Tracheobronchial diseases--dogs Flashcards Preview

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Flashcards in Tracheobronchial diseases--dogs Deck (31):
1

What signs are associated with disease in the following areas:

Larynx (voicebox)?

Trachea (windpipe)?

Bronchi?

  • Larynx = hoarse bark, gagging, inspiratory difficulty
  • Trachea = cough and resp distress
  • Bronchi = cough and resp distress

2

Clinical signs?

  • Cough (most common)
    • +/- productive
  • Retch/gag
  • Wheezing
  • Inspiratory sounds 
  • Tachypnea
  • Resp distress
  • Cyanosis if severe

3

Canine etiology

  • Brachycephalic airway syndrome and laryngeal paralysis--know hallmarks
  • Canine infectious respiratory disease complex: kennel cough
  • Canine influenze
  • Oslerus osleri
  • Collapsing trachea, bronchi
  • Canine chronic bronchitis
  • Bronchiectasis

4

Canine infectious respiratory disease complex (CIRD): kennel cough

Pathogens responsible?

  • Parainfluenza virus--mild clinical signs
  • Canine adenovirus (CAV-2)
  • Mycoplasma spp.--mild to severe clinical signs
  • Bordetella spp.--mild to severe clinical signs
    • Attaches to cilia of bronchial epithelium and interferes with motility--resulting in mucous accumulation and inflammation
  • Other viruses--canine distemper virus (CDV), canine respiratory coronavirus (CRCoV), canine herpes virus (CHV-1), and canine influenza virus (CIV)
  • Secondary bac. invaders are comon

5

CIRD: kennel cough

Contagious?

Spread?

Incubation?

Most common clinical sign?

  • Very contagious--acquire pathogen from dog shows, kennels, vet clinics, etc.
  • Spread through resp secretions and fomites
  • Incubation 3-7 days
  • Coughing is most common clinical sign

6

CIRD: kennel cough

Clinical signs

  • Usually develop 4-10 days post exposure
  • Uncomplicated
    • Non-sick animals
    • Involves upper airways
    • Dry cough is elicited on tracheal palpation
    • Serous oculonasal discharge, gagging, and retching can be found
  • Complicated
    • Sick animals
    • Upper and lower airways
    • Moist cough
    • Oculonasal discharge more mucopurulent
    • May develop into bronchopneumonia

7

CIRD: kennel cough

Diagnosis

  • History
    • Where has the dog been? Kennels?
    • Has the dog received bordetella vaccine recently?
  • Clinical signs
  • In uncomplicated cases further diagnostics may be included
    • Hemogram--left shift neutrophilia
    • Thoracic radiographs
    • Transtracheal wash, cytology and culture
    • PCR panels for upper resp viruses and bac.

8

CIRD: kennel cough

Treatment: uncomplicated

  • Uncomplicated
    • Restricted exercise
    • Use doxycycline if Bordetella spp is suspected
    • Usually resolves w/in 2 weeks
    • Cough suppressants
      • Butorphanol, hydrocodone, codeine derivative, dextromethorphan

9

CIRD: kennel cough

Treatment: complicated

  • Restrict exercise
  • Systemic antibiotic for 2 wks
    • Doxycycline, tetracycline, sulphonamides, enrofloxacin
    • Penicillins are not a good choice for Bordetella spp as they reach poor concentrations in the respiratory secretions
  • Nebulization w/ or w/o gentamycin (only antibiotic that can actually have an effect when added to nebulizer)
  • Cough suppressants (avoid if bac. pneumonia is present) 
  • Bronchodilators
    • Albuterol, theophylline (avoid or reduce dose by 30% if using together w/ fluoroquinolones)

10

CIRD: kennel cough

Prognosis?

Prevention?

