Exam 3 Flashcards
Common causes of Suppurative Bronchopneumonia in young calves
BRD, and most often associated with P. multocida infections.
Common causes of Fibrinous Pneumonia or fibrinous pleuropneumonia
M. haemolytica and maybe H somni (to a leser extent). Most common form of acute pneumonia in weaned stressed beef cattle. (shipping fever)
what lung pattern is most common with shipping fever?
Fibrinous pneumonia, Fibrinous pleuropneumonia
This tends to be a bilateral cranioventrally distributed finding. also characterized by wide distension of interlobar septa.
Fibrinous adhesions are likely present between parietal and visceral pleura.
Common cause of Caseonecrotic Bronchopneumonia.
Mycoplasma infection (especially chronic infections).
Mycoplasma and its ability to cause pneumonia
Colonizes the ciliated epitheiium of the respiratory tract producing a mild mucopurulent bronchitis and bronchiolitis and through persistent infection, pulmonary lesions develop.
This will form a caseonecrotic bronchopneumonia with mutifocal nodules that can coalesce to form one large nodule.
Casues of interstitial pneumonia
May be acquired by delivery of causative factors through pulonary circulation or by airways. cuases severe edema in intraalveolar hyaline membranes.
Alveolar septal fibrosis, type 2 pneumocyte hyperplasia can be extensive. Emphysema, edema, and overinflated lungs are often found.
Many causes: Viruses (BRSV), parasite larvae, immune mechanisms, toxic gases etc.
Causes of AIP in pastured cattle
Moving pastured cattle to lush green grass “fog fever” or by exposure to chemicals.
Movement of cattle to lush green pastures results in excess ingestion of L-tryptophan with conversion to 3MI by rumen flora, causing pneumocyte necrosis and exfoliation.
AIP in feedlot cattle
Cuased by severeal mechanism. 3MI has a potential role in.
Bronchiolitis obliterans and bronchiolar necrosis are common findings in feeder cattle.
in summary it is thought to be associated with endotoxin from gram-negative infections.
Bronchointerstitial pneumonia
Used to describe uncomplicated viral infections of the lung due to BHV-1, PI-3 and BRSV infections.
Bronchiolar epithelial and pneumocytic damage resulting in bronchiolar necrosis, mild inflammatory cell influx, and type II pneumocyte hyperplasia. this is often complicated with seconary bacterial infections.
BRSV pneumonia description
cranioventral distribution of bronchiointerstitial pneumonia. This ranges from reddened areas of atelectasis to rubbery gray lobules. There may be exudate present that is mucoid to mucopurulent.
Anemia and its potential affects on the lungs
Lungs fail to collapse and are pale, overinflated and markedly puffy. Yellowish tint may occur due to helolysis
Aspiration pneumonia
Associated with inhalation of foreign material. this typically has a cranioventral pattern that is often unilatera, necrotizing to gangrenous.
Embolic pneumonia
This is often preceded by bacterial infection and suppuratiion at another location, which in cattle is most commonly liver, but other loci may occur.
Verminous pneumonia
Associated with the cattle lungworm Dictyocaulus viviparous
Eosinophilic bronchiolitis develops. Lesions begin as bilateral in the caudal lung lobes consisting of caudal dorsal, wedge-shaped aras of moderate firmness.
Emphasema is associated with this, and is often the reason that this is misdiagnosed as AIP.
TB pneumonia
Reportable disease.
Tubercles are usually circumsribed, encapsulated, with granulomatous foci containing white to pale yellow caseous necrosis with or without mineralization.
