Cardio - Heartworm Disease Flashcards
Heartworms are adapted to live in the _____.
pulmonary artery
What is the cycle of HWD?
Mosquito bites infected dog and ingests microfilaria –> Mff grow to L3 (Infective) –> mosquito bites new dog and injects L3 into dog –> L3s grow to adults in the dog –> migrate to PA –> adults mate and produce more Mff –> cycle repeats
What is clinical HWD in dogs due to?
Mature adults
What is clinical HWD in cats due to?
HARD - larvae producing a respiratory disease
How do dogs and cats respond to the antigen test?
Dogs will test positive if infected, cats may or may not test positive (have very few # of worms so may not have females to produce uterine Ag)
Ab test suggests _____.
exposure
Ag test suggests _____.
infection
When are HW preventatives effective?
They kill L3s and early L4s
When should pets begin getting HW preventative?
At 8 weeks
How often should you test for HW?
Ag test annually and Mff test if positive
What should you do if you suspect a false (+) on an Ag test?
Repeat test (preferably one from a different manufacturer)
What is the protocol for HW treatment in dogs?
- Positive Hw Ag detected
- Begin/continue preventative
- Doxycycline 10 mg/kg BID x 4 weeks
- In 2 months: 3-injection protocol of melarsomine
- Injection #1 @ day 60
- Injection #2 @ day 90
- Injection #3 @ day 91
- Pred taper with each melarsomine injection
- EXERCISE RESTRICTION
- Repeat Ag test 6 months after completion
What are some complications of HWD?
Eosinophilic pneumonitis, pulmonary vasculat disease (PHT), R-CHF (PHT), caval syndrome, immune-mediated disease (glomerulonephritis, thrombocytopenia)
How is eosinophilic pneumonitis treated?
Prednisolone
How is pulmonary vascular disease/PHT treated?
Sildenafil
