In our society, most pets live in their owners' homes. They share furniture — and sometimes even beds and eating utensils — with their owners. They play with the children and may lick their hands and faces.
This bond with your dog or cat is wonderful. But have you considered that there are diseases that can be spread from pets to people? The list includes those caused by roundworms and hookworms.
Roundworms are common intestinal parasites of dogs and cats and are highly infectious to people. Almost every puppy and kitten has roundworms. There are four ways an animal may be exposed — in utero, nursing, eating prey, or ingesting a worm egg from the environment (such as during grooming). Even if pets are dewormed later, some of these parasites hide dormant in their bodies and become active again during pregnancy to infect the next generation.
Infected pets contaminate their surroundings quickly. A single canine roundworm can produce up to 85,000 eggs a day. The eggs are passed from the dog's or cat's stool to the environment. Pets and people become infected when these eggs are eaten. Worm eggs are commonly found in the soil at playgrounds, parks and even some backyards. A recent New England study revealed that more than 25 percent of playground soil samples are contaminated with roundworm eggs. The eggs remain infective for years, and do not die during the cold winter or hot summer months.
Infected dogs and cats may have various clinical signs, including a pot-bellied appearance, failure to thrive, poor hair coat, vomiting and diarrhea. Some pets don't exhibit any symptoms, but they are still shedding roundworm eggs.
People can acquire roundworms from pets. The disease in humans is called visceral larval migrans, and it is most common in children. There are about 10,000 infections each year. During visceral larval migrans, immature worms travel through the human body. They may take up residence anywhere inside the body, but common locations are the lung, brain, liver and eye. Clinical signs depend on the site of infection, and can include asthma, abdominal pain, seizures and blindness. Sometimes people don't show any symptoms. The Centers for Disease Control and Prevention reports that more than 700 children lose some vision (called ocular larval migrans) every year due to pet roundworms.
Hookworms are another common intestinal parasite of dogs and cats. Infections occur when larvae are ingested. Hookworm larvae in the environment may also penetrate the skin, often around the footpads, then migrate into the animal.
Dog and cat hookworms may cause disease in people. Warm, sandy beaches are ideal hookworm environments, putting barefooted beach-goers at risk. The parasite enters human skin, but is unable to penetrate deeper because people are not the worm's intended host. The result is intensely itchy, linear, eruptive lesions called cutaneous larval migrans.
If you are concerned that you or your child may have been exposed to pet roundworms or hookworms, consult your physician.
How can you reduce your family's risk of getting pet roundworms and hookworms?
First, have your veterinarian perform routine fecal examinations on your pet. A diagnosis is made when worm eggs are examined under the microscope. Unfortunately, this test may produce false negative results if the parasites are not shedding eggs at the time the stool is collected for analysis. Puppies and kittens should have two to four fecal examinations in their first year; adult dogs and cats, one or two annually.
Second, regularly deworm your pet. Puppies and kittens should be medicated every two weeks for several treatments, then placed on lifelong monthly roundworm and hookworm prevention (often available in combination with many common heartworm preventives). Your veterinarian can help you.
Third, practice good hygiene. Collect and dispose of your pet's stool promptly. Obey leash laws and keep dogs away from children's playgrounds. Wash your hands and your children's hands frequently when playing outdoors or with pets. Do not walk barefoot in dirt or sand.
Last month during school break, I was at a busy local playground with my two small children. A woman was walking with her puppy around the mulched area for more than an hour. I wondered if she had any idea of the risk she was imposing on the dozens of children who use this playground. With a few simple precautions, pets can be an incredibly enjoyable experience for everyone.
If you are interested in more information, the CDC (www.cdc.gov/healthypets) and the Companion Animal Parasite Council (www.petsandparasites.org) are terrific resources.
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Dr. Heidi Bassler is medical director of the Veterinary Center of Greater Newburyport. Do you have questions for Dr. Bassler? Send them to ndn@newburyportnews.com.
