Canine Infectious Respiratory Disease
Canine infectious respiratory disease (CIRD) is a widespread syndrome, recognised as one of the most globally prevalent infectious diseases of dogs1,2. Presentation for investigation or treatment of respiratory disease is a common request in UK general practice representing around 0.9% of all dog consultations3.
Although it is typically referred to as “kennel cough”, disease transmission can occur readily wherever dogs meet or mix in common airspaces.
A wide range of pathogens have been implicated and the importance of each varies by geography, age of animal and vaccination status. Classical primary pathogens of CIRD include Bordetella bronchiseptica, canine parainfluenza virus, canine distemper virus, canine adenovirus type 2 and canine herpesvirus – all of which, with the exception of canine herpesvirus (which tends to be responsible for respiratory disease in neonates), can be included in regular vaccination schedules, and therefore vaccination has a significant role in prevention.
Lately canine influenza viruses (H3N8 and H3N2) have been recognised as serious pathogens contributing to CIRD, although they have yet to be seen to circulate in the UK and the rest of Europe. Other potential pathogens with a role in CIRD include, canine respiratory coronavirus, canine pneumovirus, Mycoplasma cynos and Streptococcus equi subspecies zooepidemicus.
A variety of host and environmental factors also play a role in the development of the disease and its severity. Hygiene, ventilation, kennel design and biosecurity therefore have an important role in this highly infectious disease.
More than just a simple cough…?
CIRD is a highly contagious respiratory disease in dogs. The disease is rapidly transmitted through droplets or asymptomatic carriers as most of its pathogens are ubiquitous.
Clinical signs include:
- Sudden onset, dry hacking cough – often described by pet owners as a “bone stuck in the dog’s throat”
- Sneezing, nasal discharge
- Rarely pyrexia, inappetence
In puppies, and dogs with immunosuppression or other concurrent diseases, CIRD can be complicated by bronchopneumonia, resulting in more severe signs such as dyspnoea, weight loss, pyrexia and even death4.
Clinical signs can last from days to weeks which can prove debilitating for the pet, and distressing for dog owners to witness.
CIRD is a social dog disease that can affect dogs of all ages and causes sporadic illness as well as outbreaks. There are very few dogs that do not socialise or mix with other dogs in some form or other, for example, whether that is meeting other dogs whilst being exercised, at doggy day care centres, gathered in close proximity with other dogs at the grooming parlour, and all these dogs are at risk for CIRD. Prevention by utilising vaccination for these individuals is an important consideration.
Why is Bordetella bronchiseptica such an effective respiratory pathogen?
Bordetella bronchiseptica can act as a primary pathogen on its own in dogs5 or contribute to CIRD alongside other bacteria and/or viruses, such as canine parainfluenza virus. Other aspects that make this bacterium a successful respiratory pathogen include:
- Bordetella bronchiseptica can survive in the environment, hence dogs can be infected via contaminated bedding or water, as well as direct or indirect contact with other animals.
- Potential cross-species infection with a number of domestic species such as cats and guinea pigs. Immune compromised people may also be potentially at risk.
- The ability of Bordetella bronchiseptica to shed from infected dogs prior to clinical signs occurring and take up to 14 weeks to be cleared from infected dogs, even after clinical signs have resolved6.
Evidence of exposure to Bordetella bronchiseptica is frequently found in both healthy and diseased dogs and client-owned dogs are as likely to be infected as kennelled dogs. Co-infections with viral pathogens are common7 and typically present with severe clinical signs more frequently than dogs infected with single infections8.
What about the role of canine parainfluenza virus (CPiV)?
CPiV has been recognised as an infectious trigger in CIRD for almost 50 years9 and is often present in the mixed coinfections which correlate with the more severe and protracted disease signs. In dogs at risk of CIRD vaccination against parainfluenza remains an important consideration.
“An ounce of prevention is worth a pound of cure” (Benjamin Franklin)
Bordetella bronchiseptica and CPiV are two of the most significant infectious pathogens in CIRD and increasing vaccination, in all dogs that mix with others in their day to day lives against these, is an effective and recommended control measure.
Vaccination reduces spread, increases herd immunity and decreases usage of antimicrobials. Recommending vaccination of dogs against pathogens of CIRD will directly provide epidemiological advantages to the population and the individual dog.
(Day et.al 2020)
Increased flexibility in the method of administration of vaccines against Bordetella bronchiseptica and CPiV will allow more dogs at risk to be protected against two of the most significant infectious respiratory pathogens within this syndrome.
Nobivac® Respira Bb is an inactivated subunit vaccine containing the fimbrial antigen of Bordetella bronchiscepta. POM-V
Further information is available from the SPC, Datasheet or package leaflet.
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2. Schulz BS, Kurz S, Weber K, Balzer HJ, Hartmann K (2014) Detection of respiratory viruses and Bordetella bronchiseptica in dogs with acute respiratory tract infections. Veterinary Journal, 201, 365-369.
3. Singleton DA, Smyth S, Brant B, Smyth S, Brant B et al. (2019) Small animal disease surveillance 2019: respiratory disease, antibiotic prescription and canine infectious respiratory disease complex. Veterinary Record, 184, 640-645.
4. Radhakrishnan A, Drobatz KJ, Culp WTN, King LG (2007) Community-acquired infectious pneumonia in puppies: 65 cases (1993-2002). JAVMA, 10, 1493-1497.
5. Wright NG, Thompson H, Taylor D, Cornwell HJ (1973) Bordetella bronchiseptica: a re-assessment of its role in canine respiratory disease. Veterinary Record, 93, 486-487.
6. Bemis DA, Greisen HA, Appel MJG (1977). Pathogenesis of canine bordetellosis. J Inf Dis 135(5):753-762.
7. Day MJ et al. (2020) Aetiology of canine infectious respiratory disease complex and prevalence of its pathogens in Europe. J. Comp. Path., 176, 86-108.
8. Maboni G, Seguel M, Lorton A, Berghaus R, Sanchez S (2018) Canine infectious respiratory disease: new insights into the etiology and epidemiology of associated pathogens. PloS One, 14, e0215817.
9. Ellis J, Krakowa GS (2012) A review of canine parainfluenza virus infection in dogs. JAVMA, 240, 273-284.