DEAR READERS: The journal Emerging Infectious Diseases published an article last fall on cats and COVID-19. Researchers reported that serum samples from cats sent to a veterinary diagnostic lab for conditions unrelated to COVID-19 revealed SARS-CoV-2 antibody seroprevalence levels similar to those of people in the same geographic areas. This suggested that humans transmitted the virus to the cats. (Full story: News Medical, Oct. 27)
This summer, the same journal reports that people who share a bed with, cuddle and kiss cats and dogs while sick with COVID-19 are more likely to pass the disease to their pets. The study's lead author, professor Dorothee Bienzle from the University of Guelph, said the results suggest that cats have a higher rate of COVID-19 infection than dogs. She added that the team was surprised by the high prevalence of COVID-19 antibodies in cats: "We did not expect quite that many," she said. "Over half of the cats that live in a household with a person who had COVID had antibodies. That's very high." (Full story: The Globe and Mail, June 26)
This timely study confirms what I consistently advocate, as do others with veterinary, medical and scientific backgrounds and an understanding of epidemiology and zoonoses: All owned cats should be contained or enclosed and not be allowed to go off their owners' property. This would help prevent local wildlife and stray and feral cats from being infected with the SARS-CoV-2 virus and becoming a public health risk as reservoirs of potential infection for years to come.
Also, cats infected by humans with this virus could pass on the infection to people, as has happened in Thailand. Virologists have established that a cat belonging to a COVID-19 positive family sneezed in the face of a veterinarian testing the cat for this disease, and that the doctor soon tested positive. Such cases of cat-to-human transmission are probably rare, and researchers emphasize that people should care for their infected cats -- taking extra precautions when handling them -- and not abandon them.
Another viral complication to be aware of is myocarditis. Amid the surge in COVID-19 cases late last year, veterinarians in the U.K. saw a higher-than-usual number of dogs and cats with depression, lethargy, poor appetite, abnormal heart rhythm and fluid in the lungs, all of which are signs of myocarditis. The owners of many pets with confirmed myocarditis seen at The Ralph Veterinary Referral Centre had confirmed or suspected COVID-19. Six of 11 animals tested positive for the SARS-CoV-2 alpha variant or antibodies to the virus, researchers reported in Veterinary Record. (Full story: NBC News, Nov. 5)
DEAR DR. FOX: What is your opinion of Alley Cat Allies? I deal with stray and feral cats in my neighborhood constantly, and the TNR (trap, neuter, release) activities by some resident volunteers only make matters worse. -- J.H., Minneapolis
DEAR J.H.: The propaganda of Alley Cat Allies is well known, as are their activities. They are absurd from a science-based perspective, with regard to cats carrying diseases transmissible to humans, and from an ecological perspective of feral cat colonies' impact on wildlife. Cats outdoors are super-predators that, even after being fed by humans, will kill birds and small mammals in their domain.
The only ethically and biologically acceptable feral cat colonies are isolated from all wildlife, and their feline residents must be fed regularly by volunteers, provided with shelter, neutered, vaccinated and given veterinary care as needed. Few such colonies meet these basic standards of cat welfare, too often being open to other free-roaming, diseased and unneutered cats. These insufficient facilities then suffer the consequences of fights, infection and territorial competition.
Alley Cat Allies has, without local veterinary support and supervision, become a cult of well-meaning but misguided cat lovers. Human sentiment leads to the avoidable suffering of cats living outdoors and the wild animals who fall prey to them.
(Send all mail to animaldocfox@gmail.com or to Dr. Michael Fox in care of Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.
Visit Dr. Fox’s website at DrFoxOneHealth.com.)