respiratory 2

Question 1

streptococcus

Answer 1

gram positive cocci

respiratory dz (but also others)

commensal flora of oronasopharyngeal and genital mucosa

strepto - chains

Question 2

streptococci can cause 3 kinds of hemolysis

Answer 2

beta - complete hemolysis
commensals and common opportunists

alpha - incomplete hemolysis
commensals but rare opportunitists
viridis

y - no hemolysis
always commensals and nonpathogens

Question 3

beta streptococci

Answer 3

s. pyogenes GAS
s. agalactiae GBS
s. equi subsp. zooepidemicus GCS
s. equi subsp, equi GCS
s. canis GGS
s. dysgalactiae GCS
s. porcinus GES

Question 4

streptococcal virulence factor

Answer 4

MSCRAMMS - M protein and hyaluronic acid

superantigens - activates CD4+ T cells = cytokine storm

hemolysins

generate a lot of pus

Question 4

M protein in MSCRAMMS

Answer 4

binds host fibrinogen

decreases complement activity

antiphagocytic

adherence to epithelia

Question 5

hyaluronic acid in MSCRAMMS

Answer 5

adhesive

antiphagocytic

Question 6

S. equi subsp. zooepidemicus

Answer 6

horses: noncontagious, 80% isolates from pleuropneumonia, 20% opportunistic infections (wounds, UG tract, sepsis, keratitis, etc)

dogs: severe hemorrhagic bronchopneumonia (shelter), possibly contagious

Question 7

S. equi subsp. equi

Answer 7

horses only

contagious

strangles - rhinopharyngitis

gutteral puch empyema

bastard strangles - complication of regular strangles spreading to distant LNs

pupura hemorrhagica - a type III hypersensitivity, systemic infarctive vascululitis - death

Question 8

Streptococcus canis

Answer 8

all around opportunist of dogs and cats

common cause of aspiration pneumonia

infect wounds, can cause pyoderma

endocarditis
septic arthritis
diskospondylitis
necrotizing fasciitis
UTI (rare)
keratitis (cornea)
sepsis

Question 9

streptococcus porcinus and suis

Answer 9

porcinus:
beta hemolytic
analogous to strangles, not as severe, often an incidental finding

suis:
alpha hemolytic - the ONE alpha to worry about
in weaners and early growers
bronchopneomia
neonatal bacteremia
sepsis
endocarditis
septic arthritis
abscesses

Question 10

Rhodococcus equi

Answer 10

not a cocci……

gram positive

pleomorphic coccobacilli

obligate aerobes

facultative intracellular

partially acid fast

major disease in foals - rarely seen in other species

Question 11

Rhodococcus equi encounter

Answer 11

environmental organism

grows in horse manure

most soil around horses is contaminated

tends to be inhaled (most commonly) or ingested

horse to horse is unlikely

amplification in environment is important

Question 12

rhodococcus equi virulence factors

Answer 12

vapA- virulence associated protein

lipoarabinomannan (LAM)

cell wall lipids

Question 13

vapA

Answer 13

gene is on plasmid
necessary for survival in macrophages
prevents phagosome-lysosome fusion

Question 14

lipoarabinomannan (LAM) - cell membrane lipid

Answer 14

similar to M. tuberculosis
influences macrophage response

Question 15

cell wall lipids

Answer 15

stimulates IFN gamma production –> recruits more macrophages to infect

Question 16

Rhodococcus equi damage

Answer 16

survives in multiple macrophages

causes pyogranulomatous inflammation

TH1 response - abscesses and granulomas

potential to spread beyond lung
- abdominal lymph nodes
- bone
- eye
- liver
- intestine

Question 17

what are the most common lower respiratory infections seen in dogs, cats, and horses?

Answer 17

aspiration pneumonia and bronchopneumonia

Question 18

sources of bacteria infections of pneumonia

Answer 18

poor bottle feeding technique
esophageal disease
reflux
vomiting
“choke” in horses
laryngeal dysfunction
airway disease (inflammatory, congenital, neoplastic)

Question 19

aspiration pneumonia

Answer 19

inhalation of GI contents

usually polymicrobial –> antibiotic therapy is therefore a challenge

Question 20

Dx of lower respiratry dz in small animals

Answer 20

samples should represent the lower RT

take a concurrent sample for cytology

transtrachael wash (TTW)

bronchoalveolar lavage (BAL)

postmortem lung biospy/culture

DO NOT SUBMIT NASAL OR ORAL SAMPLES FOR BACTERIOLOGY FROM A DOG OR CAT unless first discussed with a specialist..

Question 21

what are the special considerations when culturing haemophilus spp. and actinobacillus pasteurellaceae?

Answer 21

fastidious and need NAD to grow. = need chocolate agar or nurse streak on blood agar with s. aureus

Question 22

Dx of respiratory tract in horses

Answer 22

upper RT - sampling IS useful to rule in S. equi subsp. equi carrier status. Gutteral pouch lavage
Deep nasal swab
lymph node aspirate’

lower RT -
TTW
BAL
thoracocentesis if concurrent pleuritis (pleuropneumonia)

Question 23

sample handling and transport

Answer 23

chill - do NOT FREEZE

fluid samples -
place in sterile container with NO ADDITIVE.
never use EDTA tubes!

tissue samples -
sterile container

culturettes-
have taq inhibitors and are NOT appropriate for PCR

Question 24

laboratory testing

Answer 24

aerobic culture on all lower RT samples add anaerobic IF - Lobar consolidation (lobe in inflated) - all equine pleuropneumonia NO NASAL CULTURES - unless its a horse and youre looking for s. equi equi

Question 25

mycoplasma diagnosis

Answer 25

have "fried egg: appearance usually diagnosed via PCR and/or serology

Question 26

treatment and control of respiratory disease

Answer 26

antimicrobial agents and support care treatment metaphylaxis - treat a whole group even when theyre not all infected infection control and biosecurity - manage animal density and contagious dz, reduce shipping stress vaccinate when available and feasible

Question 27

management of bovine RD

Answer 27

institute appropriate vaccination protocols for control of underlying viral dz's M. haemolytica, P. multocida, H. somni vaccines antimicrobial therapy in sick cattle - ceftiofur macrolides florfenicol

Question 28

management of swine RD

Answer 28

all-in/all-out management - maintain closed herds manage underlying viral dz vaccinations for APP, M. hypopneumoniae, Bp, P. multocida

Question 29

management of equine RD

Answer 29

isolate animals of equi equi, disinfect everything, can be shed for 6 weeks after clinical resolution drain abscesses or gutteral pouches antimicrobials - penicillin, ceftiofur, TMS surveillance for carrier animals - PCR gutteral pouch lavage 3 samples X 7 days apart = negative vaccination of equi equi

Question 30

treating aspiration pneumonia

Answer 30

address underlying cause antimicrobial therapy - broadspectrum therapy nebulized agents adjustment or de-escalation to address organism identified on culture ancillary care - oxygen, reduce fever, fluid support, coupage periodic thoacocentesis if concurrent pleuritis - diagnostic and therapeutic

Question 31

management of canine and feline UPR

Answer 31

vaccinate for viral diseases dogs - Bp vaccination cats - Bp vaccination exists but not recommended by AAFP most presentation for RD are mild UPD and DO NOT require antimicrobial agents if severe: doxycycline, amoxicillin + clavulanate can shed for 1-6 months biosecurity!! - shelter cats esp.