Infectious Dog Respiratory Disease Flashcards
Other names for kennel cough complex?
- infectious canine tracheobronchitis
- canine infectious respiratory disease (CIRD) complex
Which pathogens are mainly involved in kennel cough/CIRD complex?
- canine parainfluenza virus
- canine adenovirus type 2
- bordatella bronchiseptica
Is bordatella bronchiseptica a 1* pathogen? How does it cause damage?
can be
- frequently found in infected dogs but ALSO found in healthy dogs!
- releases bacterial toxins to damage respiratory epithelium and MCE (ciliostatic)
What is the commonest viral cause of kennel cough
Canine parainfluenza virus (CPIV)
- causes mild respiratory disease
When is more severe disease seen with CPIV?
Combination with Bordatella
Which canine adenovirus causes respiratory disease in dogs?
Type 2
Is adenovirus commonly associated with KC in the UK?
No due to good vaccination uptake
What does type 1 adenovirus cause?
Hepatitis (ICH)
- may cause respiratoy disease too
Does kennel cough ever cause death?
Rarely - more of a problem in rehoming centres, kennels etc. outbreaks
Which minor pathogens are often associated with CIRD?
- canine herpesvirus 1
- canine respiratory coronavirus
- mycoplasmas
- canine pneumovirus
What disease does canine herpesvirus (CHV) commonly cause? Prophylaxis? How is it involved in respiratory disease?
- systemic, often fatal disease of neonatal puppies ( vax for dams available
- isolated from dogs with respiratory disease (potential reactivation of latent virus due to other disease)
Path at PM with CHV infection?
petechial haemorrhage in kidneys
What is the equivalent to the common cold in dogs? Is there a vaccine for this?
- canine respiratory coronavirus (CRCoV)
- highly contagious URTI
- distinct from canine enteric coronavirus (mild D+ in young dogs)*
- vaccine under development, but NO cross protection between enteric and repsiratory strains
Which is the only mycoplasma associated with disease in dogs?
Mycoplasma cynos (m. canis and other spp. may be found incidentally in healthy dogs)
What disease does mycoplasma cause? In what animals?
- pneumonia in puppies and chemosuppressed individuals eg. chemo patients
How is CIRD spread? Where is it commonly seen?
- aerosol/contact with infected dogs
- rehoming centres, kennels etc.
- highlyl contagious
Pathogenesis of CIRD?
- infection of resp epithelium with viruses or bordatella
- cell damage and MCE inhibition
- potential 2* bacterial infections (eg. strep, pasteurella)
- different mixes of infectious agents may cause same clinical signs
How long after exposure do clinical signs of CIRD appear?
3-7d
Clinical signs of CIRD?
- cough dry -> productive
- retching esp. excercise or on lead
- nasal +- occular disacharge
- recovery ~ 3 weeks even if NOT TREATED!
CLinical signs of systemic disease? what causes these clinical signs?
- depression, pyrexia, inappetence
> progression to bronchopneumonia - canine distemper virus
- streptococcus equi. zooepidemicus
How is CIRD diagnosed?
- history and clinical signs
- dx tests usually only necessary if no improvement after 2 weeks or with signs of systemic disease
- or persistent problems in boarding kennels, vet hospitals or rehoming centres
Which diagnostic tests may be indicated in CIRD cases?
- bacterial culture and sensitivity
- viral isolation or PCR to rule out distemper
> tracheobronchial wash or deep pharyngeal swab (NB; bacterial v viral swabs) - serology paired samples
- feacal sample smear/serology to rule out Angiostrongylus sp. SNAP test
- haemotology (neutrophilia)
- radiography/rhinoscopy (heart failure/FB/tumour metastasis)
Tx of CIRD?
- rest
- Abx
- cough suppressants, bronchodilators, mucolytics
- supportive care for systemic disease (fluids)
Prevention and control of CIRD?
> vaccines
- prevent or reduce severity and length of disease caused by B. Bronchiseptica, parainfluenza and adenovirus
- NB: other infectious agents cause CIRD complex and vaccinated animals can still develop disease!
What IGs do differnt vax stimulate?
