Bovine Respiratory Disease

Question 1

what does bovine herpesvirus 1 do?

Answer 1

replicates in and destroys airway epithelial cells
latency

Question 2

what is bovine herpesvirus 1 termed?

Answer 2

bovine infectious rhinotracheitis (IBR)

Question 3

how do viral particles spread cell to cell?

Answer 3

directly: avoid neutralizing antibodies in extracellular fluid

Question 4

what are the immunosuppressive effects of bovine herpesvirus 1?

Answer 4

induction of apoptosis in CD4+ T cells
MHC I and MHC II molecule expression down regulated
lysis of ciliated epithelial cells: decreased mucociliary clearance

Question 5

what are two paramyxoviruses that infect the bovine respiratory tract?

Answer 5

bovine respiratory syncytial virus (BRSV)
parainfluenza-3 (PI-3)

Question 6

what is the hallmark of infectious bovine rhinotracheitis?

Answer 6

erosions and ulcers in upper respiratory tract

Question 7

what is the etiologic agent of contagious bovine pleuropneumonia (CBPP)?

Answer 7

Mycoplasma mycoides var. mycoides small-colony (SC) type

Question 8

where is contagious bovine pleuropneumonia prominent?

Answer 8

Africa
Aisa
sometimes Europe
eradicated from US in 19th century

Question 9

what is Mannheimia haemolytica?

Answer 9

gram negative bacterium associated with acute fulminating pleuropneumonia in cattle

Question 10

what are the virulence factors of Mannheimia haemolytica?

Answer 10

protein adherence to tracheal epithelial cells
endotoxin
secreted enzymes
specific leukotoxin produced during log phase growth

Question 11

how does the leukotoxin that Mannheimia haemolytica secretes lyse cells (high contentrations)?

Answer 11

forms transmembrane pores that allow ion influx and ultimately cell rupture

Question 12

what organism is most commonly associated with bovine respiratory disease complex (shipping fever pneumonia)?

Answer 12

Mannheimia haemolytica

Question 13

what is Mannheimia haemolytica pneumonia characterized by?

Answer 13

cranioventral fibrinopurulent pleuropneumonia

Question 14

what happens in bovine respiratory disease complex (BRDC/shipping fever) after bacteria enter the deeper lung tissues?

Answer 14

cranioventral pneumonia characterized by fibrin exudation, neutrophil and macrophage influx, capillary thrombosis, and coagulation necrosis

Question 15

what does enzootic calf pneumonia cause?

Answer 15

young calves
mild cranioventral pneumonia to extensive fibrinopurulent pneumonia
can result in long-lasting chronic infections and slow growth

Question 16

what bacterial pathogens are associated with enzootic calf pneumonia?

Answer 16

Mannheimia haemolytica
Pasteurella multocida
Corynebacterium pyogenes

Question 17

what is the causative agent of calf diptheria?

Answer 17

Fusobacterium necrophorum
common soil inhabitant

Question 18

what does Fusobacterium necrophorum do?

Answer 18

colonizes pharyngeal tissue: extensive necrosis with inflammation and edema in mouth, pharynx, larynx, and possibly lungs

Question 19

what causes acute bovine pulmonary edema and emphysema or fog fever (ABPEE)?

Answer 19

tryptophan ingested, to 3-methyl indole, metabolized by pulmonary Clara cells enzymes
pulmonary cells injured by final toxin

Question 20

when is acute bovine pulmonary edema and emphysema or fog fever seen?

Answer 20

14 days after moving cattle to grass pasture: dry summer grass to better quality grass
dairy cattle on late spring grass after first cutting of hay

Question 21

what substance other than tryptophan can cause acute bovine pulmonary edema and emphysema or fog fever?

Answer 21

4,ipomeanol: produced by mold

Question 22

what happens in hypersensitivity pneumonitis (bovine farmer’s lung)?

Answer 22

cattle develop hypersensitivity pneumonitis to Micropolysporum faeni: common mold that grows in hay

Question 23

what develops in hypersensitivity pneumonitis?

Answer 23

immune complexes of IgG and mold antigen in alveolar spaces
recruitment of neutrophils, phagocytosis, and inflammation

Question 24

what causes verminous pneumonia?

Answer 24

Dictyocaulus viviparus
trichostrongylid nematode with a direct life cycle

Question 25

what happens in bovine septic thromboembolism?

Answer 25

liver abscesses form after change in diet emboli from abscesses to lungs and erode through poor prognosis

Question 26

where can bovine herpesvirus 1 infect in the animal?

Answer 26

respiratory fetus reproductive tract conjunctivitis

Question 27

how does bovine herpesvirus 1 induce cell death?

Answer 27

necrosis and apoptosis as cell membrane integrity is lost, calcium influx directly results in lysis and release of viral particles

Question 28

what acts as a receptor for the leukotoxin of M. haemolytica in bovine herpesvirus 1?

Answer 28

B2-integrin on bovin alveolar macrophages and neutrophils

Question 29

what are the clinical signs associated with bovine herpesvirus 1?

Answer 29

erosions and ulcers in upper respiratory tract fever, reduced appetite, rapid respiration, dyspnea

Question 30

what does ovine herpesvirus type 2 cause?

Answer 30

malignant catarrhal fever mucopurulent inflammation of the conjunctiva and oral and nasal mucosa ulcerations of mouth, tongue, esophagus

Question 31

why may bovine viral diarrhea virus contribute to bovine respiratory disease complex?

Answer 31

immunosuppressive

Question 32

what does bovine respiratory syncytial virus do?

Answer 32

infects respiratory epithelial cells

Question 33

who is Mycoplasma mycoides large-colony type pathogenic for?

Answer 33

sheep and goats not cattle

Question 34

does Mycoplasma mycoides survive well in the environment?

Answer 34

no

Question 35

what disease has similar lesions to Mannheimia haemolytica?

Answer 35

porcine contagious pleuropneumonia: Actinobacillus pleuropneumoniae

Question 36

what type of lesions are associated with Mannheimia haemolytica?

Answer 36

carnioventral fibrinopurulent pleuropnuemonia hemorrhage/coagulation necrosis to whole lung lobes

Question 37

what has Histophilus somni been associated with?

Answer 37

pneumonia septicemia myocarditis abortion thrombotic meningoencephalomyelitis synovitis

Question 38

what is characteristic of Histophilus somni infection?

Answer 38

formation of thrombi in vessels

Question 39

what does Pasteurella multocida cause?

Answer 39

pneumonia associated with stress, transportation, overcrowding, and co-mingling

Question 40

what is bovine respiratory disease complex?

Answer 40

pneumonia of variable severity cranioventral pneumonia: fibrin, neutrophils/macrophages, capillary thrombosis, coagulation necrosis