Parasitic Protozoa, 4 - Apicomplexa (42)

Question 1

What is cytauxzoon felis?

Answer 1

intercellular haemoprotozoan parasite in wild and domestic felidae

Question 2

Distribution of cytauxzoon felis appears to coincide with ______

Answer 2

ambylomma americanum

Question 3

What is cytauxzoonosis?

Answer 3

disease in domestic cats associated with asexual replication (schizogony) in macrophages in spleen and hepatic tissues

Question 4

What happens in cytauxzoonosis?

Answer 4

engorged leukocytes adhere to the walls in the lumen of veins in various organs

• obstruction of blood flow
• tissue ischemia

Question 5

In cytauxzoonosis, ____ develop into merozoites rupture host cells and infect ______

Answer 5

schizonts

erythrocytes

Question 6

Parasitemia of cytauxzoonosis is detected where?

Answer 6

stained blood smear

late stage disease with eminent death

Question 7

A cat was diagnosed with feline cytauxzoonosis. How was it infected?

Answer 7

ambylomma americanum

(image specifically showed infected macrophages in a splenic blood vessel from a positive case of feline cytauxoonosis)

Question 8

How is cytauxzoon felis transmitted?

Answer 8

bobcats are natural asymptomatic hosts for the parasite - nymphs feed on infected bobcats, allowed to molt, adult ticks fed on domestic cats produce clinically fatal disease

ambylomma americanum

Question 9

Regarding cytauxzoon felis, a direct host role of tick is implied from direct ________ of infected Bobcat blood into domestic cat

Answer 9

SQ inoculation
non-fatal persistent parasitemia without schizogony 6 months PI

Question 10

What is the clinical presentation of feline cytauxzoonosis?

Answer 10

infected cats often - exhibit non-specific signs of disease

icteric with pale mucous membranes, dehydrated, polydipsic

Question 11

How do you diagnose feline cytauxzoonosis?

Answer 11

hematology - leukopenia with left shift and toxic change of neutrophils, thrombocytopenia

clinical chemistry

Question 11

Regarding feline cytauxzoonosis, parasites are detected in host cells how?

Answer 11

piroplasms in erythrocytes
schizonts in macrophages

Question 11

A cat is icteric with pale mucous membranes, dehydrated, and polydipsic. How was it infected, and what is the parasite?

Answer 11

amblyopia americanum
cytauxzoon felis

Question 11

Where is cytauxzoon felis focused in TN?

Answer 11

5 middle TN counties

Question 11

Who is the reservoir for cytauxzoon felis?

Answer 11

bobcats

obligate relationship with ticks

Question 11

What are factors for facilitating spread and growth of TN bobcat populations?

Answer 11

territorial
long-lived
preference for areas with rocky shallow soil, broken terrain, shrub cover-recovering forests

Question 12

What is a facilitating factor for bobcat habitats and thus spread of transmission?

Answer 12

land use and vegetation patterning

Question 13

What is prognosis and treatment of cytauxzoonosis?

Answer 13

used to be 100% fatal

Question 14

Treatment success of cytauxzoonosis is likely a function _______ it is initiated

Answer 14

when in the disease process

Question 14

When is the apparent therapeutic target of cytauxzoonosis? Goal?

Answer 14

schizogonous stage of the organism in the WBC
- goal: to shut down the asexual replication

Question 15

Treatment of cytauxzoonosis should be initiated for any cat (with outdoor access) presenting with _____ from which month? What should be submitted?

Answer 15

acute lethargy
March through October

Question 16

What are recommendations for cytauxzoonosis?

Answer 16

prevention has more promise than cure

Question 17

Review these points

Answer 17