- parenteral (SC) -> IgG in bloodstream but low IgA and mucosal IgG
- intranasal -> IgA on mucosal surfaces (faster onset but shorter duration)
When should B. Bronchiseptica vaccines be administered? What type of vax are they? Problems?
5d before kenelling
- live attenuated
> immunity short lived, will need revax ~6 months if going back into kennels
> strains may be old and different to current ones
What type of vax are canine parainfluenza?
> live attenuated
- systemic combination vax eg. Nobivac DHPPi
- Intranasal with bordatella eg. Nobivac KC
annual booster recommended but controversial
What types of canine adenovirus are there? Do these cross protect?
CAV 1 and 2
+ do cross protect
> systemic vax with either strain eg. Nobivac DHPPi
What is the most important aspect of CIRD management?
Husbandry!!
- isolate infected animals
- cleaning, disinfection and drying of kennels
- good ventilation
- isolating newcomers
- avoiding high pop density
Where is canine distemper endemic?
- India and Africa
What type of virus is distemper?
Morbillivirus - related to measles
How can distemper be spread?
- aerosol
- close contact
- shed in all bodily fluids but cannot survive in environment
Pathogenesis of distemper?
> Replicates in immune tissues -> immunosupression and 2* bacterial infection (-> broncho-interstital pattern of pneumonia)
- enters via resp tract
- spread to tonsils and LNs
- infects monocytes/macrophages
- viraemia, systemic dissemination -> interstitial pneumonia, GIT, genitourinary and CNS problems
- 2-3 weeks post infection good humoral and cellular immune response develops -> recovery or milder disease
Clinical signs of distemper CDV?
- nasal and occular discharge
- cough
- diarrhoea
- vomiting
- depresion
- anorexia
- enamel hypoplasia
- CNS signs (seizures, incoordination, paresis/paralysis, tremors, ocular lesions, neuronal destruction, demyelinatio)
What infectious disease should always be a “rule out” for canine CNS disease?
distemper
What are some strains of distemper also known as?
- hard pad and hard nose disease
- hyperkeratosis of the epithelium caused by some strainsCDV
What oral lesions may be seen with distemper?
enamel hypoplasia if dogs infected before permenant teeth erupt due to infection of ameloblasts
- may be seen with current infecton or previous infection that has been cleared
Diagnosis of distemper made on?
- clinical signs and hx
- haematology: lymphopenia
- serology: IgM indicative of recent infection
- virus isolation/PCR, immunoflueorescance on conjunctival smears
- CSF antibody detection
Tx of distemper
- Abx to prevent 2* infection
- fluid
- sedative.anticonvulsants (CNS signs may improve with time)
- often succumb to 2* bacterial pneumonia
Which species are particularly susceptable to CDV? Prevention?
Ferrets! Can vaccinate (none licensed Uk but use off label)
Prevention and control of distemper?
- liver attenuated vax
- 8 weeks, 10-12 weeks and 1 year
- boosters ~ 2 years
> isoalte dogs
> disinfect kennel
where is influenza commonly seen? (CIV)
racetracks
- mild respiraotry disease
- some haemorrhagic pnuemonia
What other virus is canine influenza virus closely related to?
Equine influenza virus H3N8
- CIV is entirely derived from this virus but now spread dog -dog ie. NOT associated with horse contact
Is a CIV vax available?
in USA yes, no strong evidence to support in UK
Where are streptococci found normally?
URT
Which type of streptococci are highly virulent in the lung?
B haemolytic
Lancefield group C most pathogenic
What is strep equi zooepidemicus associated with in horses?
- abortion
- low grade resp disease
which pathogen has recently become increasingly reported in dogs? what does it cause?
strep equi zooepidemicus
- severe necro-haemorrhagic and fibrino-supparative bronchopneumonia with lung consolidation
Is strep equi zooepidemicus infection associated with horse dog contact?
NO spread dog - dog via fomites
Diagnosis of strep zooepidemicus?
growth from lung samples or swabs
tx of strep zooepidemicus?
- iv fluids
- ABx
- intensive care
Prognosis of strep zooepidemicus infection?
Poor - high mortality sue to sudden onset
BUT ^ number “carrier” animals
What is important about strep equi zooepidemicus?
ZOONOTIC!
