Bacterial & Rickettsial Diseases

Question 1

What is the most common clinical manifestation of B. burgdorferi in dogs and cats

Answer 1

Most commonly nothing!

but
acute syndrome- fever and lameness (acute polyarthritis)

chronic syndromes (dogs): lameness, glomerulonephropathy, cardiac? neurologic?

Question 2

What chronic syndromes do you see in dogs with Borrelia burgdorferi

Answer 2

lameness
glomerulonephropathy
cardiac?
neurologic?

Question 3

What breeds are over-represented for lyme glomerulonephritis

Answer 3

labrador and golden retrievers

Question 4

How is lyme disease nephritis different from other causes (ie HWD nephritis)

Answer 4

can progress from glomerulonephritis to tubular necrosis and interstitial inflammation

Question 5

______% of dogs with lyme nephropathy have been vaccinated

Answer 5

30%

Question 6

T/F: lyme nephropathy can be predicted

Answer 6

false - not all go on to get nephritis

Question 7

How do you test for Borrelia burgdorferi

Answer 7

1) ELISA/IFA using whole organism
-may cross reactive antibodies
-endemic areas, many positive dogs
-positives do not prove disease

2) Western blot immunoassay
-Many cross reactive antibodies
-Positives do not prove disease
-differentiates vaccinated dogs from naturally exposed

Question 8

Borrelia burgdorferi C6 AB

Answer 8

differentiates vaccines from natural exposire
does not differentiate clinical from subclinical

Question 9

What other B.burgdorferi antigen can you differentiate from vaccination

Answer 9

F and C6

Question 10

T/F: borrelia antibody tests are not lyme disease tests

Answer 10

True

Question 11

Borreliosis antemortem diagnosis relies on

Answer 11

1) Documented clinical syndromes
2) Serology positive- seronegative does not have lyme disease, usually AB positive when signs develop, excellent negative predictive value
3) Exclusion of other causes
4) Response to therapy

Question 12

Why do you often need to do serology for Borrelia burgdorferi

Answer 12

Not really in blood or joints (all negative)

no need for Borrelia assay

Question 13

How do you treat Borrelia burgdorferi

Answer 13

1) Doxycycline (doesnt help nephritis)
2) Amoxicillin
3) Lyme nephritis- ace inhibitor, low dose aspirin, immune suppression (pred, azathioprine, cyclosporine, mycophenolate)

Question 14

What form of immune suppression is recommended for dogs with lyme azotemia

Answer 14

Prednisone + Mycophenolate

Question 15

Is the quantitative C6 worth the money?

Answer 15

No- because doxy reduces the antibody level
dont know if titer magnitude makes the animal more sick

Question 16

T/F: lyme disease vaccine probably not needed in non-endemic areas

Answer 16

true

Question 17

What are the characteristics of rickettsial organisms

Answer 17

lack cell walls and LPS biosynthetic pathways
ex: Anaplasma, Ehrlichia, Neorickettsia, Rickettsia

Question 18

What tick spread Ehrlichia canis

Answer 18

Rhipicephalus sanguineus (Brown dog tick)
year round
likes to live in kennels

Question 19

What is the vector for Anaplasma phagocytophilum

Answer 19

Ixodes spp

Question 20

If you have Rhipicephalus tick, what 6 agents can be transmitted

Answer 20

1) Ehrlichia canis
2) Babesia vogeli
3) Anaplasma platys
4) Hepatozoon canis
5) Mycoplasma haemocanis
6) Rickettsia rickettsii

Question 21

Why do Ehrlichia canis dogs bleed

Answer 21

Vasculitis- primarily acute phase
Anti-platelet antibodies- platelet dysfunction
Severe thrombocytopenia- chronic phase only

Question 22

What is the number one infectious cause of monoclonal gammopathy

Answer 22

Ehlichia canis

Question 23

Dog in Colorado with postive Anaplasma SNAP4DX and no travel history, what species of anaplasma do they most likely have

Answer 23

A. platys (likely from brown brown dog tick)

A. phagocytophilum is spread via Ixodes tick which isnt in colorado

Question 24

What test is best for detecting earlier E. canis infections? What about later?

Answer 24

Earlier: PCR

Later: Antibodies

Question 25

If a dog with brown dogs ticks fail Doxycycline treatment. What is your next step

Answer 25

Treat for Babesia- Imidocarb diproprionate

Question 26

How do long do you treat for E. canis

Answer 26

minimum treatment duration is 28 days until platelets and globulins normalize or plateau for 2-4 weeks

Question 27

Why is it not important to follow E. canis PCR assay or antibody titers

Answer 27

Titers usually dont go negative Blood PCR assay results can go negative but E. canis is usually hiding in the spleen

Question 28

What do you do for E. canis patients that have pancytopenia

Answer 28

Treating chronic cases (pancytopenia); erythropoietin, granulocyte colony stimulating factor, prednisone 1mg/kg - pancytopenia very difficult to correct; can stop treating

Question 29

What is the only tickborne agent with a sterilizing immunity

Answer 29

RMSF- rickettsia rickettsia

Question 30

For heavy brown dog tick location, is repellant or bite to die product more favorable for preventing E. canis

Answer 30

Repellant - E. canis has short transmission time (3hours)

Question 31

What tick spreads Ehrlichia ewingii

Answer 31

Lone-star tick (Amblyomma americanum)

Question 32

What does Ehrlichia ewingii cause

Answer 32

acute fever, polyarthritis, mild to moderate thrombocytopenia no known chronic phase

Question 33

How do you treat E. ewingii

Answer 33

Doxycycline 14-28 days duration

Question 34

Monocytotropic or granulocytotropic? E. ewingii

Answer 34

Granulocytotropic

Question 35

Monocytotropic or granulocytotropic? E. canis

Answer 35

Monocytotropic

Question 36

What is the human monocytotropic ehrlichiosis

Answer 36

Ehrlichia chaffeensis

Question 37

Anaplasma, Ehrlichia, and Rickettsia species all respond to

Answer 37

Doxycycline