Exam 2 - Ruminant Lower Respiratory Tract Flashcards
what is bronchial pneumonia?
invasion of pathogenic organisms that gain access to the lung through the pulmonary tree
what are the typical clinical signs of bronchial pneumonia?
lethargy, fever, & indications of sepsis
what is the typical distribution of bronchial pneumonia?
cranioventral localization
what is interstitial pneumonia?
diverse group of diseases - typically non-infectious
interstitial reaction that usually results from ingestion/inhalation of toxins/allergens
what are the clinical signs of interstitial pneumonia?
abnormal lung sounds, not as ill-appearing as bronchial pneumonia
what is the typical distribution of interstitial pneumonia?
diffuse
what is metastatic pneumonia?
septic embolization of lungs or other body locations - commonly liver
what are the clinical signs of metastatic pneumonia?
septic with widespread abnormal lung sounds that eventually lead to hemoptysis
what are the bronchopneumonias complex made up of?
multi-factorial disease complexes with no single etiologic agent, compromised host defense scenarios, contributing environmental factors, & management decisions
what is BRDC?
bovine respiratory disease complex
what is the pathogenesis of bovine herpesvirus-1?
direct contact with infected cattle or aerosol transmission
epithelial cells of respiratory tract are initial target - direct injury in upper respiratory tract & bronchi leading to inflammation/increased susceptibility because of dysfunction of neutrophils, lymphocytes, & macrophages
virus spreads by intracellular bridges between cells
lymphocytes & monocytes are susceptible to infection leading to extra-respiratory site transport to spleen, esophagus, & liver
what is the pathogenesis of bovine herpesvirus-1 in latent infections?
latent infection in neural tissues - trigeminal gangli & tonsils, not actively produced/shedding
can be reactivated by stress & glucocorticoids
what is the etiology of bovine herpesvirus-1?
enveloped DNA virus, subfamily alphaherpesvirinae, varicellovirus
what are some diseases in which bovine herpesvirus-1 is the causative agent?
IBR, conjunctivitis, pustular vulvovaginitis, abortion, mastitis, etc
what is ‘red nose’ in bovine herpesvirus-1 infections?
hyperemic & reddening of muzzle
what are the clinical signs of bovine herpesvirus-1?
rhinitis, tracheitis, pyrexia, reduced milk production, coughing, & open mouth breathing as mucopurulent debris accumulates in the upper respiratory tract
how is bovine herpesvirus-1 prevented?
vaccinations, reduce stress, minimize co-mingling
what is the treatment used for bovine herpesvirus-1 infections?
supportive care - reduce stress, maintain feed/water intake
NSAIDS
no steroids
vaccinate in outbreaks
when are bovine herpesvirus-1 infections most common?
when large groups of cattle come together - more severe in feedlot cattle
adults serve as reservoirs
what diagnostics are used for bovine herpesvirus-1?
virus isolation - IFA, PCR of nasal swabs or conjunctival scrapings, or paired serology
what is the etiology of bovine respiratory syncytial virus?
enveloped RNA virus, family paramyxoviridae - very similar to human RSV
what is the pathogenesis of bovine respiratory syncytial virus?
contact with infected animals/aerosols/fomites
incubation of 3-5 days
bronchitis/alveolitis/interstitial pneumonia
affects epithelial cells from nasal passages to alveoli
epithelial cells fuse to multinucleated cells = syncytia
aggressive invasion, attack, & destruction of tracheal/bronchial to alveolar epithelium
what is the treatment for bovine respiratory syncytial virus?
supportive care to limit inflammatory response in bronchioles & alveoli & to prevent secondary bacterial infections
how is bovine respiratory syncytial virus prevented?
vaccine, IM/SQ/IN - reduces morbidity & mortality
how is bovine respiratory syncytial virus diagnosed?
virus ID of nasal secretions, tracheal aspirates, or lung lavage fluid - difficult to isolate
when is the best time to try and diagnose bovine respiratory syncytial virus?
