As the COVID-19 restrictions lift and cases continue to diminish, people are joyfully taking to the skies (or roads) for long-overdue travel and vacation. This is especially true now that the holidays are upon us – but frequently pets are not included in the holiday plans.  As the boarding facilities hit capacity, it becomes much easier for bacterial and viral diseases to spread.

As you sit on an airplane loaded with holiday travelers who may or may not be carrying a virus, so too will Fluffy be in close contact with other pets who may or may not be harboring germs of their own. 

I’d like to preface by saying that our local boarding institutions do a very good job of keeping their charges safe, and the facilities are as clean as possible.

I take my own two dogs to a local daycare, and have always been extremely pleased with their services. The socialization and wonderful care they provide is worth the chance that my dogs may pick up a respiratory infection.   

Like kids in school, boarding dogs and cats may come home to you with snotty noses or a cough.

How much do you need to worry? Let’s review some of the common upper respiratory infections we see in dogs and cats.  

Canine Respiratory Disease Complex:

Also known colloquially as “kennel cough” or infectious tracheobronchitis.

This disease is most often caused by the bacteria Bordetella bronchiseptica, Mycoplasma, Strep equi zooepidemicus, and the Parainfluenza and Adenovirus-2 viruses, among others.

This disease complex is very common and very contagious, though the disease it produces is typically not severe.  

Dogs do not have to be at a kennel to acquire this disease; they can get it from exposure in any location – even just walking around your block.

Dogs who acquire “kennel cough” typically have a dry, retching cough that can be mild or severe. Sometimes they will even produce white mucus-y foam at the end of a coughing fit.

They are otherwise happy, energetic dogs who are eating well and don’t seem too bothered by their own coughing and retching. Untreated, it will resolve on its own within a few weeks.

A PCR test is available to determine the causative agent of your dog’s symptoms. Veterinarians may prescribe an antibiotic, such as Doxycycline, if a bacterial agent is identified.

A cough suppressant may also be prescribed.  

Canine Influenza Virus (CIV): This causes a highly contagious infection that is typically much more severe than your run-of-the-mill “kennel cough.”

Currently in the United States, CIV infection in dogs is usually caused by the Influenza-A subtype H3N2. Dogs can also be infected with other types of influenza viruses but this is less common.

CIV infections in the United States tend to be sporadic, leading to regional outbreaks, such as the outbreak that swept through Los Angeles in 2021.   

CIV infection causes mild to severe symptoms, typically consisting of coughing, fever, loss of appetite, and lethargy. Sneezing and eye discharge may also be noted.

Treatment is supportive, and may include antibiotics for secondary infections, appetite support, and fluid therapy. Dogs will typically recover in 1-2 weeks, but there is a small mortality rate of 1-2%.   

Feline Respiratory Disease Complex : Most causes of upper respiratory disease in cats are caused by Feline Herpes Virus-1, Calicivirus, Mycoplasma, Bordetella, and Chlamydia felis.

Since the majority of our household cats have been adopted from shelters, it is reasonable to assume that many of them have been exposed to one or more of these diseases already by the time they arrive in their new home.

Upper respiratory disease in cats typically presents with sneezing, nasal discharge and stertor (or stuffy nose breathing). They may also have conjunctivitis, eye discharge, and loss of appetite.

Often these symptoms will resolve on their own within a few weeks, but on occasion a cat might develop chronic sneezing, snuffling, or eye discharge.

In this case, your veterinarian might treat with antibiotics, anti-virals, or topical eye drops. There is a PCR test that can be used to determine the causative agent of your cat’s symptoms.      


You know what they say about an ounce of prevention. We don’t even need an ounce – we just need about 1 milliliter (the volume of a typical vaccine).

The best way to prevent these diseases is to vaccinate when able, and to limit exposure. There are very effective canine vaccines for Bordetella, Adenovirus-2, and Parainfluenza — which are all considered core immunizations.

There is a vaccine for Canine Influenza virus H3N2/H3N8, but it is currently in short supply and may soon be on national backorder.

 For cats, the combo vaccine FVRCP will protect against Feline Herpes-1 and Calicivirus, among others. 

Although limiting exposure to these diseases is wonderful in theory, sometimes pets need to be boarded (and dogs especially enjoy being social). Make sure you contact your boarding facility ahead of time and determine what vaccines are needed, and whether your pet is a good fit for their services.

Happy pawlidays and safe travels! 

Dr. Hilary Quinn is a small animal veterinarian in Santa Barbara. She owns and operates Wilder Animal Hospital, and shares her own home with three humans (her husband and two kids) as well as two rowdy dogs, a very calm kitty, two fish, and six chickens. Contact her at