Pulmonary disease Flashcards
What are the various pulmonary disorders (list–9)?
- Pneumonia
- Eosinophilic bronchopneumopathy (EBP)
- Pulmonary neoplasia
- Pulmonary edema: non-cardiogenic
- Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS)
- Pulmonary contusions
- Pulmonary thromboembolism (PTE)
- Idiopathic pulmonary fibrosis (progressive interstitial fibrosis)
- Lung lobe torsion and diaphragmatic hernias
Pulmonary disease–clinical signs
- Difficulty breathing–often expiratory pattern
- Inc. rate and effort
- Coughing
- Exercise intolerance
- Abnormal pulmonary sounds
- Compare to pleural disease
- Abnormal posture–orthopnea
Pneumonia
Overview
- Inflammatory disorder of pulmonary parenchyma
- Etiology (infectious)
- Bacterial–most common cause in dogs
- Viral–most common cause in cats
- Aspiration
- Fungal
- Parasitic (Paragonimus spp, Aelurostrongylus spp)
Pneumonia
Radiographs?
Characterized by?
Other clinical signs?
- Radiographic pattern helps distinguish dif. etiologies
- Characterized by soft, ineffectual cough
- Difficulty in breathing on expiration (animals often have both inspiratory and expiratory attern), dyspnea, tachypnea, cyanosis if severe
- Other clinical signs
- Nasal discharge
- Exercise intolerance
- Systemic signs–pyrexia, lethargy, anorexia
Bacterial pneumonia
More common in?
What occurs?
Primary bac. pneumonia?
- More common in dogs than cats
- Inflammation and consolidation of pulmonary tissue occurs
- Primary
- Younger dogs
- Bordetella
- Pasteurella
- Younger dogs
Bacterial pneumonia
Secondary bac. pneumonia
If history of recent sedation/anesthesia?
- Secondary bac. pneumonia
- Often older animals
- Aspiration
- Iatrogenic, loss of normal airway protection, megaesophagus, cleft palate, nasogastric tube, laryngeal paralysis, consciousness: anesthesia or neuro disease
- Foreign body (not common in lung tissue)
- Neoplasia
- Viral or fungal infection
- Bronchitis
- If hx of recent sedation/anesthesia, organism most likely is more resistant b/c it is assoc. w/ hospital infection; hospital/super bug
Bacterial pneumonia
Diagnosis
- Hematology
- L shift neutrophilic leucocytosis
- Monocytosis if more chronic
- Thoracic rads
- Interstitial pattern early in disease
- Alveolar pattern: air bronchograms are classical
- Often assoc. w/ R middle lung lobe pathology or cranioventral distribution
- Look for foreign bodies, megaesophagus, and other thoracic disease
- Radiographic changes lag behind clinical signs
- Transtracheal/endotracheal wash and cytology/culture
- Bronchoscopy w/ BAL and culture/cytology
- Can direct endoscopy to the lesion
- Usually get BAL samples from R middle and L caudal lung lobes (unless pus is visible elsewhere)
- Cytology–degen. neut, monocytes, intracellular bac.
- Bac. pneumonia can result in sepsis which can lead to ALI and ARDS (death)
Bacterial pneumonia
Treatment: antibiotics
- Begin empirical treatment pending culture results
- Broad coverage
- 4 quadrants: gram (+), (-), anaerobes, Mycoplasma spp
- Begin w/ injectable therapy, then change over to oral medication once under control
- Long-term therapy usually required–4-8wks, esp. if secondary
Bacterial pneumonia
Treatment: nebulization
Supportive care
- Nebulization
- Travels all the way down to lungs–> attaches to pus–> easier for animal to cough it up
- Mobilizes airway secretions
- Sterile saline +/- gentamycin
- May result in bronchoconstriction, may need to use a bronchodilator before nebulization
- Supportive care
- IV fluids, O2 therapy, and coupage
- Bronchodilators if required
Mycotic pneumonia
Etiology
- Blastomycosis
- Histomycosis
- Coccidiomycosis
- Aspergillosis
- Others
Mycotic pneumonia
Respiratory clinical signs
- Similar for all (chronic)
- Abnormal resp pattern
- Tachypnea
- Cough
- Exercise intolerance
- Systemic signs
- Inappetance, weight loss, fever, lameness, lymphadenopathy, chorio-retinitis or anterior uveitis, draining fistula tracts
Mycotic pneumonia
Diagnosis
Treatment
- Diagnosis
- Urine or serum ag titres
- Cytology/histopathology (biopsy)
- Treatment
- Depends on fungal sensitivity
- Polyene antifungals–amphotericin B ($$$)
- Triazoles–itraconazole, posaconazole, voriconazole, fluconazole
- Imadazoles–clotrimazole, ketoconazole
Mycotic pneumonia
How to tell which fungal organism is causing the clinical signs?
