Pets and People Can Share Germs

An In-Depth Look with Dr. Ingrid Pyka

Pug licks face

Not many pet owners realize that the more we interact with our pets, the potential to share germs increases. It’s true: “zoonosis”, a disease of animals transmissible to humans, exists — and happens more often than one would expect.

The Centers for Disease Control and Prevention estimates that 70,000 people get salmonellosis from contact with reptiles in the United States each year. Reptiles, including turtles, lizards, and snakes, can carry germs that make people sick. An estimated 3 percent of households in the United States own at least one reptile.

Zoonosis is certainly not limited to diseases transmitted from reptiles; diseases may be bacterial, viral, protozoal, fungal or parasitic and can spread to us from wildlife, our household pets, and even through the food we eat.

How Is a Zoonotic Disease Spread?

Zoonoses can be transmitted either through direct contact with the infected animal or indirectly via exposure in our shared surroundings.

Many diseases spread by touching a contaminated hand to the mouth or to the delicate mucosal tissues of the nose.

Labrador retriever licks owner's hand

Contracting a zoonotic disease can also be as simple as brushing up against an infected animal, such as one with ringworm. Or, it can have the complexity of needing a specific insect for transmission. Lyme disease uses the deer tick, which carries the bacteria until the tick bites and injects the infection into the next host, whether animal or human.

Some zoonoses rely on the infectious agent sitting dormant in the environment until the appropriate conditions of temperature, moisture, and host vulnerability allow it to reach and infect the new host. Leptospirosis is spread through a wound on the skin, ingestion or contact with water contaminated by urine of infected wildlife.

Who Is At Risk Of Zoonosis?

Anyone exposed to a zoonotic agent can become a victim, but children, elderly and other immunocompromised individuals do have a higher potential of becoming infected.

Zoonotic infections can cause the same symptoms in animals and humans. Giardia, for example, is a commonly shared household infection causing a dreadful case of diarrhea in all afflicted humans, dogs, cats and wildlife.

Other times, individual species will be affected very differently. Roundworms, for example, live in the intestinal tract of the dog and cat. In humans, however, the worm may migrate through the liver or eye, seriously damaging the organs in its unsuccessful path to reproduce.

Common zoonotic diseases include roundworms, ringworm, rabies, Salmonella and Giardia.

Pets and Potentially Zoonotic Diseases

Cat licks his paw

If your pet is diagnosed with an infectious disease, ask your veterinarian if there is a zoonotic potential. Discuss what risks are involved and what specific precautions you and your family may need to take, especially if a family member is immunocompromised or immunosuppressed. Since many of these infections can be readily passed back and forth between pets, remind your veterinarian if you have other pets. They may need treatment as well.

Always follow your veterinarian’s instructions for the treatment protocol. The duration of the therapy is often very important in the success or failure in treating or controlling the infection. Always recheck as recommended in order to assure complete treatment or control.

Some zoonotic diseases such as rabies, Lyme disease and leptospirosis have vaccines available for dogs, cats and other animals.

If you or anyone in you family begins to have any medical symptoms, inform your doctor of the animals in your household and any infections they may have had.

Minimize Your Risks

Much of the safety concerns regarding zoonotic diseases revolve around basic personal hygiene.

  1. Wash your hands after handling an animal.
  2. Wash your hands before eating.
  3. Clean the litter box and yard once or twice daily to keep the parasite load low.
  4. Clearly mark and separate human and pet food containers.
  5. When eating outside, use thick blankets and tablecloths to separate yourself, your food and the utensils from the ground or picnic table.
  6. Enjoy wildlife from a distance and do not let your pets have access to wildlife either.
  7. Maintain your pets’ vaccinations, along with internal and external parasite control as recommended by your veterinarian.

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