Cattle Respiratory Problems in Adults

Question 1

Herd problems causing bovine respiratory disease in adults.

Answer 1

Parasitic bronchitis (Dictyocaulus viviparus).
Shipping fever.
IBR (rhinotracheitis) (BHV-1).
Bovine Farmers Lung.
Fog Fever (Acute interstitial pneumonia).
Dusty feed.
Contagious Bovine Pleuropneumonia (not UK).

Question 2

Individual problems that cause respiratory disease in adults.

Answer 2

Acute exudative pneumonia.
Chronic suppurative pneumonia.
Diffuse fibrosing alveolitis.
Posterior vena cava thrombosis.
Milk allergy.
Pulmonary abscess.
Tumours.
Tuberculosis.

Question 3

1. Name the condition commonly seen post housing.
2. In what cattle is this condition more commonly seen?
3. Peak incidence of this condition?

Answer 3

1. Pasteurellosis, Transit Fever, Shipping Fever (may be multiple pathogens - Mannheimia haemolytica (A1)*, Pasteurella multocida, Histophilus somni).
2. Weaned suckled calves.
3. September-December - w/in 4wks of housing.

Question 4

Stress factors associated w/ shipping fever/transit fever/pasteurellosis.

Answer 4

Weaning.
Transport.
Mixing.
Housing.
Diet change.
Others.

Question 5

Pathogenicity of Mannheimia Haemolytica?

Answer 5

Initiating agent of pneumonic pasteurellosis.
Strains A1 and A6.
Present in nasal cavity of healthy carriers.
Mixing of carriers and susceptible animals + stress precipitates pneumonia.

Question 6

Culture of Mannheimia haemolytica.

Answer 6

Tracheobronchial lavage / BAL.
Lung lesions at PM exam.
Tonsillar and nasal isolates (not always pathogenic).
Isolation difficult from animals treated w/ ABX.
Serology can be performed to helped ID animals who have been exposed to pathogens and mounted immune response or have been vaccinated (Ab’s).

Question 7

Pneumonic pasteurellosis / shipping fever/ transit fever clinical signs.

Answer 7

Dull.
Anorexia.
Tachypnoea (60-100bpm).
Hyperpnoeic.
Pyrexia (up to 42C).
Nasal discharge.
*Adventitious lung sounds and coughing not as marked as in enzootic pneumonia
- lungs may be so consolidated that some areas have v minimal air movement. May hear rubbing of pleura on attempt to breathe.

Question 8

Pasteurella multocida pathogenicity and culture.

Answer 8

Present in nasal cavity of most cattle.
Colonises lesions induced by other agents (mycoplasma, viruses): secondary pathogen.
Some strains are primary pathogens (type B).
Readily isolated from lung lesions of untreated animals (isolates from URT may not be significant).
Possible to cause disease even in animals at pasture.

Question 9

Histophilus somni pathogenicity and culture.

Answer 9

Present in URT and LRT of some healthy cattle.
Can cause Thromboembolic Meningocephalitis (rare in UK).
Isolated from calf pneumonias in UK.
Difficult to isolate:
- needs transport medium.
- Chocolate agar in 10% CO2.

Question 10

Diagnosing Pneumonic Pasteurellosis.

Answer 10

History - weaning, transport, market, housing, no vacs, stress-inducing procedures.
Clinical signs - may not necessarily be cough, but may be off food etc, pyrexia.
Nasopharyngeal swabs - culture.
BAL or tracheal wash - culture.
PM exam.
Serology (historical perspective).

Question 11

1. Tx of pneumonic pasteurellosis.
2. Control of pneumonic pasteurellosis.

Answer 11

1. NSAIDs, air quality and housing improvements, antimicrobials.
2. Reduce stress, housing design, management.
   Vaccination.
   Viral vaccines (RSV, PI3, BHV-1, BVDV).
   Pre-conditioning.

Question 12

Pneumonic pasteurellosis vaccines.

Answer 12

Rispoval pasteurella (Zoetis) - M. haemolytica A1 + leucotoxoid IM >3m single dose.
Bovipast RSP (MSD) - M. haemolytica A1, PI3 and RSV SC 2 doses 4w apart starting at or after 2w old.
Bovalto Pastobov (Boehringer Ingelheim) - M. haemolytica A1 IM or SC at or after 4w old, 21-28d apart.

Question 13

1. IBR stand for and causing agent?
2. What other diseases can this agent cause?

Answer 13

1. Infectious Bovine Rhinotracheitis.
   BHV-1.
2. Infectious Pustular Vulvovaginitis (IPV).
   Infectious Pustular Balanoposthitis (IPB).
   Abortion.
   Conjunctivitis.
   (Generalised Alimentary Forms).
   (CNS form).

