Infectious Dz - Blood Borne 2

Question 1

What are hemotropic mycoplasmas also known as?

Answer 1

Haemobartonellosis

Question 2

Where do hemotropic mycoplasmas reside?

Answer 2

on the RBC surface

Question 3

What causes haemobartonellosis in cats?

Answer 3

Mycoplasma haemofelis, Candidatus mycoplasma haemominutum, and Candidatus mycoplasma turicensus

Question 4

What is the most pathogenic cause of haemobartonellosis in cats?

Answer 4

Mycoplasma haemofelis

Question 5

What does Mycoplasma haemofelis cause in immunocompetent cats?

Answer 5

moderate to severe hemolytic anemia

Question 6

What causes feline infectious anemia?

Answer 6

Mycoplasma haemofelis

Question 7

What is infection with hemoplasmas associated with in cats (risk factors)?

Answer 7

the male sex, nonpedigree status, and outdoor access

Question 8

What causes haemobartonellosis in dogs?

Answer 8

Mycoplasma haemocanis and Candidatus mycoplasma haematoparvum

Question 9

True or False: Clinical disease of Haemobartonellosis is more common in dogs.

Answer 9

False - it is more common in cats

Question 10

How are hemotropic Mycoplasmas transmitted?

Answer 10

Not entirely known - fleas and other arthropod vectors, biting (blood exchange not just saliva), and blood transfusions

Question 11

When does anemia occur post infection of Mycoplasma haemofelis?

Answer 11

2-34 days after infection

Question 12

What occurs in the acute phase of M. haemofelis infection?

Answer 12

Extravascular hemolysis

Question 13

What causes the anemia in the acute phase of M. haemofelis infection?

Answer 13

It is caused by erythrocyte bound antibodies leading to extravascular hemolysis

Question 14

If the acute phase of M. haemofelis infection is not treated, what is the mortality rate?

Answer 14

1/3 of cats will die

Question 15

True or False: Cats can be chronically infected with M. haemofelis even though they have recovered from their illness.

Answer 15

True

Question 16

What are the clinical signs of M. haemofelis infection?

Answer 16

Lethargy, inappetence, pallor, weakness, weight loss, and dehydration

Question 17

If anemia develops rapidly in patients with infection of M. haemofelis, what clinical signs will be present?

Answer 17

Vocalize, collapse, neurologic signs, and death

Question 18

What will a patient show in physical examination when infected with M. haemofelis?

Answer 18

Fever, weakness, pallor, tachypnea, and tachycardia

Question 19

What will a CBC show in actively infected M. haemofelis patients?

Answer 19

regenerative anemia (reticulocytosis, macrocytosis, nucleated RBCs, polychromasia, hypochromasia) and the blood may autoagglutinate

Question 20

What will a chemistry show in actively infected M. haemofelis patients?

Answer 20

Increased ALT from hypoxia, mild to moderate hyperbilirubinemia, prerenal azotemia, and hyperproteinemia

Question 21

What will a UA show in patients with M. haemofelis?

Answer 21

+/- bilirubinuria

Question 22

How can Haemobartonellosis be diagnosed?

Answer 22

Cytology and PCR

Question 23

What is the test of choice for diagnosing Haemobartonellosis?

Answer 23

PCR

Question 24

If a cat tests positive for M. haemominutum or M. turicensus on PCR and has anemia, what should be done next?

Answer 24

You should look for alternate causes of anemia because these agents are unlikely to cause anemia

Question 25

When should Haemobartonellosis be treated?

Answer 25

When clinical signs and lab abnormalities are consistent with hemoplasmosis

Question 26

What can be used to treat Haemobartonellosis?

Answer 26

Doxycycline (tx of choice). Marbofloxacin, and Pradofloxacin as well as supportive care

Question 27

What supportive care should be given to patients with Haemobartonellosis?

Answer 27

IV fluids, blood transfusions, +/- glucocorticoid to suppress associated immune-mediated hemolytic process

Question 28

How is Haemobartonellosis prevented?

Answer 28

Keep cats indoors, flea and tick control, and screen blood donors

Question 29

Which of the following should make you question your diagnosis of anemia due to hemotropic Mycoplasma in a 2 YO MC DSH cat? a. The cats anemia resolved with doxycycline therapy b. The cat is FeLV/FIV negative c. The cat lives in a multicat household and none of the other cats are sick d. The cat's blood is autoagglutinating e. Your PCR comes back as positive for M. haemominutum, but negative for M. haemofelis and M. turicensis

Answer 29

e. Your PCR comes back as positive for M. haemominutum, but negative for M. haemofelis and M. turicensis

Question 30

What structures do Erlichia species create in their infected hosts?

Answer 30

morulae (bacterial cluster) within phagosomes of circulating leukocytes

Question 31

What does Ehrlichia canis infect and what does it cause?

Answer 31

monocytes causing canine monocytic ehrlichiosis

Question 32

What does Ehrlichia ewingii infect and what does it cause?

Answer 32

Infects granulocytes causing canine granulocytic ehrlichiosis

Question 33

What does Ehrlichia chaffeensis infect and what does it cause?

