Lungworms of dogs and cats Flashcards
(39 cards)
What are some characteristics of metastrongyles?
- Lungs or related blood vessels
- Normally L1 in faeces
- L1 have typically ‘kinky’ tails – helps differentiate the species
- Normally indirect life cycles with mollusc intermediate hosts (snails and slugs)
- Lympho-tracheal migration
Name two metastrongyle species of dogs
Angiostrongylus vasorum
Oslerus osleri
Name a metastrongyle species of cats
Aelurostrongylus abstrusus
Angiostrongylus vasorum is also know as?
The French heartworm
Where do adult Angiostrongylus vasorum worms live?
In the pulmonary artery and right ventricle
Describe 2 morphological features of Angiostrongylus vasorum
2cm long
Barber pole - ovaries and gut
What are the 3 hosts of Angiostrongylus vasorum?
- Intermediate host – slugs and snails
- Paratenic hosts –frogs
- Dog/fox - main host
What is a paratenic host?
Hosts where there is no development, just allows the passing from one host to another
Define ovoviviparous
Pass eggs with the larvae already developed within them and are ready to hatch
Describe the life cycle of Angiostrongylus vasorum
- Adults go from the heart and pulmonary artery in capillaries to the lungs, eggs almost immediately hatch into L1 larvae which then move across the alveoli, up the pharynx where they are coughed up and swallowed
- No further development and L1 are passed out in the faeces, when they moult to L3 (temp dependant)
- Once in the dog the L3 larvae cross the intestinal wall, mature to L4 and into L5 adults in the abdominal LN
- Within the blood and lymphatic system they migrate via the liver and blood vessels to the heart
How are snails/slugs involved in the life cycle of Angiostrongylus vasorum?
L1 in faeces
Ingestion by slug/snail
L1 -> L3 development is temperature dependant
Slugs are ingested by dog
What is the PPP for Angiostrongylus vasorum?
5-8 weeks
What are the respiratory clinical signs of Angiostrongylus vasorum?
- Coughing
- Dyspnoea
- Weight loss
- Pulmonary hypertension
What are the non-respiratory clinical signs of Angiostrongylus vasorum?
- Often asymptomatic but can cause sudden death
- Coagulopathies: fluctuating haematoma/bleeding disorders. Worms secrete a range of anticoagulants
- Neurological
How can Angiostrongylus vasorum be diagnosed?
- Antigen SNAP test
- Radiography: Enlarged heart and pulmonary artery. Patchy alveolar and interstitial pattern.
How can Angiostrongylus vasorum be differentiated from other lungworms diagnostically?
- L1 in faeces, trans-tracheal wash or bronchoalveolar lavage
- ‘Dorsal notch’ on the tail of the L1
- 300 to 400 µm
- Baermann apparatus to detect L1
What are 2 considerations when using a Baermann apparatus?
Low sensitivity
Repeat samples every 3 days
How is Angiostrongylus vasorum treated?
- Moxidectin
- Milbemycin oxime
- Fenbendazole
How is Angiostrongylus vasorum controlled?
- Corticosteroids
- Cage rest during treatment (2-3 days)
- Prophylaxis: monthly treatment with macrocyclic lactones
- When possible, dogs should be prevented from ingesting snails or slugs.
What is the role of foxes in the epidemiology of Angiostrongylus vasorum?
They act as reservoir hosts
What is the main feature of Oslerus osleri life cycle?
Direct
Where are adult Oslerus osleri worms found?
In nodules in the trachea
How long is the PPP of Oslerus osleri?
10-18 weeks
What is the infective stage of Oslerus osleri?
L1 in sputum (thick type of mucus made in your lungs)
