Dr. Cathy Lund gives Oreo a checkup. Sheila Braddock, of Providence, brought her cat in to be dewormed. Dr. Lund helped plan a conference in Providence last week on diseases passed from animals to humans. Providence Journal photos / Steve Szydlowski

Our pets scratch and bite us. They leave worms, protozoan cysts and ticks in our yards. They expose us to a fearsome range of infections.

And many of us respond by having more pets than ever.

What’s more, many of us are picking up our pets and moving to rural communities, where we, and our pets, are infected with even more diseases transmitted by wildlife.

Diseases spread by animals are called zoonotic diseases, and they comprise most of the serious diseases that have emerged in the last 25 years.

The U.S. Centers for Disease Control says that 75 percent of the recently emerging infectious diseases affecting humans — diseases ranging from West Nile virus to AIDS — are of animal origin.

Such diseases are of such concern to local veterinarians and medical doctors that more than 200 of them from Connecticut, Massachusetts and Rhode Island met with a panel of national experts for a conference in Providence last week. The gathering was described as a first for Rhode Island, and possibly the country.

“Pets, People, & Pathogens — Be a Victor, not a Vector,” was the name of the conference, which attracted a crowd at The Renaissance Hotel Providence. So many more attended than expected, hotel staff had to rush in dozens of extra chairs.

Dr. Peter Karczmar, one of the conference organizers, said concerns are growing about avian influenza, the SARS epidemic and mad cow disease at the same time as people are having increasing contact with pets and domestic animals.

He said that is why he helped organize what he believes was a “unique and unprecedented educational forum.” The original concept arose in talks with Karczmar’s wife, Dr. Cathy Lund, a veterinarian who treats only cats. The couple lives in Providence with four cats.

Experts in zoonotic diseases dispelled some myths and provided new information on diseases associated with animals.

Dr. Michael R. Lappin, a veterinarian with a doctorate in parasitology who is also professor at Colorado State University, said the Centers for Disease Control has announced that, contrary to the advice of many doctors, HIV positive people don’t have to give up their pets.

“Pets make us happy,” said Dr. Lappin. “I know — I have eight.”

Throughout the conference, Dr. Lappin repeated this mantra: “A healthy pet without parasites is a minimal danger to public health.”

Dr. Richard Glew, an infectious-disease expert and professor of medicine at the University of Massachusetts, sought to dispel one person’s concern that growing fears of zoonotic diseases could lead to extreme measures with local wildlife.

Dr. Janet Martin, a veterinarian at Tufts University, said she has become anxious that people will take fears about diseases such as avian influenza and use them to get rid of such animals as resident Canada geese, which many people dislike already.

But Glew said that avian influenza has stricken only people in Asia who live and work with birds.

“Not too many people get out with geese,” he said.

The session fit with a new campaign launched by Dr. Roger Mahr, past president of the American Veterinary Medical Association, called “One Health.”

Mahr has given speeches around the country describing the growth in zoonotic disease and calling for improvements to animal and human health around the world.

Every year in Rhode Island, hundreds of people get Lyme disease. Last year, 61 people were stricken with babesiosis, another disease spread by deer ticks; 117 Rhode Islanders got giardiasis, a parasite spread by animals; and 119 people got salmonellosis, a bacteria often spread by animals. There were 14 cases of cryptosporidiosis, another parasite often found in streams, pools and hot tubs, according to the state Department of Health.

Here are some of the issues the experts focused on.

TICKS

A quarter of the ticks in Rhode Island carry at least two diseases that can harm humans, according to Glew. Ticks used to be a problem only in coastal communities, but now they are endemic far inland.

Dr. Byron L. Blagburn, a professor at Auburn University College of Veterinary Medicine and a researcher of parasite-induced diseases, said ticks are “loathsome” and incredibly adaptable. Regardless of most weather conditions, “They will survive, feed on our animals and transmit diseases.”