  • Prognosis = good to excellent
  • Prevention
    • Avoid places where dog could get infected
    • Vaccination
    • Sanitation--household bleach dilated 1:32
    • Ventilation in kennels

11

CIRD: kennel cough

Vaccination

  • Parenteral vaccination
    • CAV-2, CPIV, CDV and Bordetella spp (dogs)
    • Blocked by maternal antibodies so repeat every 3-4wks until 16wks of age
  • Intranasal vaccination
    • Bordetella spp and CPIV
    • Important for high- or at-risk animals
  • New vaccinations against CIV
  • Need vaccine 2-3 wks BEFORE going to kennels for protection

12

Canine influenza

Influenza type A?

Spread?

  • Type A
    • H3N8 (related to equine flu)
    • H3N2 (related to avian flu)
  • Spread through direct contact (resp secretions) and fomites or indirect contact through kennel surfaces, water/food bowls, toys, collars and leashes

13

Canine influenza

Clinical signs

Diagnosis

  • Clinical signs
    • 2-5 days post exposure
    • Usually results in coughing, sneezing, nasal discharge and fever; may result in hemorrhagic pneumonia
    • Disease has high morbidity but low mortality
    • 20% don't show clinical signs and just shed virus
    • Most animals dev. mild clinical signs, but some can dev. severe (2 forms)
  • Diagnosis--PCR, serology (acute and convalescent titres) or viral isolation

14

Canine influenza

2 forms?

  • Mild/uncomplicated--typical mild uncomplicated kennel cough
  • Severe/complicated
    • Pyrexia (104-106F)
    • Hemorrhagic pneumonia--dyspnea, tacypnea, hemoptysis
    • Rapid onset and animal can die w/in hours
    • 5-8% mortality

15

Canine influenza

Treatment

Prevention

  • Treatment
    • Supportive care, NSAIDs to reduce fever, and IV fluids
    • Systemic antibiotics in the severe form--may require ICU but extremely contagious and requires isolation
  • Prevention
    • Vaccination
    • Isolate sick and exposed dogs
    • Change clothes/wash hands
    • Virus does not persist in environment >48hrs--good quality bleach/disinfectant solution

16

Oslerus osleri

What is it?

Generally affects?

Life cycle?

Causes what?

Clinical signs?

  • Canine parasite on resp. passages
  • Generally affects younger dogs in kennels
  • Direct life cycle--larvae ingested, molt in small bowel and migrate to lungs, bronchi, and trachea
  • Cause cream-colored nodules in trachea
  • Clinical signs: coughing, wheezing, dyspnea

17

Oslerus osleri

Diagnosis

  • Radiographs--may see tracheal mass
  • Bronchoscopy--masses are found
  • Tracheal/bronchial brushes or biopsies
  • Fecal

18

What parasite is this indicative of (white plaques)?

Oslerus osleri

19

Oslerus osleri

Treatment

  • Fenbendazole
  • Ivermectin

20

Tracheal collapse

Signalment?

Usually acquired reduction in what?

Pathophysiology?

 

  • Signalment
    • Middle aged to older dogs (rarely cats--full cartilagenous rings in trachea)
    • Toy or small breed dogs--usually obese
  • Usually acquired reduction in chondrocytes
    • Lack glycosaminoglycans and chondroitin sulfate in tracheal cartilage
  • Pathophysiology
    • Weak cartilage w/ flattening of tracheal rings, resulting in mechanical irritation, edema, and inflammation
    • Tracheal rings lose their firmness and collapse

21

Tracheal collapse

Clinical signs

  • Goose honking cough
  • Exacerbated by exercise, excitement and eating
  • Elicited w/ tracheal palpation
  • Causes cyanosis and collase/syncope
  • Many dogs have hepatomegaly
    • Theory: O2 deprivation--> significant liver disease 
  • Many have cardiac murmur
  • Variable breath sounds

22

Tracheal collapse

Diagnosis

  • Signalment, history, clinical signs
  • Thoracic/cervical rads
    • Inspiratory AND expiratory films
    • May/may not be diagnostic
    • Often underestimate severity
    • Extra-thoracic and intra-thoracic collapse occurs
  • Fluoroscopy
  • Bronchoscopy
    • Best diagnostic tool
    • Assess dynamic change
    • Grade extent of collapse
    • Look for concurrent diseases

23

Tracheal collapse

Grading scale?

