Three of the dogs died, state veterinarian Martha Littlefield said Friday. They had symptoms that included seizures, trouble walking, "stargazing," and flinching at a gentle touch.

The virus may not have caused the disease, but veterinarians should consider West Nile as a possible cause of brain or central nervous system trouble in dogs, Littlefield said.

Mostly spread through mosquito bites, West Nile virus has infected 2,768 people in 34 states and Washington, D.C. so far this year and killed 146 people, the federal Centers for Disease Control and Prevention said.

It has also infected more than 110 species of birds, including the bald eagle and the endangered Mississippi sandhill crane. Horses have also been susceptible. The American Veterinary Medical Association has estimated at least 40 percent of the horses infected with West Nile during a 1999 outbreak died.

But the disease has been rarer in dogs and cats. Officials at the University of Illinois at Urbana-Champaign reported last month the deaths of a 3-month-old wolf and an 8-year-old dog were linked to West Nile.

The American Veterinary Medical Association's Web site reported three cats who died in 1999 and 2000 were believed to be infected.

"The biggest thing right now is that so many people have been told it's not a big deal in dogs, so a lot of veterinarians don't look for it," Littlefield said.

None of the dogs in Louisiana was old or otherwise ill, she said.

The youngest was a 5-month-old German shepherd. The oldest, a 6-year-old Dalmatian, has recovered.