resp 2

Question 1

Respiratory disease complex
- factors

Answer 1

• Combination of infectious agents
• Compromised host defenses
• Environmental conditions

Question 2

Respiratory disease complex
- transmission
- beef cattle vs dairy cattle: when they get it

Answer 2

Transmission
◦ Direct contact
◦ Droplets
◦ Aerosols
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Beef cattle
◦ “Shipping fever”
◦ After shipment to feedlot or stocker operation
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Dairy cattle
◦ “Enzootic pneumonia”
◦ Calves up to 6mo of age
◦ Sporadic occurrence in adults

Question 3

Bovine Herpesvirus Type 1
- disease caused in adults
- clinical signs

Answer 3

Infectious Bovine Rhinotracheitis
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Clinical signs
◦ Fever
◦ Nasal discharge
◦ Cough
◦ Decreased appetite
◦ Decreased milk production
◦ Conjunctivitis, corneal opacities
◦ Nasal plaques/pustules
◦ Hyperemia of muzzle → red nose

Question 4

Bovine Herpesvirus Type 1
- disease in neonatal calves, and clinical signs
- vaccine?

Answer 4

Neonatal calves
◦ Acute respiratory disease
◦ Systemic infection
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Clinical signs
◦ Rhinitis
◦ Marked lacrimation
◦ Soft palate necrosis
◦ Laryngotracheitis
◦ GIT ulceration
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Vaccination at <3 days of age with MLV vaccine →severe fatal BHV-1 infection

Question 5

Bovine Herpesvirus Type 1
- pathogenesis
- geographic locations

Answer 5

Pathogenesis
◦ Direct injury and destruction of epithelial cells
◦ Immunosuppression > Neutrophil, lymphocyte and macrophage dysfunction
◦ Trigeminal nerve latency > ~100% of infected cattle
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Epidemiology
◦ Widespread
◦ Feedlot→higher attack rate and more severe disease

Question 6

Bovine Herpesvirus Type 1
- dx, tx, vaccination

Answer 6

Diagnosis
◦ Nasal swab or conjunctival scraping
◦ Virus isolation, IFA, PCR
◦ Paired serology
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Treatment is supportive
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Vaccination
◦ MLV – intramuscular
◦ MLV – intranasal
◦ Inactivated

Question 7

Respiratory Syncytial Virus
- pathogen
- species affected
- cytopathic effects

Answer 7

RNA virus- Pneumoviridae family
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Infects cattle, sheep and goats
◦ Bovine RSV
◦ Caprine RSV
◦ Ovine RSV
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Characteristic cytopathic effect
◦ Formation of syncytial cells

Question 8

Bovine Respiratory Syncytial Virus
Clinical signs, progression

Answer 8

Clinical signs
◦ Fever
◦ Depression
◦ Decreased feed intake
◦ Tachypnea and cough
◦ Ptyalism, nasal and lacrimal discharge
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Rapid progression of clinical signs
◦ Dyspnea, inc expiratory effort
◦ Bullae rupture→ pneumothorax
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Acute interstitial pneumonia

Question 9

Bovine Respiratory Syncytial Virus
- Epidemiology: reservoir, important for what disease, fatality

Answer 9

◦ Cattle principial reservoir
◦ Important virus in BRD complex
◦ Case fatality rate- 0-20%

Question 10

Bovine Respiratory Syncytial Virus dx

Answer 10

◦ Nasal swab, tracheal aspirate or BAL > Immunoflurescence, IHC, RT-PCR
◦ Paired serology

Question 11

Bovine Respiratory Syncytial Virus
- tx, vaccine and efficacy

Answer 11

Treatment
◦ Supportive
◦ If severe disease or interstitial pneumonia > 1-2 doses of corticosteroid
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Vaccination
◦ MLV-IN
◦ MLV-parenteral
◦ Inactivated-parenteral
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Cattle vaccinated for BRSV= lower morbidity, mortality and respiratory deaths than those vaccinated without including BRSV

Question 12

Bovine Parainfluenza Virus 3
- pathogen
- species affected
- clinical signs

Answer 12

RNA virus from Paramyxoviridae family
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Infects cattle, sheep and goats
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Clinical signs
◦ Uncomplicated= subclinical- mild signs
◦ Fever
◦ Cough
◦ Nasal and ocular discharge
◦ Increased respiratory rate
◦ Secondary infection increases severity

Question 13

Bovine Parainfluenza Virus 3
- pathogenesis
- geography, importance

Answer 13

Pathogenesis
◦ Damages pulmonary mucociliary apparatus
◦ Depresses function of alveolar macrophages
◦ Predisposes to subsequent viral or bacterial infections
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Epidemiology
◦ Widespread prevalence
◦ Important initiator of respiratory disease

Question 14

Bovine Parainfluenza Virus 3
- dx, tx, vaccine

Answer 14

Diagnosis
◦ Nasal swabs > Virus isolation or RT-PCR, Paired serology
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Treatment → Supportive care
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Vaccination
◦ MLV-IN
◦ MLV- parenteral
◦ Inactivated
No evaluation of vaccination efficacy to decrease respiratory disease