- Geographical location
- Coccidiomycosis–Arizona
- Blastomycosis/Histoplasmosis–Ohio river valley
- Difference in clinical signs or organs that are affected
- GI signs–histoplasmosis (+/- organism on rectal scrape)
- Cytology–lymph nodes, draining lesions, TTW, ETW, BAL, pulmonary aspirate
- Serology
- Serum antigen titre for Cryptococcus spp., Aspergillosis spp.
- Urine antigen titre for blastomycosis and histoplasmosis and valley fever (Miravista lab), Aspergillosis
Mycotic pneumonia
Treatment
- Expensive and long-term (4-12 mo)
- Oral medications
- Itraconazole more costly, fluconazole generics now avail.
- Posaconazole very $$–less hepatotoxic, esp. for cats
- Voriconazole very $$
- Side effects: inappetance, elevated liver enzymes
- IV/SC
- Amphotericin B–nephrotoxic (monitor BUN and Cr)
- Lipid complex form is more $$ but has fewer side effects, less nephrotoxic
- Amphotericin B–nephrotoxic (monitor BUN and Cr)
Mycotic pneumonia
Prognosis
- How disseminated is the infection
- Poorer prognosis if CNS is involved
- 1st week of treatment–greater chance of worsening resp signs
- Blastomycosis and cryptococcus–80% effectively treated
- Histoplasmosis–disseminated form has guarded prognosis, localized form has better prognosis
- Coccidiomycosis–60% recovery rate but medication often needed for 6-12 mo or longer (lifelong)
Blastomycosis
Geographical distribution?
Mode of infection?
Location in body?
- Distribution–North America
- Mississippi, Missouri and Ohio river valleys, Mid-Atlantic states and Canadian provinces of Quebec, Manitoba, and Ontario
- MOI
- Inhalation of spores from mycelial growth in environment
- Blastomyces dermatitis establishes in the lungs then disseminates throughout body
- Lungs
- Skin, eyes, bones, LN, SQ, nares, brain, testes
Blastomycosis
Clinical findings
- Often show no clinical signs–but then the signs develop and worsen very quickly
- 40-60% w/ fever
- Emaciated
- Lymphadenomegaly common
- 85% w/ dry harsh cough
- Exercise intolerance
- 40% w/ ocular lesions–uveitis, iridic hyperemia, aqueous flare, myosis, chorioretinitis, optic neuritis, retinal detachment
- 20-50% w/ skin lesions
- 30% w/ bone lesions
Blastomycosis
Diagnosis
- Imaging–rads, U/S, MRI
- Hematology and biochemistry
- Chronic anemia
- Moderate leucocytosis w/ L shift + lymphopenia
- Hyperglobulinemia
- Hypercalcemia
- Cytology or histopathology
- LN, skin lesions, TTW (69-76% sensitive), FNA of lung (81% sensitive) (pot. risk of pneumothorax w/ FNA)
- Serology
- PCR available
Blastomycosis
Diagnosis–serology
- AGID test
- Serum and urine samples
- 41-90% sensitive
- 90-100%
- Radioimmunoassays for Blastomyces
- 92% sensitive
- ELISA on urine
- 93.5% sensitive; also cross-react w/ histoplasma and blastomyces
What is this?

