Fever/Immune

Question 1

what is the difference between a fever and hyperthermia?

Answer 1

fever is a raised thermoregulatory set point, set by the anterior hypothalamus and the presence of pyrogens

with hyperthermia there is no alteration of the thermoregulatory set point, can be caused by exercise, seizures, stress, etc

Question 2

what are the things that cause fever?

Answer 2

the knights who say NIII

neoplasia, infection, immune mediated, inflammation

Question 3

what is a FUO?

Answer 3

fever of unknown origin: when fever persists long enough to where the common self limiting causes are ruled out and initial diagnostics do not reveal a cause for a fever

Question 4

a dog presents for fever. what history questions will you ask the owner?

Answer 4

• travel history?
• any recent medications?
• recent history of fighting or trauma?
• recent heat? (pyo)
• any animals or humans in close contact showing signs?

Question 5

what sorts of things might you be looking for on PE with a pet with a fever?

Answer 5

heart murmur, joint effusion, back pain, bone pain, bite wounds, renal pain, organ enlargement, rectal exam, masses, URI, lung auscultation, enlarged LNs, abdominal or chest effusion, oral exam, ocular exam, derm lesions?

Question 6

what are some first line diagnostic tools you can use for working up a fever?

Answer 6

CBC/blood smear, biochemistry, urinalysis, urine culture, FeLV, FIV in cats, imaging

others: ultrasound, echocardiogram, joint taps, FNAs, biopsies, etc

Question 7

autoimmune diseases are most mediated by ___ cells and ______

Answer 7

Th2 cells and autoantibodies

Question 8

what are 3 characteristics of immune mediated diseases and therefore 3 treatment targets?

Answer 8

-autoantibody production by lymphocytes
-opsonized cells cleared by marcophages or complement
- inflammatory cytokines

Question 9

what is the difference between primary and secondary autoimmune disease

Answer 9

primary is idiopathic and is a diagnosis of exclusion
secondary has an underlying cause you can identify

Question 10

immune mediated diseases require complete workups to:

Answer 10

look for an underlying cause and rule out infectious etiology BEFORE you suppress the immune system

Question 11

what us SLE?

Answer 11

systemic lupus erythematosus

a multisystemic autoimmune disorder where there are antibodies against many tissues, including the nucleus of cells. opsonization happens as well as the formation of immune complexes.

common in dogs, GSDs and duck tollers, usually middle aged

Question 12

a 6 yo duck toller presents for fever and joint swelling. upon further examination you notice skin lesions on the muzzle and in the oral cavity. The LNs are enlarged. differential? what diagnostics tests do you want?

Answer 12

systemic lupus erythematosus

hard to diagnose with 100% certainty
first, rule out underlying disorders. consider a urinalysis to check for proteinuria which could be indicative of glomerulonephritis

ideally do a ANA test (antinuclear antibody test) or a LE test

Question 13

what is the ANA test?

Answer 13

autonuclear antibody test for SLE. tests for antibodies agaisnt DNA, RNA, and hostones. false positives and false negatives possible.

usually an ELISA test

Question 14

what is an LE test?

Answer 14

for SLE diagnosois

looking for lupus erythematosus cells: neutrohpils containing phagovytized nucleus. not sensitive, but very specific.

Question 15

the 6yo duck toller tests positive for the ANA test and the LE test. how will you treat and what is the prognosis?

Answer 15

immunosuppressive therapy

adjunct therapy for secondary issues like IMHA or PLN
supportive care

prognosis is variable and relapse is very possible

Question 16

what causes non inflammatory joint disease?

Answer 16

developmental joint disease (like OCD)
degenerative (like arthritis)
trauma
tumors

Question 17

what can cause inflammatory joint disease?

Answer 17

either septic or sterile, will see neutrophils in the joint

septic: bacterial infection
immune complexes: type III hypersensitivity reaction, complexes depositied in joints, activating complement and inflammation
sterile: inflammation within the joint itself

Question 18

how do you differentiate between an infectious joint disease and an immune mediated joint disease?

Answer 18

septic: more likely a single swollen joint, history or surgery or trauma, or a previous infection

immune: multiple joints, often smaller more distal joints, history of antibiotic or vaccination

Question 19

how do you differentiate between septic and sterile joints?

Answer 19

sample the synovial fluid

Question 20

when should you consider doing a joint tap?

Answer 20

if you have solitary joint disease with signs of inflammation or systemic illness, evidence of polyarthritis, or if you have a FUO

ALWAYS CULTURE A JOINT TAP

Question 21

what does normal joint fluid look like?

Answer 21

clear, colorless, viscous, with low cellularity, mononulcear cells and very few neutrophils

Question 22

what does abnormal joint fluid look like?