Question 15

Bovine coronavirus
- pathogen
- also causes what disease?
- spread
- pathogenesis
- resp clinical signs

Answer 15

RNA virus from the Coronaviridae family
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Also the cause of Winter Dysentery and calf diarrhea
◦ virus shed in nasal secretions
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Pathogenesis
◦ Not clearly defined
◦ Not consistently reproducible
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Clinical signs
◦ Fever
◦ Nasal discharge
◦ Tachypnea
◦ Coughing

Question 16

Bovine coronavirus
- dx, tx, prevention

Answer 16

Diagnosis
◦ PCR of respiratory secretions
◦ Positive result ≠ causative agent of disease
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Treatment
◦ Supportive
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Prevention
◦ None currently marketed in North America > For respiratory disease
◦ Recently approved > MLV IN vaccine for reduction in GI disease

Question 17

Bovine Viral Diarrhea Virus
- pathogen
- disease caused, resp contribution
- vaccines?

Answer 17

RNA virus from Pestivirus family
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Causes wide-spectrum of disease
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Role in BRD complex
◦ Previously controversial now supported
◦ Causes mild pneumonia > Fever, tachypnea
◦ Immunosuppression → co-infections
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MLV and killed vaccines
◦ Unknown role in reduction of BRD

Question 18

Malignant Catarrhal Fever
- pathogens
- risk factors, geography
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- hosts, significance

Answer 18

Etiology
◦ Ovine herpesvirus type 2
> Cattle exposed to sheep → most common in North America
◦ Alcelaphine herpesvirus types 1 and 2 > Cattle exposed to exotic hoofstock
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Disease occurs in aberrant hosts
◦ Ex: cattle, deer, bison, pigs, alpacas
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Aberrant hosts are dead-end

Question 19

Malignant Catarrhal Fever
Clinical signs

Answer 19

◦ Fever
◦ Inappetance
◦ Profuse ocular and nasal discharge
◦ Dyspnea
◦ Corneal opacities and conjunctivitis
◦ Enlarged lymph nodes
◦ Lameness, hyperemic coronary bands
◦ GI disease
◦ Encephalitis

Question 20

Malignant Catarrhal Fever
- epidemiology of most importance to us
- dx
- tx, prognosis

Answer 20

Epidemiology
◦ Sheep-associated most important outside of Africa
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Diagnosis
◦ Definitive is post-mortem only
◦ Histopathology and supportive diagnostic testing
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Treatment
◦ Supportive care
◦ If severe, 100% fatal

Question 21

Ovine Progressive Pneumonia
- agents
- infections rate
- risk factors

Answer 21

Small ruminant lentiviruses
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Etiology
◦ Ovine progressive pneumonia virus
◦ Maedi-visna virus
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Epidemiology
◦ 30-67% infection rate
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Risk factors
◦ Large flock size
◦ Purchase of >50 sheep
◦ Flocks on non-fenced land

Question 22

Ovine Progressive Pneumonia
- clinical signs

Answer 22

• Progressive emaciation
• Progressive respiratory failure
• Indurative lymphocytic mastitis
• Posterior paresis
• Chronic nonsuppurative paresis

Question 23

Ovine Progressive Pneumonia
- prevalence of clinical signs and seropositivity
- presenting complaints

Answer 23

25-30% of infected sheep display clinical signs
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50% of flock seropositivity typical prior to clinical cases
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◦ Emaciation with good appetite
◦ Tachypnea
◦ Respiratory distress > Flared nostrils, Neck extension, Open-mouth breathing
◦ Wool loss

Question 24

Ovine Progressive Pneumonia
- dx, tx, prevention

Answer 24

Diagnosis
◦ AGID – preferred test for a long time
◦ ELISA – more sensitive, screen large group at one time
◦ Western blot
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Treatment
◦ Not treatable
◦ Antimicrobials for secondary infections
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Prevention
◦ Strict biosecurity protocols for uninfected flocks
◦ Infected flocks – test-and-cull or isolation of infected adults
◦ Increasing flock replacement rate

Question 25

Ovine Pulmonary Adenocarcinoma
- agent
- disease
- clinical signs
- tx

Answer 25

Etiology
◦ Jaagsiekte retrovirus > Betaretrovirus
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Bronchioalveolar carcinoma
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Clinical signs
◦ Weight loss with a good appetite
◦ Tachypnea
◦ Cough
◦ Frothy clear-milky nasal secretions
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No treatment available

Question 26

Caprine Arthritis and Encephalitis
- pathogen
- disease syndromes

Answer 26

Small ruminant lentivirus
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Etiology
◦ Caprine arthritis and encephalitis virus
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Seropositive adults
◦ 60% chronic interstitial pneumonia
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Disease syndromes
◦ Leukoencephalomyelitis
◦ Arthritis/polysynovitis
◦ Interstitial pneumonia
◦ Mastitis

Question 27

Caprine Arthritis and Encephalitis
- respiratory signs
- dx
- tx

Answer 27

Respiratory clinical signs
◦ Exercise intolerance
◦ Dyspnea
◦ Weight loss
◦ Cough
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Diagnosis
◦ Serologic testing not useful
◦ Lung biopsy histopath
◦ Post-mortem lung lesions
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Treatment
◦ None