Question 14

1. How is IBR spread?
2. Latent infection?

Answer 14

1. Aerosol route. Requires close animal contact (<3m) and slowly spreads w/in a group.
2. Latent infection in trigeminal (+ sciatic) nerve ganglia –> stress causes recrudescence.
   - infected animal = infected for life, but not necessarily infectious for life.
   Morbidity usually ~50%.
   Mortality variable <10%.

Question 15

1. Spread of BHV-1 w/in animal.
2. Corticosteroid effect.
3. Effect of BHV-1 on respiratory tissue.

Answer 15

1. Via cell-associated viraemia.
2. Periodic shedding. Promote re-activation.
3. Focal areas of epithelial necrosis causing reduced ciliary clearance.
   Inflamed nasal mucosa - “red nose”.
   Viral infection causes increase in divalent cations (Zn, Fe) which favour colonisation of lungs by bacteria.
   Impairment of macrophage, neutrophil and lymphocyte function.
   Eosinophilic inclusion bodies in nuclei.
   Marked inflammatory response.

Question 16

1. Ages of cattle generally affected by IBR.
2. Clinical signs of IBR.

Answer 16

1. Usually >6mths.
   Worst cases 6-24mths.
2. Cough.
   Reduced appetite so reduced growth rate.
   Dull.
   Pyrexic (40-42C).
   Nasal discharge ranging from serous to purulent and crusting.
   Necrotic plaques on the mucosa - halitosis.
   Ocular discharge / conjunctivitis.
   Enlarged LNs - retropharyngeal, submandibular.
   Reduced milk yield in lactating cattle.
   Drooling saliva.
   Upper airway noise, rhinitis, pharyngitis.
   Abortion (can occur w/o overt respiratory clinical signs).

Question 17

Dx BHV-1 (IBR).

Answer 17

Serology (paired samples).
Immunofluorescent antibody staining.
Virus isolation from nasal/nasopharyngeal, ocular/conjunctival and bronchoalveolar lavage swabs.
- requires transport medium.
Immunohistochemistry.
PCR.
Surveillance: ELISA on bulk milk.

Question 18

Tx of IBR?

Answer 18

ABX to control secondary infection.
Vac in face of outbreak (live intra-nasal vacs can stimulate rapid immune response in airway).
NEVER give corticosteroids! - immunosuppressive.

Question 19

IBR prevention and control.

Answer 19

Management, closed herd.
Intranasal vaccine: live, temperature sensitive (only grow in upper airway).
- rapid protection w/in 48-96hrs.
- does not cause abortion.
- can get vac virus spread.

Question 20

Disadvantages of conventional vaccines.

Answer 20

Cannot be distinguished from field Ab titres.
Problem in high health status herds.
Cannot vaccinate potential AI studs as cannot prove Ab’s due to vaccine and not due to past infection.
Issue w/ imports and exports also.
Cattle health schemes.
Need for attenuated glycoprotein E deleted marker vaccines and specific ELISA tests to distinguish.

Question 21

1. Differentials of IBR.
2. Dx of IBR?

Answer 21

1. Photosensitisation (reddening).
   Infectious Bovine Keratoconjunctivitis (eye lesions, runny eyes).
   FMD (drooling and discharges).
   Mucosal disease (confused w/ more severe IBR cases).
2. Clinical picture.
   Virus isolation.
   Rising Ab titre.

Question 22

IBR vaccination.

Answer 22

Useful even in the face of an outbreak.
- live intranasal vaccines – nasal gamma interferon.
Marker vaccines:
- gpE deletion.
- if exporting or selling pedigree stock.
- eradication programmes.
Live vacs for young and naive animals.
Inactivated to improve immunity in infected herds and to reduce shedding.

Question 23

1. Bovine Farmer’s Lung caused by.

Answer 23

1. Is an extrinsic allergic alveolitis due to hypersensitivity to fungal spores and bacterial antigens.
   Exposure of housed cattle to mouldy food (hay).
   - Multiplication of Saccharopolyspora rectivirgula.
   - In wet upland areas of UK where the hay is baled wet.
   - Affects older cattle early in winter when fed poor quality dried forage.

Question 24

Clinical signs of Farmer’s lung.

Answer 24

Chronic is commonest form.
- Several animals in herd often affected.
- Frequent coughing.
- Hyperpnoea.
- Reduced milk yield.
- Weight loss.
- Cow still bright.
- Exercise intolerance.
Acute form.
- usually single individual.
- Sudden onset.
- Dyspnoea.
- Tachypnoea.
- Milk yield disappears.
- Anorexic.

Question 25

Effect of chronic Bovine Farmer's Lung on lung tissue.

Answer 25

Cor pulmonale or diffuse fibrosing alveolitis. Lung consolidation. Emphysema.

