contact with the dog. The dog was the only symptomatic dog at the time of the examination and in a week to two from the time of examination, making kennel cough a less likely diagnosis,” says the paper, adding that the polymerase chain reaction (PCR) tests results were weakly positive for Covid-19.
“Without exerting undue discomfort to the dog”, samples taken from it and referred to the Botswana Harvard HIV Reference Laboratory (BHHRL) for SARS-CoV-2 testing. The results came back positive.
“We presumed that the SARS-CoV-2 infection from the dog was from the owners, who had Covid at the time. However, we cannot exclude the possibility that the dog acquired the infection from the environment including licking surfaces with SARS-CoV-2,” says the paper, adding in another part that the constitution of a near-full length SARS-COV-2 genome (all genetic material of an organism) was successfully investigated and classified under a sub-lineage of the Delta variant that was reported in Botswana within the same time frame.
The researchers also made descriptive comparisons to known sequences in Botswana and abroad.
Beginning in late 2019 when the virus was discovered in China to date, there is raging debate about the origins of Covid-19. One theory is that the virus was developed in a lab in Wuhan city as part of a chemical warfare programme and was accidentally released. Among those who support this theory is Robert Redfield, the former Center for Disease Control director who worked on the United States response to the pandemic under ex-President Donald Trump. Conversely, there is a natural-origin theory which proposes that the virus came from a bat and was passed on to the human population in Wuhan. This theory is supported by the World Health Organization which stated in a report last year that it was “extremely unlikely” that the virus was introduced to humans through an accidental lab leak.
In their paper, the Covid-19 dog researchers align themselves with the latter position.
They write: “Strong support for this zoonotic origin is the fact that bat betacoronavirus was linked to the 2002–2003 SARS epidemic (SARS-CoV), which was thought to be transmitted to humans either directly or through an intermediate host that is yet to be identified. Prior to the discovery of SARS-CoV-2, pets such as dogs could be infected with an Alphacoronavirus (α-CoV), canine enteric coronavirus (CCoV), known to have mild symptoms and are not life-threatening. New evidence shows that anthroponotic infections of SARS-CoV-2 between animals and humans exist. The infection in dogs and cats, although rare is biologically feasible since they share the same cellular receptor, the angiotensin-converting enzyme type 2.”
The paper also notes that dogs that get infected with SARS-CoV-2 often become asymptomatic with low viral ribonucleic acid (RNA) levels unless the RNA is isolated from nasal, oropharyngeal and rectal swabs within six to nine days post-infection field. It adds that SARS-CoV-2 infection has also been reported in wild animals including minks, tigers, lions, and ferrets.
The researchers conclude that SARS-CoV-2 outbreaks are primarily driven by person-to-person transmission and the risk of animal-to-human transmission remains very low.
“However, our data suggest that persons with COVID-19 infection should minimize contact with animals during illness or convalescent period,” they note in their paper.
The researchers are from BHP; the Department of Pathology at the University of Cape Town; the Botswana National Veterinary Laboratory; VetPro Consultants in Gaborone; the departments of Biological Sciences, Medical Laboratory Sciences and Internal Medicine at the University of Botswana; the Ministry of Health; Kweneng Veterinary Clinic; the Department of Veterinary Services; the Presidential COVID-19 Taskforce; the National Health Laboratory; Botswana-Baylor Children’s Clinic Centre of Excellence; and the Department of Immunology and Infectious Diseases at the Harvard T.H. Chan School of Public Health.
All told, the paper was written by 17 people: Wonderful Choga, Samantha Letsholo, Chandapiwa Marobela-Raborokgwe, Mbatshi Mazwiduma, Dorcas Maruapula, John Rukuva, Mary Binta, Letlhogile Oarabile, Boitumelo Zuze, Legodile Koopile, Kedumetse Seru, Patience Motshosi, Ontlametse Bareng, Botshelo Radibe, Pamela Lawrence-Smith, Kutlo Macheke, Lesego Kuate-Lere, Modisa Motswaledi, Mpaphi Mbulawa, Mogomotsi Matshaba, Kereng Masupu, Shahin Lockman, Roger Shapiro, Joseph Makhema, Mosepele Mosepele, Simani Gaseitsiwe and Sikhulile Moyo.