Some dogs in Casper are sick as… well, dogs.

Area veterinarians and animal hospitals have seen an increase in "kennel cough" this season, possibly due to a mutated strain of the canine virus.

"Kennel cough" - the common name for tracheal bronchitis in dogs - is an illness caused by a combination of a virus (parainfluenza) and two bacterial infections (bordetella and bronchiseptica). Like humans, dogs experience symtoms similar to human bronchitis during the extra-long Wyoming cold and flu season.

Most common in dogs that come in close contact with other dogs, kennel cough earned its nickname by infecting dogs in shelters and boarding kennels. The highly contageous illness can be passed through nasal secretion, contact with items such as food and water bowls, and the air.

"It's always hard to know exactly what illness it is," said Steven Popish, a veterinarian at Popish Veterinary Clinic. "We tend to see different respiratory illnesses every day, just like in humans."

Popish said that kennel cough is often used as a generic term for similar illnesses.

Symptoms include gagging and coughing up phlegm or mucous. Some dogs vomit from the excess phlegm in their bodies. Eventually, the gagging turns into a more severe cough. Popish said dogs often sound like they're choking, but in reality they just have a very dry cough. Swollen lymph nodes and enlarged tonsils also indicate a bronchial infection in dogs.

Popish has noticed an increased number of coughing canine visitors this season, as have other area vets and animal shelters.

Metro Animal Control said a pretty persistent strain of kennel cough has run through the shelter in the last few months. Employees gave infected dogs Amoxycillin and vaccines to fight the disease.

All Creatures Veterinary Hospital representatives said that although they always see kennel cough during this season, they have noticed an increase. Ark Animal Hospital had a group of puppies show up with a particularly vehement strain recently.

And while vets may not have an effective vaccine against new strains of the illness, Popish said pet owners should take action to ensure their canine companions remain healthy.

"Most clinics and shelters go through painstaking vaccines and disinfection to make sure this doesn't get out of control, and for the most part I think we do a good job," Popish said. "But that's the way respiratory bugs work - by mutating and changing every year. So no vaccine can be 100 percent effective."

Popish said epidemics usually occur around holidays, when more people go on vacation and board their pets. He expects the number of cases to go down after Easter.

"People basically need to take a good semaritan approach," Popish said. "It's very similar to day care exposure. If dogs are sick, they should be isolated from other animals and kept mostly quiet."

Popish suggested that kennel cough can generally be treated with simple medication, but if symptoms persist or get worse, dogs should see their veterinarians.

Contact reporter Megan Lee at (307) 266-0589 or megan.lee@trib.com