Canine coronavirus causes 'severe vomiting' in dogs, study reveals

·4 min read
Dogs have become ill with a canine-specific strain of the coronavirus. (Stock, Getty Images)
Dogs have become ill with a canine-specific strain of the coronavirus. (Stock, Getty Images)

A coronavirus strain can cause "severe vomiting" in dogs, research suggests.

"Coronavirus" has become something of an everyday term, with the ongoing pandemic having claimed the lives of more than 2.9 million people since the outbreak was identified at the end of 2019.

The circulating variant is one of seven pathogens of the coronavirus class that are known to infect humans. Others can cause mild common cold-like symptoms or even Severe acute respiratory syndrome (Sars), which killed 774 people during its 2003 outbreak.

Humans are far from the only affected species, with dogs, minks and even a New York zoo tiger testing positive for the circulating coronavirus amid the pandemic.

In January 2020, a vet in North-West England noticed "an unusually high number" of dogs had extreme gastroenteritis, with social media suggesting similar cases were arising elsewhere in the country.

Read more: Dogs could be trained to sniff coronavirus in sweat

To learn more, veterinary scientists from the University of Liverpool analysed the electronic health records of more than 4.6 million dogs spanning from March 2014 to February 2020.

Results reveal there was a significant increase in "gastroenteric disease" between December 2019 and March 2020, which was later linked to a canine-specific coronavirus.

The scientists have warned the infection could become seasonal, but stressed humans cannot catch this strain of the virus.

Coronavirus COVID-19 computer generated image.
There are many strains of the coronavirus, not all of which infect humans. (Stock, Getty Images)

Vomiting is relatively common among dogs, however, the widespread uptake of vaccines means infections are rarely to blame, according to the scientists.

To better understand the 2020 vomiting outbreak, the team analysed electronic health records via the Small Animal Veterinary Surveillance Network; made up of 301 veterinary practices across the UK.

Read more: Dog walkers 78% more likely to catch coronavirus in first lockdown

More than 1,000 vets and pet owners also completed an online questionnaire asking if they had treated or owned a dog that vomited at least five times over a 12-hour period.

To uncover any infectious cause, the scientists compared the mouth swabs, faecal samples and any vomit of ill dogs against those of healthy controls.

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As well as an increase in vomiting cases, the scientists also found use of the anti-sickness drug maropitant spiked in dogs from December 2019 to March 2020.

Both the vomiting cases and prescriptions peaked in the week ending 2 February.

The cases were particularly clustered in North-West and South-West England, as well as in Edinburgh.

Male dogs and those living with other vomiting canines were most likely to be affected, with the latter suggesting "either transmission between dogs or a common environmental source", the scientists wrote in the journal Emerging Infectious Diseases.

Read more: Why coronavirus infects some animals and not others

Single-household dogs were more likely to become ill than those living with multiple pets where just one was vomiting, however.

"Some authors have shown dogs from single-dog households are walked more and therefore could be at greater risk for infection," wrote the scientists.

The affected dogs were of "a range of breeds".

Overall, around half of the cases also developed diarrhoea, the results show.

The results of the various samples revealed "a canine enteric coronavirus was significantly associated with illness". Enteric describes a condition related to the intestines.

The canine coronavirus in question is "generally associated with mild gastroenteritis". Although unclear, genetic mutations may have made the infection more severe, according to the scientists. 

Treatment generally focused on prescribing anti-vomiting drugs, with most of the dogs recovering in three to seven days.

Just 1% of the ill dogs reported by their owner and 0.6% flagged by vets later died.

"In conclusion, this multidisciplinary approach enabled a rapid response to a newly described outbreak of canine gastroenteritis and identified a [canine coronavirus] as a potential cause," wrote the scientists. 

"Previous [canine coronavirus] seasonality suggests further outbreaks may occur."

Study author Dr Barry Rowlingson from Lancaster University added: "Being able to rapidly detect increased incidence, without triggering a false alarm from a natural random variation, is the key problem here. 

"Early detection is crucial to early treatment and enhanced monitoring."

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