83 | The top 3 things every vet nurse needs to know about caring for kennel cough

PodcastInfectious diseaseRespiratory Disease
Written By Laura Jones

Today we’re talking all things CIRDC - canine infectious respiratory disease complex - or to use its old name, “kennel cough”.

 

We see these patients super commonly - but it’s not always a case of ‘just’ a bit of kennel cough. That name undersells how complex, contagious (and at times serious) this disease can be.

In this episode, we’re going to look at what CIRDC actually is, the different pathogens that can cause it, and the signs we see in patients with it - as well as the nursing care these patients need, and the skills we can use when delivering that care.

So if you’re ready to give even better care to these patients, let’s get started.

First things first - what is Canine Infectious Respiratory Disease Complex (CIRDC?)

Well, the first thing to say is this - it’s a syndrome, not a disease in itself. It’s kind of like FLUTD or cat ‘flu in cats - oversimplified by the title, but with a lot of different infections and conditions involved.

Patients with CIRDC can have a variety of different infectious agents - each with similar and in some cases overlapping signs, which often work together to overwhelm the host and cause disease.

These pathogens include: 

  • Bordetella bronchiseptica - the bacteria we think of in kennel cough cases

  • Canine parainfluenza virus (CPiV) - which is common, usually causes mild signs when present on its own, and is a virus we vaccinate against

  • Canine adenovirus type 2 (CAV2) - which is less common than parainfluenza virus, but causes quite marked inflammation of the respiratory tract

  • Canine herpesvirus type 1 (CHV1)

  • Canine respiratory coronavirus (CRCoV) - as we discussed in episode 78 on FIP, there are lots of different coronaviruses out there, and some cause respiratory disease, whereas others (like FCoV) cause GI signs

  • Canine pneumovirus (CPnV)

  • Canine distemper virus (CDV) - as we discussed in episode 82

  • Canine retroviruses types 1, 2 and 3

  • And canine influenza virus - specifically strains H3N8 and H3N2.

Streptococcus equi zooepidemicus is another pathogen playing a role in CIRDC. This bacterium causes zoonotic infection in horses, but can also colonise the respiratory tract in dogs and contribute to upper respiratory infections.

And lastly, we have Mycoplasma - specifically, Mycoplasma cynos and Mycoplasma canis. These two bacteria are usually found in the upper respiratory tract in small numbers. Hence, their significance in CIRDC is not entirely known, but Mycoplasma has been cultured as a single agent causing pneumonia in dogs, so it’s likely to play some role.

Patients may be infected with one of these pathogens or varying combinations of them.

Ok, so that’s what CIRDC is. How is it spread?

A patient will become infected via the oronasal route, either via indirect or direct contact. Most patients will either inhale airborne pathogens, come into contact with mucosal secretions or be exposed to contaminated fomites. Direct spread from infected to susceptible host is also common.

The incubation period, again, varies depending on the specific pathogen. Some infections will incubate for just a couple of days before clinical signs begin, whereas other pathogens will be present without clinical signs for up to 10 days. Infected patients can shed infectious material for up to 2 weeks after clinical signs develop, and some patients will be asymptomatic carriers.

The survival and resistance of each pathogen vary; most are relatively stable outside of the host and can survive from hours to weeks in the environment. This, combined with the airborne transmission, means that spread is common inside the veterinary clinic, and infection control is a key nursing consideration when managing a potential CIRDC patient.

What happens when a patient gets CIRDC?

CIRDC primarily causes varying degrees of airway inflammation. In many cases, CIRDC is a mild and self-limiting disease. However, it can have significant consequences on some of our patients, particularly younger patients and older dogs with immunocompromise or significant concurrent disease.

Puppies under 6 months can develop severe bronchopneumonia following infection with CIRDC, requiring oxygen therapy, respiratory physiotherapy and intensive supportive care.

And our older dogs with concurrent disease can easily develop chronic bronchitis, secondary to the severe inflammation CIRDC causes. This can significantly impact quality of life, causing airway inflammation, remodelling, and collapse over time.

Ok, so that’s what CIRDC is. What signs do we see in these patients?

Patients with CIRDC usually present with an acute onset of coughing after a history of exposure (or potential exposure) to other affected dogs. 

The disease spreads rapidly among densely populated areas where dogs are in close proximity, such as boarding kennels (hence the old name, kennel cough), shelters, or dog parks.

Patients with mild cases will usually present with a dry, hacking or honking cough, with or without nasal discharge, ocular discharge, pyrexia and sneezing. They may be slightly lethargic or have a reduced appetite, but are typically bright and otherwise well.

In more severe cases, patients will present with a productive and moist-sounding cough, mucopurulent nasal discharge, pyrexia, lethargy and anorexia. Tachypnoea or dyspnoea may be present, and harsh lung sounds and crackles may be noted on auscultation. Patients may be in respiratory distress, with evidence of hypoxaemia.

