Infectious respiratory diseases Flashcards
CIRD = ?
Describe it.
Canine infectious respiratory disease
complex
- CIRD, kennel cough, infectious tracheobronchitis
- Very common worldwide
- Highly contagious
- Most prevalent in dense dog populations
- Affects larynx, trachea, bronchi, nasal mucosa
CIRD – etiology (5+3)
multifactorial
- Viruses
Canine parainfluenza virus
Canine respiratory coronavirus
Canine adenovirus-2
Canine herpesvirus
Canine influenza virus - Bacteria
Bordetella bronchiseptica
Mycoplasma spp.
Streptococcus equi sp. zooepidemicus
Which of these CIRD pathogens can be vaccinated against?
- Viruses
Canine parainfluenza virus
Canine respiratory coronavirus
Canine adenovirus-2
Canine herpesvirus
Canine influenza virus - Bacteria
Bordetella bronchiseptica
Mycoplasma spp.
Streptococcus equi sp. zooepidemicus
parainfluenza
adenovirus
bordetella
CIRD – clinical signs and findings (4)
- Loud and persistent cough
- Bright, alert, no fever
- Normal respiratory rate and pattern
- No crackles or wheezes on auscultation,
lung sound may be increased
CIRD – diagnostic evaluation
Physical exam, no further testing
Otherwise healthy dog
Cough but in good condition
History of Recent exposure to other dogs
Usually is mild and self-limiting disease (< 10 days).
Complications:
Bacterial pneumonia (especially irish wolfhounds), Bordetella -tracheobronchitis (which can last weeks)
All coughing dogs do not need antibiotic treatment!
CIRD – diagnostic evaluation.
Do further diagnostic testing in which cases?
Febrile, inappetent, lethargic dog
Concurrent illnesses
Immunosuppressive medication
Breed
History of Long-lasting cough
Do Thoracic radiography, blood work,
bronchoscopy, bacterial culture
Describe Bacterial tracheobronchitis.
Occurs in Dogs. Is a Bacterial infection of the airways, but not parenchyma (so not pneumonia). Can be a complication of CIRD.
Most commonly Bordetella bronchiseptica.
You can die of pneumonia but not of tracheobronchitis cause its on the surface of the airways not within the parenchyma.
Bacterial tracheobronchitis presents with (4)
Acute or chronic cough
+ bacterial growth in respiratory sample
+ lack of alveolar infiltrates in thoracic radiographs
+ usually no fever or hematological changes
Treatment of Bacterial tracheobronchitis.
- Treatment
Doxycycline 10-14 days
NB enamel discoloration can occur
Left: normal
Right: bacterial pneumonia with inflammatory cell infiltrate
Describe Bacterial pneumonia
Bacterial infection of airways and
pulmonary parenchyma.
Also called bronchopneumonia
Is more common in Dogs > cats
A potentially severe systemic infection!
50-70 % of cases require hospital treatment
Canine bacterial pneumonia - predisposing factors. (9)
- Viral respiratory infections
- Aspiration
- Ciliary dyskinesia
- Neoplasia
- Trauma, bleeding
- Smoke inhalation
- Pulmonary parasites
- Structural changes
Tracheal collapse, bronchiectasis,
bronchoesophageal fistula - Immune dysfunction
Medications, illnesses, primary dysfunction
Bronchiectasis is…
a long-term condition where the airways of the lungs become widened, leading to a build-up of excess mucus that can make the lungs more vulnerable to infection.
mirrored organ syndrome also called
Situs inversus
Canine bacterial pneumonia - causative bacteria (4)
- Gram negative rods (40-60% of cases)
E. coli, Pasteurella spp., Klebsiella spp. - Gram positive cocci (5-20% of cases)
Streptococcus spp., Staphylococcus spp. - Bordetella bronchiseptica
Significant in puppies and young dogs - Mycoplasma spp.
