Respiratory Infections

• Chronic Bronchitis

  • Most common chronic canine airway disorder
• Chronic Bronchitis

  • Inflammation within airways causes chronic cough and excessive mucus production
  • Causes difficulty maintaining appropriate oxygen levels
• Chronic Bronchitis

  • May be caused by bacterial infections, hypersensitivities, parasites, or chronic inhalation of airway irritants (second-hand smoke, dusts, exhaust fumes, etc.)
• Chronic Bronchitis

  • Overall cause is unknown
• Chronic Bronchitis- Risk Factors

  • No sex or breed predilection but do see a lot in toy breeds
  • Average age: 6 years or older
• Chronic Bronchitis- Clinical signs

  • Deep harsh cough
  • Wheezing
  • Dyspnea
  • +/- gagging, choking, or swallowing after coughing
  • Exercise intolerance
• Chronic Bronchitis- Physical exam

  • BAR-QAR
  • Most come in looking grossly normal
  • Some may come in a little lethargic
• Chronic Bronchitis- Physical exam

  • Can hear inspiratory and expiratory crackles/harshness
  • All other vitals and rest of physical exam generally normal
• Chronic Bronchitis- Diagnostics

  • Radiographs
  • Interstitial or bronchointerstitial pattern in dorsal aspect of caudal lung lobes
  • NOT definitive diagnosis
• Chronic Bronchitis- Diagnostics

  • Bronchoalveolar lavage
  • Can evaluate through cytology
  • Usually see excessive amounts of neutrophils +/- lymphocytes, eosinophils, and epithelial cells
• Chronic Bronchitis- Diagnostics

  • Tracheobronchial culture
  • Use if believe possible infection
• Chronic Bronchitis- Diagnostics

  • Bronchoscopy with biopsy
  • Provides definitive diagnosis but not mandatory to diagnose in general
  • Disease is usually clinically diagnosed
• Chronic Bronchitis- Diagnostics

  • Rule out tests
  • Heartworm disease, PCR/ELISA for other infectious/parasitic agents, cocci-titer
• Chronic Bronchitis- treatment

  • Prednisone 1 mg/kg q12h PO for one week, then 0.5 mg/kg 2h PO for an additional week q1
  • Used to decrease inflammation and it reduces mucus production
  • Taper to lowest effective dose for chronic management
• Chronic Bronchitis- treatment

  • Antibiotics/anti-parasitics/anti-fungals if necessary
  • Do not give any of these unless you know they are needed to treat an underlying condition
• Chronic Bronchitis- treatment

  • Cough suppressants
  • Recommend if it’s a dry cough to alleviate some discomfort
• Chronic Bronchitis- Prognosis

  • Treatable but not curable disease
  • If well managed, can have a long normal life
  • Need to emphasize these points with owners
• Upper respiratory infections

  • Can be viral or bacterial
  • Most common in cats: Feline Herpesvirus type-1 (FHV), Feline Calicivirus (FCV), Bordetella bronchiseptica, and Chlamydophila felis
• Upper respiratory infections

  • Can be viral or bacterial
  • Most common in dogs: Bordetella bronchiseptica, Canine Adenovirus type 2, Canine Parainfluenza virus, and Canine Influenza virus
• Upper respiratory infections

  • Infect the conjunctiva of the eye and nasal cavity
  • Organisms are shed in ocular, nasal, and oral secretions to transmit infection by direct contact
  • Some animals will be asymptomatic
• URI: Infectious agents- Viruses (cats)

  • FHV- infects conjunctiva of eyes, will go into latent stage in trigeminal ganglion for long periods of time
• URI: Infectious agents- Viruses (cats)

  • FHV:
  • Clinical signs: sneezing, conjunctivitis, oculonasal discharges, depression,inappetence, dehydration, salivation with drooling, and ulcerative keratitis
• URI: Infectious agents- Viruses (cats)

  • FHV:
  • Most common cause of URIs in cats
  • Takes 10-14 days after exposure for signs to appear
• URI: Infectious agents- Viruses (cats)

  • FCV- causes moderate, self-limiting acute disease, but some strains can induce lameness
• URI: Infectious agents- Viruses (cats)

  • FCV:
  • Clinical signs: sneezing, nasal congestion, fever, drooling, oculonasal discharge, inflammation and ulcers on the tongue and lining of the mouth
• URI: Infectious agents- Viruses (cats)

  • FCV:
  • Virulent Systemic Disease: swelling of the head and legs, crusting sores and hair loss on the nose, eyes, ears and footpads, liver damage, and spontaneous bleeding; fatal in up to 60% of cats
• URI: Infectious agents- Viruses (cats)

  • FCV:
  • Takes ~14 days for signs to show and can take 5 days- 6 weeks to resolve
• URI: Infectious agents- Viruses (Dogs)

  • Adenovirus type-2
  • Transmitted between dogs through close contact with respiratory secretions
• URI: Infectious agents- Viruses (Dogs)

  • Adenovirus type-2
  • Clinical signs: dry, hacking cough, retching and gagging, coughing up a white foamy discharge, fever, nasal discharge, and conjunctivitis
• URI: Infectious agents- Viruses (Dogs)

  • Adenovirus type-2
  • Incubation period ~3-10 days
• URI: Infectious agents- Viruses (Dogs)

  • Parainfluenza
  • Spread through aerosolized respiratory secretions
• URI: Infectious agents- Viruses (Dogs)

  • Parainfluenza
  • Clinical signs: low-grade fever, deep sounding dry cough, watery nasal discharge, pharyngitis, and tonsillitis; in puppies, may have lethargy, fever, inappetence, and pneumonia
• URI: Infectious agents- Viruses (Dogs)

  • Parainfluenza
  • Incubation period ~2-8 days
• URI: Infectious agents- Viruses (Dogs)

  • Influenza (H3N8 and H3N2)
  • Spread through aerosolized respiratory secretions and fomites
• URI: Infectious agents- Viruses (Dogs)

  • Influenza (H3N8 and H3N2)
  • Clinical signs: oculonasal discharge (may be purulent), sneezing, lethargy, anorexia, and fever
• URI: Infectious agents- Viruses (Dogs)

  • Influenza (H3N8 and H3N2)
  • Incubation period ~1-5 days
• URI: Infectious agents- Bacteria

  • Chlamydophila felis
  • Requires direct contact between cats
• URI: Infectious agents- Bacteria

  • Chlamydophila felis
  • Clinical signs: conjunctivitis, protruding 3rd eyelids, low grade fever, purulent ocular discharge, and sneezing
• URI: Infectious agents- Bacteria

  • Chlamydophila felis
  • Incubation period ~3-10 days
• URI: Infectious agents- Bacteria

  • Bordetella bronchiseptica
  • Highly infectious- through aerosolized respiratory secretions and fomites