Resp3- BRD

  1. BRD is a disease of... (4)
    stress, immunity (or lack of), pathogens, and environment/management
  2. What viral agents are involved in BRD complex? (6)
    IBR (bovine herpesvirus-1), BVDv, BRSV, PI-3, BRCV (bovine respiratory coronavirus), alcephaline herpes virus types 1 and 2 (ovine herpes virus type 2--> malignant catarrhal fever)
  3. Describe BRD in dairy calves.
    bronchopneumonia- "enzootic pneumonia"- housed calves
  4. Describe BRD in beef calves.
    bronchopneumonia- "Shipping fever"- recently shipped to stocker/feedlot
  5. Describe the general pathophysiology of the progression of BRD.
    viral infection-- (3-5 days)--> bacterial bronchopneumonia
  6. What are the 3 clinical entities of BRDC?
    infectious agents, compromised host defense, sub-optimal environment
  7. What commensal bacteria are often associated with BRDC? (5)
    Manheimia haemolytica, Pasteruella multocida, Histophilus somnus, Truperella pyogenes, Mycoplasma bovis
  8. Which BRD bacterium produces leukotoxin?
    Manheimia haemolytica
  9. What are the periods of highest incidence of BRD-associated disease? (3)
    birth to weaning, weaning to market (esp. beef calves), +/- adult diseases
  10. How do viral infections occur?
    stress induces cortisol, which is a major homeostatic hormone--> reduces innate/acquired immune responses--> novel or recrudescent viral infections
  11. How do bacterial infections enter and damage the lungs?
    gain access to lung after virus destroys mucociliary elevator/ epithelial barrier--> proliferation--> releases toxins--> recruits cells--> damage lung tissue
  12. What environmental factors can cause stress/decrease immunity? (8)
    heat, cold, moisture, dust, gases, crowding, filth, feed (dusty, moldy, etc)
  13. What predisposing factors can cause stress and lead to BRDC? (4)
    adverse environment, transportation, surgery, co-mingling of calves
  14. How can we manage the predisposing factors of BRDC to decrease morbidity and mortality? (5)
    weaning (backgrounding), processing procedures (vaccinating), feed type and quality (high quality feed, palatable feed, TMR), water (don't add antibiotics to water...unreliable method of delivery), maintain clean/stable environment
  15. Calves with __________ are at a higher risk for respiratory disease.
  16. What trace minerals must be supplied to increase immune function? (5)
    Cu, Zn, Se, Mn, Fe
  17. What vitamins must be supplied in order to ensure optimal immune function? (3)
    Vit A, D, E
  18. What are predisposing factors of the anatomy of the ruminant lung for BRD? (6)
    • intra- and interlobular connective tissue septae (if a portion becomes consolidated, there is no way to open it back up)
    • tracheal bronchus
    • pleura is thick
    • no collateral ventilation
    • long, narrow terminal bronchioles
    • marked hypoxic responses affecting ventilation/perfusion
  19. What are the major consequences of ruminant lung anatomy? (3)
    little lung unit interdependence, no collateral ventilation (lobules that become atelectic stay that way), well- developed inflammatory response (limits extension, inflammatory process confined, exudate removal is limited)
  20. Clinical signs of BRD. (15)
    depression, anorexia, tachypnea, shallow breathing, moist cough, head/neck extension, fever, droopy ears, lacrimation/discharge, dyspnea, rattle on auscultation, abducted elbows, lameness, bloat, diarrhea
  21. What causes a calf with pneumonia to look "sucked up"?
    decreased abdominal fill (anorexia)--> sunken paralumbar fossa
  22. What diseases are associated with hemoptysis? (2)
    [blood from nose and mouth] grain engorgement, subacute rumen acidosis
  23. Neonates are almost always predisposed to pneumonia by _____________.
    an episode of diarrhea
  24. What are predisposing factors for neonatal BRD? (5)
    diarrhea**, FPT (low IgG), LPS, sepsis, bad nipple (aspiration pneumonia)
  25. What is the main guiding principal for treating of bronchopneumonia in weaned calves?
    knowledge of acute or chronic
  26. Describe the pathophysiology of BRD in weaned calves.
    viral infection (BVD, IBR,PI3, BRSV, coronvirus)--> bacterial secondary infection (manheimia, histophilus, pasteruella, truperella, mycoplasma)
  27. What are organisms that cause acute bacterial bronchopneumonia in weaned calves? (3)
    Manheimia, Histophilus, Pasteruella
  28. What are organisms that cause chronic bacterial bronchopneumonia in weaned calves? (2)
    Mycoplasma, Arcanobacterium/ Truperella
  29. Describe the distribution of P. multocida and the macroscopic pathology associated. (3)
    cranioventral, firm sharp area of demarcation, suppurative
  30. P. multocida bronchopneumonia is ___________ and usually occurs in ___________.
    suppurative; housed dairy calves
  31. Describe the distribution of shipping fever and the macroscopic pathology associated. (4)
    bilateral, cranioventral, interlobular edema, fulminant (crosses interlobular septae)
  32. Shipping fever is ____________ bronchopneumonia that presents as a(n) __________ process that involves __(2)__.
    fibrinous; acute; LPS and leukocyte death (Manheimia)
  33. Describe the distribution of Mycoplasma pneumonia and the macroscopic pathology associated. (5)
    chronic, airway centered, lymphoid hyperplasia, caseonecrotic bronchopneumonia, polyarthritis, nodular
  34. Describe the auscultation of an adult ruminant.
    inspiratory sounds are soft, expiratory sounds are nearly inaudible, significant pulmonary pathology can be present without any abnormal lung sounds