Commonly a co-infection - Mixed infection in 10-40% of cases
Canine bacterial pneumonia - typical patient
- Large breed dogs
- Less than 5 years of age
- Males overrepresented but we don’t know why
Canine bacterial pneumonia - clinical signs and findings
most typical: tachypnea, lethargy, abnormal auscultation
Next,
* Cough
* Fever
* Respiratory distress
* Anorexia
* Nasal discharge
* Weight loss
Irish Wolfhounds are prone to what respiratory disease?
immune mediated ciliary deficiency / ciliary dyskinesia / Rhinitis/Bronchopneumonia Syndrome
a rare congenital defect where the ciliary throughout the body do not function properly.
This can cause respiratory issues such as coughing, nasal congestion and exercise intolerance.
Canine bacterial pneumonia
- typical blood work (4+2)
Hematology
Left shift (too many immature in circulation)
Neutrophilia
Leukocytosis
Leukopenia
Hypoxemia common
Elevated C-reactive protein (CRP)
Canine bacterial pneumonia - thoracic radiography findings.
- Most important single diagnostic measure.
- Typical findings
Alveolar pattern
Usually several lung lobes affected
Cranial and ventral lobes, both sides - Take 2-3 views! (VD + 2 x lat)
patchy alveolar pattern
only 10% of dogs have this type of change in bacterial pneumonia
Canine bacterial pneumonia - respiratory sample
- Sampling, yes or no?
Antibiotic selection according to susceptibility
Bacterial culture takes time
Samples do not always grow
Bronchoalveolar lavage vs. transtracheal wash
Consider sampling at least in recurrent infections - Neutrophilic inflammation
Possibly intracellular bacteria
Feline bacterial pneumonia - diagnosis
- Hematology can be normal
Leukocytosis
Leukopenia and left shift uncommon
SAA can be elevated in acute cases but also can be normal. But you should do SAA anyway.
- Thoracic radiography (min. 2 views!)
Any pattern is possible!
Often alveolar changes
Interstitial, bronchial pattern
Can be normal - Respiratory sample? Can be challenging in cats.
FURTD – clinical signs
Nasal and ocular discharge, conjunctivitis should self-resolve in 1-2 weeks unless complications.
Calicivirus
Oral ulceration
Hypervirulent strains
Herpesvirus
Ulcerative keratitis, sometimes coughing and systemic disease
Image: left is calici, right is herpes
FURTD – clinical signs of Chlamydia felis (bacteria)
More an ocular than a respiratory pathogen!
Acute and chronic conjunctivitis,
ocular ulceration uncommon.
How to differentiate herpes and calici?
Calicivirus causes ulcers in the mouth.
Herpesvirus causes ulcers in the eyes.
Describe Eucoleus aerophilus (Capillaria aerophila) (in both dogs and cats)
Transmission from Ingesting eggs or earthworms
Infects airway mucosa and becomes embedded
Subclinical infection, chronic cough, respiratory distress. Can cause Eosinophilic bronchitis.
Fecal flotation better than Baermann in this case. But false negatives can occur so deworm anyway.
Fenbedazole 50mg/kg daily 10-14 days, ivermectin, maybe moxidectin too. NB long AB course
Describe Aelurostrongylus abstrusus (affects cats)
Common feline lungworm
Transmission by Ingestion of an intermediate host (snail, slug) or a bird or rodent which has ingested it.
Adult worms reside in terminal bronchioles and alveolar ducts.
Cough, wheezing, respiratory distress,
even death
Mimics asthma!
Larvae in feces (Baermann) or BAL
Fenbendazole 50mg/kg daily 10-14 days,
ivermectin, selamectin NB long AB course
Angiostrongylus vasorum vs. Dirofilaria immitis
predilection site?
size?
transmission?
migration?
Both parasites reside in the right heart and pulmonary arteries. Dirofilaria can grow up to 30 cm and Angiostrongylus only up to 1 inch.
Differences in Transmission:
Av: Eating slug, snail, frog containing infective larvae
Di: Transmitted by a bite of a mosquito containing infective larvae
Migration:
Av travels through the gut wall – liver – liver vasculature to right heart and pulmonary arteries, L1 penetrate bronchial and alveolar walls, are coughed up and ingested and passed out in feces.
Di travels in SC tissue and ends up pulmonary arteries and right
heart.
