L07 Pt. 2

Question 1

What causes Ehrlichiosis in cats?

Answer 1

Ehrlichia canis

Anaplasma phagocytophilum

Question 2

Forms of Ehrlichiosis in dogs

Answer 2

1) Monocytic (caused by E. Canis and E. Chaffensis)
2) Granulocytic (caused by E. Ewingii and Anaplasma phagocytophilum)
3) Infectious thrombocytopenia (Anaplasma platys)

Question 3

Monocytic Ehrlichiosis

Answer 3

• Caused by E. Canis and E. Chaffensis
• infects monocyts and lymphocytes
• 3 clinical phases: acute, subclinical, and chronic
• Dx w/ snap test or indirect IFA
• Tx w/ supportive care, doxy, tetracycline

Question 4

Acute phase monocytic ehrlichiosis CS

Answer 4

-Fever, depression, lethargy, wt. loss, ocular/nasal dc, hemorrhage
-thrombocytopenia most consistent finding**
+/- anemia, leukopenia

Question 5

Subclinical phase monocytic ehrlichiosis clinical findings

Answer 5

Thrombocytopenia, strong Ab titer

Question 6

Chronic phase monocytic ehrlichiosis

Answer 6

Severe cases develop anorexia, lymphadenopathy, splenomegaly, edema, retinal lesions, ataxia, hepatomegaly, aplastic anemia

Question 7

Granulocytic Ehrlichiosis due to E. Ewingii char. By:

Answer 7

• mild nonregenerative anemia and thrombocytopenia
• Ehrlichia morulae in neuts
• neuts and high protein in joint fluid
• CS fever, malaise, swollen joints

Question 8

Chars. Of Granulocytic Ehrlichiosis caused by A. Phagocytophilum

Answer 8

• similar to monocytic ehrlichiosis
• weakness, depression, anorexia, lymphadenopathy, wt. loss
• nonregenerative anemia, lymphopenia, thrombocytopenia
• morulae in neuts**

Question 9

Tx of granulocytic ehrlichiosis

Answer 9

(Same as monocytic form) Tetracycline or doxy

Question 10

Infectious thrombocytopenia form of Ehrlichiosis caused by what? Chars?

Answer 10

Anaplasma platys

• infectious cyclic thrombocytopenias
• very low platelet counts
• rare CS: intermittent fever, occasional epistaxis, petechia and ecchymosis
• can be dx on blood smear, IFA, or PCR

Question 11

Rocky Mountain Spotted Fever (RMSF) caused by

Answer 11

Rickettsia rickettsii transmitted by Dermacentor tick vector

-vascular endothelium invaded –> necrotizing vasculitis, 2ary petechial hemorrhages, and multi-organ damage leading to DIC

Question 12

CS of RMSF

Answer 12

• fever, lethargy, inappetence, non-localizing pain
• oculonasal dc, cough, lymphadenopathy, peripheral edema, +/- skin sloughing
• 30% of cases develop paresis, vestibular signs, ataxia, meningitis

Question 13

Tx of RMSF

Answer 13

Tetracycline, Doxy, or Chloramphenicol for 2-3 wks

Question 14

Salmon poisoning caused by

Answer 14

Neorickettsia helminthoeca trans. By fluke metacercariae

Question 15

Pathogenesis of salmon poisoning

Answer 15

• adult trematodes develop in intestines of dogs that eat raw fish
• rickettsiae replicates in gut –> enteritis,and can spread to all organs

Question 16

CS of salmon poisoning

Answer 16

5-7 days post infection:

-fever, bloody d, frequent vomiting, anorexia, wt. loss, dehydration, lymphadenopathy, splenomegaly, +/- nasal/ocular dc

Question 17

Dx of Salmon poisoning

Answer 17

• PCR (definitive)
• suggestive: organisms primarily in lymphoid tissues and SI, CS in endemic area, operculated eggs in feces, intracytoplasmic rickettsiae in mononuclear phagocytes

Question 18

Tx of salmon poisoning

Answer 18

-supportive
-tetracycline
Praziquantel
-fatal in 90% if untreated
-freeze/cook fish before feeding

Question 19

Bartonella vinsonii

Answer 19

• emerging infectious dz in dogs
• can cause endocarditis, granulomatous lymphadenitis
• trans. By ticks, fleas, exposure to cattle

Question 20

Bartonella henselae chars.

Answer 20

• primary causative agent of cat scratch dz in humans
• trans. By fleas, ear mites, maybe ticks
• most infections subclinical in cats
• may cause fever, lethargy, lymphadenopathy, gingivitis, stomatitis, oral ulcers in cats
• in humans, can see papules, lymphadenopathy, splenomegaly, encephalitis, endocarditis

Question 21

Dx and tx of Bartonella henselae

Answer 21

Dx: western blot Ab test or blood culture

Tx: azithromycin (alternatives: enro, doxy, or rifampin). Eliminate vectors

Question 22

Rickettsiaceae include:

Answer 22

Ehrlichia spp.
Anaplasma sp.
Rickettsia rickettsia
Neorickettsia helminthoeca & N. Elokominica