first 7 days of infection - easier to find virus in the infection
what are the clinical signs associated with bovine respiratory syncytial virus?
fever, dullness, anorexia, tachypnea, ptyalism, discharge, cough, SQ emphysema
what is seen on necropsy of an animal with bovine respiratory syncytial virus?
acute, interstitial edema & expanded lungs
what is the etiology of bovine viral diarrhea virus?
enveloped RNA virus, flavivirus - causes immunosuppression & persistent infections
what age of animal is affected by bovine viral diarrhea virus?
any age can become infected**
what is the pathogenesis of bovine viral diarrhea virus?
co-infection with m. hemolytica, BHV-1, BRSV - exacerbates disease
what are the clinical signs associated with bovine viral diarrhea virus?
mild pneumonia, fever, tachypnea, increased lung sounds
what diagnostics are used for bovine viral diarrhea virus?
IHC, virus isolation, PCR
how is bovine viral diarrhea virus prevented?
vaccination & biosecurity practices
what is the etiology of parainfluenza-3?
enveloped RNA virus, paramyxoviridae - widespread infection in small ruminants & cattle
what animals are typically affected by parainfluenza-3?
mostly young animals
what is the pathogenesis of parainfluenza-3?
predisposes the respiratory tract to other agents, inhibits the mucociliary apparatus, & reduces alveolar macrophage function
what are the clinical signs of parainfluenza-3?
subclinical mild symptoms - cough, nasal/ocular discharge, fever, tachypnea, & lung sounds
what diagnostics are used for parainfluenza-3?
virus isolation, rt-PCR - easy to isolate
what is the treatment for parainfluenza-3?
supportive care
what is the prevention for parainfluenza-3?
vaccination in cattle
none labelled for sheep/goat
what is the etiology of bovine coronavirus?
enveloped RNA - affects calves
what are the clinical signs associated with bovine coronavirus?
mild & unnoticed or confounded by other pathogens
what diagnostics used for bovine coronavirus?
rt-PCR, & antigen capture enzyme linked immunoassay (ACE)
what is the etiology of malignant catarrhal fever?
lymphoproliferative disease due to gamma herpesvirus
what age of animals are affected by malignant catarrhal fever?
over 4 weeks old
what is the pathogenesis of malignant catarrhal fever?
inhalation of aerosolized virus or direct contact
infiltrates the lymphocytes
dysregulation of cytotoxic t-cells
what diseases must malignant catarrhal fever be differentiated from?
BVD, rinderpest, foot & mouth, & blue tongue
what are the clinical signs associated with malignant catarrhal fever?
acute inappetence, fever, ocular/nasal discharge, conjunctivitis, & gi lesions
coronitis - hoof/horns may shed, scabs on muzzle
what is the most common bacteria identified in feedlot cattle?
mannheima haemolytica
what is the etiology of mannheima haemolytica?
gram negative aerobe bacteria - pasteurellaceae family
what age of animals are typically affected by mannheima haemolytica?
calves - young ruminants
what is the pathogenesis of mannheima haemolytica?
endotoxin release - typically become infected early in life & carry long term
stress/transport allows for proliferation
what are the clinical signs of mannheima haemolytica?
severe, lobar necrotizing fibrinous pleuropneumonia - diffuse hemorrhage
dullness, anorexia, cough, thoracic pain, harsh lung sounds, tachypnea, & tachycardia
what diagnostics are used for mannheima haemolytica?
culture from lungs, ultrasound, radiography, TTA, BAL, swab, thoracocentesis
what is the treatment used for mannheima haemolytica?
antimicrobials & nsaids
how is mannheima haemolytica prevented?
vaccination, prophylactic antimicrobials, & minimize stress
what is the etiology of pasteurella multocida?
gram negative aerobic bacteria, pasteurellaceae family - causes multiple diseases
what animals are most commonly affected by pasteurella multocida?
calves, young ruminants, dairy cows
what is the pathogenesis of pasteurella multocida?
shorter and less severe than M. haemolytica
we know very little about the mechanism
endotoxin produced
what is seen on necropsy in an animal with pasteurella multocida?
