Heartworm

Question 1

what is the science name for heartworm

Answer 1

Dirofilaria immitis

Question 2

what is the primary host of heartworm

Answer 2

dogs

Question 3

true or false:
heartworm is the most important parasite in dogs

Answer 3

true

Question 4

true or false:
prevalence of heartworm parallels that in dogs in the same area

Answer 4

true

Question 5

true or false:
all ages are equally as susceptible

Answer 5

true

Question 6

what is the needed to complete the life cycle of Dirofilaria immitis

Answer 6

mosquitos

Question 7

where do adult heartworms live

Answer 7

pulmonary artery

Question 8

what part of the heartworm life cycle circulates in the blood

Answer 8

microfilariae

Question 9

what is the infective stage of the heartworm life cycle

Answer 9

L3

Question 10

where do the microfilaria become L3

Answer 10

in mosquitos

Question 11

where does the L3 larvae of the heartworm mature to adults

Answer 11

dog host

Question 12

how long is normal development from L1 to L3 in the mosquito

Answer 12

10-14 days (2 weeks)

Question 13

how many days after infection with L3 are there adult worms in the pulmonary vessels

Answer 13

70 days post infection

Question 14

when can vascular damage from heartworm begin after infection

Answer 14

70 days - adult worms make their way to the pulmonary artery

Question 15

how long does it take for to heartworms fully develop into an adult

Answer 15

about 6 months

Question 16

when can heartworm start producing microfilaria

Answer 16

at fully maturity (6 months)

Question 17

true or false:
in cats, although the life cycle is the same it takes longer to complete

Answer 17

true

Question 18

true or false:
dogs are more likely to have aberrant migration of worms to ectopic sites

Answer 18

false
cats

Question 19

how many worms are needed to cause life-threatening disease in cats

Answer 19

few worms
<5 worms

Question 20

why is diagnosis of heartworm difficult in cats

Answer 20

fewer worms
only females can be detected
theres a risk of having only 1-2 worms and both could be males
this would result in 0 detection

Question 21

true or false:
cats will have a prominence of microfilaria at times of exams

Answer 21

false
<5% of cats are MF+ at time of exam
this is because cats are likely to become infected from other HW+ dogs and not cats

Question 22

what are the main organs involved in heartworm cases

Answer 22

heart
lungs

Question 23

what determines the severity of HW disease

Answer 23

number of adult worms
duration of infection
individual host response

Question 24

what is the impact on the heart / pulmonary vessels from HW disease

Answer 24

pulmonary arterial disease

Question 25

what is the pathology of pulmonary arterial disease

Answer 25

inflammation (endarteritis) villous thickening of tunica intima (1-3 months after worms arrive to heart)

Question 26

what would the heart look like during a pathologic post-mortem exam

Answer 26

roughened, stippled appearance of pulmonary artery

Question 27

what are the complications from pulmonary aterialitis

Answer 27

thickening of vessels loss of vessel elasticity increased pressure

Question 28

what is the bacterial endosymbiont found in many filarial worms and insects

Answer 28

wolbachia

Question 29

what is the importance of wolbachia to the worms

Answer 29

perform beneficial functions for the worms

Question 30

how does Wolbachia impact pulmonary arterialitis and inflammation

Answer 30

induced innate inflammatory response by macrophages and neutrophils

Question 31

what are the 3 stages to feline HWD

Answer 31

1. worms reach blood vessels of the lung 2. degenerating worms induce pulmonary inflammation and thromboembolism 3. chronic respiratory disease

Question 32

what is the effect the worms have on the pulmonary artery at arrival

Answer 32

acute inflammatory response

Question 33

what part of heartworm disease is caused by immature worms and important in cats

Answer 33

HARD heartworm-associated respiratory disease

Question 34

what is caused by large numbers of worms in the tricuspid valve and causes hemoglubinuria in dogs

Answer 34

caval syndrome

Question 35

true or false: caval syndrome is treatable in dogs

Answer 35

false

Question 36

what is the TOC for caval syndrome is wanted

Answer 36

surgical removal of worms via jugular vein

Question 37

how is caval syndrome different from typical pulmonary aterialitis in dogs

Answer 37

worms are backed up through the tricuspid valve

Question 38

what are the clinical signs for mild to moderate heartworm disease in dogs

Answer 38

chronic cough dyspnea decreased exercise tolerance

Question 39

what are the clinical signs of moderate to severe heartworm disease in dogs

Answer 39

syncope hemoptysis

Question 40

what is the clinical sign for severe heartworm disease in a dog

Answer 40

congestive heart failure

Question 41

what are some clinical signs associated with chronic cases of heartworm disease in a cat

Answer 41

coughing, dyspnea vomiting unrelated to eating lethargy, anorexia, weight loss systolic heart murmur

Question 42

what is the most important thing to do before initiating a treatment regimen

Answer 42

determining what class of disease is present

Question 43

what are the common signs seen on a physical exam of a cat for heartworm

Answer 43

often transient and non-specific mainly respiratory, gastrointestinal and occasionally neurologic

Question 44

what is used in the adult heartworm antigen kits to detect worms

Answer 44

female uterine antigen

Question 45

when can the antigen test start to detect worms at the earliest

Answer 45

5 months

Question 46

when would you for sure see a + for a + case of heartworm

Answer 46

7 months