GREENSBORO, NC -- As summer quickly approaches, the dog park can be a perfect place for your four-legged pal to burn off some energy.

But between the wagging tails and wet noses, there's a hidden danger that could potentially be deadly for your pet.

Health officials are issuing a warning to pet owners about dog flu.

The virus has already killed two dogs in North Carolina and experts say it's highly contagious.

Some pet owners in Greensboro are worried about dog flu spreading to the Triad.

Jason Daniels was keeping a close eye on his dog, Bumble, as she played at Lebauer Park Thursday.

“There is just that unconditional love with a dog,” said Daniels. “They're kind of like your best bud right from the first day.”

Dog flu hasn't appeared in the Triad.

But Dr. Janine Oliver, a veterinarian in Greensboro, isn't taking any chances with her dog, Tyrion.

"His chest and abdomen feel good. His chest sounds normal,” said Oliver as she checked her dog for symptoms of dog flu. “His heart sounds normal. He doesn't have a cough."

Oliver says the symptoms of dog flu are a lot like the symptoms of human flu including hacking cough, lack of appetite, lethargy, discharge from the nose or eyes, and fever.

“They feel pain, they feel itch, they feel body aches. They just show it differently,” said Oliver. “You're not going to hear a dog complain like you're going to hear a person complain.”

Oliver says all dogs are at risk catching the dog flu if they're not vaccinated.

If exposed to the virus, Oliver says dogs can be contagious for up to four weeks.

Dog flu is an airborne virus and it spreads through close proximity to infected dogs.

Oliver says a dog park is an ideal place for the virus to spread.

"You've got a lot of dogs who are un-vaccinated in an area where we do have exposure," said Oliver.

Oliver says pet owners should try to limit their dogs’ contact with contaminated items including bowls, leashes, and toys.

80 percent of all dogs exposed to the virus will contract dog flu.

Still, Daniels and Bumble will continue to enjoy their summer.

"She wouldn't let me not come to the park,” Daniels laughed. “She just wouldn't."

The best protection against dog flu is a vaccine.

Oliver says the dog flu vaccine costs between $40-150, depending on your veterinarian.

Dog flu cannot be spread to humans.