And these patients - the severe cases - will need rapid triage and stabilisation, alongside oxygen therapy and supportive care, just like any other respiratory distress patient.

Ok, so that’s the signs we see - what about diagnostic tests?

Well, diagnosis is pretty straightforward - usually, we don’t test patients with mild cases and a suspicious history. These patients generally resolve with symptomatic treatment only and have self-limiting disease.

However, patients with prolonged signs, signs not responding to treatment, or severe disease will require further diagnostics.

These tests include:

  • Biochemistry and haematology testing to look for evidence of inflammation, dehydration, electrolyte imbalances or secondary metabolic changes

  • Pulse oximetry or arterial blood gas analysis (if available) to assess oxygenation and ventilation

  • Thoracic imaging - usually X-rays, or CT depending on the patient and the equipment you have available

  • And potentially tracheal wash or bronchoalveolar lavage, with or without bronchoscopy, for cytology and culture.

Alongside these tests, we’ll perform infectious respiratory disease testing to identify the specific pathogen or pathogens present. This is usually a PCR panel from either a oropharyngeal swab or BAL; we typically perform ours on BAL samples in dogs.

And once your patient has a diagnosis, it’s time to think about their treatment and nursing care.

Now in most cases, treatment is simple and performed on an outpatient basis - mild cases are self-limiting, and usually resolve quickly at home. But those severe cases need a LOT of support from us.

Like most of our other infectious diseases, we’ll be supporting the patients whilst the immune system clears the pathogen - unless they have a bacterial infection, which we’ll treat with antibiotics.

These patients need:

  • Antibiotics where a secondary infection is likely, or an infection is confirmed on culture

  • NSAIDs where indicated, to manage pyrexia or airway inflammation and discomfort (provided the patient’s renal function is normal, and they’re well hydrated with no GI signs)

  • IV fluids if they’re dehydrated, or anorexic/not drinking (respiratory patients can get behind on fluids quickly, especially if they’re on drying oxygen therapy, or have lots of respiratory secretions)

  • Oxygen therapy where hypoxaemia is present, via an appropriate method for the individual patient

Alongside this, we’ll provide other supportive treatments including antitussive agents where needed (these must be used cautiously, and not in any patients with pneumonia), and potentially bronchodilators in some specific cases.

Nursing-wise, there’s a lot to consider.

These patients will need intensive respiratory monitoring, respiratory physiotherapy and potentially recumbency care, alongside a low-stress approach, elimination management, special sense care, nutritional support and additional interventions.

Infection control is an absolutely essential consideration, too. We know how contagious this disease is, and isolation will be necessary. However, isolation and barrier nursing bring with it its own challenges and can make patients harder to monitor closely and care for as well as we’d like. These respiratory cases NEED that intensive monitoring, so creating a makeshift isolation or assigning a dedicated nurse to manage the patient (and keeping them away from other dogs on that shift) is usually necessary.

And then lastly, we need to think about prevention.

Like our other infectious diseases, prevention is better than cure. And whilst we can’t prevent all pathogens that cause CIRDC, we can vaccinate against some of them.

Vaccines are available against Bordetella bronchiseptica, canine parainfluenza virus, canine adenovirus-2 and canine influenza virus (in some areas). They don’t eliminate the risk of disease. However, they significantly reduce the severity and spread of disease, and whilst vaccinated dogs may still pick up CIRDC, it is usually much milder.

Client support and education are also essential - not just when discussing vaccinations, but in infection cases, too. Clients should avoid areas with other dogs for at least 1-2 weeks after clinical signs resolve, to prevent spread to other patients - and, as always, veterinary nurses and technicians are ideally placed to have these discussions and provide advice and support to clients.

So that’s it for today’s episode on managing canine infectious respiratory disease! I want to leave you with the three most important considerations we’ve mentioned in this episode. First, this is a common, contagious, and usually mild disease affecting dogs, but don’t forget that those young puppies and susceptible patients can develop severe, and sometimes chronic, forms of the disease. 

Second, it’s not just a bit of kennel cough - a wide variety of pathogens can cause signs, either alone or in combination. 

And lastly, our patients usually respond well to supportive care, which may be intensive in pneumonia cases, and our role in providing this care can’t be underestimated.

Did you enjoy this episode? If so, I’d love to hear what you think. Take a screenshot and tag me on Instagram (@vetinternalmedicinenursing) so I can give you a shout-out and share it with a colleague who’d find it helpful!

Thanks for learning with me this week, and I’ll see you next time!


References and Further Reading

Laura Jones
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82 | The five most vital considerations when caring for dogs with distemper virus