Zoonotic Diseases in Dogs

Dogs can carry over a dozen forms of zoonotic, or human-transmissible, diseases. While the Centers for Disease Control note that pet ownership can provide several health benefits, dog owners are at risk of contracting zoonotic disease if they do not practice appropriate hygiene and disease-control measures. Most pet owners are unlikely to contract zoonotic diseases from their dogs; however, some groups are at a higher risk than others. People who are at highest risk of contracting zoonotic diseases include cancer patients, young children and people whose immune systems are compromised by HIV/AIDS.

  1. Common Infections

    • Some zoonotic diseases are fairly common in dogs, while others are exceedingly rare. Campylobacter, a form of bacteria found in dog stool, can cause gastrointestinal infections in humans. This is most commonly spread when pet owners fail to wash their hands thoroughly after handling dog feces. In developing nations, campylobacter may contaminate water-supplies, leading to human infection.
      Another common disease, ringworm, is a mild skin infection caused by a fungus (not a worm). Though ringworm is most commonly seen in pet owners, it can also spread through human hosts who share personal items like hairbrushes and towels. Puppies are more likely to spread ringworm than adult dogs.

    Diseases Spread by Fleas and Ticks

    • Fleas and ticks can cause problems far more severe than itching and discomfort--they are responsible for some of the most deadly zoonotic diseases found in dogs and cats. Tickborne and fleaborne illnesses cannot spread directly from a pet to a human, but dogs with fleas and ticks are likely to spread infected parasites to their owners.
      Rocky Mountain Spotted Fever and Lyme disease are relatively common bacterial infections that are spread from dogs to humans (and vice versa) through ticks. These diseases can be debilitating and even deadly. Additionally, dipylidium (tapeworm) infection can be spread when humans accidentally ingest fleas that contain tapeworm eggs.

    Intestinal Parasites

    • In addition to tapeworm, many other forms of intestinal parasite can spread from dogs to humans. Hookworm and roundworm are both zoonotic infections that can be spread through the improper handling of contaminated dog feces. Several species of these parasites can thrive in the colons of both humans and dogs.
      Hookworm and roundworm can both be spread through the accidental ingestion of dog feces that is contaminated with parasite eggs or larvae. This can occur through improper handling of waste, and people may become infected by walking barefoot on soil that has been contaminated with infected dog feces. Children are at highest risk of contracting these parasitic infections.

    Rare Zoonotic Diseases

    • Some zoonotic diseases in dogs are only rarely trasmitted to human hosts. Brucellosis salmonella and giardia are both relatively severe infections, but they are not commonly passed between dogs and humans in the United States. These diseases are generally prevented through proper hygeine measures.
      Rabies, another infamous zoonotic disease, has been nearly eliminated in pet dogs in the United States, thanks to the common use of the rabies vaccine. Leishmania is also rare in the developed world, but these diseases remain somewhat common in non-industrialized countries.

    Prevention and Control

    • Fortunately for dog owners, it is extremely unlikely that a healthy individual will contract an illness from simply petting or handling a dog. To prevent the spread of zoonotic disease, the Centers for Disease Control recommend that pet owners wash their hands with soap and water after touching dog feces or saliva. High-risk and immunocompromised people must be especially cautious about personal hygiene.
      Pets are less likely to carry zoonotic diseases if they are in good overall health. A sanitary environment is the key to avoiding infectious diseases in both humans and pets. Additionally, exercise and a healthy diet--for both pets and owners--can help to boost immune defenses against zoonotic disease.