(CBS) — A form of bronchitis that’s affecting dogs appears to be on the rise in Chicago and surrounding suburbs, reports Mariam Sobh.

It is commonly referred to as kennel cough but the proper term is acute tracheobronchitis.

“In my ten years in Chicago, this has been largest outbreak we’ve seen,” said Dr. Natalie Marks at Blum Animal Hospital.

Dr. Marks says it’s not just one viral strain, it’s many.

James Miles with the St. Charles Veterinary Clinic says they’ve seen 15 cases in the last two weeks.

Miles says the outbreak could be due to folks boarding their dogs for Spring Break. He says that’s when they can come into contact with other dogs who may have the virus.

The virus has been spreading rapidly at some area doggy daycares to the point where they have had to close down for a few days.

That is not an unusual step to take, says Dr. Brendan McKiernan, director of the Veterinary Teaching Hospital at the University of Illinois Urbana Champaign.

“Just as your kids go to school, kindergarten or something first time of the year, they pass everything back and forth and that is exactly what happens wherever dogs are,” Dr. McKiernan said.

But the virus is now affecting some businesses. Beverly Petrunich, one of the owners of the Near South Side doggy daycare Dogone Fun, told owners not to bring their dogs in and not to expose them to other dogs to help curb the spread.

Petrunich says the move is costing her business thousands of dollars a day, but until a vet gives her the go-ahead to re-open, only one dog remains in her facility.

“Our rule of thumb here always: if it were my dog at home what would I want for my dog and if it were my dog I would want someone to tell me so I would keep my dog home and that’s what we’re doing,” Petrunich said.

Dr. Marks says the only true way to combat the illness is to keep sick dogs away from all other canines for at least a week.

“We feel that it would be nearly impossible to disinfect any facility while you have active dogs there because how contagious this has been,” Dr. Marks said.

Vets say the vaccination for kennel cough, or bordatella, is not foolproof. Dogs can still contract a virus but a vaccination will lessen the severity of the illness.

Experts say they’re not sure what’ causing the outbreak, but it’s common to see clusters every now and then.