Blastsomyces dermatitis
Blastomycosis
Pathological findings?
Therapy?
- Pathological findings–pyogranulomatous lesions
- Therapy
- Amphotericin B
- Nephrotoxic–give slowly through IV
- 0.5mk/kg every other day
- Accumulated dose of 8-10mg/kg is required to cure blastomycosis
- Comes in lipid complex (less toxic)
- Costs more, high dose required
- Amphotericin B
Blastomycosis
Treatment
- Triazole
- Itraconazole
- Oral administration 5mg/kg OD for dogs, TD for cats
- In dogs start w/ TD administration for 5 days to inc. serum conc., then reduce to OD
- 60-90 days administration
- 68% response rate
- Adverse effects, anorexia assoc. w/ hepatotoxicity
- Oral administration 5mg/kg OD for dogs, TD for cats
- Itraconazole
Histoplasmosis
Epidemiology
- Histoplasma capsulatum
- Worldwide
- Midwestern and Southern US
- Regions along Mississippi, Missouri and Ohio river
- Likes soil that is high in bird or bat feces
- Midwestern and Southern US
Histoplasmosis
Clinical findings: dogs vs. cats
- Cats
- 2nd most common systemic fungal disease
- Disseminated dz
- Mental depression, wt. loss, fever, anorexia, pale mm
- Coughing uncommon, but dyspnea, tachypnea, and abnormal lung sounds are found
- Dogs
- Inappetance, wt. loss, fever unresponsive to antibiotics
- Signs can be limited to resp tract–dyspnea, coughing, abnormal lung sounds
- Signs are generally disseminated
Histoplasmosis
Diagnosis
- Hematology
- Chronic anemia
- Thrombocytopenia (50% dogs, 33% cats)
- Leukocyte counts vary–often get neutrophilic leucocytosis, monocytosis, and eosinopenia
- Biochemistry–may show hypoalbuminemia
- Imaging–rads, U/S
- TTA/BAL (cytology)
- Organism found w/in mononuclear-phagocyte system
- Single or multiple organisms
- FNA/biopsy–cytology/histo
- Serology–no test is reliable
What is this?

Histoplasmosis
Histoplasmosis
Therapy
-
Itraconazole treatment of choice
- 10mg/kg once to twice daily (some cats)
- Treat 4-6mo
- Fluconazole
- Better penetration into brain and eye (good for cats w/ neuro signs)
- But not that effective
- Voriconazole and posaconazole
- Penetrates blood brain barrier
- Amphotericin B used in severe cases
Cryptococcosis
Etiology/epidemiology
- Cryptococcus neoformans and C. gattii
- Worldwide
-
C. neoformans
- Usually assoc. w/ avian droppings
-
C. gattii
- Assoc. w/ Eucalyptus trees
- Also found in British Columbia and California
Cryptococcosis
Clinical findings (cats and dogs)
- Animals often immunosuppressed
- Cats
- Chronic infection, chronic listlessness, wt. loss, poor appetite
- Bilateral nasal discharge, snuffly
- Firm to flucuant swelling over bridge of nose
- Lymphadenopathy–mandibular
- Neuro signs if CNS affected, ocular lesions
- Dogs
- Frequently have disseminated dz
- 2/3 have neuro signs
Cryptococcosis
Diagnosis
- Hematology and biochemistry
- Usually non-specific
- Cytology
- Nasal swab, nasal wash, FNAs, BAL, pleural fluid, CSF, urine
- Thick capsulated yeast
- Tissue biopsy
- Fungal isolation
- Easy to grow
- Serology
- Serum, CSF
- Latex-agglutination procedure test (90-100% sensitive, 97-100% specific)
- Nucleic acid detection
- PCR–highly sensitive and specific (only used if other methods fail)
What organism is this?

Cryptococcus spp
(Cytology on L, histopathology on R)
Cryptococcosis
Treatment
- Surgery
- Therapy (long–8-9mo)
- Amphotericin B
- Fluconazole–10mg/kg BD
- Itraconazole–10mg/kg OD
- Voriconazole and posaconazole
- Monitoring
- Use LAT–antigen titre should drop at least one dilution (2 fold) per month during effective treatment
- Continue therapy until LAT is negative
Coccidioidomycosis
Organism?