24

Tracheal collapse

Treatment: calm patient (/owner)

  • Sedation often required
    • Acepromazine, butorphanol, diazepam
  • O2-rich environment
    • O2 cage, nasal catheterization
  • Use cough suppressant (antitussive)
    • Butorphanol injectable/oral
    • Oral hydrocodone
  • Corticosteroid
    • Single dose for anti-inflammatory effects
    • 0.1mg/kg IV dexamethasone
  • Intubation may be required

25

Tracheal collapse

Treatment: break the cycle

  • Weight loss
  • Avoid neck collars
  • Avoid excitement
    • Use sedative if required
    • Behavioral--reward quiet behavior
  • Avoid dust, smoke, pollens, carpet powders, etc.
  • Use cough suuppressants--butorphanol, codeine, hydrocodone
  • Use corticosteroids--very short course if required
    • Too long--> suppress immune system--> secondary bac. pneumonia
  • Antibiotics for secondary infection if suspected

26

Tracheal collapse

Response to medical management?

Surgery?

  • 30% of dogs do not respond to medical management
  • Surgical intervention--referral
    • Extraluminal stents
      • For extrathoracic or cervical collapse
    • Endoluminal stents
      • For intrathoracic or entire tracheal collapse
      • Nitinol stents are used

27

Canine chronic bronchitis

What is it?

Clinical signs?

Cause?

Long-term sequelae?

Not similar to what?

  • Inflammation of bronchial walls--> thickened walls, increased mucous --> obstruction of small airways
    • Chronic obstructive pulmonary disease
  • Clinical signs--daily cough > 2mo
  • By the time it is diagnosed there is rarely a cause found for the underlying inflammation
    • Etiology is rarely determined
  • Long term sequelae--emphysema, bronchiectasis, pneumonia
  • Not similar to asthma in cats or people

28

Canine chronic bronchitis

Signalment

Client complaint

Clinical signs

Diagnostics

  • Signalment: small breeds, usually >6yrs
    • Often obese
  • Client compliant: chronic cough, audible wheezes, exercise intolerance
    • Usually BAR, signs wax and wane
  • Clinical signs--expiratory wheezes, crackles audible on inspiration and expiration
    • Dog can also have concurrent tracheal collapse or mitral valve insufficiency
  • Diagnostics--exclude other causes of a cough
    • Rads, bronchoscopy, bronchial cytology and culture

29

Canine chronic bronchitis

Treatment

  • Eliminate triggers--smoke, excitement, allergens
  • Keep hydrated--to aid mucociliary clearance
  • Reduce weight if obese
  • Prednisolone--reduce inflammation
  • Bronchodilators--only in reversible stages, use only w/ corticosteroids
  • Antibiotics--if secondary bac. infection found
  • Avoid cough suppressants--unless a tracheal collapse is present or the cough is inconsistent and dry
  • Metered dose inhalers (MDI)--inhalation steroids
  •  

30

Bronchiectasis

Secondary to?

Pathophysiology?

  • Secondary to chronic conditions like chronic bronchitis
  • Pathophysiology
    • Damage to bronchial structure--> thickened wall, dilation of structure
    • Mucous cannot be cleared--> builds up 
    • Secondary infection --> recurrent bronchopneumonia --> more damage to airways
    • Dilation of bronchial tree is irreversible caused by the destruction of the muscle and elastic tissue 

31

What specific diseases in the various lung lobes can cause bronchiectasis?

  • Upper lung lobe
    • Cystic fibrosis
    • Tuberculosis
  • Central
    • Cystic fibrosis
    • ABPA
    • Congenital tracheobronchomegaly
  • Lower
    • Childhood infection
    • Aspirations
    • Immunodeficiencies