2: Tick-borne Diseases Flashcards
E. canis or E chafeensis
What organism is responsible for Canine Monocytic Ehrlichiosis?
E. canis
What tick spreads E. canis?
Brown Dog Tick - R. sanguineus
What three presentations are possible for Canine Monocytic Ehrlichiosis?
Acute, Subclinical, Chronic
What is consistent with acute canine monocytic ehrlichiosis?
Fever, lethargy, inappetence
Lymphadenopathy, hepatomegaly
Thrombocytopenia/-pathia
Peripheral edema, ocular disease, neuro signs
What is consistent with chronic canine monocytic ehrlichiosis?
Acute phase signs +
BM Hypoplasia- pancytopenia
Protein Losing Nephropathy
Marked lymphocytosis/hyperglobulinemic- may mimic neoplasia
In which cells can you visualize E. canis?
Monocytes/lymohocytes
How to increase sensitivity for monocytic ehrlichiosis on blood smear?
Buffy coat, LN or splenic aspirates
Diagnostic testing for E. canis:
Morulae visualized on blood smear
Antibody Testing- POC ELISA Snap
IFA
PCR
What tickborne diseases are treated with doxycycline?
Monocytic Ehrlichiosis (E. canis)
Granulocytic Ehrlichiosis (E. ewingii)
Granulocytic Anaplasmosis (A. phagocytophilum)
Rocky Mountain Spotted Fever (R. rickettsii)
What bacteria can cause human monocytic ehrlichiosis?
E. chaffeensis
What tick transmits E. chaffeensis?
Amblyomma americanum
(Lone Star Tick)
What tick transmits E. ewingii?
Amblyomma americanum
(Lone Star Tick)
Clinical Signs of E. chaffeensis:
Rarely causes clinical signs in dogs
Fever, lethargy, inappetence
Lymphadenomegaly
Mild thrombocytopenia, monocytosis
E. ewingii or A. phagocytophilum
Clinical Signs of Granulocytic Ehrlichiosis:
Fever, lethargy, inappetence
Lymphadenomegaly
Peripheral Edema
Polyarthritis
Neuro Signs
Mild/Mod Thrombocytopenia
Proteinuria
What organism is responsible for Granulocytic ehrlichiosis?
E. ewingii
In which cells are A. phagocytophilum and E. ewingii visualized in on blood smear?
Granulocytes
Diagnostic Testing for E. ewingii:
Morulae visualized in granulocytes
POC ELISA
Whole Blood PCR
Which tickborne disease can also affect cats?
Granulocytic Anaplasmosis
What organism is responsible for granulocytic anaplasmosis?
A. phagocytophilum
What tick transmits A. phagocytophilum
Ixodes scapularis (Deer tick) or I. pacificus
What tick borne disease is commonly found with a co-infection of B. burgdorferi?
Granulocytic Anaplasmosis (A. phagocytophilum)
Clinical signs of Granulocytic Anaplasmosis:
Majority of dogs do not show clinical signs
Fever, lethargy, inappetence
Lymphadenomegaly, hepatomegaly,
Polyarthritis
Thrombocytopenia/ Leukopenia
Diagnosis of Granulocytic Anaplasmosis:
Morulae visualized in granulocytes
POC ELISA
What organism causes RMSF:
Rickettsia rickettsii
What tick spreads Rickettsia rickettsii
Primarily Transmitted by:
Primarily Transmitted by: Dermacentor andersoni (Wood Tick) and D. variabilis (American Dog Tick)
Diagnostic testing for R. rickesii
IFA
PCR not as sensitive
Early recognition & tx is key to reduce mortality
What two tickborne diseases are NOT treated with doxycycline?
American Canine Hepatozoonosis & Canine Babesiosis
What organism causes American canine hepatozoonosis?
H. americanum
What tick spreads H. americanum?
INGESTION of:
Amblyomma maculatum (Gulf Coast Tick)
What clinical signs are consistent with Hepatozoonosis?
Fever, lethargy, inappetence
Weight Loss
Severe Muscle Wasting
Generalized Hyperesthesia
Stiff Gait
Purulent Ocular Discharge
Potentially Fatal
Clin Signs Wax/Wane
What lab findings are consistent with hepatozoonosis?
Leukocytosis (20k-200k)
Mild normocytic, normochromic, non-regenerative anemia
Normal-Increased Platelets
(Thrombocytopenia may indicate coinfection)
Increased ALP activity
Hypoglycemia
Hypoalbuminemia
Periosteal Bone proliferation
Diagnostic testing for hepatozoonosis:
Blood Smears reveal gamonts in leukocytes
-Buffy coat smear increases sensitivity
Skeletal Muscle Biopsy
- Most reliable
- Onion Cysts
- Marked Pyogranulomatous myositis
Whole Blood PCR
Treatment for Canine Hepatozoonosis:
Combination Therapy x2 weeks
(Trimethoprim-Sulfa, Clindamycin, Pyrimethamine)
Not effective at eliminating tissue stages; relapse common
- Decoquinate x2 years to maintain remission
H. americanum
B. canis
B. gibsoni
Clinical Presentations of Canine Babesiosis
Uncomplicated, Complicated (South Africa), Subclinical
What populations have high prevalence of subclinical babesiosis?
Greyhounds and pitbulls
What organism is responsible for canine babesiosis?
B. canis and B. gibsoni
What tick spreads canine babesiosis?
R. sanguineus
(Brown Dog Tick)
What is the clinical presentation of uncomplicated babesiosis?
Fever, lethargy, inappetence
Lymphadenomegaly, splenomegaly
Thrombocytopenia
Hemolytic Anemia: intra- and extravascular
- RBC Fragility
- IMHA
- RBC Shearing
What is the clinical presentation of complicated babesiosis?
Uncomplicated signs +
Acute Renal Failure
Neuro Signs
Hepatic Injury
Acute Resp. Distress Syndrome
Pancreatitis
Red Biliary Syndrome
- Congested MM, Inc Hematocrit
- Hemoglobinuria/-emia
- Intravascular hemolysis/ hemoconcentration
*Associated with a strain found in South Africa
Diagnostic Testing for Babesiosis:
Blood Smears reveal infected erythrocytes
- Able to distinguish between B. canis and B. gibsoni
IFA
PCR
Treatment for B. canis:
NOT Doxycycline
Imidocarb, Dipropionate
Treatment for B. gibsoni:
NOT Doxycycline
Atovaquone, Azithromycin