plum-colored lung
what are the clinical signs associated with pasteurella multocida?
fever, tachypnea, dullness, nasal discharge, coughing, & increased lung sounds
what are the diagnostics used for pasteurella multocida?
culture, ultrasound
what is the treatment of pasteurella multocida?
longer term therapy of antimicrobials & nsaids
how is pasteurella multocida prevented?
prevent respiratory insult & viral infections - less stress, immunity
what is the etiology of histophilus somni?
gram negative aerobe, pasteurellaceae family
what is the pathogenesis of histophilus somni?
commensal in healthy ruminants - vasculitis & vascular thrombi formation
what clinical signs are seen with histophilus somni?
depends on the organ system affected
respiratory - fever, tachypnea, nasal discharge, dullness, cough, increased lung sounds
what diagnostics are used for histophilus somni?
necropsy - abscesses, edema, fibrin, & hemorrhage
difficult to isolate on culture
what is the treatment for histophilus somni?
antimicrobials
what is the prevention for histophilus somni?
vaccination
what is the major disease that mycoplasma bovis causes?
chronic pneumonia
what age of animal is typically affected by mycoplasma bovis?
young, under 2 years old
what is the pathogenesis of mycoplasma bovis?
opportunistic infection, exact mechanism unknown, evades immune system
what are the clinical signs associated with mycoplasma bovis infections?
tachypnea, fever, inappetence, respiratory distress, & can see CNS signs
what is seen on necropsy that is supportive of mycoplasma bovis infection?
dark red nodules on the lungs
how is mycoplasma bovis diagnosed?
culture or IHC
what is the treatment for mycoplasma bovis infections?
tilmicosin
multiple antibiotics labelled to treat
how is mycoplasma bovis infection prevented?
vaccines - not proven
what agent is associated with significant mortality in kids & does?
mycoplasma mycoides
what are the clinical signs associated with mycoplasma mycoides infections?
acute/sub-acute syndrome of high fever, swollen joints, pneumonia
what diagnostics are used for mycoplasma mycoides infections?
necropsy - isolate organism
what is the treatment for mycoplasma mycoides?
antimicrobials don’t work - unsuccessful treatment
animals rarely recover
how is mycoplasma mycoides infection prevented?
don’t bring it into the herd
what is the etiology of trueperella pyogenes?
gram positive rod-shaped anaerobic bacteria
what age of animal is typically affected by trueperella pyogenes?
any age
young animals typically get pneumonia
what is the pathogenesis of trueperella pyogenes?
cytolytic toxin & other virulence factors
what are the clinical signs of trueperella pyogenes infections?
chronic respiratory disease
what are the diagnostics used for trueperella pyogenes?
necropsy & culture
what is the treatment for trueperella pyogenes infections?
prevent primary causes of pneumonia & don’t treat the pathogen
what is the etiology of bibersteinia trehalosi?
gram negative aerobe, pasteurellaceae family
what age of animals are typically affected by bibersteinia trehalosi?
young
what is the pathogenesis of bibersteinia trehalosi?
produces severe leukotoxin
what are the clinical signs associated with bibersteinia trehalosi?
they typically die before clinical signs are seen
what diagnostics are used for bibersteinia trehalosi?
culture & PCR
what treatment is used for bibersteinia trehalosi?
none - they die
what prevention is used for bibersteinia trehalosi?
vaccines for mannheima haemolytica may be helpful
why are chlamydial agents such a problem?
there are so many, and they infect the animal early in life where they become chronic carriers
what are some other names for interstitial pneumonias?
bovine pulmonary emphysema, atypical interstitial pneumonia (AIP), fog fever, pulmonary adenomatosis, farmer’s lung, acute respiratory distress syndrome (ARDS)
what is acute interstitial pneumonia?
any respiratory condition characterized by a sudden onset of dyspnea, typically severe, with gross and histopathologic findings consistent with AIP
what is seen on necropsy of an animal with acute interstitial pneumonia?
