By Jessica Wiant -- Daily Staff Writer

Nice fall walks through autumn leaves, an afternoon playing with a Frisbee disc in the backyard — these are some of man's best friend's favorite activities, but they can also be dangerous for four-legged family members.

As it has in humans, Lyme disease has become a more common diagnosis at veterinarians' offices, says Dr. R. Marcelo Melivilu of Linden Heights Animal Hospital in Winchester.

"We are getting more and more dogs that are Lyme positive," Melivilu says.

While it could be a result of more testing, Lyme disease is being found in more dogs, and often in dogs that don't show symptoms, he says. Just because there aren't any symptoms, however, doesn't mean the dogs do not feel pain.

Veterinarians' offices can offer a vaccine against Lyme disease, he says, but different veterinarians have different policies on how often it is given.

A Lyme disease brochure at Linden Heights recommends an annual Lyme vaccination, but the vaccine is controversial.

The Veterinary Information Network, a resource for veterinarians, says there is debate about both whether dogs should have the vaccine, as well as how effective it is.

The better solution, according to VIN and Melivilu, is tick prevention.

Melivilu promotes once-monthly prevention year-round.

"It's better prevention than treatment," he says. "You know we are seeing mosquitoes, especially ticks, all year round.

"You don't want fleas, you don't want ticks."

And, you don't want mosquitoes either. While Advantix flea medicine claims to prevent mosquitoes, mosquitoes are harder to control, according to Melivilu.

With dogs, the biggest threat from mosquitoes is heartworm, he says.

Infected mosquitoes transmit larvae to dogs through bites, and the larvae eventually migrate to the pulmonary arteries where they grow, according to Melivilu.

Heartworm pills once per month do not prevent mosquito bites or the transmission of the larvae throughout the month, but rather they kill any larvae that might be in the dog at the time the pill is given, according to Melivilu.

By giving the dog a pill each month, heartworm will never have a chance to fully develop, since it takes several months for that to happen, according to Melivilu.