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Flashcards in Pulmonary disease Deck (69)
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1

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 

2

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

3

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)

4

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

5

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

6

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

7

Bacterial pneumonia

Diagnosis

  1. Hematology
    • L shift neutrophilic leucocytosis 
    • Monocytosis if more chronic 
  2. 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
  3. Transtracheal/endotracheal wash and cytology/culture
  4. 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.
  5. Bac. pneumonia can result in sepsis which can lead to ALI and ARDS (death)

8

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

9

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

10

Mycotic pneumonia

Etiology

  • Blastomycosis
  • Histomycosis
  • Coccidiomycosis
  • Aspergillosis
  • Others

11

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

12

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

13

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

14

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

15

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)

16

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

17

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

18

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

19

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

20

What is this?

Blastsomyces dermatitis

21

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

22

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

23

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

24

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 

25

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

26

What is this?

Histoplasmosis

27

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

28

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

29

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

30

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)