Heartworm Infections & Disease in Dogs I (16) - End E2 Flashcards
What is the canine Heartworm?
dirofilaria immitis
large, filamentous worms living in pulmonary artery and vasculature of dog, cats, and other mammals
Reproduction for heartworms is ______ [oviparous/viviparous]
viviparous
What is the lifecycle for dirofilaria immitis?
obligate indirect lifecycle - has to go to the mosquito!! can’t inject microfilaria into another dog
cannot pass vertically
The lifecycle of heartowmrs is dependent on ______
infected animals for transmission of microfilariae to mosquito hosts
What factors affect transmission of heartworms?
vector efficiency (#L3/#MF)
mosquito feeding activity
microfilarial activity in host
course and average blood meals
day/night time temp variation
prevalence of microfilaremic hosts in area
What is the canine Heartworm disease pathogenesis?
worms live in pulmonary arteries and right side of heart
immune stimulation of host tissues by adult worms and their products
obstructive fibrosis, pulmonary endothelial damage, & narrowing of vasculature bed with impaired blood flow
reduced cardiac output
On an xray, how does heartworms look?
enlarged right side of heart
enlarged, thickened and tortuous pulmonary artery
pulmonary infiltrates in caudal lung lobes
What is the canine Heartworm disease pathogenesis?
kidney disease from obstruction of glomeruli
endosymbiotic gram-negative bacteria
caval syndrome
What is caval syndrome?
large numbers of adult worms are pushed through the right atrium into the vena cava
presence obstructs blood flow and interferes with action of tricuspid valve
What is DIC?
disseminated intravascular coagulation
disorder associated with massive activation and consumption of proteins involved in coagulation
uncontrolled hemorrhaging
heartworm-induced pulmonary thromboembolism can be a facilitating factor
