Erlichia and Anaplasma

Question 1

Where is E.canis found?

Answer 1

All European countries bordering the Mediterranean

Sea are endemic for E. canis

Question 2

How are Erlichia and Anaplasma trasmitted

Answer 2

Via ticks
E. canis - Rhipicephalus sanguineus
A. phagocytophilum - Ixodes ricinus
A, platys - R. sanguineus (probably)

Also possible via blood transfusion

Question 3

Where is anaplasma phagocytophilium found?

Answer 3

All over europe

Question 4

Where is A. platys found?

Answer 4

Mostly mediteranian

Question 5

When are ticks most active

Answer 5

Spring to Autumn

Question 6

Are these diseases zoonotic?

Answer 6

E. canis - not considered a threat
Anaplasma phagocytophilum causes human granulocytic anaplasmosis, a febrile illness that closely resembles the disease in dogs

Question 7

Is there a breed, age, or sex predisposition for canine

ehrlichiosis or anaplasmosis?

Answer 7

E.canis - GSDs and Huskies get worse version of dz and px is worse

Anaplasma phagocytophilum - No

A platys - No

Question 8

What stages of disease can be identified during infections with Ehrlichia ?

Answer 8

Incubation period of 1-3 weeks
The acute phase can last 2 to 4 weeks; then, clinical signs may vary or disappear spontaneously, even without treatment.
However, some dogs that show clinical improvement may remain persistent subclinical carriers for month/ years
In the subclinical stage dogs present no clinical signs; and may not seem to require veterinary attention.
However, when screened, may have subnormal platelet concentrations [127].
Some infected dogs may advance to a chronic phase, where signs are more severe.
The acute and chronic phases are not always easy to distinguish because many of the clinical signs are
similar.

Question 9

How may you differentiate the acute and chronic forms of erlichia?

Answer 9

A complete blood count and bone marrow aspiration may assist in diagnosing the chronic severe form
of the disease. Dogs in the chronic phase exhibit bone
marrow hypoplasia and severe pancytopenia

Question 10

What happens during Anaplasma phagocytophilum infection?

Answer 10

Incubation period 1-2 weeks
Dog may then develop a febrile illness
Dogs normally present in the acute phase of the disease but many show no illness at all

Question 11

What occurs in A platys infection

Answer 11

Incubation 1-2 weeks
After that, alternate periods of thrombocytopenia and
fever are observed, which appear and disappear cyclically every 1-2 weeks
Chronic infection is associated with low-level bacteremia and mild thrombocytopenia, which may reflect a process where the host attempts to adapt to the A. platys infection

Question 12

What are the clinical signs of E.canis

Answer 12

Variable, tends to be more severe than anaplasmosis
may include nonspecific signs, like fever, weakness, lethargy, anorexia, lymphadenomegaly, splenomegaly, hepatomegaly, or weight loss. Other signs have also been described, including vomiting, diarrhea, pain, exercise intolerance, edema (in hind legs, tail, or scrotum), cough and/or dyspnea (associated with pneumonia), serous or mucopurulent oculonasal discharge, abortion or neonatal death, and skin ulcers

No evidence to suggest causes IMPA

Most common are pale mucous membranes, due to anemia, epistaxis, petechiae, ecchymoses, prolonged bleeding during estrus, hematuria or melena associated with thrombocytopenia, thrombocytopathy, or vasculitis
May see ocular signs

Question 13

What are the clinical signs of A phagocytophilum

Answer 13

lethargy, inappetence/anorexia, and fever. Other findings are pale mucous membranes, a tense abdomen, and gastrointestinal signs (vomiting/diarrhea). Lameness may result from secondary immune-mediated (neutrophilic) polyarthritis. Mildly enlarged lymph nodes, tachypnea, and surface bleeding (petechiae, melena, epistaxis) may occur.
Whether neuro signs are seen is controversial
A. phagocytophilum infection may trigger some immunopathies, such as immune-mediated thrombocytopenia/ anemia. Splenomegaly diagnosed with radiography and ultrasonography is a very common finding

Question 14

WHat are the clinical signs of A platys

Answer 14

fever, lethargy, anorexia, weight loss, pale mucous membranes, petechiae, nasal discharge, and lymphadenomegaly. Furthermore, single case studies have described bilateral uveitis and epistaxis.