Environment?
Epidemiology?
Known as?
- Coccidioides spp.
- Likes dry environment
- Epidemiology
- Southwestern US
- A few places w/in South America
- “Valley fever”
Coccidioidomycosis
Clinical findings?
- Dogs
- Dry, harsh cough–usually due to hilar lymphadenopathy or diffuse pulmonary interstitial disease
- Fever, partial anorexia, wt. loss, weakness, lameness
- Can become disseminated
- Cats
- Similar signs as dogs, but the cutaneous lesions are most common in cats
Coccidioidomycosis–diagnosis
Hematology?
Imaging?
- Hematology
- Non-regenerative anemia
- L-shift neutrophilia and monocytosis
- Eosinophilia–variable
- Imaging
- Thoracic rads
- Diffuse interstitial pattern
- Miliary to nodular interstitial densities
- Solitary nodules
- Hilar lymphadenopathy
- U/S
- MRI
- Thoracic rads
Coccidioidomycosis–diagnosis
Cytology/histopathology
Fungal culture
Serology
- Cytology or histo
- Organism found along w/ pyogranulomatous inflammation
- Round, double-walled structure containing endospores
- Fungal culture–difficult, use proper labs
- Serology
- Tube precipitation antigens (less use today)
- Body produces IgM antibodies
- Complement fixation antigens (less use today)
- Body produces IgG antibodies
- Latex agglutination for IgM or IgG
- AGID test for IgM or IgG–antibodies
- Elisa test for IgM or IgG–antibodies
- Tube precipitation antigens (less use today)
What organism is this?

Coccidioides spp
Coccidioidomycosis
Treatment
Prognosis
- Treatment
- Azoles
- 3-6mo past resolution of clinical signs
- Ketoconazole, itraconazole, or fluconazole
- Azoles
- Prognosis
- Good for resp disease
- Poor for disseminated disease
Parasitic pneumonia
Two main worms (cats/dogs)?
-
Aleurostrongylus abstrusus (cat lungworm)
- Larvae may be found in feces
- TTW/ETW–cytology
- BAL–cytology
-
Paragonimus kellicoti (dog/cat lung fluke)
- Operculated egg
Aleurostrongylus abstrusus
What is it?
Signs?
Diagnosis?
Treatment?
- Feline lungworm
- Can have subclinical to clinical signs similar to asthma
- Usually younger cats
- Diagnosis
- Hematology–poss. eosinophilia
- Thoracic rads–diffuse nodular densities, caudal lobes
- TTW/BAL–inc. # of eosinophils and/or larvae
- Fecal–larvae evident
- Treatment
- Fenbendazole
- Ivermectin

Aleurostrongylus abstrusus
Life cycle?

Paragonimus spp. pneumonia
Signs?
What forms?
Possible end result?
- Can be subclinical or clinical–cough, wheeze, or resp distress
- Flukes form cysts w/in lungs
- Cysts can easily rupture–> pneumothorax
Paragonimus spp pneumonia
Diagnosis?
- CBC–eosinophilia
- Thoracic rads–air-filled cysts
- TTW/BAL
- Fecal–zinc sulphate fecal float
- Operculated egg

Paragonimus spp
Life cycle?

Idiopathic pulmonary fibrosis–progressive interstitial fibrosis
What is it?
Signalment?
- Chronic fibrosis of the lung interstitium characterized by infiltration of fibroblasts; collagen deposits in alveolar septa
- Signalment
- West Highland White Terrier
- Middle or older
- Some cats
Idiopathic pulmonary fibrosis–progressive interstitial fibrosis
History?
Clinical signs?