Answer 33

It causes human monocytic ehrlichiosis, dogs are the reservoir for this organism

Question 34

What transmits E. canis?

Answer 34

Rhipicephalus sanguineus Just know ticks

Question 35

What transmits E. ewingii and E. chaffeensis?

Answer 35

Ambylomma americanum Just know ticks

Question 36

How do ticks pick up E. canis?

Answer 36

Tick larvae or nymphs acquire infection when they feed on infected dogs and it is transmitted transstadially within the tick

Question 37

What classifications of disease does Canine Monocytic Ehrlichiosis present as?

Answer 37

Acute, subclinical, and chronic

Question 38

When does acute Canine Monocytic Ehrlichiosis present?

Answer 38

Within 1-4 weeks post infection

Question 39

What mechanisms are important in disease pathogenesis of acute Canine Monocytic Ehrlichiosis?

Answer 39

immune-mediated mechanisms

Question 40

What clinical signs are associated with acute Canine Monocytic Ehrlichiosis (CME)?

Answer 40

Lethargy, inappetence, fever, weight loss, lymphadenopathy, splenomegaly, petechial/ecchymotic hemorrhages, neurologic signs

Question 41

What causes the lymphadenopathy and splenomegaly in acute CME cases?

Answer 41

The replication of E. canis in reticuloendothelial tissues

Question 42

What causes the petechial ecchymotic hemorrhages in acute CME cases?

Answer 42

thrombocytopenia and platelet dysfunction from immune-mediated platelet attack

Question 43

What happens in subclinical cases of CME?

Answer 43

The organism is sequestered in the spleen allowing it to avoid host immune system via antigenic variation

Question 44

What CBC changes are associated with subclinical CME?

Answer 44

Only platelet counts may be subnormal

Question 45

What disease process is associated with chronic CME?

Answer 45

pancytopenia

Question 46

What clinical signs are associated with chronic CME?

Answer 46

Fever, lethargy, inappetance, bleeding tendencies, weight loss, and vision change

Question 47

What will you find on a PE of a patient with ehrlichiosis?

Answer 47

lethargy, fever, peripheral lymphadenopathy, splenomegaly, mucosal petechial hemorrhages, epistaxis, neurological signs, ocular abnormalities, and thin and muscle atrophy in chronic ehrlichiosis

Question 48

What will you find on CBC in acute cases of CME?

Answer 48

thrombocytopenia and non regenerative anemia (Reticulocytosis, microcytosis, normocytic, normochromia)

Question 49

What will you find on CBC in chronic cases of CME?

Answer 49

Pancytopenia with nonregenerative anemia and thrombocytopenia

Question 50

What will you find on a chemistry in patients with CME?

Answer 50

hypoalbuminemia, hyperglobulinemia (usually polyclonal), +/- elevated ALT and ALP

Question 51

What irregularity may you seen on a UA in patients with CME?

Answer 51

+/- proteinuria

Question 52

How is CME diagnosed?

Answer 52

Serology (IFA or ELISA snap test) and PCR

Question 53

True or False: Positive initial serum antibody titer reflects active ehrlichial disease.

Answer 53

False - it may reflect previous exposure and not ehrlichial disease so it is important to retest 3-4 weeks later to demonstrate seroconversion

Question 54

What do you do if you find incidental Ehrlichia positive in a dog you were just testing for heartworm?

Answer 54

Thorough PE and lab testing to look for signs of CME Only a positive SNAP plus clinical signs supports an ehrlichia diagnosis

Question 55

What if a sick dog tests positive for Ehrlichia on a SNAP 4Dx test?

Answer 55

Perform quantitative serologic testing so a titer can be obtained as a baseline for acute and convalescent serologic testing

Question 56

What stage of disease is PCR better than serology in diagnosing Ehrlichia?

Answer 56

It is more sensitive for early diagnosis of CME than serology in acute disease cases because there is not enough time for antibody production for serology to detect

Question 57

When is serology better than PCR in diagnosing Ehrlichia?

Answer 57

In chronic CME because there are low circulating organism numbers

Question 58

What 'test' is very important in diagnosing Ehrlichia?

Answer 58

Resolution of clinical signs in response to therapy

Question 59

What is the treatment of choice for CME?

Answer 59

Doxycycline and supportive cares as needed

Question 60

How quick does improvement occur once treatment has started in patients with acute CME?

Answer 60

in 24-48 hours

Question 61

Do dogs with chronic CME always respond to treatment?

Answer 61

Dogs with severe chronic CME may not respond to treatment or cytopenias may resolve over several months

Question 62

How is CME prevented?

Answer 62

avoid tick infested areas, remove ticks early if infected with ticks, ectoparasiticides, and screen blood donors

Question 63

Bear is a 4 YO MC Flatcoat retriever that has presented for acute epistaxis. He recently moved to Iowa from Puerto Rico. On PE you discovered epistaxis and a mild fever of 103.0 F. He has thrombocytopenia, a PCV of 27%, and he has 20,000 reticulocytes (low). He is 4Dx Ehrlichia SNAP positive. What do you want to do next for Bear? a. Start treating with doxycycline b. Euthanize because Ehrlichia has a terrible prognosis c. Send of a tick panel for Ehrlichia PCR and serology, and to look for other co-infections d. Transfuse with pRBCs because he is anemic

Answer 63

a and c

Question 64

What is the reservoir for E. ewingii?

