Wild deer add to concerns about disease

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Wild deer add to concerns about disease

Posted at 10:46 p.m. PST Friday, March 16, 2001


Mercury News

In Europe, the grim surveys of foot-and-mouth disease have focused on animals with wool, horns and curly tails. But in California, worried livestock and wildlife watchers are also eyeing a creature with antlers.

Deer can contract and carry the highly contagious viral illness, suffering from its hobbling, wasting effects as badly as farm animals. California has hundreds of thousands of deer, moving freely between wilderness, agricultural regions and semi-urban areas in herds that are difficult to track and all but impossible to quarantine.

``We're very concerned about it,'' said Steve Martarano, spokesman for the California Department of Fish and Game.``If there are any reports of limping deer, we'd be right on it.''

The state, with the nation's largest agricultural economy, has no reported cases of the outbreak. But travelers from England -- origin of the current outbreak -- are facing extra scrutiny at airports, and large California ranches and dairy farms have shut their gates to outsiders as a precaution. The disease already has spread to France and Saudi Arabia.

While the disease has not yet been identified among wild animals in Europe, it was abundant in California deer during one of the state's last major outbreaks, in 1924. More than 2,000 of the 22,000 deer killed during that epidemic showed active or healed lesions from the disease, according to wildlife studies.

Santa Clara County is estimated to have 8 to 10 deer per square mile. In California, an estimated 750,000 deer roam parklands and open spaces near ranches and homes, where well-tended lawns and gardens offer a gourmet menu.

Authorities still note that it is people and not wild animals who are most likely to turn an isolated viral outbreak into a widespread and out-of-control epidemic.

``By far, the most substantial risk is farm-to-farm travel, even if that farm is in England to a farm in California,'' said Steve Lyle, spokesman for the California Department of Food and Agriculture. But because foot-and-mouth disease affects nearly all cloven-footed mammals, authorities worry an outbreak could quickly spread to wildlife. The virus is shed in urine, feces, saliva, milk, semen and even on the breath.

Wildlife could be exposed to the virus directly, from infected livestock, or indirectly, after it has been spread in the countryside by people or vehicles. Ranches tend to border on wildlife areas populated by deer, noted Lyle and wildlife experts. ``You want to get it before it gets into the wildlife population,'' Lyle said.

Control measures such as quarantines may work on farm animals but are impossible against deer, which travel readily from place to place and are very hard to trap.``There are no boundaries for wildlife, as there are for cattle and sheep,'' said Santa Clara County game warden Henry J. Coletto.

The original source of California's last outbreak in 1929 -- infecting animals in 16 of the state's 58 counties -- was thought to be a garbage dump at the former Mare Island Navy Yard used by a docked ship from Asia, according to the 1981 textbook ``Infectious Diseases of Wild Mammals.''

Diagnosis of the disease was made in hogs fed garbage from the Mare Island location in Vallejo, as well as in East Bay dairy herds. But over the next several months, the most serious outbreak emerged in the mountainous and inaccessible rangeland of Tuolumne County. There, the disease appeared in a large herd of cattle on summer range in the Stanislaus National Forest and quickly spread to deer in the forest, according to the textbook.

Deer aren't the only wild animals that are susceptible. Bison, elk and antelope also are vulnerable. Horses do not become sick from infection, but can transmit the virus.

A 1963 review of the disease in African wildlife also identified the disease in at least 29 species, including elephants, yaks, impalas, camels and giraffes. Even hedgehogs were infected during a previous British epidemic. The hedgehogs were found to harbor the virus during hibernation and then transmit it upon awakening in the spring.

With wildlife concerns growing, the disease has taken its toll on Europe's sporting class. France imposed restrictions Wednesday on riding and fox-hunting. Officials urged the public to notify authorities immediately if they spotted any wild animal showing any signs of the ailment.

In Scotland, the national pastime of trout fishing is the latest victim of the foot-and-mouth chaos. With the long-awaited season due to start this week at Loch Lomand and elsewhere, Scottish anglers were urged to stay home to avoid spreading the disease.

And in England's Wiltshire County, security guards have been hired to ensure that no one uses foot trails or bridle paths through open grasslands. In a more desperate bid to halt the spread of disease, military snipers may be let loose to slaughter deer, pigs and other wild animals in parts of England and Scotland, where cases are most concentrated. These marksmen are on standby to shoot in open fields from long range.

But here in California, guns and bows and arrows often aren't welcome in the residential neighborhoods that usually harbor high concentrations of deer.``It would be hard to explain to the general population why we're out there destroying wild populations of animals,'' Coletto said.

``How could you possibly control it?'' he asked. ``It would be difficult, if not impossible.''

Contact Lisa M. Krieger at lkrieger@sjmercury.com or (408) 920-5565. Contact John Woolfolk at (408)278-3410 or jwoolfolk@sjmercury.com.

-- Swissrose (celiier3@mindspring.com), March 17, 2001

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