- History
- Slow onset, exercise intolerance
- Clinical signs
- Depends on severity, resp distress, tachypnea
- Coughing increases as it progresses
- Wt. loss in cats
Idiopathic pulmonary fibrosis–progressive interstitial fibrosis
Diagnosis
- Very difficult
- Inspiratory crackles on auscultation (hallmark)
- Thoracic rads
- Generalized or diffuse interstitial pattern
- Arterial blood gas
- Hypoxemia if severe
- TTW/BAL
- Eliminate other differentials
- Epithelial dysplasia? Non-regenerative neut and lymphocytes
- Lung FNA
- Lung biopsies–definitive diagnosis
Idiopathic pulmonary fibrosis–progressive interstitial fibrosis
Treatment?
Prognosis?
- Lack of specific treatment
- Corticosteroids (not very effective alone) + bronchodilators aleviate clinical signs of chronic bronchitis
- Cyclophosphamide or azathioprine?
- Colchicine?
- Prognosis
- Guarded
- Progressive resp failure
Pulmonary neoplasia
Etiology–primary vs. metastatic vs. multicentric
- Primary
- Adenocarcinoma (alveolar or bronchogenic)
- SCC
- Metastatic
- Many sources
- Adenocarcinoma
- Osteosarcoma/chrondrosarcoma
- Hemangiosarcoma/oral or digital melanoma
- Many sources
- Multicentric
- Lymphoma, malignant histiocytosis, mastocytoma
Pulmonary neoplasia
Signalment?
Clinical signs?
- Signalment–usually older animals
- Clinical signs
- Wide spectrum
- Respiratory
- Abnormal thoracic auscultation, crackles, wheezes, or muffled sounds
- Cough (from compression), dyspnea, tachypnea, hemoptysis
- Non-resp signs
- Wt. loss, inappetance
- Lameness (hypertrophic osteopathy)
- Dyshagia/regurgiation (MG)
- Edema of head/neck (venous obstruction)
Pulmonary neoplasia
Radiographs?
Cytology/histo?
- Thoracic rads
- 3 views essential (2 laterals and DV/VD)
- Assess LN size
- Assess pleural space (pneumothorax, effusion)
- Cytology/histopathology
- FNA–lung/mass
- Bronchoscopy (BAL or biopsy)
- If metastatic find primary mass and sample
Pulmonary neoplasia
Treatment
Prognosis
- Treatment
- Primary
- Surgical removal–lung lobectomy
- Metastatic/multicentric
- Treat primary mass
- Chemotherapy (lymphoma)
- Primary
- Prognosis
- Guarded to poor
- If it is a solitary mass or benign mass–prognosis good w/ surgical removal
Pulmonary neoplasia
Prognostic factors (common sense)
- Benign better than malignant
- Primary better than metastatic
- Adenocarcinoma better than SCC
- Small tumors better than large tumors
- Tumors involving one lobe better than mult. lobes
- No LN involvement is better
Pulmonary edema
What is it
2 possible origins
- Accumulation of fluid in alveoli or pulmonary interstitium
- Cardiogenic or non-cardiogenic in origin
Non-cardiogenic pulmonary edema
4 mechanisms?
- Vascular overload/inc. hydrostatic pressure
- IV fluid overload
- Decreased plasma oncotic pressure
- Low albumin
- Increased alveolar-capillary membrane permeability
- Pulmonary insults–aspiration, upper airway obstruction, smoke
- Non-pulmonary insults–sepsis, electric shock, CNS (seizures, head trauma), pancreatitis, DIC
- Lymphatic obstruction
Non-cardiogenic pulmonary edema
Interference?
Can progress to?
- Fluid accumulation interferes w/ ventilation and perfusion
- Can progress to
- Accute lung injury and/or
- ARDS
- Resp failure
Non-cardiogenic pulmonary edema
Thoracic auscultation?
Thoracic rads?
Looks for what?
