Some have theorized that the Omicron variant of COVID-19 was circulating widely in populations of mice before it found its way back into human hosts. That would explain why the variant was so completely different that the previous variants of COVID. It came out of left field, unrelated to strains of the virus that had been mutating in the human population.
Humans as a rule tend to think of themselves as the center of the universe. They are however only a fraction of the life on the planet. Scientists have known for a long time that animals can catch COVID-19. However research has been scant as to exactly which animals have contracted the virus and more importantly how often animals have passed the virus back to humans.
Undoubtedly people have passed the virus to their pets as they become infected multiple times. COVID may have infected over 500 other mammal species. Humans have become complacent about the virus spreading from human to human so of course there is little concern about the virus spreading among animals. The only problem is that the virus tends to mutate differently in other mammals. COVID is not a human virus it is a virus that attacks many species. Mutants of the virus could become more transmissible but no one knows it that has happened.
17 million mink were murdered in Finland in an effort to stop the spread of the virus. China began killing pet store hamsters in another effort stop the spread. It is fascinating how murder is often considered the best solution to a public health issue. Animals who get the virus are often asymptomatic or have mild symptoms. That is another reason people seem blissfully ignorant of this issue.
White tailed deer in America have been rather susceptible to the scourge of the virus. Since hunters wander the woods to kill the deer they might be the ones spreading the disease to the deer population. Researchers test some of the deer killed and an amazing number are infected. Of 481 deer tested, 30% were infected. Another surprise is the the variants found are different that those circulating among humans. One bit of advice to hunters is that they should not eat the brains of their kill.
Sars Ani-Vis has built a site that shows the animal species that are becoming infected and where they are found. The deer population in America has the largest number of documented cases followed by dogs and cats. The numbers however are very small compared to the millions of humans that have died from COVID-19. Not many researchers are following this lead. There is probably not much money in knowing animals are getting infected.