Rickettsia, Anaplasma, Ehrlichia, Neorickettsia Flashcards
(24 cards)
What are the signs of Anaplasma phagocytophilum infection in dogs?
Fever, lethargy, anorexia, relucance to move, muscle pain
Lameness (similar in Lyme disease), polyarthritis, joint pain
Meningitis, pneumonia, GI signs
What are the clinical signs of Neorickettsia risticii infection?
Anorexia, biphasic fever, mild depression, colic
May have: mild/moderate diarrhea, toxemia, dehydration, laminitis, edema
During what stage of Anaplasma phagocytophilum do dogs show signs of disease?
During the acute bacteremic phase- not all animals will develop clinical signs though
Chronic or subclinical infections also possible
True or false:
Anaplasma phagocytophilum infections have a high mortality rate.
False. It’s seldom fatal, however it can cause reduced weight gain and secondary infections.
How is Anaplasma marginale treated?
Antibiotics- oxytetracycline
Will help infected animals survive acute infection but will not eliminate the carrier state
How is Anaplasma phagocytophilum treated in cows and dogs?
Cows- short acting oxytetracyclines, sulfamethazine
Dogs- doxycycline
What is the only intracellular organism known to infect platlets?
Which species are susceptible?
Anaplasma platys
Dogs, cats, humans
How is Ehrlichia canis treated?
What is the prognosis?
Doxycycline
Prognosis good unless there is severe pancytopenia or aplastic bone marrow
How is Neorickettsia risticii diagnosed?
PCR from blood or fecal samples, IFA
How is Ehrlichia canis diagnosed?
Presumptive based on clinical signs and lab findings (thrombocytopenia, nonregenerative anemia, etc.)
Serology (SNAP, IFA), PCR
Ehrlichia canis infects what cell types in the host?
Monocytes and lymphocytes
What are the clinical signs seen in the acute phase of Ehrlichia canis infection?
Fever, lethargy, weight loss, anorexia
Thrombocytopenia with or without anemia, leukopenia
May have negative titer
What are the clinical signs seen in the subclinical phase of Ehrlichia canis infection?
Few clinical signs
Mild thrombocytopenia, hyperglobulinemia
Positive titer
Anaplasma phagocytophilum infects what cell types in the host?
Neutrophils and neutrophil precursors, endothlial cells
How is Anaplasma phagocytophilum diagnosed?
CBC findings- severe transient neutropenia
Blood, buffy coat, or synovial fluid smears- can see morulae in neutrophils/eosinophils
Serology (SNAP test, IFA)
What is the principle host species of Anaplamsa marginale?
Cattle
What are the clinical signs of Anaplasma marginale infection?
Anemia (a PCV of less than 25%), blood is watery
Fever, anorexia, rumen stasis, rapid weight loss, weakness, staggering, pale MM, decreased milk production, abortion
What are the clinical signs seen in the chronic phase of Ehrlichia canis infection?
Weakness, anorexia, weight loss, pallor
Lymphadenopathy, hepatomegaly, splenomegaly, nephropathies, retinal lesions, edema, nonseptic polyarthritis, CNS disease, death
True or false:
If a SNAP 4DX test comes back positive for Ehrlichia, you can be positive the causative organism is Ehrlichia canis.
False. Both E. chaffeensis and E. ewingii can crossreact with E. canis on a SNAP test
How is Anaplasma marginale diagnosed?
Blood smears, serology (SNAP test), PCR
What are the clinical signs of Anaplasma phagocytophilum in ruminants and horses?
High fever (can be over 105ºF), coughing, decreased appetite, dullness, increased respiration and pulse
Can lead to hemorrhagic syndromes
Neorickettsia risticii causes what disease in horses?
Equine monocytic ehrlichiosis
“Potomac horse fever”
Anaplasma marginale infects what cell types in the host?
RBCs (form inclusion bodies), endothelial cells
How are Neorickettsia risticii infections treated?
Oxytetracycline and supportive care
