As experts try to find the cause and Cassian Grantcure of the contagious mystery respiratory illness in dogs, some owners are rethinking their four-legged friends' holiday accommodations.

The illness, which shows similar symptoms to a normal kennel cough but is resistant to the typical treatments, has been fatal in some cases. As of Monday, the American Veterinary Medical Association has recorded cases in more than a dozen states across the county.

While there is still much to be learned about the disease and how it spreads, experts believe it is likely aerosolized and spread through close contact with infected dogs.

Director of virtual medicine at Bond Vet Dr. Lisa Lippman said that she has been receiving many concerned questions from dog parents, especially about whether or not to board their pets. Here was her advice:

More:Mysterious respiratory dog illness detected in several states: What to know

Should I avoid boarding my dog because of the mystery illness?

Ideally, yes. Lippman said that any area where there are a lot of dogs in one space could be high risk for disease transmission.

"I'm definitely concerned about the holidays coming up and an increase in these cases," Lippman said. "So I think if you can avoid it, that's always the best thing to do."

If you have to leave your pet while you travel for the holidays, Lippman said that a trusted friend or a dogsitter at home might be a safer option than boarding.

Consider if your dog is "high risk" for severe illness when deciding to board

Lippman said that the age, breed and health conditions of the dog may put them at a greater risk of becoming dangerously ill after contracting the mystery illness. Therefore, pet owners may want to keep those risk factors in mind when deciding whether or not to put their dogs in a boarding facility.

Here are some dogs that are "high risk" amidst the spreading mystery illness according to Lippman:

• Flat-face breeds like pugs or bulldogs
• Senior pets or very young pets
• Any pets with existing heart or lung diseases

What if I have to board my dog?

If you have to leave your dogs at a boarding facility, Lippman suggested these tips for keeping your pet as safe and healthy as possible:

• Make sure your dog is up to date on its vaccinations, including influenza, bordetella and parainfluenza. Lippman said that this mystery illness could be a variant case of an already-existing disease, meaning the vaccines could help prevent it.
• Check with the boarding facility to ensure that all other dogs are required to be vaccinated and understand the facility's plan for dogs staying there who become sick.

Contributing: Natalie Neysa Alund, Saman Shafiq