Canine infectious respiratory disease Flashcards
List 7 viral causes of canine infectious respiratory disease
- canine parainfluenza
- canine adenovirus 2
- canine herpesvirus 1
- canine distemper virus
- canine respiratory corona virus
- canine influenza virus
- canine pneumovirus
Name 3 bacterial types associated with canine infectious respiratory disease
Bordetella bronchiseptica
Mycoplasma Cynos
Streptococcus equi subsp Zooepidemicus
How is canine infectious respiratory disease transmitted
Oronasal exposure to contaminated virus secretions and environmental formites.
What is the incubation period of CIRD
3-10 days
How long does shedding in CIRD last
Shedding generally ceases in 10 days
Describe the pathogenesis of CIRD
Initial infection in the ciliated epithelial cells. Most do not spread beyond the nasal cavity, sinuses, trachea and bronchi.
How does viral replication affect the respiratory tract
Loss of coordinated beating of the cilia, followed by loss of cilia; resulting in rhinitis, sinusitis, tracheitis and bronchitis
Describe the colonisation effect of B. Brochiseptica
B. Bronchiseptica produces toxins to aid colonisation and infection
- tracheal cytotoxic seems which cause ciliostasis
- adenylate cyclase which inhibits neutrophil phagocytosis.
B. Bronchiseptica is often harmlessly carried, but co-infection with CPIV or CRCoV and subsequent ciliostasis allows pathological infection.
Describe typical presentation of CIRD patients
Generally well, with a loud, persistent cough.
Patients should be examined closely for signs of systemic inflammation and/or pneumonia.
Mucopurulent nasal discharge requires further evaluation.
Describe the diagnostic rational for dogs with CIRD
In bright well dogs without evidence of systemic inflammation, physical exam may be adequate.
In febrile, inappetent, lethargic dogs or those with concurrent illness, mucopurulent nasal discharge, or cough lasting greater than 7 days further tests may be warranted
Describe diagnostic tests which may be considered for CIRD patients when further tests are warranted
- orthogonal thoracic radiographs for; pneumonia, radio-opaque FB, other changes
- BAL/trans trach where indicated
- CBC for left shift or toxic changes
- Baermann test in geographically appropriate areas.
- Nasal swabs are usually contaminated with ubiquitous bacteria, and aren’t useful.
Discuss useful treatments for CIRD
- Simple viral conditions may spontaneously resolve.
- over the counter antitussives may be considered but are rarely useful
- narcotic antitussives eg codeine for severe cough
- corticosteroids 0.25-0.5mg/kg PO q12h pred bid for <5d. Not with doxycycline, as this is bacteriostatic.
- antibiotics: not for every case
Discuss antibiotic use in dogs with CIRD
Many causes are viral and will spontaneously resolve, so antibiotics aren’t indicated in every case.
With severe or protracted cases, or when concurrent disease exists and predisposes to more severe disease, consider doxycycline 10mg/kg PO BID x>10d (effects on bordetella/mycoplasma) or amoxicillin/clavulanate 12.25mg/kg 10-14 days.
