Ticks on parade: Experts see significant increase in reports on pets

By Cleve Wiese

Published: May 14, 2008

Two consecutive mild winters and a moist spring might have helped bring out a blood-sucking, disease-ridden parasite sooner and in greater number than ever before.
Ticks started turning up last year on pets, particularly dogs, at an alarming rate, said Dr. Erica Vaughn, a veterinarian at the Animal Health Care Center in Waynesboro. Continued warm temperatures have made the pests even more prevalent this year, striking earlier in the season and posing more of a health risk, she said. About 70 percent of animals tested at her clinic for Lyme disease have been exposed to the bacteria, she said. That’s 30 percent more than in the last two years.
“We are seeing a huge influx and it is a concern and we should all be careful of it,” Vaughn said.
Lyme disease is transmitted to humans and pets by the blacklegged tick, also known as the deer tick, said Dr. David Gaines, a public health entomologist with the Virginia Department of Health. Although there have been no studies to document the increase, the species appears to have become more active in Virginia in recent years, he said.
What can be clearly quantified is the rate of Lyme disease in the state: Human infections — which have gone up steadily since 1995, according to Centers for Disease Control statistics – skyrocketed last year, with 588 more cases reported in 2007 than 2006, Vaughn said. That probably means that there are more ticks, more of the bacteria that causes the disease – or both.
Symptoms in humans include fever, fatigue and distinctive, circular skin rashes, according to the Centers for Disease Control Web site. If left untreated, Lyme disease can threaten the heart, joints and nervous system. Infected pets might have a fever and show signs of joint pain.
Pets cannot transmit the disease, Vaughn said, but if a dog has been exposed to an infected tick, there’s a much greater chance its owner has as well.
The Augusta County region is not in the middle of a Lyme disease epidemic, said Dr. Steven Mumbauer, of Waynesboro Pediatrics, but the condition is becoming more common.
“I treated two kids for Lyme disease in the past year,” Mumbauer said. “That’s pretty unheard of in this area.”
The cause of the increase might have less to do with weather than with wildlife and the rapid encroachment of residential development in rural areas, Gaines said. Housing sites carved out of forest or agricultural land actually increase deer populations, he said. Because deer serve as breeding grounds for ticks, that could mean more bites – and possibly more disease – for people living near them.
“If you have 100 acres of forest, that might support two or three deer, but if you take those 100 acres and carve openings into it and let the sunlight in, it will support a whole lot more deer, because the sunlight is able to reach plants that serve as good forage,” Gaines said.
Deer living near homes are also less vulnerable to hunters, he said. 
Development increases the risk of the disease in other ways as well: Blacklegged ticks usually contract Lyme disease during the early stages of their 2-year life span by feeding on white-footed mice, which thrive in residential areas, Gaines said.
Because a variety of rodents proliferate in an undeveloped field or forest, the chances of a tick feeding on one carrying the bacteria that causes Lyme disease are reduced in the wild. But in the edge-land surrounding houses, white-footed mice vastly outnumber other species, so that the number of infected ticks in an area might rise even if the total number of ticks remains fairly constant, Gaines said.
It takes 48 hours for Lyme disease to be transmitted to a human or animal, so people should carefully check themselves and their pets for ticks at least every couple of days, Vaughn said.
“We are seeing more Lyme disease in pets, so there are obviously ticks here that are carrying the disease,” Vaughn said, “and I feel I would be remiss if I didn’t tell people that they are at risk of getting it too.”