1.1.2: Infectious respiratory disease - Kennel Cough Flashcards
Which of the following clinical signs indicates upper respiratory disease?
* Ocular discharge
* Nasal discharge
* Cough
- Ocular discharge - upper
- Nasal discharge - upper
- Cough - upper or lower
Stertor
a.k.a. snoring
low-pitched soft tissue vibration
Stridor
high-pitched wheezing; vibration of rigid tissues
Which structures does stertor involve?
Soft tissues: the soft palate or everted laryngeal saccules
Which structures does stridor involve?
Rigid tissues: trachea (e.g. tracheal collapse) and larynx (e.g. laryngeal paralysis)
Inspiratory dyspnoea occurs with what type of lesions to the respiratory tract?
Inspiratory dyspnoea occurs with extrathoracic lesions in the respiratory tract
e.g. brachycephalic dogs with an elongated soft palate
Expiratory dyspnoea occurs with what type of lesions to the respiratory tract?
Expiratory dyspnoea occurs with intrathoracic airway disease.
What are some systemic clinical signs that can arise with respiratory disease in dogs?
- Pyrexia
- Depression
- Lethargy
- Inappetance
Describe the clinical presentation of Kennel Cough/CIRD
- Hacking cough that may be productive.
- Submandibular lymphadenopathy
- Ocular/nasal discharge
- ± Lethargy
- ± Pyrexia
How is Kennel Cough transmitted?
Mainly by aersol transmission
Some direct transmission is also possible
CIRDc
Canine infectious respiratory disease complex
What are some common causes of CIRD/Kennel Cough?
- Canine parainfluenza virus
- Canine adenovirus-2
- Canine respiratory coronavirus
- Bordetella bronchoseptica
What are some uncommon causes of CIRD/Kennel Cough?
- Canine Distemper Virus
- Novel respiratory pathogens like influenza
- Strep equi
Of the 3 viruses that commonly cause CIRD, which are DNA/RNA viruses? Which are enveloped? Why does this matter?
- Canine parainfluenza virus - enveloped RNA virus
- Canine adenovirus-2 - non-enveloped DNA virus
- Canine respiratory coronavirus - enveloped RNA virus
Enveloped viruses generally less stable in extremes of heat/pH/detergent. Non-enveloped = harder to kill.
RNA viruses are prone to error so mutate very quickly.
Describe the broad pathogenesis of CIRD
- A low pathogenicity virus (CPiV, CAV-2, CRCoV) infects the dog
- This virus disrupts the mucociliary escaltor
- This allows invasion of secondary bacteria
There are 3 viruses that commonly cause CIRD. Which ones have vaccines available?
- Canine parainfluenza virus - SC and intranasal vaccines available
- Canine adenovirus-2 - closely related to CAV-1 (causes infectious canine hepatitis) and vaccine for both is part of core schedule
- Canine respiratory coronavirus - no vaccine yet widely recommended
What type of organism is Bordetella bronchoseptica? Which species does it cause disease in?
A small, gram -ve, rod-shaped bacterium
Can spread between dogs, cats and humans
Describe the significance of the presence of Bordetella bronchoseptica in a dog and the characteristics of the disease it causes.
- Bordetella may be primary or secondary; it could be causing CIRD or may just be opportunistic. Therefore, a positive swab could be meaningless in identifying the cause of disease.
- Disease can be mild-severe.
- Shedding post-infection can occur for up to 12 weeks.
- It is therefore best to avoid exposing an immunocompromised person to a recently vaccinated animal.
Describe the characteristics of Canine Distemper Virus, how it is transmitted and clinical signs of infection
Enveloped RNA virus
Shed in all body fluids
Clinical signs:
* Bronchopneumonia
* Purulent ocular and nasal discharge
* Haemorrhgaic vomiting and diarrhoea -> rapid weight loss
* Neuro signs
* Hyperketaratosis (hard pad)
Describe the clinical signs and testing of canine influenza as a novel resp pathogen
Animals shed before they show clinical signs
Clinical signs
* Cough
* Purulent nasal discharge
* 20% of cases become very unwell: pyrexia, pneumonia; 8% die
Test: big groups, both healthy and sick animals
Describe the clinical signs of Strep equi infection
- Pyrexia
- Bloody nasal discharge
- Haematemesis
- High morbidity (90%) and high mortality (50%)
Which species can be affected by Strep equi?
- Dogs
- Cats
- Humans
- Horses
When should we aim to diagnose and locate the cause of CIRD?
Diagnose if it will change management/if pattern of disease changes/if disease is refractory
How can we diagnose CIRD?
- Paired serology
- Nasal/oropharyngeal swab then PCR
- Conjunctival swab for distemper then IFA
(Broadly) how can we treat CIRD?
- Symptomatic
- Antibiotics - not always indicated
Symptomatic treatment of CIRD
- Avoid choke chains/pulling on collar -> use harness
- Try to reduce excitement/stress
- Clean eyes and nose
- NSAIDs may aid if pyrexic, but could harm the protective mechanisms of lungs
- Steroids are preferable to NSAIDs to relieve cough unless heavy infection
- Paracetamol better than meloxicam for pyrexia (NOT CATS)
- Others: butorphanol, codiene (stop coughing -> reduce inflammation), glycerin (cough syrup) -> may not help but little proven efficacy
Describe when to use antibiotics in CIRD infections, and which ones you would select
- Only when you have to!
- Use culture and sensitivity
- If suspect Bordetella use gram -ve cover
- Secondary pathogens are usually gram -ve e.g. Pseudomonas, Klebsiella but could be gram +ve
- Options: tetracyclines, potentiated sulphonamides, potentiated amoxycillin
- Majority of CIRD cases = viral in aetiology and antibiotics not indicated
Describe prevention of CIRD
- Environmental hygiene
- Dog-to-dog contact
- Fomite transmission
- Ventilation
- Vaccination
What vaccines are available for CIRD?
- Parainfluenza + Bordetella - live; SC or intranasal
- Distemper - live; SC
Reasons against vaccinating for CIRD/Kennel Cough
- Vaccine not guaranteed to prevent disease
- Intranasal vaccine can cause dogs to become head shy
- Concerns re immunocompromised people
- Perceived low risk of infections/complications - consider in puppies, brachys
- Often not recommended as core but lecturer thinks it should be
What vaccines are available for Kennel Cough?
