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What are Zoonotic Diseases?

Written by Anna Hollisey


Cavalier King Charles Spaniel feeling under the weather

Zoonoses are diseases which can be transmitted between animals and humans. Rabies, Ebola, and Salmonellosis are the most well-known examples of zoonoses. 

Like many animals, dogs carry pathogens which they pick up from other dogs, people, infected water, or food. Some of these don’t affect dogs. Others affect humans, and some can affect dogs as well as humans – they’re the ones which cause zoonotic diseases.

According to the World Health Organization, there are currently around 200 known zoonoses. Like SARS, COVID-19 is a zoonotic disease, although it is believed to have very mild effects on animals.

Birds and mammals are the main carriers of zoonotic diseases. Respiratory viruses have the greatest potential for causing human pandemic: influenza and coronaviruses are known for “jumping” between animals and humans. Most human versions of influenza have come from poultry or water birds, while coronaviruses seem to come from large populations of bats, rodents, or animals which cohabit with humans.

Have our dogs surged the spread of COVID? Because animal origins were suspected, people began to wonder whether our domestic pets were transferring the disease. All over the world, researchers tested dogs to see how many of them were carrying COVID – the results ranged from 7.5% (Austria) to 54% (North America). But nobody could find a correlation between dog-ownership and the risk of catching COVID-19. In fact, one team of researchers concluded that being exposed to small doses of COVID-19 may have increased dog owners’ immunity.

One thing which prevents zoonotic diseases from spreading easily is the fact that humans have little contact with most wild animals. But our domestic dogs can carry and increase the spread of several groups of viruses, worsening the potential for a pandemic.

Zoonoses can be transmitted through contact with:

  • Saliva (airborne or contact)
  • Blood, urine, or faeces
  • Bedding and food dishes
  • Insects (including fleas)
  • Contaminated food or water.

At home, we can take some measures to prevent animals from passing diseases to family members:

  • Handwashing, especially after playing with pets
  • Keeping our dogs protected against parasites like fleas and ticks
  • Preparing, handling, and storing food safely – especially foods with known risk of contamination
  • Avoiding contact with wild animals.

What is currently being done on a global scale to tackle the problem of zoonoses?

In the wild, it is very difficult to manage zoonoses – since that would involve testing millions of animals for every type of virus. According to Science journal, live animal markets have been identified as a high risk for transmission of zoonoses Author Edward Holmes recommended that surveillance and testing should be increased in order to discover zoonoses in people who are working at these markets, and that handling protocol and physical distancing should be improved.

Further Reading

Find out if your dog’s mouth is as clean as you think it is/learn/dog-health/are-dogs-mouths-cleaner-than-human-mouths. Can your dog catch your cold?/learn/dog-health/can-my-dog-catch-a-cold Even if they do pass us some germs, we still think having a dog has loads of awesome benefits/learn/dog-lifestyle/how-do-dogs-help-humans (and science agrees).