- Hear crackles–caudal/dorsal area
- Thoracic rads
- Alveolar pattern–bilateral
- Caudo-dorsal lung fields
- Looks for underlying disease

Non-cardiogenic pulmonary edema
Treatment
- Aggressive control of primary/underlying disease
- Cage rest and O2 therapy
- Supportive care
- Sedation–reduce anxiety, O2 requirements and cardiac workload
- IV fluids–be very careful
- Positive pressure ventilation–if required
Non-cardiogenic pulmonary edema
Prognosis
- Guarded w/ permeability edema pathogenesis
- Depends on underlying disease
- Ex: Ehrlichia–more difficult to treat
- Increase alveolar-capillary membrane permability
- Depends on underlying disease
- Better when there is no fluid overload or renal function is intact
Respiratory distress
Types?
Commonly secondary to what?
- Acute lung injury (ALI)–pulmonary inflammation and edema resulting in acute resp failure
- Acute resp distress syndrome (ARDS)–severe manifestation of ALI; hypoxemia is worse
- ALI/ARDS commonly secondary to sepsis, systemic inflmmatory distress syndrome, sock or bac. pneumonia
- With known FiO2:
- PaO2/FiO2 < 300 = ALI
- PaO2/FiO2 <200 = ARDS
- Raised alveolar-arterial O2 gradient
- With known FiO2:
Respiratory distress
Clinical signs?
Current theray?
Prognosis?
- Clinical signs can be delayed 1-4d after inciting event
- Progressive hypoxemia, resp distress, cyanosis
- Therapy
- Aggressive supportive care that requires ICU
- Positive pressure ventilation
- Prognosis
- Mortality rate very high–close to 100%
Pulmonary contusions
Various degrees of what?
Thoracic auscultation?
Concurrent pathology w/ trauma?
- Various degrees of resp distress
- Thoracic auscultation–crackles
- Concurrent pathology
- Pneumothorax/hemothorax
- Herniation
- Myocarditis
- Rib fractures
- Hypotension
Pulmonary contusions
Thoracic radiographs
Treatment
- Radiographic evidence can take 2-12hrs to show up
- Consolidation
- Treatment
- Monitor closely for 24-48hrs
- O2 therapy
- IV fluids
- Pain medication for trauma

Eosinophilic bronchopneumopathy
What is it?
Antigen?
Signalment?
- Inflammation of lungs–thought to be due to a hypersensitivity to some unknown antigen
- Lots of eosinophils roduced–>infiltrates to lungs
- Usually the antigen is not detected, but possibilities include:
- HW, lung parasites, drugs, inhaled allergens, neoplasia, fungal, bac. infections
- Signalment
- Siberian huskies predisposed
- Young to middle-aged
Eosinophilic bronchopneumopathy
Clinical signs
- Harsh cough
- Progressive resp difficulty, exercise intolerance
- Some have nasal discharge or anorexia/lethargy
- Lack of response to antibiotics
Eosinophilic bronchopneumopathy
Diagnosis
- Thoracic auscultation–harsh crackles, expiratory wheezes
- Tracheal palpation may elicit moist productive cough
- Hematology–50% have inc. neuts or eos
- Ensure HW (-) and fecal float (-)
- Eosinophilia often assoc. w/ parasites
- Pulse oximetry and arterial blood gas
- Hypoxemia can be marked
- Can persist post-recovery
- Thoracic rads
- Diffuse bronchointerstitial pattern, alveolar infiltrates, bronchiectasis
- Cytology–eos predominate (>20-25%)
Eosinophilic bronchopneumopathy
Treatment
- Find and treat any underlying disease
- Even if no evidence of lungworms–fenbendazole
- Corticosteroids
- Prednisolone–taper over several months depending on clinical radiographic response
- Often required long-term due to relapses
- Try inhalation steroids
- Other immunosuppressives can be tried–cyclosporin, azathioprine
Pulmonary thromboembolism (PTE)
Associated with?
- HW
- Immune-mediated hemolytic anemia
- Nephrotic syndrome
- Hyperadrenocorticism–hypercoagulability
- Pancreatitis
- DIC
- Endocarditis
PTE
Treatment
Prognosis
- O2 supplementation
- No stress
- Treat underlying disease
- Bronchodilators
- Prednisolone in IMHA and HW cases
- Low dose heparin if DIC or hypercoagulable
- Prognosis–poor to grave