Bovine Respiratory Disease Flashcards
Which lung lobe is commonly the first affected?
the accessory lobe
Describe the characteristic stance of a cow in respiratory distress
- standing motionless
- elbows abducted
- head lowered with neck extension
- open mouth breathing
What are the clinical manifestations of sinusitis?
- discharge from head
- squinted eyes, heads held in unusual position, head pressing, head shy
What are the most common causes of pharyngeal/retropharyngeal abscesses?
- inappropriate use of oral dosing equipment
- stomach tubes
- coarse feedstuffs
Which organisms are usually involved in pharyngeal/retropharyngeal abscesses?
Arcanobacter pyogenes (Trueperella) - anaerobic bacteria
What are the clinical signs associated with pharyngeal/retropharyngeal abscesses?
- head and neck extension
- pharyngeal swelling
- excessive salivation
- increased water, decreased feed
- malodorous breath
- severe pain on palpation
What are the treatment options for pharyngeal/retropharyngeal abscesses?
- lance the abscess
- rumen cannula if the animal cannot swallow
- tracheotomy if respiration is compromised
- antiobiotics
- NSAIDs
What virus causes infectious bovine rhinotracheitis (red nose)?
bovine herpes virus -1
What are the three subtypes of bovine herpes virus 1 and what do they each cause?
BHV 1.1 - respiratory disease and abortion
BHV 1.2a - genital tract infection
BHV 1.2b - respiratory disease
How is bovine herpesvirus diagnosed?
- nasal swabs for viral isolation (ELISA, PCR, IF)
- histopath of tissue
- immunochemistry to detect antigen
- serum virus neutralizing antibody titers
What are the clinical signs associated with bovine herpesvirus?
- fever, rhinitis, conjunctivitis
- inappetence, drop in milk production
- labored breathing, hyperemia of muzzle
- pustules and diphtheritis plaques, ulceration of nasal mucosa and trachea
What is affected by bovine parainfluenza virus 3?
epithelial cells of upper respiratory tract
- damage to ciliated epithelial cells, mucus layer, and mucocilliary transport
What are the clinical signs associated with bovine parainfluenza virus 3?
- fever
- depression, anorexia
- nasal and ocular discharge
- increased respiratory rate with tracheal rales
How is bovine parainfluenza virus diagnosed?
antemorte - clinical signs, recent co-mingling, serum virus neutralization antibody titer
postmortem - mild interstitial pneumonia, intracytoplasmic inclusion in nasal mucosa
Where is bovine adenovirus found?
respiratory and GI tract of inapparently sick and diseased animals
In which animals does bovine respiratory syncytial virus occur?
younger cattle, 3-12 months old
What is affected by bovine respiratory syncytial virus?
- epithelial cells from nasal mucosa to the bronchi, including type II penumocytes and alveolar macrophage
What are the clinical signs associated with bovine respiratory syncytial virus?
- mild to severe respiratory disease
- fever
- +/- cough
- nasal and ocular discharge
- +/- pulmonary emphysema
What are the most important reservoirs of bovine viral diarrhea virus?
persistently infected cattle
How do cattle become persistently infected with BVDV?
susceptible pregnant cattle becoming infected between 42 and 125 days of gestation
- infected fetus born infected and immunotolerant
What are the clinical signs associated with bovine viral diarrhea virus?
- severe digestive tract disease with ulcers and erosions
- skin lesions and hoof lesions
What is the primary pathogen responsible for shipping fever?
Mannheimia haemolytica
How is Mannheimia haemolytica transmitted?
- inhalation of bacteria-containing droplets
- direct nose to nose contact
- ingestion of food contaminated with nasal discharge from infected cattle
What are the clinical signs associated with Mannheimia haemolytica infect?
- depression, anorexia, fever
- nasal discharge, soft and moist cough
What are the virulence factors of Mannheimia haemolytica?
- leukotoxin
- lipopolysaccharide
- capsular polysaccharide
- fimbriae
- siderophore
- O-sialoglycoprotein endopeptidase
- neuraminidase
What are the lesions caused by Mannheimia haemolytica?
- severe fibrinous pleuropneumonia
- cranioventral lung lobes are dark reddish-black to grayish brown and firm, with marked distension of interlobular septae by gelatinous yellow fluid
“hepatization of lung”
What is the second most common pathogen associated with Shipping fever?
Pasteurella multocida
What are the lesions caused by Pasteurella multocida?
- fibrinopurulent bronchopneumonia
- multiple, coalescing abcesses
What is caused by Histophilus somni?
- bronchopneumonia
- pleuritis (excess fibrin on pleural surface)
What is caused by Mycoplasma?
lobar bronchopneumonia with severe peribronchial cuffing
What are the two mycoplasma species of interest?
M. dispar
M. bovis
What is the characteristic presentation of Mycoplasma bovis?
“Pneumonia-arthritis syndrome”
What lesions are caused by Mycoplasma bovis?
- suppurative bronchopneumonia, edematous pulmonary septa, and pleuritis
- coagulative necrosis lesions: purulent center arising from affected bronchiole
Describe the pathogenesis of Acute Bovine Pulmonary Emphysema
- L-tryptphan present in pasture is metabolized by the rumen to 3-methylindole, which is absorbed into bloodstream and carried to the lungs
What are the gross lesions associated with Acute Bovine Pulmonary emphysema?
- diffuse interstitial pneumonia with severe alveolar and interstitial edema and interlobular emphysema
- lungs expanded, pale, and rubbery
What are the other names for Acute Bovine Pulmonary Emphysema?
Atypical Interstitial Pneumonia
“Fog Fever”
What are the clinical signs associated with Acute Bovine Pulmonary Emphysema?
- severe respiratory distress within 10 days
- expiratory dyspnea and oral breathing
- emphysema within lungs and along the back
How can Acute Bovine Pulmonary Emphysema be prevented?
- Allow younger animals to graze the pastures first
- feed ionophores