The most common disease spread by ticks is Lyme disease. Blagburn said the CDC reported a 40-percent increase in the incidence of Lyme disease in the last several years.

More people are getting Lyme disease, he said, because more people are moving to rural areas, more natural vegetation is being preserved, people frown on widespread use of pesticides and they let their pets roam.

Glew pointed out that deer (which host deer ticks) are exploding in numbers while hunting is declining.

Another problem is that Lyme disease and other diseases transmitted by ticks are “great imitators,” Blagburn said. Symptoms — fever, lack of appetite, lethargy and anemia — are the same as with many other infections.

People need to control ticks on their animals, modify surrounding habitats and follow tick-avoidance strategies, Blagburn said. Doctors, he added, should counsel their patients on how to avoid ticks.

Lappin said the last time he visited Rhode Island, he played a round of golf and couldn’t figure out why the other golfers left their stray golf balls in the woods.

“I left with my pockets filled with balls, and then as I drove down the highway I saw the sign for Lyme [Connecticut] and I suddenly knew why,” Dr. Lappin said. Deer ticks aren’t a problem in Colorado (wood ticks are), but in Rhode Island, deer ticks are especially prevalent in high grass and shrubs.

BITES

Dr. Glew said animal bites account for about 1 percent of all emergency-room visits.

Every year about 1 million people in the nation get bitten by dogs, and about 10 percent of those bites get infected.

About 400,000 people are bitten by cats every year, and some 35 percent of those bites lead to infections.

The reason cats are more infectious is because their bites are deep and narrow, so resulting wounds don’t drain well, according to Glew.

Dog owners always blame their dogs, Blagburn said. Cat owners always blame themselves.

And despite what some people think, it is not a good idea to let pets to lick human wounds.

RABIES

A total of 212 people in Rhode Island were treated with rabies vaccine in the first 11 months of this year, according to preliminary data compiled by the state Department of Health.

Those treated were among a total of 1,014 people who were bitten this year by a staggering array of animals. There were 553 dog bites, 223 cat bites and 159 bat bites.

Two people were reported bitten by ferrets, 1 by a fox, 1 by a guinea pig, 10 by horses, 8 by mice, 3 by rabbits, 9 by rats, 21 by raccoons, 7 by skunks and 10 by squirrels.

“Other” animals bit 7 more people.

Most of the rabies treatments were for people who were bitten by bats, according to the data.

Most rabies is transmitted by bats, according to Glew.

“If you awaken in a room with a bat, don’t let it get away,” Glew said. Because rabies is so often fatal, the protocol calls for vaccinating people who come in contact with any animal suspected of having rabies. If you catch the offending bat, it’s easier to examine the bat for rabies. If it doesn’t have the disease, then no treatment is needed for the person who came in contact with it. If you let it go, your doctor will decide the only safe thing to do is treat you for rabies.

Each rabies shot costs a few hundred dollars, and at least five are needed.

Lappin said that veterinarians should be vaccinated because they treat so many animals. He said one study showed more than 80 percent of veterinarians are vaccinated, but fewer than 20 percent of their technicians have gotten shots.

That shows veterinarians are cheap, Lappin said with a laugh. They should pay to vaccinate their staffs.

PARASITES

In response to a question from a Massachusetts veterinarian who said more and more of his clients are feeding their pets raw meat, Blagburn said raw foods provide a great route for transmitting parasites.

And freezing meat first won’t kill all of the parasites, he said. It is best to cook meat.

CAT SCRATCH DISEASE

Lappin said 12 to 15 percent of cats have this disease. The solution is to get rid of fleas.

“If they have flea dirt, there’s a 30-percent chance they have cat scratch disease,” said Lappin.

He said cats eat most of the fleas they find on themselves.

Blagburn joked that “fleas are nasty, murderous creatures and all should be killed.”

The American Association of Feline Practitioners recommends controlling fleas, avoiding unfamiliar animals, washing wounds carefully, seeking doctors’ care and avoiding kittens.

plord@projo.com