January 28, 2020 – Kennel cough is a common respiratory infection of dogs. Although the disease has been recognized for decades, the problem isn’t as straightforward as originally suspected. Canine infectious respiratory disease complex (CIRDC) is the new name for this syndrome – it’s a mouthful but reflects the tangled association between disease-causing organisms and host factors that result in disease.
It can be confusing for dog owners to sift through all the latest information about CIRDC when it comes to treatment and prevention, but here are some facts to help you sort it out.
Many organisms, similar signs
There are many organisms, including viruses and bacteria, that are considered components of CIRDC. A dog could have one or more combinations of these agents at a given time, but clinical signs noted by the owner are the same regardless of the underlying pathogens.
Common signs include:
- Dry cough (sometimes honking)
- Runny nose
- Runny eyes
- Mild lethargy
- Mild decrease in appetite
Although several different organisms can cause CIRDC almost all share one common trait – they’re highly contagious. Any place where dogs come into close contact with each other, including dog parks, doggie day care facilities, kennels and shelters, are fertile ground for transmission.
There are host factors as well that influence the severity of signs when a dog develops CIRDC. Just like in people, the very young and the elderly tend to develop more severe signs. The same holds true for dogs with compromised immune systems, such as dogs with cancer, heart or kidney disease or any other underlying health challenge.
Most dogs recover without treatment
The vast majority of dogs recover from infection without any special treatment, although it’s not unusual for dogs to cough for up to three weeks. There’s no need to worry unless the cough changes from a more dry, unproductive cough to a moist cough, or if there’s a change in attitude or appetite.
Dogs with CIRDC should be kept away from other dogs until they’re completely recovered. In a multidog household, this can be difficult and most likely any housemates have already been exposed to disease-causing organisms.
The usual and unusual suspects
There are a lot of pathogens that can cause upper respiratory signs and they can band together in various combinations to cause disease.
Organisms commonly implicated in causing CIRDC include:
- Bordetella bronchiseptica
- Mycoplasma cynos
- Streptococcus equi subspecies zooepidemicus
- Canine adenovirus 2
- Canine distemper virus
- Canine herpesvirus 1
- Canine influenza virus
- Canine parainfluenza virus
- Canine respiratory coronavirus
Some of these organisms, such as Bordatella bronchiseptica, have been recognized for decades as causes of upper respiratory infections. Others, such as canine influenza virus, are newer pathogens, and it’s likely that we’ll see the discovery of other new viruses and bacteria from spillover diseases or outbreaks. In addition, many of these pathogens have been found in dogs with no signs of respiratory infection leading some to question whether they could be normal inhabitants of the respiratory tract that go rogue and cause clinical signs.
Making the diagnosis
Making a diagnosis of CIRDC starts with the history and physical examination findings. Bloodwork and chest X-rays are rarely needed, except in more severe cases. In order to determine which pathogens are present, more extensive testing will be needed. Experts recommend that additional testing to identify the organisms involved only if a patient:
- Has severe or rapidly progressing signs
- Has signs that last for more than seven to 10 days without improvement
- Is part of an outbreak
Further diagnostic tests require specialized collection and shipping. Your veterinarian can help determine if further testing is needed for your dog.
Treatment of CIRDC
In most cases, dogs will recover on their own with no specific treatment as long as they are bright, alert and maintain a good appetite. Cough suppressants are occasionally used to provide relief, but should not be used in dogs with a productive cough.
More severely affected patients with lethargy, fever, decreased appetite or signs of pneumonia require antibiotics and sometimes hospitalization for supportive care.
The prognosis is good even for dogs with more serious signs unless the patient is debilitated for another reason. However, recovery from illness doesn’t necessarily mean that a patient is immune to further infection.
Prevention of CIRDC
Vaccination is an important way to prevent infection. Many potential pathogens such as canine distemper virus, canine parainfluenza virus and canine adenovirus 2 are covered in the common core vaccines given to dogs over their lifetime. There are also vaccines for canine influenza virus and B. bronchiseptica. It’s important to know that, with the exception of canine distemper virus, the vaccines don’t prevent infection but decrease the severity of signs in patients who become infected.
Avoiding overcrowding and stress within a population are other important control measures. Isolating dogs entering a group housing situation can help keep respiratory infections from spreading.
Morris Animal Foundation is committed to learning more about important diseases affecting dogs, including CIRDC. Learn more about our work with this disease and all our funded studies, as well as how you can help improve the lives of the dogs we love.