Respiratory 3 Flashcards
you are talking to a bovine feelot producer and he tells you he thinks some of his new cows that just arrived have shipping fever. What do you tell him the real name of this disease is?
bovine respiratory disease complex
the bovine feedlot producer wants to know what causes bovine respiratory disease complex. what do you tell him?
it is a multifactorial disease caused by a mix of environmental factors, host factors, and pathogen factors
the bovine feedlot producer doesn’t like your explanation (what a jerk) of bovine respiratory disease complex and wants more specifics. He says “aren’t there viruses or bacteria involved?” You then say “yes, the most commonly involved viruses are _______ and the most common bacteria involved are ______
bovine respiratory syncytial virus, parainfluenza 3 virus, infectious bonvine rhinotrachetitis (bovine herpes virus 1)
manheimia haemlytica, pasturella multocida, histophilus somni, mycoplasma bovis
you go visit a dairy farm to go see a bunch of calves kept indoors. They have their necks extended, there is foaming at the mouth, and they are all standing with a wide stance. What do these dairy cows have?
enzootic pneumonia of calves caused by a combination of envionrmental, host, and pathogen factors (similar to those with shipping fever)
you explain to the dairy producer that there is a 2 hit theory when it comes to his calves with enxootic penumonia. what is the 2 hit theory and what other disease is associated with the two hit theory?
the 2 hit theory suggest that first the animal is hit with a viral infection, and the second hit is an OPPORTUNISTIC bacterial infection. another disease associated with this is shipping fever or bovine respiratory disease complex
you get a necopsy of a calf on path rotations and you were told that the calf experienced transient pyrexia and mild respiratory disease and then temporarily inmproved. The calf then experienced a severe rapid onset of respiratory distress and died shortly after. When you open up the lungs to look, it looks like bronchopneumonia: the craniocaudal lung lobes are dark red and meaty, and the caudo-dorsal lung is voluminous and puffy. when you look at the histology slides you see that the alevolar epithelial cells have formed large multinucelated syncytial cells. What did this calf die from, and explain the pathogenesis
bovine respiratory syncytial virus:
the virus impairs alevolar macrophages which allows for opportunisitc bacterial infections.
bovine respiratory synsyctial virus technically causes what kind of penumonia?
bronchointerstisial pneumonia with inflammation centered on airways and the alveoli
I’m a commensalistic bacteria normally found in the nasopharynx in cattle and I cause fibrinous bronchopneumonia. I am a part of the bovine respiratory disease complex. What am I? What do you expect the lungs to look like in which I invade?
mannheimia haemolytica
classic cranioventral bronchopneumonia, well demarcated areas of caogulative necrosis
what are “oat cells” and what bacterial disease are they indicitave of?
mannheimia maemolytica: production of a leukotoxin causes lysis of neutrophils forming streams of neclear material fromthe dead neutrophils and this looks like oats on histo
there are 3 bacteria that look similar upon presentation on lung necropsy. what are these 3 bacteria and how do they present? How do you differentiate them?
Mannheimia haemolytica, histophilus somni, and pasturella multocida. All present as fibrinous bronchopneumonoa or fibrinous pleuritis. CULTURE
respiratory infection of histophilus somni causes 4 conditions. what are they? can all 4 of these happen at the same time?
bronchopneumonia and pleuritis
pericarditis
polyarthritis (septic joints)
thromboembolic meningoencephalitis
usually or 1 or 2 of these happen, never all 4 at once
mycoplasma bacteria species show high levels of antibiotic resistance.why?
they lack cell walls which means certain types of antibiotics don’t work on them
You are talking to a fellow vet student working on a necropsy of a cow that you both think is infected with a mycoplasma bacteria. The student suggests that the lung samples be cultured to find out. Is this the right move? Why or why not?
NO this is NOT the right move! Mycoplasms are slow groing and therefore difficult to culture so PCR is a better diagnostic!
how do mycoplasma bacteria spp cause disease?
mycoplasma adhere to the ciliated epithelium of the respiratory tract and cause ciliostasis which impais the mucociliary clearance
what is the most important mycoplasma species in all of canada?
mycoplasma bovis
what 3 syndromes are caused by mycoplasma bovis?
penumonia, polyarthritis, otitis media
you are doing a necropsy and you find caseonecrotic bronchopneumonia with cranioventral consolidation with multifocal, raised, white, sharply demarcated, friable foci of caneous necrosis. what is your number 1 differential? if you were to do histology, what would you likely see?
mycoplasma bovis
histology: bronchietasis
what is that DARN BACTERIA that kills THEM BISON?
mycoplasma bovis
if you suscpect mycobacteria are responsible for a penumonia case you just saw, what will you tell the histology people to do?
use acid fast stain because the bacteria don’t stain with a gram stain because of their high lipid content (even though they are gram positive)
what are the 3 big important mycobacterial diseases?
tuberculosis
jonhe’s disease
leprosy
the gross lesion of respiratory tuberculosis is
the tubercle, a nodular granuloma that is often mineralized
you have been asked to look at the histology slide for the case you had for suscepted mycobacterium. What 3 things do you expect to see on the slides?
central necrosis, small numbers of acid fast bacteria, rim of epitheliod marcophages and multinucleated giant cells
what kind of pneumonia would you expect to see in a patient with a mycobacterium infection?
granulomatous
what are the two bacteria that are abbreviated M bovis? which is reportable?
