Resp3- BRD

stress, immunity (or lack of), pathogens, and environment/management

IBR (bovine herpesvirus-1), BVDv, BRSV, PI-3, BRCV (bovine respiratory coronavirus), alcephaline herpes virus types 1 and 2 (ovine herpes virus type 2--> malignant catarrhal fever)

bronchopneumonia- "enzootic pneumonia"- housed calves

bronchopneumonia- "Shipping fever"- recently shipped to stocker/feedlot

viral infection-- (3-5 days)--> bacterial bronchopneumonia

infectious agents, compromised host defense, sub-optimal environment

Manheimia haemolytica, Pasteruella multocida, Histophilus somnus, Truperella pyogenes, Mycoplasma bovis

Manheimia haemolytica

birth to weaning, weaning to market (esp. beef calves), +/- adult diseases

stress induces cortisol, which is a major homeostatic hormone--> reduces innate/acquired immune responses--> novel or recrudescent viral infections

gain access to lung after virus destroys mucociliary elevator/ epithelial barrier--> proliferation--> releases toxins--> recruits cells--> damage lung tissue

heat, cold, moisture, dust, gases, crowding, filth, feed (dusty, moldy, etc)

adverse environment, transportation, surgery, co-mingling of calves

weaning (backgrounding), processing procedures (vaccinating), feed type and quality (high quality feed, palatable feed, TMR), water (don't add antibiotics to water...unreliable method of delivery), maintain clean/stable environment

diarrhea

Cu, Zn, Se, Mn, Fe

Vit A, D, E

• intra- and interlobular connective tissue septae (if a portion becomes consolidated, there is no way to open it back up)
• tracheal bronchus
• pleura is thick
• no collateral ventilation
• long, narrow terminal bronchioles
• marked hypoxic responses affecting ventilation/perfusion

little lung unit interdependence, no collateral ventilation (lobules that become atelectic stay that way), well- developed inflammatory response (limits extension, inflammatory process confined, exudate removal is limited)

depression, anorexia, tachypnea, shallow breathing, moist cough, head/neck extension, fever, droopy ears, lacrimation/discharge, dyspnea, rattle on auscultation, abducted elbows, lameness, bloat, diarrhea

decreased abdominal fill (anorexia)--> sunken paralumbar fossa

[blood from nose and mouth] grain engorgement, subacute rumen acidosis

an episode of diarrhea

diarrhea**, FPT (low IgG), LPS, sepsis, bad nipple (aspiration pneumonia)

knowledge of acute or chronic

viral infection (BVD, IBR,PI3, BRSV, coronvirus)--> bacterial secondary infection (manheimia, histophilus, pasteruella, truperella, mycoplasma)

Manheimia, Histophilus, Pasteruella

Mycoplasma, Arcanobacterium/ Truperella

cranioventral, firm sharp area of demarcation, suppurative

suppurative; housed dairy calves

bilateral, cranioventral, interlobular edema, fulminant (crosses interlobular septae)

fibrinous; acute; LPS and leukocyte death (Manheimia)

chronic, airway centered, lymphoid hyperplasia, caseonecrotic bronchopneumonia, polyarthritis, nodular

inspiratory sounds are soft, expiratory sounds are nearly inaudible, significant pulmonary pathology can be present without any abnormal lung sounds

normal, pleural effusion, pneumothorax

11th rib at point of hip (tuber coxae), 9th rib at point of shoulder, 5th rip at point of elbow

tube fed (accidentally put tube in wrong pipe), re-using nipple bottles for too long

• milk fever, down, weak, aspirates rumen content
• milk fever, treated with oral propylene glycol, wrong pipe accidentally

• control inflammation: dexamethasone or banamine
• antimicrobials: ceftiofur, oxytet
• Supportive care: fluids, electrolytes, nutrition

mastitis/metritis/rumenitis/liver abscess/endocarditis--> bacterial embolic shower--> emboli lodge in lung--> lung abscesses

usually repeated episodes of rumenitis--> liver abscess follows--> septic thrombi develop in caudal vena cava--> anemia, hemoptysis, melena

often unrewarding but you can do long-term penicillin (watch out for residues!)

interstitial pneumonia; fog fever, moldy sweet potatoes, perilla ketones

adult cows moved from sparse dry forage to lush grass > 4% tryptophan--> metabolized to 3-methylindole in rumen--> 3-MI goes to lung and is metabolized by Clara cells to reactive intermediates--> cell necrosis--> lung inflammation

diffuse alveolar epithelial necrosis, hyaline membrane formation, type II alveolar epithelial cell hyperplasia, +/- multinucleate giant cells, edema, transcellular necrosis, coagulation of blood proteins

severe dyspnea, expiratory grunting, foam from mouth and nostrils, head/neck extended, open mouth, soft respiratory sounds, no coughing

generally palliative, banamine, monensin (1 day prior to changing feed), lasalocid (requires feeding 6 days prior to exposure)

protein coagulates into a firm clot in the alveolus

feedlot animals; multinucleate giant cells (syncytia) in parenchyma (often associated with BRSV)

4-ipomeanol- mold toxin found in moldy sweet potatoes that is a potent lung toxicant (more severe than 3-MI with fog fever)

theres no treatment! don't feed cows moldy potatoes!

perilla (purple) mint- grows well in late summer, fall in semi-shaded areas [Missouri]

lung worms- Dictyocaulus viviparous

alveolar and interstitial pneumonia

[direct life cycle] adults live in airways, lay eggs, larvae are coughed up and swallowed, larvae passed in feces--> L3 on grass are eaten, migrate to airways--> repeat

21-28 days

eosinophilic exudate, coughing, tachypnea, pneumonia with caudoventral consolidation, fever, harsh lung sounds, open mouth breathing, +/- death if a large number of larvae penetrate at once

larvae penetrate the alveoli

the pre-patent period is complete.

after treatment, when larvae rapidly re-infect lungs of cattle introduced to infected pastures

• Baermann sedimentation of feces
• trans-tracheal wash and visualization of larvae, eggs, adults

• Levamisole phosphate (oral, SQ, topical)
• Ivermectin
• Benzimidazole (fenbendazole, panacur)