Unit 3 - Respiratory Lecture 3 Flashcards
What are some differentials for a dog that is coughing?
infectious, heart disease, allergies, tonsillitis/sore throat, collapsing trachea, neoplasia
What are some infectious causes that cause a dog to cough?
kennel cough, pneumonia, parasitic, fungal
What breeds are commonly affected with collapsing trachea?
toy and miniature breeds - Yorkshire terriers, pomeranians, toy poodles, maltese, italian greyhounds, and chihuahuas
Is collapsing trachea chronic or acute?
chronic
How do you induce a cough in a dog with collapsing trachea?
by putting pressure on the trachea
What body condition can lead to collapsing trachea?
obesity
What type of environment can lead to collapsing trachea in a dog?
a household with smokers
What age is typically affected with collapsing trachea?
middle age or older dogs
Where does the trachea typically collapse?
at the thoracic inlet
What are the different grades of tracheal collapse and what percentage of collapse is associated with them?
grade 1 - 25%
grade 2 - 50%
grade 3 - 75%
grade 4 - 100%
What is the pathogenesis of collapsing trachea?
- C-shaped cartilaginous rings start to weaken and begin to flatten out
- As cartilaginous rings weaken, the dorsal tracheal membrane and trachealis muscle stretches, becomes wider
- The trachea collapses under negative pressure
- Collapse leads to mucosal irritation, increased secretion, inflammation, and cough
What is brachycephalic airway syndrome?
a heritable condition of brachycephalic breeds that causes undersized and/or malformed air-passages
What clinical signs are associated with brachycephalic airway syndrome?
stertorous breathing, loud snoring, coughing, gagging, exercise intolerance with cyanosis, may prefer to sleep on their backs
What may exacerbate clincial signs in dogs with Brachycephalic Airway Syndrome?
obesity or stressful situations such as overheating, excitement, and exercise
What primary anatomic components are associated with Brachycephalic Airway Syndrome (morphologic changes)?
elongated soft palate, stenotic nares, hypoplastic trachea
What secondary anatomic components are are associated with Brachycephalic Airway Syndrome (morphologic changes)?
everted laryngeal saccules, everted tonsils, laryngeal collapse
When should you consider distemper as a disgnosis based on clinical signs?
unvaccinated animal with GI and/or respiratory and/or neurologic signs
What is the pathogenesis of canine distemper virus (CDV)?
- unvaccinated
- Exposed to CDV
- CDV viremia
- Spreads to the epithelium of the respiratory, gastrointestinal, urogenital tracts, and the central nervous system
What is the link between CDV and bacterial pneumonia?
CDV is immunosuppresive and causes pneumocyte, bronchiolar, and alveolar epithelial and macrophage necrosis that causes bacterial bronchopneumonia
What clinical signs are associated with blastomyces infections in dogs (these are from a sepcific case)?
mild fever, visual difficulties, anorexia and weight loss, non-healing draining skin lesion, depression and decreased stamina, persistant cough and shortness of breath that gets worse over time
What population of dogs are Blastomyces infections common in?
large, male dogs 1-5 years of age especially in dogs that hunt or roam
What type of pneumonia does Blastomyces cause in dogs?
interstitial pneumonia
What is the pathogenesis of Blastomyces infection?
- fungus grows in soil
- Conidia inhaled
- Fungus becomes a yeast at elevated temperature of host
- hematogenous and lymphatic dissemination (lung, bone, skin, brain, eyes)
- systemic blastomycosis
- in lung, macrophages release cytokines recruiting additional inflammatory cells into the interstitium
- interstitial pneumonia
In lung lobe torsion, where does the lobe typically twist?
at the level of the base of the heart
What is the pathogenesis of lung lobe torsion turning into respiratory distress?
- Torsion
- Muscular artery continues to pump blood into the lobe but vein is compressed
- venous congestion
- infarction
- Serosanguinous fluid leaks from necrotic lung
- serosanguinous thoracic effusion
- Atelectasis
- Respiratory distress
What is the pathogenesis of progressive atrophic rhinitis in swine?
- Bordatella bronchiseptica coloniezes nasal epithelium
- Rhinitis
- Toxigenic Pasteurella multocida type D colonizes damaged nasal mucosa
- elaboration of cytotoxins which disrupt osteogenesis of the turbinate bone
- Atrophic rhinitis
What are some clinical signs associated with swine influenza?
acute onset, fever, high morbidity, barking cough
What gross appearance does SIV have in the lungs?
pigs have patchy, lobar consolidation, that is more severe in the anteroventral lung
What damage does Mycoplasma hyopneumoniae do?
it binds to the cilia causing ciliostasis, clumping and loss of cilia, and loss of airway epithelial cells
What clinical signs are associated with a Mycoplasma hyopneumoniae infection?
there are typically no clinical signs
What gross lesions are associated with Mycoplasma hyopneumoniae?
mild, patchy, anteroventral consolidation
What type of pneumonia does Mycoplasma hyopneumonia + a secondary bacterial infection cause?
bronchopneumonia
What is the pathogenesis of Mycoplasma hyopneumoniae + a secondary bacteria leading to bacterial bronchopneumonia?
- Mycoplasma hyopneumoniae colonizes respiratory epithelium
- Causes ciliostasis, loss of cilia, decreased epithelial cells and goblet cells
- decreased mucociliary clearance
- Bacterial broncopneumonia
What clinical signs are associated with a Mycoplasma hyopneumoniae and a secondary bacterial infection?
chronic, non-productive cough with decreased weight gain
What key gross features are associated with a Mycoplasma hyopneumoniae and a secondary bacterial infection?
well-demarcated, tan colored, anteroventral consolidation in the lung
Where do lesions associated with Actinobacillus pleuropneumonia typically localize?
NOTE: the pathogenesis will be in the picture flashcard set
the dorsal portion of the caudal lung lobe in the region of the hilus
What causative agents cause the lungs in a pig to be diffusely tan, mottled, heavy, rubbery and non collapsing (interstitial pneumonia)?
PRRSV (porcine reproductive and respiratory syndrome virus), PCV2 (porcine circovitus type II), Salmonella choleraesuis septicema, ascarid larval migration
What is the pathogenesis of Haemophilus parasuis infection?
- Aerosol exposure to new strain
- Colonizes nasal cavity
- Bacteremia
4a. Seeds in the meninges causing meningitis
4b. Seeds in the joints causing arthritis
4c. Seeds in serosal surfaces causing polyserositis