Mycoplasma bovis (not reportable) and mycobacteria bovis (reportable)
what are the two main mycobacteria species that you should care about? Why do we care so much? Which one is worse than the other?
mycobacterium bovis and mycobacterium tuberculosis. they are both zoonotic! M bovis has a much lower zoonotic risk than M tuberculosis
a cattle farmer comes to you and says that the adults in his herd are experiencing acute onset od dyspnea with expiratory effort, tachypnea, open mouth breathing, and froth coming from the mouth. The calves seem to be fine. He tells you that he just recently moved his cattle from the barn into the pasture. It happens to be early summer and the pasture is looking very green and lovely. What is going on here? What is causing this disese? Why are the calves okay?
the sheep have acute bovine pulmonary emphysema and edema aka fog fever.
the cause is 3-methylindole toxicity from lush green plants
you need an active and working rumen to form the toxin that causes the disease
your dad saks you, “hey kid, what’s vermin pneumonia?” what do you tell him?
you say “it’s a type of pneumonia in cattle caused by lungworms named dictyocaulus viviparus which is a nematode, and the worm likes to live in the bronchi. it causes eosiniophilic granulomas”
a sheep farmer comes to you and says, “hey doc I’m worried about my sheep getting lung parasites, tell me more” so what do you say?
lungworm in the sheep is called muelleris capillaris, and in small numbers they are usually OK but large numbers can cause poor wight gain and predispose some sheep to infections.
what kind of virus is OPP, what animal does it infect, and what are the gross pulmonary lesions?
ovine progressive pleuropenumonia is a lentivirus infecting sheep.
gross lesions: heavy, pale lungs that fail to collapse, caudal lobes more affected, rubbery lungs, rib impressions
what is the virus responsible for inducing tumors in sheep?
ovine pulmonary adenocarcinoma caused by jaagsiekte sheep retrovirus
what is APP in pigs and what kind of pneumonia does it cause? what is unique about the gross presentation?
actinobacillus pleuropneumoniae, aka, contagious pleuropneumonia. it causes fibrinous bronchopneumonia with extensive pleuritis
gross presentation: usually the middle or caudal lung lobes are affected even though it is a bronchopneumonia
what are the 3 important things to remember about mycoplasmas?
they lack a cell wall, they are slow growing, and they cause ciliostasis
what is PRRS and what kind of pneumonia does it cause? what do the gross lesions look like?
porcine respiratory and rproductive syndrome, causing granulomatous interstisial penumonia (must be diagnosed by histo to see the granulomatous part)
lesions: lungs fail to collapse, rib impressions and firm on palpation, patchy discoloration
what is the name of the syndrome that is caused by porcine circovirus 2. What is the main clinical sign?
porcine circovirus and postweaning multisystemic wasting syndrome
lymphadenopathy
what are the gross lesions associated with swine influeza? how about on histo?
cranioventral lobular distribution of atelectasis and large edematous lymph nodes
histo: epithelial necrosis
recurrent airway obstruction is called what in lay man’s terms? What does it cause? where does it target?
heaves
reversible airway obstruction due to bronchospasm
targets small bronchioles and caudodorsal lung
what are the 3 disease presentations with rhodococcus equi?
enteritis, polyarthritis, pneumonia
what kind of penumonia does rhodococcus equi cause?
pyogranulomatous bronchopneumonia
if you have a foal with pyogranulomatous bronchopneumonia, what is the cause?
rodococcus equi
what is kennel cough?
canine infectious respiratory disease complex
what are the 3 systems that canine distemper virus affects?
respiratory, GI, and CNS
when do dogs usually develop pneumonia?
when pulmonary defences have been impaired
which bacteria is famous for being a part of the canine infectious respiratory disease complex?
bordetella bronchiseptica
name the 4 big system mycoses!
blastomyces dermatitidis
coccidioides immitis
crptococcus neoformans
histoplasma capsulatum
ALL ZOONOTIC
if you suspect that a dog has blastomycosis or coccidioides, should you send away a sample for culture?
NO, IT IS ZOONOTIC AND IS NOT SAFE TO SEND FOR CULTURE
what is the most common systemic mycoctic disease in cats?
cryptococcosis
why do fungi usually cause granulomatous pneumonia?
because the macropahes in the lung can’t digest them, causing them to live in the macrophages causing a granuloma
you have a dog named Bunny coming to see you because she has heartworm. What will cause her clinical signs?
pulmonary hypertension and vascular sclerosis due to the prescence of worms in the arteries
feline asthma causes
revesible airway obstruction, bronchospasm, inflammation
