Prevent disease transfer between pets, humans

There is no more heartwarming picture than that of a young child holding a new puppy.

The joy and health benefits of pet ownership for the elderly and infirmed also are well documented. Pets provide unconditional love and companionship and help children learn responsibility and compassion.

However, it is important to realize that animals may harbor parasites and other diseases that can be transmitted to humans. This phenomenon, where a disease is transmitted from animal to human, is referred to as zoonosis. Rabies is one of the best-known examples of zoonosis.

The good news is that simple, common sense precautions can prevent these diseases and preserve the special relationship between pets and their people. The people most at risk for developing adverse effects from these zoonotic diseases are young children, the elderly, and immunosuppressed individuals.

Recent examples in the news involved 21 children in Florida who contracted E. coli infections from a local petting zoo and three human transplant patients who died after receiving organs from a single donor who was believed to have contracted the disease from a hamster purchased at a pet store.

Reptiles, as well as animals at petting zoos, can also transmit a bacteria called salmonella, which causes severe gastrointestinal disease.

One common parasite that can affect animals and people is giardia. Most people become infected with giardia either by ingesting the parasite (often from contaminated water) or by direct contact with an infected person. There are strains of giardia that infect only dogs or cats, but there is the potential for dogs and cats to serve as a reservoir for giardia that can infect humans.

Furthermore, dogs and cats can become infected from their human companions and then pass it on to others.

To prevent pets from acquiring the human strains of giardia, keep toilet lids down to prevent animals from drinking from the toilet bowl and make sure that any infected humans wash their hands after using the toilet.

Another preventive measure for pets is to restrict them from drinking from ponds, streams, gutters and other outdoor water sources.

An invisible threat, a pond at a local park can be teeming with giardia, and your dog and you would never recognize the danger that lurks at the surface. It is better to carry a portable bowl and a water bottle to give water to your dog when it gets thirsty.

Keeping dogs away from outdoor water sources will also help to prevent another emerging zoonosis – leptospirosis. Leptospira are bacteria that can cause kidney and liver disease in dogs and people.

According to Dr. Stephanie Lifton, Diplomate ACVIM, a specialist in small animal internal medicine, diagnosis of leptospirosis has been on the rise around the country over the past several years.

“Leptospirosis is transmitted through the urine, so make sure to wash your hands after handling any dog waste,” said Lifton. “In addition, there are new vaccines that can protect dogs from this disease, so talk to your veterinarian to assess the risk of leptospirosis in your pet.”

Two other types of intestinal parasites that can cause illness, particularly in young children, are roundworms (Toxocara) and hookworms (Ancylostoma).

Dogs and cats shed the eggs of these parasites, which develop into larvae either in the environment or in another host. The infective forms of the larvae can be either ingested or, in the case of hookworms, penetrate the skin of accidental hosts, such as humans, where they migrate through the body, eyes, or skin causing disease (called visceral larval migrans or cutaneous larval migrans).

Places where dogs congregate and defecate (parks, sidewalks, etc.) are potential sources of infection for humans, especially for young children who run barefoot in these “hot zone” areas.

Fortunately, decreasing the risk of these infections is fairly easy. It takes several days to weeks for the eggs passed in feces to develop into infective larvae. Therefore, prompt removal of feces from the environment (back yard) and litter boxes is crucial.

If you walk your dog in parks or along city streets, pick up after your dog! Puppies and kittens tend to have the highest worm burdens, so they need to be properly dewormed by your veterinarian.

Most heartworm preventatives now contain anthelmintics (anti-parasitics or wormers) that are effective at controlling the most common zoonotic intestinal parasites as well. When it comes to parasite prevention, it should be noted that the Companion Animal Parasite Council, www.capcvet.org, recommends lifetime, year-round parasite control for all pets regardless of geographic location.

“Veterinarians are increasingly recognized as essential to the public health mission at all levels of public health practice, but I believe that our most effective potential role in preventing human disease is through good preventive veterinary practice,” says Peter Schantz, VMD, Ph.D., of the Centers for Disease Control and Prevention in Atlanta.

Providing timely educational advice to pet owners and administering vaccinations and timely preventive anthelmintic treatments to pets, we can play the role of effective, if unsung, heroes in public health”

Finally, everyone should follow good, basic hygiene. Children should be taught to wash their hands after playing with pets or any type of animal, especially before eating.

Following these simple steps will greatly reduce the risk of acquiring any of these infections and allow us to maintain a mutually healthy relationship between people and pets.