Blood Parasites

Question 1

Anaplasma marginale

Answer 1

• transmitted by ticks
• cattle remain carriers, may relapse when immunosuppressed
• in older cattle severe and fatal - progressive anemia due to destruction of RBC’s
• diagnosis serological testing ELISA
• obligate intraerythrocytic bacteria that affects ruminants

Question 2

Ehrilichia canis

Answer 2

• causes ehriliciosis (involving monocytes and neutrophils) in dogs
• transmitted by the brown dog tick Rhipicephalus sanguineus
• appears as morulae (small clusters) in blood smears
• immunologic testing is recommended
• a rickettsial organism

Question 3

Ehrilichia platys

Answer 3

• infection is often mild and subclinical
• most commonly causes thrombocytopenia in dogs which slowly resolves on own
• treat with doxycycline

Question 4

Mycoplasma spp.

Answer 4

• hemoplasmas, gram negative bacteria lacking a cell wall
• they attach to the surface of the RBC’s but do not penetrate
• transmitted by lice, fleas, ticks, mosquitos and directly
• causes hemolytic anemia, M. haemofelis causes acute anemia in cats which can be fatal
• diagnose with Wright’s stain on a blood smear, die quickly in a blood sample
• treat with tetracycline

Question 5

Babesiosis bovis

Answer 5

• known as Texas fever, redwater fever or cattle tick fever
• seen under the microscope they often appear as pairs within a cell
• transmitted by ticks, can affect people
• causes muscle tremors, jaundice, anemia, abortion of late terms calves, makes bull temporarily infertile
• cattle remains carriers even after recovery
• diagnose via ELISA, PCR, or blood smear
• treat with antiparasitic drugs & blood transfusion