heavy, firm, textured lungs that don’t collapse
what is seen on histopathology of an animal with acute interstitial pneumonia?
alveolar hyaline membrane formation, fibrin deposition, interstitial edema
what animals are commonly affected by acute bovine pulmonary edema?
cows changed from dry, sparse forage to lush green pastures
typically over 2 years old
what is the pathogenesis of acute bovine pulmonary edema? what plants is it seen with?
cell damage, degeneration, necrosis
alfalfa, rape, kale, turnip top
what are the clinical signs seen with acute bovine pulmonary edema?
dyspnea, expiratory grunt, frothing at mouth, mouth breathing, head and neck extension – drastically improve after 3 days if survive
what is seen on necropsy of an animal with acute bovine pulmonary edema?
ecchymoses or petechial hemorrhage, congestion, edema
what is seen on histopathology of an animal with acute bovine pulmonary edema?
eosinophilic hyaline membrane, history of lush green pasture
what is the treatment for acute bovine pulmonary edema?
stress can exacerbate, antihistamines, corticosteroids
how is acute bovine pulmonary edema prevented?
management strategies
what is the etiology of feedlot acute interstitial pneumonia?
unknown - likely multifactorial
what clinical signs are seen in feedlot acute interstitial pneumonia?
dead in pen, dyspnea, tachypnea, open mouth breathing, cyanosis, SQ emphysema
what is found on necropsy in an animal with feedlot acute interstitial pneumonia?
identical to acute bovine pulmonary edema - dark & light-colored lobules
how is feedlot acute interstitial pneumonia diagnosed?
histopathologic evaluation is definitive
what is the treatment for feedlot acute interstitial pneumonia?
supportive - nsaids, antimicrobials, & diuretics
what is the etiology of 4-ipomeanol (moldy sweet potato toxicity)?
infestation of toxin in response to infestation with fusarium solani (fungi)
what age of animals are affected by 4-ipomeanol toxicity?
nursing cows unaffected even if the cow is affected
what is the pathogenesis of 4-ipomeanol toxicity?
toxin is absorbed in rumen & travels to the lungs in the blood
what are the clinical signs of 4-ipomeanol toxicity?
acute tachypnea, tachycardia, hyperpnea, dyspnea, expiratory grunting, frothing at the mouth, head/neck extension, cough, harsh lung sounds
how is 4-ipomeanol toxicity diagnosed?
based on the history of finding sweet potatoes in the feed, clinical signs
what is seen on necropsy of an animal that died from 4-ipomeanol toxicity?
lungs are firm, wet, fail to collapse, hemorrhage, yellow gelatinous edema
what is the treatment for 4-ipomeanol toxicity?
nothing specific - similar to acute bovine pulmonary edema
diuretics, nsaids, & antimicrobials
what is the prognosis of 4-ipomeanol toxicity?
grave if severe case
how is 4-ipomeanol toxicity prevented?
don’t feed mold-damaged sweet potatoes
An 18 month old beef steer is presented for evaluation of severe cough that has
persisted after 2 treatments for pneumonia. Physical examination leads you to a diagnosis of calf
diphtheria. What is the best treatment strategy?
A) sinocentesis and antibiotic impregnated bead placement
B) systemic antibiotics and NSAID therapy
C) tracheal lavage with 3 liters of sterile saline for 5
consecutive days
D) sedated abscess drainage
E) tracheal stent placement via endoscopy
B) systemic antibiotics and NSAID therapy
A 5 year old horned bull presents with a
slight head tilt, copious mucopurulent
nasal discharge, and halitosis. Which of
the following is an appropriate
diagnostic and treatment plan for this
bull?
A) endoscopy with a one time local infusion of
oxytetracycline
B) radiographs to determine affected sinus(es)
trephination and lavage
C) no diagnostics needed, dehorn the bull and let
the flies clean up the infection
D) percuss the sinuses, use the nasolacrimal duct to
lavage Nal into the affected sinus
E) None of the above
B) radiographs to determine affected sinus(es) trephination and lavage
