Ruminant Respiratory Diseases Flashcards
Describe the pathogenesis and clinical signs associated with BRSV
The virus is inhaled and replicates in the respiratory epithelium, it disperses through the URT and bro hi and syncytial spread through the bronchioles. Clinical signs - interstitial pneumonia and emphysema (severe in youngstock),
Bovine respiratory syncytial virus is what type of virus?
Pneumovirinae
What histological lesions are associated with BRSV?
Formation of multinucleated giant cell syncitia, may contain eosinophilic inclusion bodies
What husbandry practices are associated with BRSV?
Winter housing, stress periods (mixing and during transport)
Outline three ways in which BRSV can be diagnosed.. Describe findings.
PM - pulmonary atelectasis, emphysema in the caudal lungs, bronchoconstriction
Histo - giant cell syncitia with eosinophilic inclusion bodies
ELISA
Which bovine respiratory pathogen is a paramyxoviridae?
Parainfluenza 3
Outline the pathogenesis and clinical signs of Bovine PI-3
Pathogenesis - Virus infects the respiratory mucosa, ciliary clearance ceases, epithelial necrosis, secondary bacterial infection.
Clinical signs - Bronchitis, bronchiolitis, alveolar thickening and hyperplasia, intracytoplasmic inclusion bodies in the lung (around d 5-7)
How can PI-3 be diagnosed and treated/ controlled ?
- Dx - iFAT, ELISA (from BAL/ dead tissue)
- Tx/ control - Improve management (hygiene), ensure adequate colostrum intake, vaccination
Which respiratory pathogens form the Bovine Respiratory Disease Complex?
- BRSV
- BHV1 - IBR
- PI-3
- BVD
Cows of what age are most susceptible to the Bovine Respiratory Disease Complex?
<6 months (2-10 wks usually)
What clinical signs are associated with the Bovine Respiratory Disease Complex?
How can diagnosis be achieved?
- Cough
- > RR
- Nasal/ Lacrimal discharge
- Fever
Dx. NP swabs, BAL - viral isolation/ PCR
IBR is caused by which type of virus?
Type 1 Herpes virus
Outline the clinical signs assocaited with IBR.
- Nasal discharge - progressive
- Bronchopneumonia
- > RR
- Calves - mucosal ulcerative lesions in oesophafus and forestomach
- High morbidity, low mortality
- 6-18 month cattle
Outline the sequelae of BVD during the 1st/2nd/3rd trimester of pregnancy.
- Reproductive losses
- Persistently infected calves
- Foetus fight off virus
Ovine pulmonary adenocarcinoma are associated with which type of virus?
What clinical signs are associated with the disease?
Retrovirus - Jaagsiekte
Clinical signs - ++ respiratory discharges, weight loss, progressive dyspnoea
Which type of cell are targetted by Jaagsiekte?
Type 2 pneumocytes
This small ruminant lentivirus causes pneumonia and wasting and is highly contagious and fatal. It takes years for clinical signs to manifest.
Outline its pathogenesis.
Maedi Visna
Virus is transmitted through respiratory route and infected colostrum/ milk. It infects monocytes and infiltrates lymphoid tissue and causes smooth muscle hyperplasia in the lung/
Which mycoplasma has been shown to cause “cuffing pneumonia”, septic arthritis, otitis media and mastitis?
Bovis
Describe what is meant by cuffing pneumonia.
Histologically there appears to be lymphocytic cuffing areound the small airways
Name the species of Pasturellaceae which are relevant in cattle?
What are the morphological features of the Pasteurellaceae bacteria?
Mannheimia haemolytica, Pasteurella multocida, Histophilus somni
Morph - gram -ve bacilli/ coccobacilli, facultative anaerobes
What clinical signs are associated with Pasturellaceae infections?
- Fibrinous pleurisy/ intra-alveolar fibrin
- Acute depression, lethergy, anorexia
- Endotoxaemia
- Sudden death
- Increased RR + abdo involvement - laboured
- Fever
- Dehydration
- < GI
Systemic spread of Histophilus somni occurs where?
- Myocardium
- Pericardium
- Pleura
- Synoviae
Shipping fever and bacterial infection secondary to IBR are often associated with which Pasturellaceae?
Mannheimia haemolytica
How can Histophilus somni cause thrombus formation?
Lipoligossacharides provoke host inflammatory response, histamine release and thrombus formation.
Remember, its a commensal in the genital tract.
Which antibiotics are used in the treatment of Pasturellaceae infection?
Oxytet
Flurfenicol
Tylosin
(remember NSAIDs aswell)
Which bacterial species are associated with Pasturellosis in sheep?
Mannheimia haemolytica
Bibersteinia trehalosi
Atypical pneumonia in sheep is associated with which bacterial species?
What clinical signs are seen with such infection?
Mycoplasma ovipneumoniae
- Non-progessive chronic pneumonia
- Chronic soft cough/ nasal discharge
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What epidemiological features are associated with Pasturellosis infection?
How can infection be prevented?
- Close contact
- Age-mixing
- Carriers
- Poor ventilation
- Poor immunity
Control - colostrum intake, housing and husbandry, vaccination
