L07 Pt. 2 Flashcards
What causes Ehrlichiosis in cats?
Ehrlichia canis
Anaplasma phagocytophilum
Forms of Ehrlichiosis in dogs
1) Monocytic (caused by E. Canis and E. Chaffensis)
2) Granulocytic (caused by E. Ewingii and Anaplasma phagocytophilum)
3) Infectious thrombocytopenia (Anaplasma platys)
Monocytic Ehrlichiosis
- 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
Acute phase monocytic ehrlichiosis CS
-Fever, depression, lethargy, wt. loss, ocular/nasal dc, hemorrhage
-thrombocytopenia most consistent finding**
+/- anemia, leukopenia
Subclinical phase monocytic ehrlichiosis clinical findings
Thrombocytopenia, strong Ab titer
Chronic phase monocytic ehrlichiosis
Severe cases develop anorexia, lymphadenopathy, splenomegaly, edema, retinal lesions, ataxia, hepatomegaly, aplastic anemia
Granulocytic Ehrlichiosis due to E. Ewingii char. By:
- mild nonregenerative anemia and thrombocytopenia
- Ehrlichia morulae in neuts
- neuts and high protein in joint fluid
- CS fever, malaise, swollen joints
Chars. Of Granulocytic Ehrlichiosis caused by A. Phagocytophilum
- similar to monocytic ehrlichiosis
- weakness, depression, anorexia, lymphadenopathy, wt. loss
- nonregenerative anemia, lymphopenia, thrombocytopenia
- morulae in neuts**
Tx of granulocytic ehrlichiosis
(Same as monocytic form) Tetracycline or doxy
Infectious thrombocytopenia form of Ehrlichiosis caused by what? Chars?
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
Rocky Mountain Spotted Fever (RMSF) caused by
Rickettsia rickettsii transmitted by Dermacentor tick vector
-vascular endothelium invaded –> necrotizing vasculitis, 2ary petechial hemorrhages, and multi-organ damage leading to DIC
CS of RMSF
- fever, lethargy, inappetence, non-localizing pain
- oculonasal dc, cough, lymphadenopathy, peripheral edema, +/- skin sloughing
- 30% of cases develop paresis, vestibular signs, ataxia, meningitis
Tx of RMSF
Tetracycline, Doxy, or Chloramphenicol for 2-3 wks
Salmon poisoning caused by
Neorickettsia helminthoeca trans. By fluke metacercariae
Pathogenesis of salmon poisoning
- adult trematodes develop in intestines of dogs that eat raw fish
- rickettsiae replicates in gut –> enteritis,and can spread to all organs
CS of salmon poisoning
5-7 days post infection:
-fever, bloody d, frequent vomiting, anorexia, wt. loss, dehydration, lymphadenopathy, splenomegaly, +/- nasal/ocular dc
Dx of Salmon poisoning
- PCR (definitive)
- suggestive: organisms primarily in lymphoid tissues and SI, CS in endemic area, operculated eggs in feces, intracytoplasmic rickettsiae in mononuclear phagocytes
Tx of salmon poisoning
-supportive
-tetracycline
Praziquantel
-fatal in 90% if untreated
-freeze/cook fish before feeding
Bartonella vinsonii
- emerging infectious dz in dogs
- can cause endocarditis, granulomatous lymphadenitis
- trans. By ticks, fleas, exposure to cattle
Bartonella henselae chars.
- 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
Dx and tx of Bartonella henselae
Dx: western blot Ab test or blood culture
Tx: azithromycin (alternatives: enro, doxy, or rifampin). Eliminate vectors
Rickettsiaceae include:
Ehrlichia spp.
Anaplasma sp.
Rickettsia rickettsia
Neorickettsia helminthoeca & N. Elokominica
