Respiratory tract

Question 1

Rhinitis

Answer 1

A. Non-infectious: v. common, due to inhalation of material – inflam. of mucosa
B. Infectious: due to obligatory pathogens – airborne/droblets/haematogenous/intracanalicular spreading
-Forms: serous, catarrhal, fibrinous, croupous, diphtheroid, purulent

Question 2

Tracheitis

Answer 2

• (usually w. rhinitis, laryngitis, bronchitis)
• Causes: mechanical, bacteria, viruses, spores of moulds, parasites
• IBR
• Malignant Catarrhal Fever (Herpervirus)
• Influenza (Orthomyxov.)
• Aujeszky´s (Herpesv.)
• Distemper (Paramyxov.)
• Forms: catarrhal, purulent, fibrinous

Question 3

Bronchitis

Answer 3

• Bronchitis= macrobronchitis
• Bronchiolitis = microbronchitis
• Causes: bacteria, viruses, parasites, physic-chemical, allergens, toxins
• Macrobronchitis: Exudative inflam. – Acute/Chronic catarrhal, purulent, croupous, diphteroid, hemorrhagic, necrotic, putrid, granulomatous
• Microbronchitis: Endo- (serous, desquamative, purulent, proliferative, granulomatous), Peri- (acute/subacute/chronic)
• Conseq.: healing, changes in lumen: narrowing (bronchostenosis, obturation, compression), dilation (bronchiectasia, can be atrophic/hypertrophic), atelectasia, emphysema, pneumonia, secondary amyloidosis, FB: putrid bronchitis / gangrenous pneumonia

Question 4

Atelectasis

Answer 4

= less/no air, due to failure of alveoli to open/remain open

• Causes:
  
  • Congenital: aspiration of fetal fluids, obturation of bronchi, interstitial pneumonia
  • Aquired: obturation (exudate, bronchiolith, parasites, FB), compression (hydro-, pneumo-thorax, ascites, meteorism, tumor, granuloma)
• Location: diffuse/circumscribed – often in cran. Lobes
• Lesions: smaller, shrunken, darker, red/greyish-red, firmer, Ø crepitation when cut

Question 5

Emphysema

Answer 5

= more air than normal, air within the tissues

• Causes: forced inspiration/incomplete expiration -> excess residual air, animals “worked to death”, long-lasting agony, shock, drowning, allergic bronchio-spasm, etc.
• Location: diffuse/circumscribed
• Acute; pneumonia, atelectasis, bronchitis/chronic; narrow bronchial lumen, repeated physical overload, lung fibrosis
• Forms:
  1. Alveolar emphysema: due to partial obstruction of bronchus
• Acute: stretching beyond capacity
• Chronic: regressive changes, fatty degen., atrophy, necrosis…
  2. Interstitial em.:
• Acute: air from ruptured alveoli…
• Chronic: microbronchitis, recurrent phys. stress, etc.

Question 6

Circulatory disturbances of the lung

Answer 6

1. Hypostasis: PM change – blood acc. in deepest point of lung
2. Hyperemia
   - Active: physiol. – traning, pathol.; decr. O2 in alveoli (drowning/altitude), fast drainage of thoracic fluid, initial phase of inflam., perifocal hyperaemia, neural effect
   - Passive – congestion: dist. in L heart function, shock, torsion, agony
3. Congestion
4. Edema
   - Non-inflam.: haemodynamic changes, incr. permeability of capillary walls, decr. function of lymph vessels, hypoalbuminaemia
   - Inflam.: decr. work of heart -> “hypostatic pneumonia” due to passive hyperaemia
5. Hemorrhages: per diapedesis (RBC through vessel wall), per rhexin (trauma), per diabrosin (rupture)
6. Thrombosis: from blood vessels or lymph vessels
7. Embolism: thrombo-embolism, cell/cell-groups, air bubbles, fat droplets, FBs
8. Infarction: conseq. of thrombosis/embolism

Question 7

Pneumonia definition and forms

Answer 7

• Infection in one/both lungs, polyfactorial disease, mostly by microorganisms
• Bronchopneumonia: cranio-ventral lung lobes
  1. Catarrhal: serous-desquamative/purulent
  2. Fibrinous (croupous)
  3. Aspiration
  4. Interstitial: majority of lesions are in interstitium
  5. Suppurative (purulent)
  6. Embolic (metastatic)

Question 8

Catarrhal pneumonia

Answer 8

• Mildest form of inflam.
• Inf.: aerogen.
• Loc.: craniovent.
• Normal shape, slightly enlarged, dark red-grey, glandular, firm, cut surface: no crepitation + incr. fluid

Question 9

Fibrinous pneumonia

Answer 9

Fibrinous (croupous): more severe, spreads quickly, infects entire lobes

• Inf.: aerogen, hematogen.
• Loc.: craniovent./caudodors.
• Dark red, uniformly firm, usually lobar, necrotic areas, dry cut surface, usually no catarrhal-purulent exudate, fibrinous pleuritis, similar changes in regional lnn.

Question 10

Aspiration pneumonia

Answer 10

• Amniotic fluid, milk, saliva, food, drinking water
• Blood
• Fluid for gastric lavage/contrast medium
• Eructated/vomited gastric content
  a) Putrid bronchitis: putrefactive bacteria colonize MM of bronchi, necrosis, toxins->death
  b) Ichorous pneumonia: after a), from lympho-haematogenous inf./putrefactive bact./acute ichorous abscess/caverns

Question 11

Interstitial pneumonia

Answer 11

• Acute/subacute/chronic proliferative inflam.

- Darker tissue, less air – less crepit., homogenously firmer, flesh-like

Question 12

Suppurative pneumonia

Answer 12

• Typically embolic/metastatic, hematogenous/bronchiogenous
• Cattle+pig: Arcanobacterium pyogenes
• Rabbit: Staph. aureus
• Horse: Strep. equi, Rhodococcus equi

Question 13

Embolic pneumonia

Answer 13

-Possible nodules: necrotic foci, purulent abscess, gangrenous foci