Lecture 28 11/19/24

Question 1

What are the differential diagnoses for parenchymal diseases?

Answer 1

-pneumonia
-pulmonary hemorrhage
-pulmonary edema
-neoplasia
-pulmonary thromboembolism

Question 2

What are the characteristics of infectious pneumonia?

Answer 2

-lung inflammation caused by infection
-air sacs are inflamed and may fill with phlegm or pus
-infection can occur via airways, bloodstream, or secondary to trauma

Question 3

What are the infectious etiologies for pneumonia?

Answer 3

-fungal
-bacterial/Rickettsial
-viral
-protozoal
-parasitic

Question 4

Which fungal infections are most likely to lead to pneumonia?

Answer 4

-blastomycosis
-histoplasmosis
-coccidioidomycosis
-cryptococcosis

Question 5

How are fungal infections/fungal pneumonia be transmitted?

Answer 5

-infection through inhalation
-infection established in lung and then disseminated throughout body via blood/lymph

Question 6

What are the clinical findings in blastomycosis?

Answer 6

-loss of appetite
-weight loss
-fever
-possible cough
-respiratory abnormalities
-lymph node enlargement
-draining skin tracts
-lasts for days to months

Question 7

What are the clinical findings in histoplasmosis?

Answer 7

-respiratory signs
-GI disease
-joint and/or bone infections

Question 8

What are the clinical findings in coccidioidomycosis?

Answer 8

-asymptomatic or mild disease common
-acute/subchronic resp. disease
-fever
-weight loss
-skin, eye, bone, and pericardium infection
-latent infections that can reactivate

Question 9

What are the clinical findings in cryptococcus?

Answer 9

-upper resp. signs
-pulmonary signs
-mediastinal lymphadenopathy
-pleural effusion
-CNS, eye, and skin infection

Question 10

How are fungal infections diagnosed?

Answer 10

-history
-clinical signs/physical exam
-radiology
-cytology
-hematology
-serum chem
-serology
-culture

Question 11

What are the characteristics of radiology for fungal infection diagnosis?

Answer 11

-blasto can cause many different radiographic patterns
-can see miliary/snowstorm pattern, granulomas, lymphadenomegaly, etc.

Question 12

Which samples can be used for fungal diagnosis on cytology?

Answer 12

-fine needle aspirate of lymph nodes
-exudate from draining skin lesions
-TTW/ETW
-nasal exudate
-CSF
-anterior chamber aspirate
-rectal scraping

Question 13

What are the characteristics of hematology for diagnosis of histoplasma?

Answer 13

-non-specific
-leukopenia
-thrombocytopenia
-anemia
-organisms in monocytes or neutrophils

Question 14

What are the characteristics of serum chem. for diagnosis of blasto or histoplasma?

Answer 14

-increased polyclonal globulins
-decreased albumin
-potential for increased calcium

Question 15

What are the characteristics of fungal culture?

Answer 15

-dangerous outside of specialized labs
-requires special media
-results take days to weeks

Question 16

Which serology/urine tests are available for fungus?

Answer 16

-blasto: antibody; urine antigen
-histo: antibody; urine antigen
-coccidioides: antibody
-crypto: blood antigen

Question 17

Which antifungals are used to treat fungal infections in dogs and cats?

Answer 17

-itraconazole
-fluconazole
-amphotericin B/itraconazole combo for severe cases

Question 18

What are the characteristics of histo/blasto treatment?

Answer 18

-minimum of 6 months of antifungal treatment
-treat until resolution of clinical signs and diagnostic imaging abnormalities
-want a negative urine antigen test
-re-test animal 6 to 12 months are stopping therapy
-monitor anti-fungal drug levels during treatment

Question 19

What are the characteristics of fungal infection prognosis?

Answer 19

-depends on disease severity, systemic signs, and owner willingness to treat/monitor
-resp signs may get worse before animal gets better on treatment
-severe cases may require corticosteroids and hospitalization

Question 20

What are the characteristics of systemic aspergillosis?

Answer 20

-GSDs at higher risk due to hereditary IgA deficiency/dysfunction
-guarded prognosis
-can also develop cavitary lung lesions, diskospondylitis, and osteomyelitis

Question 21

What are the characteristics of bacterial pneumonia?

Answer 21

-lungs are not sterile and can have bacteria when healthy
-bacteria can reach lung via inhalation, aspiration, opportunistic invasion, or bloodstream
-animal may have underlying cause/comorbidity

Question 22

What predisposes an animal to bacterial pneumonia development?

Answer 22

-other lung disease
-parasites
-aspiration of GI contents/aerodigestive disorder
-severe debilitation/recumbency/malnutrition
-sequela to trauma or surgery
-immunosuppression
-IV catheter sepsis/urinary catheter infection
-anatomic or functional abnormality

Question 23

What are the characteristics of bacterial pneumonia presentation?

