Infectious respiratory disease of the dog Flashcards
What are the 4 main infectious respiratory diseases in the dog?
- ) Kennel Cough (KC) complex
- ) Canine Distemper Virus (CDV)
- ) Canine Influenza Virus (CIV)
- ) Streptococcus equi subsp. zooepidemicus
What is another name for KC? 2
= Infectious canine tracheobronchitis (ITB)
= Canine infectious respiratory disease complex (CIRD)
Aetiology - KC complex - 3
Usually several infectious agents: - Canine parainfluenza virus (CPIV) - Canine adenovirus type 2 (CAV-2) OTHERS: Bordatella bronchiseptica
Outline B.bronchiseptica
Primary resp. pathogen
Frequently found in dogs with resp disease (also healthy dogs)
Attaches to URT cilia and releases bacterial toxins which damage the respiratory epithelium and the MCE (ciliostatic)
Outline CPIV infection
Causes mild respiratory disease
Frequently isolated from dogs with respiratory disease
More severe if concurrent with Bordatella
Most frequent viral cause of KC
Outline CAV2 infection. What about type 1?
Causes respiratory disease
Not commonly associated with KC in UK (vaccine uptake)
Type 1 –> hepatitis (ICH) but has been reported to case respiratory disease as well.
Outline CHV infection
Systemic and often fatal (neonates, <3 days, thermosensitive virus).
Isolated from adult dogs with resp. disease
Potentially reactivated when latent due to other disease.
Outline canine respiratory coronavirus (CRCoV) infection
Associated with mild respiratory disease
Highly contagious
Vaccine being developed
Distinct from canine enteric coronavirus (CECoV)
Vaccines for CECoV don’t cross-protect
Have spike proteins to give corona appearance.
What mycoplasmas are present in dogs?
Many different mycoplasma species
Mycoplasma cynos is associated with respiratory disease
Other spp often normally present (M. canis)
Epidemiology - CRID complex
V. common in dogs housed in groups
Possible history of group
Very contagious - transmission by aerosol droplets
Pathogenesis - CRID
infection of respiratory epithelial cells (viruses or bordatella) - cell damage (viral and bacterial toxins) - inhibition of ciliary clearance (by damage to ciliated cells) - potential secondary bacterial infections (Strep., Pasteurella) - different mix of infectious agents may produce same CS.
Clinical signs - CRID
Usually apparent 3-7 days after exposure Cough (dry or productive) Retching (especially exericse or lead) Nasal +/- ocular discharge Sneezing Most cases recover after 1-3 weeks (no treatment) BUT look out for non-resolving systemic cases.
What should you do for CRID cases that don’t resolve and then show systemic signs?
CS - depression, pyrexia, inappetance
Progression - to bronchopneumonia due to secondary bacterial infections, CDV , Strep equi subsp. zooepidemicus.
Diagnosis - non-resolving (>2 weeks) systemic (pyrexia) CRID - 6
BACTERIAL ISOLATION - test for AB sensitivity
VIRAL ISOLATION or PCR - rule out distemper
BOTH of above on tracheo-bronchial wash or deep pharyngeal swab
SEROLOGY - paired for rising titre
FAECAL SMEAR/SEROLOGY - rule out Angiostrongylus
HAEMATOLOGY - neutrophilia
RADIOGRAPHY or RHINOSCOPY - to investigate other potential causes such as HF, FB or tumour metastasis.
What is rhinoscopy?
nasal endoscopy
Tx - CRID - 4
- Rest + owner pacificiation
- AB - only with culture and sensitivity
- If necessary: cough suppressants, bronchodilators, mucolytics
- Supportive care (if systemic disease, fluids)
Prevention - CRID
Prevent or reduce severity and length of disease (B. bronchiseptica, parainfluenza and adenovirus). BUT other infectious agents cause or contribute to CRID complex and vaccinated animals may still develop disease.
What are the 2 types of vaccine available against respiratory viruses?
PARENTERAL - high Ab titre (IgG mainly), on mucosal surfaces IgA and IgG much lower
INTRANASAL - stimulate mostly IgA, mostly on mucosal surface, serum IgG produced but less than parenteral
Advantages - intranasal vaccines - 2
Stimulate local immune response
Act more rapidly versus systemic vaccines