In the horror novel, Cujo, a mother and son are terrorized by a rabid St. Bernard during a hot summer in Maine. The fear of bodily injury in addition to potentially contracting a fatal disease strikes to the heart of many people. But, is rabies the only disease that our pets might spread? Is there truth to news reports of pets giving resistant staph infections to their owners?

A disease that can be spread from animals to people is known as a zoonotic disease. Rabies is the best known and perhaps the oldest known zoonotic disease. Ancient Greek and Babylonian scrolls both describe this killer. Rabies is a disease of mammals and until the second half of the 20th century, dogs and cats were the most common source for spreading rabies to people. Strict vaccination protocols have diminished the threat from our pets in the Western World, but more than 40,000 human deaths still occur worldwide due to rabies.

Rabies is an example of a viral zoonotic disease, but bacteria are also common agents, including the so-called “superbug”, MRSA. These letters stand for Methicillin resistant Staphylococcus aureus and refer to a species of bacteria commonly found on human skin. In rare cases, death has occurred from infection with MRSA. While it seems pets can harbor these bacteria as well, there has not been a strong correlation showing transmission from pets to people.

Leptospirosis is another bacterium that has the potential to infect humans as well as our pets. More than 200 species of leptospira exist, often living in damp soils, mud, or even fresh water. Leptospirosis is characterized by fever, chills, headaches, and has the potential to cause kidney failure. Fortunately, good vaccine protocols have minimized this disease in the US, Canada, and Europe, although Leptospirosis is still considered to be wide-spread throughout the rest of the world.

Likewise, Salmonella, another soil dwelling bacterium, can cause severe illness in humans. Salmonella is often associated with reptiles, but any pet with diarrhea could potentially spread Salmonella to an owner. Horse owners who spread the manure in vegetable gardens might be at risk for Salmonella, as well as anyone who drinks from groundwater that is contaminated with horse manure run-off.

Parasites have evolved to co-exist with their host species, but when they find their way into a different host, the consequences can be deadly. The common roundworms that are found in almost all puppies and kittens have been known to cause organ failure, blindness and seizures when humans contract them. The Centers for Disease Control (CDC) estimate that more than 10,000 people in the US test positive for roundworms annually and more than 750 will partially lose their vision. Similarly, raccoon roundworms are a concern. As humans move into formerly wooded areas and raccoons adapt to tolerate an urban lifestyle, infection with this parasite may become more common. Unlike the more ordinary canine roundworms, raccoon roundworms have been known to cause death in humans.

But far and above the illnesses and sickness that can be caused by our pets is the potential for trauma. Dog bites, cat scratches and horse-related injuries are all much more frequent than the above mentioned diseases and parasites. The CDC reports that more than 4 million people are bitten by dogs annually and that about 800,000 seek medical attention.

Thankfully, almost all of the diseases and injuries that are associated with our pets can be easily prevented. The routine vaccination of our pets has diminished human fatalities due to rabies to only 1 or 2 unfortunate cases per year, usually due to rabid bats. Likewise, human cases of Leptospirosis in the US are reported to be less than 200 annually. Routine hand-washing is the most effective means to reduce contamination with either Salmonella or Staphylococcus bacteria. It will also help to minimize exposure to intestinal parasites, such as roundworms.

Teach children to respect and avoid unknown dogs and other animals. With proper education and guidance, many can learn to avoid a dog bite or serious injury from a horse or other animal.

Above all, spend time with and speak to your veterinarian. Your veterinarian is the best resource for understanding zoonotic diseases and how best to avoid them. Don’t allow unfounded fears to dictate your happiness with your four-legged friend. Educate yourself and learn from the source who knows you and your pet best…your family veterinarian!