Veterinary Acronym of the Month: CIRDC

Canine Infectious Respiratory Disease Complex - Coughing Up Trouble

What is CIRDC?

CIRDC stands for Canine Infectious Respiratory Disease Complex. To break it down, its an encompassing term for lung illness in dogs that can include viruses, bacteria, or a combination of both. The truth is, most dogs become infected with one pathogen (a disease causing agent, such as a virus or bacteria) which causes damage to the respiratory tract and makes it easier for a second infection to come into play. These pathogens are usually airborne, meaning they're spread through droplets in the breath between dogs in close contact. When we think about how much dogs pant and bark, it's easy to understand why this disease complex can spread so quickly between them.

A more commonly used phrase is "kennel cough" but we're trying to move away from that terminology due to the fact that it is most notably related to Bordetella bronchiseptica, which is only one bacteria that causes respiratory disease in dogs. While Bordetella is included in the list of pathogens known to make up CIRDC, there are 9 total pathogens that we blame for causing disease. These include 6 viruses (canine parainfluenza virus, canine adenovirus type 2, canine influenza virus (subtypes H3N2 and H3N8), canine respiratory coronavirus, canine herpesvirus-1, canine distemper virus) and 3 bacteria (Bordetella bronchiseptica, Mycoplasma sp, Streptococcus equis subspecies zooepidemicus).

What are the clinical signs of CIRDC and can it be treated?

The most common clinical sign of CIRDC is a honking cough that typically lasts anywhere from 1-2 weeks. Usually, this disease is self-limiting and resolves on its own without treatment. For dogs who do not seem to be improving, or who have a fever, become lethargic, have a decreased appetite, or any other signs of illness, antibiotics are sometimes necessary. While the antibiotics do not treat viral infections, they do help reduce secondary bacterial infections that occur (remember above where I mentioned those viruses damage the lungs and let in secondary pathogens? This is where things can get complicated!).

For dogs who don't improve on their own, I often recommend a respiratory panel. This is a swab of the throat and conjunctiva (that pink part by the eye) that is submitted to the lab. They work their science on that swab to see what pathogens are present. If a bacteria is identified, they'll even culture it to tell us exactly which antibiotics will treat it. Knowing what is growing helps veterinarians determine what type of treatment may be necessary as well as guide prognosis for your pet.

For viral infections, we don't have great treatment options available. Like in humans, anti-viral medications come with a hefty list of potential side effects and some doctors question their efficacy. Typically we focus on supportive care which can include appetite stimulation for those not eating and cough suppressants where necessary. For severe cases, some pets require hospitalization with oxygen therapy and monitoring.

Who gets CIRDC?

Any dog is susceptible to infection. Dogs who are around other dogs frequently will have an increased risk. This includes dogs who go to daycare, boarding, grooming, and dog parks. Let's be honest - if you have a dog coming to visit me regularly, be it for nail trims or routine management of care, they're at an increased risk too! Sure, we disinfect everything, just like the other facilities mentioned, but these are airborne pathogens we're talking about! Even avoiding face-to-face contact isn't entirely protective. Oh, and it's not just dogs. Wild canids, such as foxes and coyote, can also carry these pathogens and expose your pet.

How can we prevent CIRDC?

That last section was a bummer. So I'm telling you any dog near other dogs can become infected? Yes. But this doesn't mean your dog needs to live in a bubble. Fortunately, for a majority of these pathogens, we have a vaccine! Every hospital carries different vaccinations and I strongly encourage you to discuss your pet's level of risk to come up with the best plan for them. At RAVH, we carry vaccines to cover canine parainfluenza virus, canine adenovirus type 2, canine influenza virus H3N8/H3N2, canine herpesvirus-1, canine distemper virus, and Bordetella bronchiseptica. That is 6 of the 9 pathogens we worry about! For the remaining 3, effective vaccines have not yet been produced. If your pet is at high risk (does any of the activities mentioned above) we strongly recommend vaccinating them so they're protected from a majority of the pathogens and therefor less likely to get secondary infections with the others.

Finally, if your pet is showing any clinical signs, it is important to keep them home! We can't tell them to cover their mouths and we all know they love to be up close and personal. Don't allow your pet into contact with other dogs for 2 weeks after clinical signs have disappeared to prevent spreading the disease even further.

Why do we care about CIRDC?

As discussed above, most dogs effected by CIRDC will clear the infection on their own in 7-10 days, but this isn't the case for everyone. For example, canine distemper virus is extremely virulent (it spreads very quickly) and results in death for a majority of dogs who become ill from it. Since all of these pathogens weaken the immune system in the respiratory tract, secondary infections are common and can be very severe. For this reason, it is important to vaccinate our pets based off of their exposure and lifestyle and also seek veterinary care when they show signs of illness.

It should be noted that there are documented cases of Bordetella bronchiseptica being zoonotic, meaning it spreads between people and animals. More specifically, there are a few cases where it has been documented to have spread from dogs to cause disease in people*. For this reason, it is recommended that those who are immune-compromised not be the primary caretaker of sick pets, when feasible.

Final Thoughts

CIRDC is a term used to describe a disease process of the respiratory tract in dogs caused by any individual or combination of 9 different pathogens, both viral and bacterial. These pathogens are spread between dogs in close contact, through water droplets in the breath. The most common clinical sign includes a hacking cough that typically resolves in 1-2 weeks. In some cases, the signs of illness do not resolve and can progress to death without treatment from a veterinarian. Vaccines do exist for a majority of the CIRDC pathogens and should be utilized based off of your pet's lifestyle and risk. Finally, Bordetella bronchiseptica has been (infrequently) documented to pass from dogs to humans, so prompt identification and management of this disease is essential for both pets and owners.

Still have questions? We have answers. And if we don't, we know how to find them! Give us a call to schedule an appointment 607-656-4285 or send us an email at info@romanacresvet.com

* Woolfrey BF, Moody JA. Human infections associated with Bordetella bronchiseptica. Clin Microbiol Rev. 1991 Jul;4(3):243-55. doi: 10.1128/CMR.4.3.243. PMID: 1889042; PMCID: PMC358197.