  35. What might absence of lung sounds mean? (3)
    normal, pleural effusion, pneumothorax
  36. What are the lung auscultation borders in an adult ruminant?
    11th rib at point of hip (tuber coxae), 9th rib at point of shoulder, 5th rip at point of elbow
  37. What are causes of aspiration pneumonia in a young calf? (2)
    tube fed (accidentally put tube in wrong pipe), re-using nipple bottles for too long
  38. What are causes of aspiration pneumonia in adult cows? (2)
    • milk fever, down, weak, aspirates rumen content
    • milk fever, treated with oral propylene glycol, wrong pipe accidentally
  39. What are the treatment recommendations for aspiration pneumonia? (3)
    • control inflammation: dexamethasone or banamine
    • antimicrobials: ceftiofur, oxytet
    • Supportive care: fluids, electrolytes, nutrition
  40. What is embolic pneumonia?
    mastitis/metritis/rumenitis/liver abscess/endocarditis--> bacterial embolic shower--> emboli lodge in lung--> lung abscesses
  41. What causes metastatic pneumonia? What are the consequences?
    usually repeated episodes of rumenitis--> liver abscess follows--> septic thrombi develop in caudal vena cava--> anemia, hemoptysis, melena
  42. What is the treatment for metastatic pneumonia?
    often unrewarding but you can do long-term penicillin (watch out for residues!)
  43. Acute bovine pulmonary emphysema is _____________ caused by... (3)
    interstitial pneumonia; fog fever, moldy sweet potatoes, perilla ketones
  44. Describe acute pulmonary emphysema and edema associated with fog fever pathogenesis.
    adult cows moved from sparse dry forage to lush grass > 4% tryptophan--> metabolized to 3-methylindole in rumen--> 3-MI goes to lung and is metabolized by Clara cells to reactive intermediates--> cell necrosis--> lung inflammation
  45. What are the classic lesions associated with acute bovine pulmonary emphysema? (7)
    diffuse alveolar epithelial necrosis, hyaline membrane formation, type II alveolar epithelial cell hyperplasia, +/- multinucleate giant cells, edema, transcellular necrosis, coagulation of blood proteins
  46. What are the clinical signs of acute bovine pulmonary emphysema? (7)
    severe dyspnea, expiratory grunting, foam from mouth and nostrils, head/neck extended, open mouth, soft respiratory sounds, no coughing
  47. What is the treatment plan for acute bovine pulmonary emphysema? (4)
    generally palliative, banamine, monensin (1 day prior to changing feed), lasalocid (requires feeding 6 days prior to exposure)
  48. How do hyaline membranes form in acute bovine pulmonary emphysema?
    protein coagulates into a firm clot in the alveolus
  49. Atypical interstitial pneumonia occurs in _________; it is characterized by...
    feedlot animals; multinucleate giant cells (syncytia) in parenchyma (often associated with BRSV)
  50. What is the "tater toxin"?
    4-ipomeanol- mold toxin found in moldy sweet potatoes that is a potent lung toxicant (more severe than 3-MI with fog fever)
  51. What is the treatment for moldy sweet potato intoxication?
    theres no treatment! don't feed cows moldy potatoes!
  52. What plant produces ketones that are potent pneumotoxicants?
    perilla (purple) mint- grows well in late summer, fall in semi-shaded areas [Missouri]
  53. What causes verminous pneumonia?
    lung worms- Dictyocaulus viviparous
  54. Parasitic bronchitis and pneumonia causes __(2)__.
    alveolar and interstitial pneumonia
  55. Describe the life cycle of D. viviparous.
    [direct life cycle] adults live in airways, lay eggs, larvae are coughed up and swallowed, larvae passed in feces--> L3 on grass are eaten, migrate to airways--> repeat
  56. How long is the pre-patent period of D. viviparous?
    21-28 days
  57. What are the clinical findings with parasitic pneumonia? (8)
    eosinophilic exudate, coughing, tachypnea, pneumonia with caudoventral consolidation, fever, harsh lung sounds, open mouth breathing, +/- death if a large number of larvae penetrate at once
  58. With parasitic pneumonia, there are no clinical signs until...
    larvae penetrate the alveoli
  59. Coughing and tachypnea associated with parasitic pneumonia persist until...
    the pre-patent period is complete.
  60. How does re-infectin syndrome occur with parasitic pneumonia?
    after treatment, when larvae rapidly re-infect lungs of cattle introduced to infected pastures
  61. How do you diagnose lungworms? (2)
    • Baermann sedimentation of feces
    • trans-tracheal wash and visualization of larvae, eggs, adults
  62. How do you treat lungworms? (3)
    • Levamisole phosphate (oral, SQ, topical)
    • Ivermectin
    • Benzimidazole (fenbendazole, panacur)
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Resp3- BRD
vetmed resp3