Bartonella - Canine Flashcards
What’s the most common causative agent of bartonella in dogs?
Bartonella heselae and B. vinsonii subsp. berkhoffii
fastidious gram (-) bacteria
transmitted by blood-sucking arthropods
How is bartonella transmitted in dogs?
Cat flea (c. felis)
1. replication in midgut of arthropods
2. inoculated by scratching insect bite with infected feces
3. in dermis, invades target cells (dendritic and endothelium), aided by “adhesin”
4. colonization of endothelial cells
“dermal and blood seeding niche”
5. periodically seeded into the blood stream to infect mature erythrocytes
6. replicate and spread infection
7. until the next arthropod meal
What’s the most common clinical sign caused by bartonella?
Endocarditis = most recognized consequence of bartonella in dogs. - – Frequently affects the aortic valves (unlike others) + congestive heart failure
- can also see heart murmur, respiration distress, weakness, and collapse
- septic thromboembolism, lameness, recumbency, anisocoria, and obtundation
- cardiac arrhythmia
What is another common c/s of Bartonella?
Arthritis
- granulomatous inflammation of the skin, LNs, liver, spleen, or disseminated granulomatous lesions
- can cause lymphatic infection
- fever, lethargy, weight loss, anorexia, lymphadenopathy, diarrhea, neurological signs, heart murmur, respiratory signs, PU/PD, lameness, vomiting, and splenomegaly
How is Bartonella diagnosed?
Positive culture or PCT does NOT = infection
- also need clinical signs and history, culture/ PCR results of affected organ or blood
- cannot be seen on blood smear
- CBC usually not very exciting, mild anemia, leukocytosis
- hyperglobulinemia without PLN or PLE\
- may have a positive Coomb’s test or antinuclear antibody (SLE)
What abnormalities can be noted on ECG for bartonella?
- sinus or ventricular tachycardia
- intermittent VPC
- atrial fibrillation
- 3rd degree AV block
What biomarkers can be related to bartonella?
cardiac troponin I
What diagnostic imaging abn can be associated with bartonella?
CXR: cardiomegaly, pulmonary edema
Echo: endocarditis, decreased fractional shortening
What specific molecular diagnostics are available for bartonella?
PCR (1-3d turn around)
culture (4-8 weeks)
enriched culture with DNA amplification (3w) - can be quite effective
none of the tests can rule out bartonella
How is bartonella treated?
Need 2 different antibiotics concurrently - start one for a week then add in, to avoid Jarisch-Herxheimer reaction = rapid die off and massive release of endotoxin –> fever, lethargy, vomiting
- ex doxycycline + enrofloxacin or azithromycin + rifampin
How is bartonella prevented?
no vaccine - rely on adequate ectoparasite control
How is bartonella in people?
- cat scratch disease
- cutaneous papules or pustule
- headache, irritability, back pain, lymphadenopathy, chronic undulant fever
- dogs shouldn’t be allowed to lick open wounds
