PEORIA Ill. (WMBD) — Veterinarians are warning dog owners of a new, mysterious respiratory illness that could be fatal to dogs.

The sickness shows similar symptoms to kennel cough, making it challenging to understand what the cause is.

Symptoms include coughing, sneezing, nasal or eye discharge, and heavy breathing while resting.

Dr. Addison Demanes with Demanes Animal Hospital has treated hundreds of cases of kennel cough in the last year. He said, in the same time frame, he had three cases of the new illness that ended in fatality.

He advises keeping an eye on your dog if it has those symptoms and to reach out if they get worse.

“I don’t want the public freaking out and thinking every eye drainage we see from pets is manifesting this disease. I certainly think it’s worth watching your dog closely for respiratory signs. If they start having difficulty breathing, we will see a lot of dogs that cough, but if they’re sitting there at rest, and they’re struggling to breathe, that is a sign that there is more going on than kennel cough,” said Dr.Demanes.

He said to keep your dog out of contact with other dogs and advises not to bring travel with them this holiday season.