Answer 64

White-tailed deer

Question 65

What form of disease does E. ewingii cause?

Answer 65

acute only

Question 66

Where does E. ewingii replicate?

Answer 66

in the neutrophil delaying neutrophil apoptosis

Question 67

What clinical signs do patients with E. ewingii infections have?

Answer 67

No signs to fever, lethargy, anorexia, and neutrophilic polyarthritis

Question 68

How is E. ewingii diagnosed?

Answer 68

4Dx SNAP test or PCR

Question 69

How is E. ewingii infection treated?

Answer 69

Doxycycline

Question 70

What causes canine granulocytic anaplasmosis?

Answer 70

Anaplasma phagocytophilum - infects neutrophils

Question 71

What causes canine thrombocytic anaplasmosis?

Answer 71

Anaplasma platys

Question 72

What is the pathogenesis of Canine granulocytic anaplasmosis (CGA) infection?

Answer 72

Once transmitted by a tick, it enters the blood stream, attaches to ligands on the surface of neutrophils. It then enters the neutrophils via endocytosis. The organism survives the harsh neutrophil environment by bypassing phagolysosome pathways and dysregulating neutrophil function.

Question 73

What clinical signs are associated with CGA?

Answer 73

A vast majority have no clinical signs! But some can be a self-limiting febrile illness, lethargy, fever, inappetence, lameness, and sometimes GI signs (vomiting +/- diarrhea)

Question 74

What will you find on a PE in a patient with CGA?

Answer 74

Fever of up to 106.7 F, lymphadenopathy, splenomegaly, +/- lameness

Question 75

What will you find on a CBC in patients with CGA?

Answer 75

Thrombocytopenia, mild nonregenerative anemia, and morulae within granulocytes

Question 76

What will you find on Chemistry in patients with CGA? UA? Synovial fluid analysis?

Answer 76

Chemistry - mild to moderate hypoalbuminemia Urinalysis - proteinuria Synovial fluid analysis - Neutrophilic polyarthritis +/- morulae

Question 77

How is CGA diagnosed?

Answer 77

Serology (IFA and SNAP 4Dx) and PCR

Question 78

What test do you want to do when diagnosing CGA early on?

Answer 78

PCR

Question 79

Do positive results imply CGA is the cause of illness? Negative results?

Answer 79

No Negative results also don't imply anything because it can be negative in early stages of disease

Question 80

Since a positive IFA titer can reflect exposure of A. phagocytophilum, what must the results be to indicate Anaplasma is the cause of the disease?

Answer 80

fourfold rise in titer

Question 81

What is the treatment of choice for CGA?

Answer 81

Doxycycline

Question 82

What is the prognosis for CGA?

Answer 82

Excellent - in 24-48 hours most dogs clinically improve and platelet counts normalize in 2-14 days

Question 83

What does A. platys cause?

Answer 83

canine cyclic thrombocytopenia

Question 84

Are there clinical signs associated with A. platys infections?

Answer 84

No, it causes thrombocytopenia without other clinical signs

Question 85

How is A. platys infection diagnosed? Treatment?

Answer 85

Diagnosed by seeing morulae in platelets or via PCR Treated with Doxycycline

Question 86

Do cats get anaplasmosis?

Answer 86

Yes, clinical signs appear similar to those in dogs. It should be considered when more common causes of disease are not apparent

Question 87

Moses is an 8 YO MC mixed breed dog presented for a sudden onset of lethargy, anorexia, and vomiting. On physical examination you noted he had a fever of 105.8 with prominent mandibular lymph nodes. He is thrombocytopenic and has a morulae located in a granulocyte. The chemistry and UA were WNL. You note that he has splenomegaly on rads. His 4Dx snap test was negative across the board. **What are your top differentials based on the morulae in a granulocyte?**

Answer 87

E. ewingii and A. phagocytophilum

Question 88

Moses is an 8 YO MC mixed breed dog presented for a sudden onset of lethargy, anorexia, and vomiting. On physical examination you noted he had a fever of 105.8 with prominent mandibular lymph nodes. He is thrombocytopenic and has a morulae located in a granulocyte. The chemistry and UA were WNL. You note that he has splenomegaly on rads. His 4Dx snap test was negative across the board. **Why do you think the snap test was negative?**

Answer 88

Too acute an infection to have performed antibodies

Question 89

Moses is an 8 YO MC mixed breed dog presented for a sudden onset of lethargy, anorexia, and vomiting. On physical examination you noted he had a fever of 105.8 with prominent mandibular lymph nodes. He is thrombocytopenic and has a morulae located in a granulocyte. The chemistry and UA were WNL. You note that he has splenomegaly on rads. His 4Dx snap test was negative across the board. **What are your next diagnostic and therapeutic tests?**

Answer 89

Baseline and convalescent serology, PCR, and treat with Doxycycline