While that might not appear to be a health risk, the dish is one of many places mosquitoes can (and do) lay egg rafts, launching a new generation of little bloodsuckers. When those airborne insects could be carrying West Nile Virus, the dog dish is indeed a dangerous prospect.

"We don't want people to panic," says Kriss Costa, community resource specialist for the Santa Clara County Vector Control District. "But we don't want them to become complacent."

Costa and health officials statewide and nationwide are warning that the risk of being bitten by a mosquito with the virus is higher than ever this year. Steady rain and slightly warmer-than-average temperatures have created the perfect breeding environment for mosquitoes, county vector ecologist Dan Strickman said.

"The set-up is about as bad as it could be," he said. "Although I suppose it could be warmer."

This has led to earlier appearance of West Nile than in the past. A dead bird found in Willow Glen on Jan. 3 tested positive for the virus. Closer to home, three birds found in the Almaden area last month also tested positive. A quail, a Lesser Goldfinch and a blackbird were all found within a 10-day period in the area of Almaden Expressway and Blossom Hill Road. More than one third of the 46 birds that have tested positive for West Nile in the county this year have come from this area.

According to the national Centers for Disease Control and Prevention, there were 2,470 human West Nile cases in the United States last year, resulting in 88 deaths. While fewer than the 10,000 U.S. cases in 2003, when 262 deaths were attributed to the disease, the numbers rose in California last year.

State data from 2004 at westnile.ca.gov shows that 830 people were infected with West Nile Virus that year, 27 of whom died, a sharp increase from three infections in 2003.

Only one human case was confirmed in Santa Clara County last year, but Strickman said that is no reason to be less diligent in preventing the spread of the virus.

"In California, 58 percent of people who got infections had neurological disease," he said, referring to the more serious symptoms such as brain swelling and paralysis.

Even those symptoms that aren't classified as "serious," such as fever, fatigue and muscle weakness, have lasting effects, Costa said.

"It is a very serious disease, and we're finding out that the mild, flu-like symptoms are more serious than we thought," she said.

People who started displaying those symptoms last summer are still feeling ill, she said, which has made some of them unable to work.

Costa also recommends the home use of residual insecticides, which should be sprayed on the exterior of buildings and especially screen doors. Outside, people are urged to wear mosquito repellant with DEET and wear long-sleeved shirts and long pants to prevent bites in the evening hours.

Humans and birds are not the only ones affected. Of the 540 horses in California that had confirmed cases of the virus, 229 reportedly died or were euthanized as a result. There is more than one vaccine available for horses, and equine veterinarians recommend inoculating the animals at least once a year if not every six months.

"It's always a serious threat for horse owners, because it's always pretty darn near fatal when a horse gets it," said John Rosica, president of the Los Gatos Horsemen's Association. "They weren't taking it as seriously last year, but they are this year."

Rosica said that the elimination of standing water is just as important on properties with horses, as large puddles and ponds are very likely to form there. For those ponds that cannot be eliminated, mosquito-eating fish are available from the vector control district.