Why December Is Flu and Respiratory Illness Season for Pets

As colder weather settles over Whatcom County and families spend more time indoors, veterinarians are warning that December marks a peak season for respiratory illnesses in pets.

Whatcom Veterinary Hospital says cases of canine influenza, kennel cough and other respiratory infections often rise during the holiday period, driven by increased boarding, indoor gatherings and reduced ventilation in homes and pet facilities.

“Keeping your pets vaccinated for the most common illnesses like kennel cough, distemper and parvovirus is the most effective way to protect your pets against contagious illnesses that can be passed along in social situations and boarding facilities,” Whatcom Veterinary Hospital says.

More Indoor Time Increases Exposure
During winter months, pets spend far more time inside, where airborne illnesses spread more easily. Close contact with other animals at dog parks, grooming appointments, daycare centers or boarding facilities increases the risk of transmission, especially in environments with limited airflow.

Boarding and Travel Play a Major Role
With many families traveling in December, kennels across Whatcom County see a surge in reservations. Whatcom Veterinary Hospital says this is one of the leading contributors to the seasonal rise in respiratory cases. Even well-managed facilities cannot eliminate all airborne pathogens, making vaccination an important preventive step for pets staying away from home.

Cold, Damp Weather Impacts Pet Immunity
The Pacific Northwest’s signature winter climate—cold, wet and unpredictable—can weaken pets’ immune systems. Dogs and cats exposed to chilly temperatures, drafts or prolonged dampness may be more susceptible to developing coughs, congestion or secondary infections.

Whatcom Veterinary Hospital notes that short-haired breeds, senior pets and those with chronic health issues are especially vulnerable during December.

Common Symptoms to Watch For
Pet owners are encouraged to monitor for signs of respiratory illness, which may include:
— Persistent coughing or gagging
— Sneezing or nasal discharge
— Low energy or lethargy
— Loss of appetite
— Fever
— Difficulty breathing

Most respiratory infections are treatable, but early intervention prevents complications and reduces the chance of spreading illness to other animals.

Vaccination and Prevention
Veterinarians recommend ensuring pets are up to date on core vaccines and, when appropriate, receiving additional protection such as the canine influenza and Bordetella vaccines. These vaccinations are often required for boarding but are also helpful for pets that regularly socialize with others.

Maintaining clean bedding, improving indoor ventilation and avoiding exposure to sick animals can further reduce risk.