Question 26

1. Dx of Bovine Farmer's Lung. 2. Tx of Bovine Farmer's Lung.

Answer 26

1. Hx. Clinical picture. Specific Ab to Saccharopolyspora rectivirgula. 2. Remove source of disease e.g. move animals outside. Treat acute cases w/ corticosteroids (avoid induced abortion). Recommend face mask/ventilator for farmer. Ensure feed is good quality.

Question 27

1. Fog Fever AKA. 2. Animals affected by Fog Fever? 3. Onset of disease? 4. Cause? 5. Predisposed breed?

Answer 27

1. Acute Bovine Pulmonary Emphysema and Oedema. 2. Usually fat adult beef-type cattle. 3. Sudden. 4. Soon after change to lush pasture (Fogage) in early autumn. L-tryptophan --> indole acetic acid --> 3-methyl indole (naturally occurring amino acid in pasture >> pneumotoxin). 5. Herefords.

Question 28

1. Fog Fever pathological effect on lung tissue. 2. Clinical signs of Fog Fever.

Answer 28

1. Congestion, oedema, interstitial emphysema and epithelialisation of alveoli. 2. Group problem. Varying clinical signs. Severe cases = acute distress, gross dyspnoea, respiratory grunt, salivation, often froth at mouth. Mild cases = look dull, some tachypnoea. Not much coughing, auscultation inconclusive, anorexic, norm. temp.

Question 29

1. Tx of Fog Fever.

Answer 29

1. Move animals off offending pasture. To other late summer pasture or to a smaller field closer to home and feed silage. - care w/ acute cases as stress of moving can cause them to drop dead. Empirical Tx w/ NSAIDs.

Question 30

1. What are some diseases that come under the umbrella term Chronic Suppurative Pneumonia? 2. Hx? 3. Tx? 4. Prevention?

Answer 30

1. Chronic bronchopneumonia, bronchiectasis, multiple lung abscessation. 2. previous pneumonia, weight loss, reduced milk yield, frequent coughing for some time, tachypnoea, variable temp./intermittently febrile, variable adventitious lung sounds esp. cranioventral, thoracic pain, halitosis if necrotising. Can get sudden deterioration. 3. Difficult to treat, often end-stage, consider culling - animals are not economical, welfare compromised, risk antimicrobial resistance w/ repeated Tx. 4. Control other primary lung pathology.

Question 31

Organisms seen in chronic suppurative pneumonia cases?

Answer 31

Pasteurella multocida. - persists in necrotic suppurative lesions. - "walled off" in abscesses. - "break out": Recrudescence of acute disease. Trueperella pyogenes. - secondary: colonises any bovine lung lesion. - pathogenicity determinant: haemolysin. - pyogenic so abscessation.

Question 32

1. Diffuse Fibrosing Alveolitis animals affected. 2. Times of prevalence. 3. Hx? 4. Clinical signs of DFA.

Answer 32

1. Old thin dairy cows. 2. All year round but greater in spring and autumn. 3. persistent cough, tachypnoea and hyperpnoea, exercise intolerance, weight loss, no temperature, no pain: bright thin cows. 4. Widespread squeaks / crackles often over whole of both lung fields, decreased resonance.

Question 33

1. DFA Tx? 2. Lung at PM? 3. May lead to?

Answer 33

1. No treatment. 2. Marked increase in lung weight, do not collapse in normal way when removed from animal, rubbery texture. 3. Cor pulmonale - Anormal enlargement of the R side of heart due to disease of the lungs or the pulmonary blood vessels - and R sided CHF.

Question 34

1. Pulmonary thromboembolism from caudal vena cava clinical presentation in acute form. 2. Chronic pulmonary thromboembolism from caudal vena cava presentation. 3. Tx for pulmonary thromboembolism from caudal vena cava.

Answer 34

1. Sudden death w/ haemoptysis (coughing blood). Find dead in pool of arterial blood. 2. Coughing and weight loss over a few weeks: - tachypnoea, shallow breathing, coughing, thoracic pain, hepatomegaly in 50% cases. 3. No treatment, invariably fatal, diagnose and cull.

Question 35

Vena caval thrombosis and metastatic pneumonia.

Answer 35

Young adults fed high concentrate diet >> ruminal acidosis >> rumenitis >> damage to ruminal wall >> bacteria into hepatic portal vein via damaged wall >> liver abscesses >> liver abscess close to vena cava can break into vena cava >> pus leaks into caudal vena cava >> pus carried to heart >> septic thromboemboli in lung >> embolic suppurative pneumonia in the lung >> pulmonary arterial aneurism >> aneurism rupture >> blood into alveoli >> blood into airway >> haemoptysis.

Question 36

Contagious Bovine Pleuropneumonia.

Answer 36

Exotic ND. Common in Africa - major economic importance. Caused by Mycoplasma mycoides subspp. mycoides. Differential for pneumonic pasteurellosis.