Dogs and cats are more susceptible to human diseases than scientists thought

Scientists have discovered that we may be transmitting more diseases to our pets than we realize.

Pets that have close contact with their owners, such as sharing beds, cuddling, and eating in the same areas as humans, are at risk of transmitting diseases from their owners. This is according to a new paper published in the journal Zoonoses: Infectious diseases that affect humans and animals.

Diseases that are transmitted between other species and humans are known as zoonotic diseases, and more than 60% of human pathogens are zoonotic in nature. Reverse zoonotic disease is when humans transmit a disease to animals. The discovery highlights that while animals can transmit diseases such as bird flu, swine flu and COVID-19 to us, we can also infect them.

“We're starting to see more examples of reverse zoonoses, and pets are probably more susceptible than we previously thought,” said study author and assistant professor at the University of Florida's School of Public Health. said Benjamin Anderson. In a statement.

In their paper, the authors explore how pets can be exposed to many infections from their human owners, from swine flu, human norovirus, COVID-19, and tuberculosis to dengue fever, fungal infections, and parasites. It explains how you can be infected with certain diseases. These were primarily seen between humans and dogs or cats, but there have also been small numbers reported between humans and horses, ferrets, and even parrots.

Diseases are usually specific to a particular species because pathogens require specific structures to bind to and enter animal cells.

“Typically, the viruses that I infect as humans are not compatible with the receptors that dogs and cats have,” Anderson said.

However, sometimes a pathogen mutates to have a structure that allows it to invade the cells of another species, allowing the disease to jump between the two species. Viruses like influenza and COVID-19 tend to mutate frequently due to the fact that they contain RNA rather than DNA.

RNA and DNA are checked for mutations by enzymes within the cell, but RNA checker enzymes are not as accurate as DNA proofreading enzymes. This means that mutations in RNA viruses are seen more frequently, and therefore RNA viruses may evolve to jump species at a faster rate.

The more closely related species are, the more likely diseases are to occur between them. As a result, zoonoses and reverse zoonoses frequently occur among mammals. But sometimes pathogens mutate enough to jump that gap, spreading between mammals, birds, and even reptiles.

The authors hope this paper will help highlight the dangers of reverse zoonoses and inform veterinarians about the causes of certain diseases.

“When you meet a human in a clinic, you can ask questions like whether there were any animals nearby, whether they had a sick pet. “We need to collect information to link it to human cases,” Anderson said.

Reverse zoonoses can also put humans at risk by providing new routes for disease spread and amplifying epidemics. Pigs in particular can be infected with both human influenza and avian influenza, so they act as a mixing pot for new viruses that could eventually spark new pandemics, the study authors said.

“Pathogens can certainly be transferred from one animal to another or transmitted from the environment, but exposure to humans also plays an important role. This constant exchange occurs over time and That increases the likelihood that mutations will occur, allowing the pathogen to infect new hosts,'' Anderson said.

When animals are involved in the spread of human diseases, tracking infections becomes more complex, especially since animals often do not show symptoms. The authors recommend that people who are sick, especially those with influenza or COVID-19, avoid close contact with pets. However, for people who have a strong bond with their pet or have a service animal, this is not always possible. In this case, it is recommended to prevent your pet from coming into contact with body fluids such as sneezes or runny noses.

“In both human and veterinary medicine, we have diagnostic tools to track a variety of pathogens, but they are not being used as extensively as necessary to understand the full range of epidemiological trends. We don't always have the resources to make sure that we're doing this, so we need to increase testing, especially among animals.'' Anderson said.

“I think it's important not only to know about human health issues, but also to get a more complete picture of what's actually going on in the environment,” Anderson said.

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