Question 15

What are the likely clin path findings with either disease?

Answer 15

Abnormal laboratory findings in canine ehrlichiosis or
anaplasmosis are variable and nonspecific. However, the most common finding in ehrlichiosis and anaplasmosis is thrombocytopenia; this finding should alert clinicians

Question 16

Can you detect E. canis microscopically

Answer 16

Rare to see in a blood smear (5%)
Best chance is to do a buffy coat smear
Best chances are LN aspirates checked by specialists (50%)

Question 17

Can you detect A phagocytophilum microscopically?

Answer 17

Morulae (groups of the organism) can be observed in neutrophils in up to 60% of clinical cases
Can look like other things so still need PCR to confirm

Question 18

What serological techniques can be used in the diagnosis of ehrlichiosis and/or anaplasmosis?

Answer 18

IFAT or ELISA
One of the advantages of these is that they allow determination of antibody levels and their changes over time.
It is important to conduct quantitative serologic
tests and to determine either the final antibody titer with the IFAT or the optical density with the ELISA for a
quantitative evaluation (negative, low, or high signals).
Quantitative laboratory techniques are more sensitive
and specific than rapid tests
Some commercial inhouse dot-ELISA kits are qualitative, and show only a positive or negative result, without providing the dog’s antibodies levels

Question 19

How should we interpret a positive serologic result for

Ehrlichia and/or Anaplasma?

Answer 19

A positive serologic result indicates a past or current infection, but it does not always denote an ongoing disease condition. A single positive titer result may only reflect a past infection that may be resolved
Remember seroprevalence is high in endemic areas
Suspected cases should be evaluated based on the performance of two or more serological tests conducted in 2-4 weeks intervals (a four fold increase in IgG is suggestive of ongoing infection
Ideally for dx you need PCR and serology

Question 20

Is there cross over in serology when assessing for the different diseases?

Answer 20

generally no, but there is potential cross reaction has been described between E. canis and A. phagocytophilum, particularly when one of the pathogens is present at very high titers or when the follow up is prolonged

Question 21

What samples should be chosen to perform a molecular diagnosis of Ehrlichia and/or Anaplasma spp. infections?

Answer 21

Blood in EDTA

Question 22

What is the clinical significance of a coinfection during

the course of the disease?

Answer 22

Co-infections are common as the vectors are shared
Can mask the signs of other diseases/ share slinincal signs
Can make clinical signs worse
If you find one you need to check the others are not present

Question 23

How do you treat the diseases

Answer 23

E.canis - doxy for 4 weeks. Aim for PCR -ve results
A. phagocytophilum - doxy 2-3 weeks
Anaplasma platys - doxy 10d, enrofloxacin 21d

Question 24

When may tx with steroids be useful?

Answer 24

only be considered when no satisfactory response is noticed, or when immune-mediated complications arise. Ehrlichia and Anaplasma species may mediate an immune response, typically indicated by hemolytic anemia, thrombocytopenia, uveitis, glomerulonephritis, vasculitis, etc. In those cases, treatment with glucocorticoids (usually prednisone or prednisolone) may be indicated; doses of prednisone should range from 0.5 to 2 mg/kg/day, and the treatment duration should vary according to the type and seriousness of the associated immune mediated condition

Question 25

What is the expected clinical response to tx?

Answer 25

Improvement within 24-48 hours

Grave px if in the severe chronic form

Question 26

What are the risk factors for poor px?

Answer 26

Thrombocytopaenia
Anaemia PCV <15%
Prolonged APTT
Hypokalaemia

Question 27

Why is PCR useful after treatment?

Answer 27

PCR is useful for monitoring dogs
treated for these diseases, because it can detect the presence of pathogen DNA, regardless of the serologic antibody titers. However, although this technique is more sensitive than serology in confirming an infection, its effectiveness may be limited for detecting pathogens in subclinically infected dogs, because the organisms may circulate intermittently in peripheral blood.
when conducted several weeks after termination of doxycycline treatment, allows clinicians to be more confident that the treatment has been effective and that the dog did not enter the subclinical stage
a negative PCR result does not guarantee that the
animal is “free of infection

Question 28

How can you prevent infection

Answer 28

Anti tick tx

In europe spring to autumn if outdoor, but if indoor/ kenneled, then need to do year round