Answer 22

turbid, cloudy, discolored (pink or yellow), very thin, high cellularity with many neutrophils and maybe some bacteria

Question 23

describe synovial fluids results for a :
sterile inflammatory joint
a septic joint
degenerative or traumatic joint

Answer 23

sterile: thin, turbid, discolored, cellularity between 3000-150,000 cells/uL, non degenerative neutrophils

septic joint: thin, turbid, discolored, cellularity more than 150,000/uL, degenerative neutrophils, maybe bacteria

degenerative: clear,colorless, could be blood with trauma, low or slightly elevated cellularity, mononuclear cells

Question 24

what is erosive polyarthritis ?

Answer 24

subchondral bone is destroyed, usually carpal bones, happens in small middle aged dogs. very UNCOMMON

Question 25

what are the most common causes of inflammatory joint disease in small animals?

Answer 25

idiopathic most common
SLE
reactive/secondary

Question 26

what is IMPA?

Answer 26

immune mediated polyarthritis, where immune complexes deposit in the synovium. can be primary/idiopathic, or reactive/secondary

Question 27

what sorts of things can cause reactive/secondary IMPA?

Answer 27

infectious anywhere in the body or from bacteremia
medications like antibiotics or vaccines
neoplasia
dietary elements (uncommon)

Question 28

list some clinical signs of IMPA

Answer 28

stiff gait/walking on eggsehlls, joint pain or swelling, inappetence, lethargy, weight loss, weakness, vomiting, fever, neck or back pain

Question 29

how do you diagnose IMPA?

Answer 29

joint tap: neutrophilic inflammation in multiple joints, negative culture

good PE, CBC/chem, urinalysis, infectious disease testing, imaging

Question 30

what is important to remember about doing a joint , urine, or blood culture?

Answer 30

ideally do this before antibiotic therapy

do sterile prep, wear sterile globes, etc

Question 31

what is a SNAP 4DX / Accuplex test?

Answer 31

tests for tick borne diseases: anaplasma, borrela burgdorferi (lyme), ehrlichia, etc, and heartworm

Question 32

if you think a patient could have IMPA, when would you consider doing joint radiographs?

Answer 32

if there’s a single joint affected, if there is any crepitation or instability, decreased range of motion

Question 33

a 3 yo MN golden retriever has a 3 week hx of intermittent lethargy, fever, and decreased appetite, and was on antbiotics 3 weeks ago. he travels to ontario and manitoba. on PE, his right carpus seems painful, there is some mild effusion of the left hock, and his temp is 40.1. what are your next steps?

Answer 33

CBC/chem/UA
joint taps/cultures
SNAP 4DX

Question 34

the 3yo MN golden retreiver’s results for CBC chem: 2+ protein in urine, and a stress lymphopenia. SNAP 4DX is negative.

joint tap: thin and cloudy, lots of neutrophils (increase in cellularity), and all joints are affected. his urine culture, blood culture, and joint culture are all negative. diagnosis? treatment?

Answer 34

IMPA, but we can’t say yet if it’s primary or secondary! we need more diagnostics like US, rads, diet analysis.

treatment: prednisone 2mg/kg/day

Question 35

after treating the 3yo MN golden with prednisone, what is your follow up plan?

Answer 35

repeat joint tap in 1 month before tapering prednisone.

Question 36

3yo MN golden is clinically better, but the joints are not responding to the prednisone you gave him. next steps?

Answer 36

add in cyclosporin

Question 37

Dopey a 8yo MN basset hound presents for lethargy, lameness, inappetence. 1.5 weeks ago became lame on RH leg and rads sus of early cruciate disease, was given rest and NSAIDs. 1 week ago he is unable to walk and is lethargic. temp is 39.9 and chest rads sus of penumonia came back normal. on PE: slightly tacky mms, reluctant to move, 2/6 systolic heart murmur, and maybe some mild joint effusion. on CBC chem he showed inflammation, a mild anemia, and his 4DX is negative. joint taps are cloudy and pink, watery. SO many neutrophils were found, but they are non-degenerative. on echocardiogram he showed signs suggesting endocarditis! blood and urine culture showed E coli but the joint cultures were negative. diagnosis?

Answer 37

endocarditis with reactive/secondary IMPA

Question 38

clinical signs of bacterial endocarditis?

Answer 38

lameness, heart failure, fever, tachycardia, murmur.

PE: newly developed or change in heart murmur with concurrent signs like fever or joint disease

Question 39

how do you treat bacterial endocarditis

Answer 39

bactericidal broad spec antibiotics, commonly aminoglycosides, beta lactams, or fluoroquinolones. also will need to reat the cardiac disease, and possible thromboprophylaxis to prevent clots from forming. treatment 4-6 weeks minimum, usually longer