Answer 23

-can range from subclinical to life-threatening
-acute and chronic presentations possible
-often presents with non-specific signs

Question 24

What are the common isolates from bacterial pneumonia?

Answer 24

-Strep. zooepidemicus
-E. coli
-Pasteurella
-Staph.
-Pseudomonas
-Enterococcus
-Mycoplasma
-Klebsiella

Question 25

What are the clinical signs of bacterial pneumonia?

Answer 25

-productive cough -fever -depression -anorexia -dyspnea/resp. distress -nasal discharge

Question 26

What sounds heard on auscultation can be indicative of bacterial pneumonia?

Answer 26

-crackles -increased breath sounds -wheezes -silent areas

Question 27

How is bacterial pneumonia diagnosed?

Answer 27

-history -clinical signs/physical exam -radiology -bloodwork -hematology -serum chem. -blood gas -TTW/ETW

Question 28

Why is it beneficial to run a C reactive test during bloodwork?

Answer 28

-routine bloodwork can look completely normal in a bacterial pneumonia case -C reactive protein is a positive acute phase protein in dogs that indicates inflammation

Question 29

What are the characteristics of radiology as a diagnostic tool for bacterial pneumonia?

Answer 29

-does not give definitive diagnosis -can see a mixed interstitial or alveolar infiltrate pattern -lobar consolidation -want to look at hilar lymph nodes

Question 30

What are the characteristics of TTW/ETW as a diagnostic tool for bacterial pneumonia?

Answer 30

-done after radiographs to prevent fluid from interfering with imaging -want to do before antibiotics when possible -fluid used for cytology and culture -want to run mycoplasma, aerobic, anaerobic, and fungal cultures

Question 31

What are the goals of treatment for bacterial pneumonia?

Answer 31

-eliminate bacteria -eliminate lung inflammation -treat/address predisposing factors -treat patient aggressively

Question 32

What are the components of treatment for bacterial pneumonia?

Answer 32

-cage rest -oxygen therapy -nebulization -turning of recumbent animals -coupage -hydration and nutrition -antibiotics

Question 33

What are the characteristics of antibiotic treatment in bacterial pneumonia?

Answer 33

-begin with broad spectrum antibiotics -base treatment of culture/sensitivity results -antibiotics can be IV or oral -want antibiotics that can cross blood-bronchus barrier

Question 34

What should be avoided in the treatment of bacterial pneumonia?

Answer 34

-corticosteroids -diuretics -cough suppressants

Question 35

Which values can be monitored to determine if a patient is responding to bacterial pneumonia treatment?

Answer 35

-temp. -WBC count -radiographs -C reactive protein -clinical signs/appetite

Question 36

What are the characteristics of bacterial pneumonia treatment?

Answer 36

-minimum duration of antibiotic treatment is 2 weeks -animals should be re-evaluated 10-14 days after starting treatment -further treatment is based on animal's re-assessment and response

Question 37

What are the characteristics of surgery for treatment of bacterial pneumonia?

Answer 37

-best for foreign body-related pneumonia cases -considered only after aggressive medical treatment is unsuccessful -pulmonary lobectomy is performed

Question 38

What are the characteristics of aspiration pneumonia?

Answer 38

-occurs when foreign material is inspired into the lungs -can be iatrogenic -severity depends on frequency, volume, character of aspirate, pH of aspirate, and host immune response

Question 39

What are the underlying causes of aspiration pneumonia?

Answer 39

-cleft palate/anatomic abnormality -abnormal consciousness -neurologic disease -severe debilitation -megaesophagus -vomiting; especially while muzzled

Question 40

Why is vomit especially bad for the lungs?

Answer 40

-contains gastric acid -pH is less than 3.5 -often large volumes -particles are present -bacteria are present -presence of food can exacerbate inflammation

Question 41

What is the pathophysiology of aspiration pneumonia?

Answer 41

phase 1: airway response -immediate -direct damage -bronchoconstriction -airway edema phase 2: inflammatory response -4 to 6 hrs after aspiration -increased capillary permeability -increased neutrophils -pulmonary edema phase 3: secondary bacterial infection -does not occur in all cases

Question 42

What are the clinical signs of acute aspiration?

Answer 42

-cough -dyspnea -tachypnea -cyanosis

Question 43

What are the clinical signs of chronic aspiration?

Answer 43

-cough -anorexia -depression -weight loss

Question 44

What are the characteristics of aspiration pneumonia on radiographs?

Answer 44

-no immediate changes -alveolar infiltrates seen 12-36 hours after aspiration event -gravity will cause settlement in cranial ventral and right middle lung lobe areas

Question 45

What are the steps of aspiration pneumonia treatment?

Answer 45

-suction/establish airway -provide O2 -hydration -bronchodilators -possible antibiotics

Question 46

What should be avoided in aspiration pneumonia treatment?

Answer 46

-corticosteroids -lavage; pushes material deeper