According to studies, these animals have spread coronaviruses to people. They hadn't done so previously

Only 07  coronaviruses have been identified as infecting humans, with three of them causing epidemics in the last two decades: MERS, SARS, and SARS-CoV-2, which produces COVID-19. However, researchers from the University of Florida claim to have discovered evidence that several coronaviruses traditionally thought to solely infect animals have crossed the species barrier, spreading from pigs and dogs to humans. The findings, which were published in two separate papers in October and November 2021, raise concerns about the possibility of new coronavirus strains capable of causing serious diseases in humans.

They've also challenged scientists' long-held views about coronavirus behavior, according to J. Glenn Morris, an infectious disease physician and co-author of both researches. "We've always worked under the notion that there were only a handful of coronaviruses capable of infecting humans," he explained. "A few cause the common cold, followed by SARS, SARS-CoV-2, and MERS." But it didn't seem like we needed to be concerned about the other coronaviruses out there, despite the fact that coronaviruses are quite abundant in animals."

Dogs and pigs are the animals mentioned in the study. The adults and children infected with the animal viruses in both experiments reported fever and mild sickness, indicating that the strains do not pose a significant risk to human health. However, the possibility of new strains developing or acquiring the genes required to cause serious sickness in humans is a matter of concern. When it comes to coronaviruses, Morris, who is also the director of the University of Florida's Emerging Pathogens Institute, which researches new and re-emerging diseases, said he's no longer sure if there's a clear line between species. "What our data is beginning to reveal... is that animal strains can transfer into people, and there are probably many animal strains that move into humans," he said. "We weren't looking very hard, and we found two separate examples, and I believe that if we really started looking, we'd find that coronavirus transmission from humans to animals, animals to humans, happens quite regularly."

Before the COVID-19 epidemic, all of the cases recorded in the two investigations occurred in Haiti. In 2014, 2015, and 2017, UF scientists collected and stored blood and urine samples from persons who had a fever or minor sickness. After research published in May 2021 claimed that physicians had found canine coronavirus in pneumonia patients hospitalized in Sarawak, Malaysia in 2017 and 2018, they opted to analyze the old specimens.

A urine sample from a UF medical team member who had "fever and malaise" after returning from a mission trip to Haiti in March 2017 was tested in the first research. Researchers discovered a 99.4% resemblance between the virus and the canine coronavirus reported in pneumonia patients in Malaysia, implying that the virus or a comparable mutation occurred in several sites.

The second study discovered evidence of porcine delta coronavirus infection in three Haitian children whose blood samples were obtained in 2014 and 2015 at a free school clinic in the Gressier district of Haiti, where UF doctors were tracking illnesses among children seen at the clinic. Fever and a minor sickness were among the children's symptoms. However, according to Morris, there are few indicators as to how far the porcine delta coronavirus traveled or how it was introduced to Haiti. The fact that scientists detected two unique strains of porcine delta coronavirus in the afflicted youngsters, one of which they connected to China and the other to the United States, adds to the mystery.

SARS-CoV-2 has been detected in 29 different animals, including cats, dogs,  white-tailed deer, ferrets, tigers, and mice, however, the animals have not been shown to transfer the virus to humans in the majority of cases. Scientists discovered that minks had communicated the virus to humans in November 2020, and a Canadian study that has yet to be published in a peer-reviewed journal identified one case of SARS-CoV-2 transmission from deer to humans.

The findings suggest that the pandemic will remain unpredictable, at least in part because coronaviruses mutate so quickly, according to scientists like Morris. He explained, "What we witness is this constant ongoing movement, swirling of different strains, diseases, genetic material, transfer from animals to humans and humans to animals." "All of this is going on, and the question is: Will we be able to develop a stable endemicity?" Perhaps, but there is a slew of issues that could arise."